Papel del radiofarmacéutico clínico en la seguridad del paciente durante los estudios de perfusión miocárdica de esfuerzo con vasodilatadores / Role of the clinical radiopharmacist in patient safety during myocardial perfusion imaging with vasodilator stress agents

Objetivos: Evaluar el papel del radiofarmacéutico en un equipo multidisciplinar en la detección de contraindicaciones del regadenosón para su uso seguro en pacientes a los que se solicitó una SPECT de perfusión miocárdica. Métodos: Se estudió ambispectivamente su uso seguro en 1.905 pacientes (54,1% mujeres, edad media: 66,6±11,7 años, rango: 20-95años). Se registraron datos relativos al sexo, a la edad, al historial médico, a la medicación, a las alergias medicamentosas y a las contraindicaciones para el estrés farmacológico, así como las recomendaciones realizadas al médico nuclear responsable. Resultados: Las contraindicaciones detectadas y las correspondientes recomendaciones fueron las siguientes: riesgo de prolongación del intervalo QTc (7,5%): comprobación previa del intervalo QTc y monitorización del ECG; ictus o AIT previo (4,2%): evaluación de estenosis carotídea; alergia a salicilatos y/o sulfamidas (3,1%): empleo de [99mTc]Tc-MIBI; epilepsia o riesgo de convulsiones (2,4%): uso de adenosina o reconsiderar su indicación; tratamiento con corticosteroides sistémicos en EPOC severa (1,3%): reevaluar las condiciones del paciente; EPOC reagudizada (0,8%): posponer hasta la resolución del episodio agudo; asma grave (0,4%): no realizar la prueba; toma de metilxantinas (0,3%): evitar su consumo previo; otras (6,1%): evaluación de cada contraindicación. No se observaron contraindicaciones en el 73,6% de los pacientes. Se anularon el 2,9% de las peticiones debido a contraindicaciones absolutas. Conclusiones: Empleando una metodología de trabajo sistemática, el radiofarmacéutico detectó un elevado número de incidencias, presentando uno de cada cuatro pacientes alguna contraindicación clínica. Las recomendaciones emitidas fueron aceptadas por los médicos nucleares, que modificaron su enfoque, incrementando así la seguridad de estos pacientes.(AU)

Aim: To assess the radiopharmacist's role in a multidisciplinary team focused on the contraindications of regadenoson in order to ensure the safe use of pharmacologic vasodilator stress agents in patients undergoing SPECT-MPI. Methods: We ambispectively studied its safe use in 1905 patients (54.1% female, mean age: 66.6±11.7 years, range: 20-95years). Sex, age, medical history, medications, drug allergies, and contraindications for stress testing were registered together with recommendations for the nuclear physician in charge. Results: Detected contraindications and corresponding recommendations were as follows: risk factors for QTc interval prolongation 7.5% — measurement of QTc interval previously to test and monitor ECG; prior stroke or TIA 4.2% — consider carotid stenosis assessment; salicylates/sulfonamides allergy 3.1% — use 99mTc-sestamibi; epilepsy or risk factors for seizures 2.4% — use of adenosine or reconsider test indication; systemic corticosteroid therapy for severe COPD 1.3% — reassessment of patient's condition; acute exacerbation of COPD 0.8% — defer test until acute episode is over; severe asthma 0.4% — do not perform test; methylxanthine ingestion 0.3% — avoid consumption previously; other 6.1% — evaluation of other contraindications. No contraindications were detected in 73.6% of patients. The test was cancelled due to absolute contraindications in 2.9% of the requests. Conclusions: Working in a systematic way, the radiopharmacist was able to detect a high number of issues related to regadenoson, with one out of four patients presenting some clinical contraindication. The recommendations given by the radiopharmacist were well accepted by the nuclear physicians who changed their approach contributing to increase the safety of patients referred for MPI.(AU)

Gammagrafía de perfusión miocárdica en la evaluación del riesgo cardiovascular en el trasplante hepático de adultos / Myocardial perfusion scintigraphy in the assessment of cardiovascular risk in adult liver transplantation

Introducción El estudio diagnóstico no invasivo del riesgo cardiovascular en pacientes que van a ser llevados a trasplante hepático no es claro especialmente en asintomáticos. Respecto a la gammagrafía de perfusión miocárdica (GPM) se ha pensado que la reserva vasodilatadora deteriorada en estos pacientes puede reducir su rendimiento. El objetivo es valorar el papel de la GPM en la evaluación prequirúrgica de los pacientes que van a ser tratados mediante un trasplante hepático. Material y métodos Estudio retrospectivo, descriptivo y observacional. Se incluyó a todos los pacientes adultos llevados a trasplante hepático entre 2017 y 2021 que tuvieran GPM previa. Se describen los hallazgos de la GPM y se correlacionaron con los hallazgos de angiografía invasiva y con la aparición o no de eventos cardiovasculares peri y postrasplante. Resultados De 188 pacientes trasplantados (edad promedio: 57 años, DE: 12), 178 tenían perfusión miocárdica previa, 82 (46%) pacientes no tenían factores de riesgo cardiovascular y 5 (2,8%) tenían antecedente de enfermedad coronaria. De las GPM, 177 fueron con estrés con dipiridamol realizadas en promedio 10 meses antes del trasplante. Únicamente 17/178 (9,5%) estudios fueron anormales. El seguimiento medio fue de 38 meses (DE: 10). De los pacientes con GPM normal, solo 2 (1,2%) presentaron eventos cardiovasculares, ambos con estudios realizados más de 2años atrás. No hubo muertes de origen cardiovascular. Conclusiones La GPM es una técnica segura y confiable en la valoración cardiovascular en pacientes candidatos a trasplante hepático dada la baja tasa de falsos negativos en el seguimiento (AU)

Introduction The non-invasive diagnostic study of cardiovascular risk in patients who are going to undergo liver transplantation is not clear, especially in asymptomatic patients. Regarding myocardial perfusion scintigraphy (MPS), it has been thought that the impaired vasodilator reserve in these patients may reduce its performance. The objective is to assess the role of the MPS in the pre-surgical evaluation of patients who are going to undergo liver transplantation. Material and methods Retrospective, descriptive and observational study was designed. All adult patients undergoing liver transplantation between 2017 and 2021 who had previous MPS were included. The findings of MPS were described and correlated with the findings of invasive angiography and with the appearance or not of peri- and post-transplant cardiovascular events. Results There were a total of 188 transplanted patients (mean age: 57 years, SD: 12), 178 had previous myocardial perfusion, 82 (46%) patients had no cardiovascular risk factors, and 5 (2.8%) had a history of coronary disease. Of the MPS, 177 were with dipyridamole stress performed on average 10 months before transplantation. Only 17/178 (9.5%) studies were abnormal. The mean follow-up was 38 months (SD: 10). Of the patients with normal MPS, only 2 (1.2%) presented cardiovascular events, both with studies performed more than 2years before the procedure. There were no deaths of cardiovascular origin. Conclusions MPS is a safe and reliable technique for cardiovascular assessment of patients who are candidates for liver transplantation, given the low rate of false negatives during follow-up (AU)

Role of the clinical radiopharmacist in patient safety during myocardial perfusion imaging with vasodilator stress agents.

AIM: To assess the radiopharmacist's role in a multidisciplinary team focused on the contraindications of regadenoson in order to ensure the safe use of pharmacologic vasodilator stress agents in patients undergoing SPECT-MPI. METHODS: We ambispectively studied its safe use in 1905 patients (54.1% female, mean age: 66.6±11.7 years, range: 20-95 years). Sex, age, medical history, medications, drug allergies, and contraindications for stress testing were registered together with recommendations for the nuclear physician in charge. RESULTS: Detected contraindications and corresponding recommendations were as follows: risk factors for QTc interval prolongation 7.5% - measurement of QTc interval previously to test and monitor ECG; prior stroke or TIA 4.2% - consider carotid stenosis assessment; salicylates/sulfonamides allergy 3.1% - use 99mTc-sestamibi; epilepsy or risk factors for seizures 2.4% - use of adenosine or reconsider test indication; systemic corticosteroid therapy for severe COPD 1.3% - reassessment of patient's condition; acute exacerbation of COPD 0.8% - defer test until acute episode is over; severe asthma 0.4% - do not perform test; methylxanthine ingestion 0.3% - avoid consumption previously; other 6.1% - evaluation of other contraindications. No contraindications were detected in 73.6% of patients. The test was canceled due to absolute contraindications in 2.9% of the requests. CONCLUSIONS: Working in a systematic way, the radiopharmacist was able to detect a high number of issues related to regadenoson, with one out of four patients presenting some clinical contraindication. The recommendations given by the radiopharmacist were well accepted by the nuclear physicians who changed their approach contributing to increase the safety of patients referred for MPI.

Myocardial perfusion scintigraphy in the assessment of cardiovascular risk in adult liver transplantation.

INTRODUCTION: The non-invasive diagnostic study of cardiovascular risk in patients who are going to undergo liver transplantation is not clear, especially in asymptomatic patients. Regarding myocardial perfusion scintigraphy (MPS), it has been thought that the impaired vasodilator reserve in these patients may reduce its performance. The objective is to assess the role of the MPS in the pre-surgical evaluation of patients who are going to undergo liver transplantation. MATERIAL AND METHODS: Retrospective, descriptive and observational study was designed. All adult patients undergoing liver transplantation between 2017 and 2021 who had previous MPS were included. The findings of MPS were described and correlated with the findings of invasive angiography and with the appearance or not of peri- and post-transplant cardiovascular events. RESULTS: There were a total of 188 transplanted patients (mean age: 57 years, SD: 12), 178 had previous myocardial perfusion, 82 (46%) patients had no cardiovascular risk factors, and 5 (2.8%) had a history of coronary disease. Of the MPS, 177 were with dipyridamole stress performed on average 10 months before transplantation. Only 17/178 (9.5%) studies were abnormal. The mean follow-up was 38 months (SD: 10). Of the patients with normal MPS, only 2 (1.2%) presented cardiovascular events, both with studies performed more than 2 years before the procedure. There were no deaths of cardiovascular origin. CONCLUSIONS: MPS is a safe and reliable technique for cardiovascular assessment of patients who are candidates for liver transplantation, given the low rate of false negatives during follow-up.

El puntaje de Framingham ayudaría en la estratificación del riesgo de pacientes con ergometría positiva y SPECT normal / The Framingham score could help in risk stratification of patients with positive ergometry and normal SPECT

Antecedentes. El valor pronóstico de una ergometría positiva en el contexto de imágenes tomográficas de perfusión miocárdica de estrés y reposo (SPECT) normales no está bien establecido. Objetivos. Documentar la incidencia de infarto, muerte y revascularización coronaria en pacientes con una ergometría positiva de riesgo intermedio e imágenes de perfusión SPECT normales, y explorar el potencial valor del puntaje de riesgo de Framingham en la estratificación pronóstica de estos pacientes. Métodos. Cohorte retrospectiva integrada por pacientes que habían presentado síntomas o hallazgos electrocardiográficos compatibles con enfermedad arterial coronaria durante la prueba de esfuerzo, con criterios de riesgo intermedio en la puntuación de Duke y perfusión miocárdica SPECT normal. Fueron identificados a partir de la base de datos del laboratorio de cardiología nuclear del Instituto de Cardiología y Cirugía Cardiovascular de la ciudad de Posadas, Argentina. Resultados. Fueron elegibles 217 pacientes. El seguimiento fue de 3 1,5 años. La sobrevida libre de eventos (muerte,infarto de miocardio no fatal, angioplastia coronaria o cirugía de bypass de arteria coronaria) a uno, tres y cinco años fue significativamente menor (Log-rank test, p= 0,001) en el grupo con puntaje de Framingham alto o muy alto (77, 71y 59 %, respectivamente) que en el grupo de puntaje bajo o intermedio (89, 87 y 83 %). Tomando como referencia a los pacientes con riesgo bajo en el puntaje de Framingham, luego de ajustar por edad, sexo y puntaje de Duke, los pacientes categorizados en los estratos alto y muy alto riesgo del puntaje de Framingham presentaron una incidencia del evento combinado cercana al triple (hazard ratio [HR] 2,81; intervalo de confianza [IC] del 95 % 0,91 a 8,72; p= 0,07 y HR 3,61;IC 95 % 1,23 a 10,56; p= 0,019 respectivamente). Conclusiones. La estimación de riesgo con el puntaje de Framingham sería de ayuda en la estratificación pronóstica de los pacientes con ergometría positiva y SPECT normal. (AU)

Background. The prognostic value of positive exercise testing with normal SPECT myocardial perfusion imaging is not well established. Objectives. To document the incidence of infarction, death, and coronary revascularization in patients with a positive intermediate-risk exercise test and normal SPECT perfusion images and to explore the potential value of the Framingham Risk Score in the prognostic stratification of these patients. Methods. A retrospective cohort comprised patients who presented symptoms or electrocardiographic findings compatible with coronary artery disease during the stress test, with intermediate risk criteria in the Duke score and normal SPECT myocardial perfusion. They were identified from the database of the nuclear cardiology laboratory of the Instituto de Cardiología y Cirugía Cardiovascular of Posadas, Argentina. Results. 217 patients were eligible. Follow-up was 3 1.5 years. Event-free survival (death, non-fatal myocardial infarction, coronary angioplasty, or coronary artery bypass surgery) at one, three, and five years was significantly lower (Log-ranktest, p: 0.001) in the group with a score of Framingham high or very high (77, 71 and 59 %, respectively) than in the lowor intermediate score group (89, 87 and 83 %). Taking as reference the low-risk patients in the Framingham score, after adjusting for age, sex, and Duke score, the patients categorized in the high-risk and very high-risk strata showed about three times higher incidence of the combined event (hazard ratio [HR] 2.81; 95 % confidence interval [CI] 0.91 to 8.72;p=0.07 and HR 3.61; 95 % CI 1.23 to 10.56; p=0.019 respectively). Conclusions. Risk estimation with the Framingham score would be helpful in the prognostic stratification of patients with positive exercise testing and normal SPECT. (AU)

El dilema clínico frente a los pacientes con ergometría positiva y prueba de perfusión miocárdica con SPECT normal / The clinical dilemma facing patients with positive stress test and normal SPECT myocardial perfusion imaging

La evaluación de la perfusión miocárdica con SPECT combina una prueba de esfuerzo (ergometría o estrés farmacológico) junto a imágenes de perfusión con radioisótopos. Este estudio es útil para establecer el diagnóstico de enfermedad arterial coronaria, estratificar el riesgo de infarto y tomar decisiones terapéuticas. Un resultado normal aporta un alto valor predictivo negativo, es decir, una muy baja probabilidad de que el paciente presente eventos cardiovasculares. El hallazgo de signos de isquemia en la ergometría podría poner en jaque el valor predictivo negativo de una perfusión normal. En presencia de este resultado, el paso siguiente es evaluar los predictores de riesgo en la ergometría, el riesgo propio del paciente en función de los antecedentes clínicos y el puntaje cálcico coronario, cuando este se encuentra disponible. Ante la presencia concomitante de otros marcadores de riesgo se sugiere completar la evaluación con un estudio anatómico.El uso de nuevas tecnologías podría mejorar la precisión en la predicción de eventos. (AU)

Assessment of myocardial perfusion with SPECT combines a stress test (ergometry or pharmacological stress) with radioisotope perfusion imaging. This test is helpful to diagnose coronary artery disease, stratify the risk of heart attack, and make therapeutic decisions. A normal result provides a high negative predictive value; therefore, the probability of cardiovascular events is very low. Signs of ischemia on an ergometry could jeopardize the negative predictive value of normal perfusion. In this clinical setting, the next step is to evaluate the risk predictors in the stress test, the individual risk based on the clinical history, and the coronary calcium score when available. Given the simultaneous presence of other risk markers,completing the evaluation with an anatomical study is suggested. The use of new technologies could improve the accuracy of event prediction. (AU)

Cuantificación del efecto del movimiento vertical del paciente durante la gated-SPECT de perfusión miocárdica sobre los índices de perfusión y de función del ventrículo izquierdo / Quantifying the effect of vertical motion of patient during gated myocardial perfusion SPECT on indices of perfusion and function of left ventricle

Objetivo Evaluar el efecto del movimiento de «rebote» simulado por ordenador en los índices de perfusión y función del ventrículo izquierdo en relación con 3determinantes principales del movimiento (duración, magnitud y tiempo) mediante la evaluación del efecto único y la interacción de estos atributos en un modelo estadístico. Métodos Para el estudio, se seleccionaron 29 exploraciones gated-SPECT de perfusión miocárdica y, a continuación, se simuló manualmente el patrón de movimiento de «rebote» con respecto a 3atributos principales del movimiento: duración (corta vs. larga), magnitud (2 vs. 4 píxeles) y tiempo (precoz vs. tardío), todo ello en la dirección vertical ascendente. Todas las imágenes SPECT se reconstruyeron y filtraron utilizando un método idéntico (algoritmo OSEM) y con los mismos parámetros. Los índices de perfusión y función miocárdica del ventrículo izquierdo se obtuvieron a partir del programa informático QGS del Cedars-Sinai en las imágenes originales y de movimiento simulado y se comparan entre sí. Se aplicaron pruebas ANOVA de medidas repetidas intrasujeto de 2y 3vías para evaluar el efecto principal de cada variable o atributo y la interacción entre ellas. Resultados Las puntuaciones sumadas aumentaron aproximadamente de manera exponencial desde «sin movimiento» hasta un rebote corto y, después, hasta un rebote largo. En el rebote largo de 4 píxeles, los defectos de perfusión fueron notables. Todas las comparaciones de la extensión del defecto y del déficit total de perfusión fueron estadísticamente significativas. La diferencia media entre los patrones de movimiento de rebote corto y «sin movimiento» fue pequeña, incluso en los movimientos de 4 píxeles (casi del 3% o menor). Por el contrario, la diferencia media entre los patrones de movimiento de rebote largo y «sin movimiento» fue superior al 5% (AU)

Objective To assess the effect of software-simulated «bouncing» motion on left ventricle (LV) perfusion and function indices concerning 3main determinants of motion (duration, magnitude and time) by evaluating the sole effect and interaction of these attributes in a statistical model. Methods Twenty-nine gated myocardial perfusion SPECT scans were selected for the study and then, «bounce» motion pattern was simulated manually regarding 3main attributes of motion including duration (short versus long), magnitude (2 versus 4 pixels) and time (early versus late), all in upward vertical direction. All SPECT images are reconstructed and filtered with an identical method (OSEM algorithm) and same parameters. Indices of LV myocardial perfusion and function are derived using QGS package of Cedars-Sinai software in original and simulated-motion images and are then compared with each other. Two- and 3-way repeated measure within-subjects ANOVA tests are conducted to evaluate the main effect of each variable or attribute and the interaction between them. Results Summed scores increase roughly exponentially from «no motion» to short bounce and then, to long bounce. In long 4-pixel bounce, perfusion defects are remarkable. All comparisons of defect extent and total perfusion deficit are statistically significant. Mean difference between short bounce motion patterns with «no motion» is small even in 4-pixel movements (almost 3% or lower). In contrast, mean difference between long bounce motion patterns with «no motion» is higher than 5%. Using a paired-sample t test, in all pairs, mean difference for ejection fraction is less than 4% which all are statistically significant (AU)

Quantifying the effect of vertical motion of patient during gated myocardial perfusion SPECT on indices of perfusion and function of left ventricle.

OBJECTIVE: To assess the effect of software-simulated "bouncing" motion on left ventricle (LV) perfusion and function indices concerning three main determinants of motion (duration, magnitude and time) by evaluating the sole effect and interaction of these attributes in a statistical model. METHODS: Twenty-nine gated myocardial perfusion SPECT scans were selected for the study and then, "bounce" motion pattern was simulated manually regarding three main attributes of motion including duration (short versus long), magnitude (2 versus 4 pixels) and time (early versus late), all in upward vertical direction. All SPECT images are reconstructed and filtered with an identical method (OSEM algorithm) and same parameters. Indices of LV myocardial perfusion and function are derived using QGS package of Cedars-Sinai software in original and simulated-motion images and are then compared with each other. Two- and three-way Repeated Measure Within-Subjects ANOVA tests are conducted to evaluate the main effect of each variable or attribute and the interaction between them. RESULTS: Summed scores increase roughly exponentially from "no motion" to short bounce and then, to long bounce. In long 4-pixel bounce, perfusion defects are remarkable. All comparisons of defect extent (DE) and total perfusion deficit (TPD) are statistically significant. Mean difference between short bounce motion patterns with "no motion" is small even in 4-pixel movements (almost 3% or lower). In contrast, mean difference between long bounce motion patterns with "no motion" is higher than 5%. Using a paired-sample t-test, in all pairs, mean difference for ejection fraction (EF) is less than 4% which all are statistically significant. Value of end-diastolic volume (EDV) and end-systolic volume (ESV) are consistently decreased based on duration (from short to long) and magnitude (from 2 to 4 pixels). Using Within-Subjects ANOVAs, in long bounce, main effect of magnitude and interaction of magnitude and time, but not time solely, were statistically significant. In 2-pixel magnitude, none of variables and their interaction were significant, but in 4-pixel magnitude, EF showed statistical significance with duration. CONCLUSION: The perfusion parameters are to a higher extent involved by motion particularly in long bounce with a 4-pixel displacement. In short bounce, the effect is negligible, and therefore, no need to repeat the scan. Parameters of function are much less vulnerable to be affected by motion. Thus, contrary to current recommendations, there may be less need to repeat the scan in short 2-pixel bounce.

Correlación de sincronía de la contracción del ventrículo izquierdo con función sisto-diastólica, masa y excentricidad en diversas afecciones cardíacas mediante un software comercial dedicado de SPECT gatillado / Gated Spect evaluation of ventricular systolic synchrony: correlation with ventricular mass and excentricity in different forms of cardiac disease

INTRODUCCIÓN: Actualmente, hay nuevas herramientas de software disponibles para medir la sincronía de la contracción intraventricular izquierda mediante SPECT de perfusión miocárdica. Esta técnica permite identificar anomalías de la conducción, apoyar la terapia de resincronización en insuficiencia cardíaca refractaria e incluso la detección precoz de isquemia. OBJETIVO: Conocer la correlación de la sincronía de contracción con otros parámetros de disfunción sisto-diastólica ventricular izquierda. MÉTODO: Estudiamos 135 pacientes remitidos para pesquisa o evaluación de enfermedad coronaria conocida mediante SPECT gatillado. La evaluación de la interpretación inicial con programas QPS/QGS® visual y cuantitativo se efectuó a 50 casos con defectos de perfusión transitoria de diversos tamaños (isquemia), 25 de tipo fijo o mixto (infarto) y 60 sin ellos (normal). Los volúmenes telesistólicos oscilaron entre 26 y 458 mL. Se excluyeron casos con arritmias, anomalías de conducción y artefactos (actividad o movimiento extracardiaco). Los SPECT se procesaron retrospectivamente utilizando el programa Emory Synctool®. Del histograma de sincronía de la contracción, el ancho de banda (BW) y la desviación estándar (SD) se correlacionaron con la fracción de eyección (FEVI), volúmenes y excentricidades sistólico / diastólico, masa ventricular izquierda, tasa máxima de llenado (PFR) y tiempo al máximo de llenado (TPFR). RESULTADOS: Los BW y SD del histograma de fase de contracción fueron mayores en el grupo con defectos fijos y mixtos en comparación con los con perfusión normal. Las correlaciones en reposo y post estrés (Spearman) entre SD y BW con FEVI, volúmenes, excentricidad y masa fueron significativas (p <0,0002) salvo TPFR que no fue significativa. CONCLUSIÓN: La sincronía de contracción intraventricular sistólica izquierda medida con SPECT se correlaciona excelentemente con los parámetros funcionales sistólicos y diastólicos, así como con masa y excentricidad en diversas condiciones y tamaños cardíacos.

INTRODUCTION: New software tools are available to measure left intraventricular contraction synchrony by myocardial perfusion SPECT. This technique allows identification of conduction abnormalities, support resynchronization therapy in refractory heart failure and even allows early detection of myocardial ischemia. OBJECTIVE: To determine the correlation of systolic synchrony with other parameters of left ventricular systolic-diastolic dysfunction. METHODS: We studied 135 patients referred for screening or known coronary artery disease evaluation by triggered SPECT. Evaluation of the initial interpretation with visual and quantitative QPS/QGS® programs was performed in 50 patients with transient perfusion defects of various sizes (ischemia), 25 of fixed or mixed type (infarction) and 60 without abnormalities. Telesystolic volumes ranged from 26 to 458 mL. Cases with arrhythmias, conduction abnormalities and artifacts (extracardiac activity or motion) were excluded. SPECT scans were retrospectively processed using the Emory Synctool® software. Histograms of systolic contraction synchrony bandwidth (BW) and standard deviation (SD) were correlated with ejection fraction (LVEF), systolic/diastolic volumes and eccentricities, left ventricular mass, peak filling rate (PFR) and time to maximum filling (TPFR). RESULTS: BW and SD of the contraction pase histogram were higher in the fixed and mixed defect group compared to studies showing normal perfusion. Spearman correlations at rest and poststress between SD and BW with LVEF, volumes, eccentricity and mass were all significant (p<0.0002) except for TPFR. CONCLUSION: Left systolic intraventricular contraction synchrony measured with SPECT presents an excellent correlation with systolic and diastolic functional parameters, as well as with mass and eccentricity in various cardiac conditions and ventricular dimensions.

La gammagrafía de perfusión miocárdica en la cardiopatía isquémica / Myocardial Perfusion Scintigraphy in Ischemic Heart Disease

RESUMEN Fundamento la cardiopatía isquémica presenta una gran prevalencia y mortalidad en Cuba y en países desarrollados. La gammagrafía de perfusión miocárdica es un método diagnóstico no invasivo que facilita el diagnóstico y la toma de decisiones médicas. Objetivo: demostrar el valor de la gammagrafía de perfusión miocárdica en el pronóstico de la cardiopatía isquémica. Método se realizó un estudio descriptivo, de corte longitudinal, prospectivo en un universo de 180 pacientes, que se realizaron estudios de perfusión miocárdica para detectar isquemia, desde enero del 2018 a diciembre del 2019 en el Centro de Investigaciones Médico Quirúrgicas. Las variables estudiadas fueron: características clínico-demográficas (edad, sexo), los factores de riesgo aterogénicos y el dolor torácico. Las variables cualitativas se expresaron en frecuencia y porcentaje y las variables cuantitativas continuas en valores de media y desviación estándar según su distribución y Chi cuadrado. Se tomó como intervalo de confianza el 95 %, con una p < 0,05 para la aceptación e interpretación de los resultados. Resultados el 53,3 % de los pacientes fueron hombres y el 78,3 % padecían hipertensión arterial. Se realizó la prueba de estrés físico para la detección de isquemia al 76,1 %. Predominó el resultado negativo en el 58,9 %; con una evolución clínica al año de solo el 2,8 % con eventos isquémicos. Se demostró isquemia en la perfusión miocárdica al 41,1 %, confirmándose lesiones obstructivas coronarias significativas al 82,4 %. Al año de evolución clínica el 97,3 % desarrolló eventos isquémicos. La caída >10 % de la fracción de eyección ventricular izquierda post-estrés evidenció eventos isquémicos en el 100 % de los pacientes. Conclusiones la gammagrafía de perfusión miocárdica es una técnica no invasiva confiable en el diagnóstico de la cardiopatía isquémica. Aportó seguridad pronóstica a largo plazo tras el resultado negativo de la perfusión miocárdica. La caída de la fracción de eyección ventricular izquierda post-estrés se comportó como una variable predictiva de realizar futuros eventos cardiacos.

ABSTRACT Background: ischemic heart disease has a high prevalence and mortality in Cuba and in developed countries. Myocardial perfusion scintigraphy is a non-invasive diagnostic method that facilitates diagnosis and medical decision-making. Objective: to demonstrate the value of myocardial perfusion scintigraphy in the ischemic heart disease prognosis. Method: a descriptive, prospective longitudinal section study was carried out in 180 patients, in which myocardial perfusion studies were performed to detect ischemia, from January 2018 to December 2019 at the Center for Surgical Medical Research. The variables studied were: clinical-demographic characteristics (age, sex), atherogenic risk factors and chest pain. The qualitative variables were expressed in frequency and percentage and the continuous quantitative variables in mean and standard deviation values according to their distribution and chi square. The 95 % confidence interval was taken, with a p <0.05 for the acceptance and interpretation of the results. Results: the 53.3 % of the patients were men and 78.3 % suffered from arterial hypertension. The physical stress test was performed to detect ischemia at 76.1 %. The negative result predominated in 58.9 %; with a clinical evolution at one year of only 2.8 % with ischemic events. Ischemia was demonstrated in myocardial perfusion in 41.1 %, confirming significant coronary obstructive lesions in 82.4 %. After one year of clinical evolution, 97.3 % developed ischemic events. The drop> 10 % in the post-stress left ventricular ejection fraction showed ischemic events in 100 % of the patients. Conclusions: myocardial perfusion scintigraphy is a reliable non-invasive technique in the ischemic heart disease diagnosis. It provided long-term prognostic security after the negative myocardial perfusion result. The fall in the post-stress left ventricular ejection fraction behaved as a predictive variable of future cardiac events.

Prognostic value of myocardial perfusion scintigraphy in diabetic patients and without coronary lesion. / Valor pronóstico de la gammagrafía de perfusión miocárdica en pacientes diabéticos sin lesiones coronarias.

OBJECTIVE: To determine the prognostic value of myocardial perfusion scintigraphy-gated SPECT in patients with diabetes mellitus and without obstructive coronary artery disease. MATERIALS AND METHODS: This retrospective study included consecutive patients undergoing adenosine stress-rest myocardial perfusion imaging (MPI) by 99mTc-tetrofosmin between 2009 and 2011. The patients had diabetes mellitus and coronary angiography without significant coronary lesions. In total, 37 diabetic patients (female/male: 20/17; mean age: 65.2 (range: 40-78). 29 non-diabetic patients were included wich are matched with the group of diabetic patients with positive MPI. The group of non-diabetic patients had scintigraphy with myocardial ischemia and without angiographic lesions. A 36-month clinical follow-up was performed, and major cardiac events were recorded. RESULTS: In 78.3% (29/37) of diabetic patients the scintigraphic study showed myocardial ischemia, while it was negative in the 21.7%. The cardiac event rate in both groups was 6%. In diabetics with a myocardial perfusion study with myocardial ischemia, there were 3 major cardiac events. In diabetic patients with negative study had no cardiac event. In the non-diabetic control group the cardiac events rate was 3.4% (1/29). CONCLUSION: In diabetic patients without obstructive coronary disease, myocardial perfusion study can be predictor of cardiac events. A negative study can be an indicator of a better cardiovascular prognosis.

Improved diagnostic accuracy for myocardial perfusion imaging using artificial neural networks on different input variables including clinical and quantification data. / Precisión diagnóstica mejorada para la imagen de perfusión miocárdica usando redes neuronales artificiales en diferentes variables de entrada incluyendo datos clínicos y de cuantificación.

OBJECTIVE: Diagnostic accuracy of myocardial perfusion imaging (MPI) is not optimal to predict the result of angiography. The current study aimed at investigating the application of artificial neural network (ANN) to integrate the clinical data with the result and quantification of MPI. METHODS: Out of 923 patients with MPI, 93 who underwent angiography were recruited. The clinical data including the cardiac risk factors were collected and the results of MPI and coronary angiography were recorded. The quantification of MPI polar plots (i.e. the counts of 20 segments of each stress and rest polar plots) and the Gensini score of angiographies were calculated. Feed-forward ANN was designed integrating clinical and quantification data to predict the result of angiography (normal vs. abnormal), non-obstructive or obstructive coronary artery disease (CAD), and Gensini score (≥10 and <10). The ANNs were designed to predict the results of angiography using different combinations of data as follows: reports of MPI, the counts of 40 segments of stress and rest polar plots, and the count of these 40 segments in addition to age, gender, and the number of risk factors. The diagnostic performance of MPI with different ANNs was compared. RESULTS: The accuracy of MPI to predict the result of angiography, obstructive CAD, and Gensini score increased from 81.7% to 92.9%, 65.0% to 85.7%, and 50.5% to 92.9%, respectively by ANN using counts and clinical risk factors. CONCLUSION: The diagnostic accuracy of MPI could be improved by ANN, using clinical and quantification data.

Appropriate use of noninvasive ischemia testing to guide revascularization decision making following acute ST elevation myocardial infarction in Latin American countries: Results from an expert panel meeting of the International Atomic Energy Agency. / Uso adecuado de las pruebas no invasivas de isquemia para guiar la toma de decisión sobre revascularización tras un infarto agudo de miocardio con elevación del segmento ST en países iberoamericanos: Resultados de la reunión de un panel de expertos de la International Atomic Energy Agency.

Across Latin American and Caribbean countries, cardiovascular disease and especially ischemic heart disease is currently the main cause of death both in men and in women. For most Latin American and Caribbean countries, public and community health efforts aim to define care strategies which are both clinically and cost effective and promote primary and secondary prevention, resulting in improved patient outcomes. The optimal approach to deal with acute events such as ST-elevation myocardial infarction (STEMI) is a matter of controversy; however, there is an expanding role for assessing residual ischemic burden in STEMI patients following primary percutaneous coronary intervention. Although randomized clinical trials have established the value of staged fractional flow reserve-guided revascularization, the use of noninvasive functional imaging modalities may play a similar role at a much lower cost. For LAC, available stress imaging techniques could be applied to define residual ischemia in the non-infarct related artery and to target revascularization in a staged procedure after primary percutaneous coronary intervention The use of nuclear cardiac imaging, supported by its relatively wide availability, moderate cost, and robust quantitative capabilities, may serve to guide effective care and to reduce subsequent cardiac events in patients with coronary artery disease. This noninvasive approach may avert potential safety issues with repeat and lengthy invasive procedures, and serve as a baseline for subsequent follow-up stress testing following the index STEMI event. This consensus document was devised from an expert panel meeting of the International Atomic Energy Agency, highlighting available evidence with a focus on the utility of stress myocardial perfusion imaging in post-STEMI patients. The document could serve as guidance to the prudent and appropriate use of nuclear imaging for targeting therapeutic management and avoiding unnecessary invasive procedures within Latin American and Caribbean countries, where resources could be scarce.

Ventajas éticas, tecnológicas y económicas de la perfusión miocárdica en la cardiopatía isquémica / Ethical, technological, and economic advantages of myocardial perfusion in ischemic heart disea

Introducción: La alta prevalencia de la cardiopatía isquémica y el progresivo aumento de la esperanza de vida son factores que están contribuyendo de forma importante a que el dolor torácico constituya en estos momentos uno de los principales motivos de consulta hospitalaria. En Cuba, las enfermedades cardiovasculares representan la primera causa de muerte. Su diagnóstico, puede ser un reto. Objetivo: Presentar las ventajas éticas, tecnológicas y económicas de la perfusión miocárdica en el proceso diagnóstico de la cardiopatía isquémica. Material y Métodos: Fue realizada una búsqueda sistematizada de literatura primaria en bases de datos como Scielo, Sciencedirect y Elsevier. Resultados: En el presente artículo se analizó como problema social de la ciencia, la tecnología y la sociedad los estudios de perfusión miocárdica en la cardiopatía isquémica, teniendo especial atención en las implicaciones sociales, éticas, tecnológicas y económicas. Los estudios de perfusión miocárdica son ampliamente utilizados como métodos funcionales no invasivos para el diagnóstico de enfermedad coronaria. Es una técnica fácilmente realizable, con mínimas complicaciones y efectos secundarios, y en consecuencia con amplia aceptación por los pacientes. Conclusiones: Las investigaciones no invasivas para el estudio de la perfusión miocárdica tienen un lugar bien establecido en el proceso diagnóstico del paciente con cardiopatía isquémica con fines de diagnóstico precoz y estratificación de riesgo con altos índices de sensibilidad, especificidad y reproducibilidad y su incorporación a la práctica social asistencial tiene además sólidos fundamentos bioéticos y económicos(AU)

Introduction: The high prevalence of ischemic heart disease and the progressive increase in life expectancy are important factors contributing to the fact that chest pain is one of the main reasons for hospital consultation. In Cuba, cardiovascular diseases are the leading cause of death. Your diagnosis can be challenging. Objective: To present the ethical, technological and economic advantages of myocardial perfusion in the diagnostic process of ischemic heart disease. Material and Methods: A systematized search of primary literature was carried out in databases such as Scielo, Sciencedirect and Elsevier. Results: In the present article, the studies of myocardial perfusion in ischemic heart disease were analyzed as a social problem of science, technology and society, paying particular attention to the social, ethical, technological and economic implications. Myocardial perfusion studies are widely used as noninvasive functional methods for the diagnosis of coronary heart disease. It is a technique easily performed, with minimal complications and side effects, and consequently with wide acceptance by the patients. Conclusions: Noninvasive investigations for the study of myocardial perfusion have a well established place in the diagnostic process of the patient with ischemic heart disease for the purposes of early diagnosis and risk stratification with high sensitivity, specificity and reproducibility indexes and their incorporation into the social welfare practice also has solid bioethical and economic foundations(AU)

Phase analysis for the assessment of left ventricular dyssynchrony by Gated Myocardial Perfusion SPECT. Importance of clinical and technical parameters / Análisis de fase para la valoración del sincronismo mecánico del ventrículo izquierdo mediante Gated-SPECT de perfusión miocárdica. Importancia de los parámetros clínicos y técnicos

Abstract Introduction: Phase analysis (PA) of the left ventricle is a new tool in nuclear cardiology studies used to assess left ventricular mechanical timing based on different clinical applications. However, the use of this tool is relatively unknown. Objective: To expose the feasibility of the new PA tool in myocardial perfusion (Gated-SPECT) to assess left ventricle mechanical timing, and to verify the differences between values depending on clinical and technical conditions. Materials and methods: The study included consecutive patients evaluated by Gated-SPECT. The main variables were different depending on clinical and technical conditions. PA was assessed using the PHASE tool of the QPS-QGS program (Cedars-Sinai Medical Center, Los Angeles, USA). The following parameters were obtained: histogram bandwith (HB), standard deviation (SD) and entropy (E). A descriptive and analytical analysis of means and/or medians was performed using parametric or non-parametric tests. Statistical significance was p <0.05. IBM-SPSS V21® was used. Results: 300 patients were included in this study with a mean age of 65±12.7. No differences were found in relation to the study phase (stress-rest) [HB (p=0.4), SD (p=0.6), E (p=0.8)], stress type [HB (p=0.38), SD (p=0.8), E (p=0.06), E (p=0.06)], dose used [HB (p=0.19), SD (p=0.05), E (p=0.06)], gamma camera [HB (p=0.02), SD (p=0.06), E (p=0.08)], or history of coronary heart disease [HB (p=0.44), SD (p=0.18), E (p=0.17)]. Furthermore, differences in conduction disorders were observed [HB (p=0.001), SD (p=0.02), E (p=0.001)], ejection fraction < or >35% (p=0.001), E (p=0.001)] normal or necrosis study [HB (p=0.001), SD (p=0.001), E (p=0.001)], and gender [HB (p=0.002), SD (p=0.006), E (p=0.005)]. Conclusions: The new PA tool of nuclear medicine is feasible in our context. The type of stress, the administered dose, the study phase or the gamma camera used did not affect the parameters. However, gender, interventricular conduction disorders, necrosis and systolic dysfunction did have an impact on them.

Resumen Introducción. El análisis de fase (AF) del ventrículo izquierdo es una herramienta de reciente introducción en los estudios de cardiología nuclear, que permite valorar el sincronismo mecánico de la contracción del ventrículo izquierdo con diferentes aplicaciones clínicas, si bien es poco conocida. Objetivo. Mostrar la factibilidad de la nueva herramienta AF por perfusión miocárdica (Gated-SPECT) para valorar el sincronismo mecánico del ventrículo izquierdo y verificar diferencias entre sus valores, según situaciones clínicas y condiciones técnicas. Materiales y métodos. En el estudio participaron pacientes consecutivos con Gated-SPECT. Las variables principales fueron diferentes condiciones clínicas y técnicas. La valoración del AF se realizó mediante la herramienta FASE del programa cardiodedicado (QPS-QGS, Cedars-Sinai Medical Center, Los Angeles, USA). Se obtuvieron los siguientes parámetros: ancho del histograma (AH), desviación estandar de la fase (DE) y entropía (E). Se realizó análisis descriptivo y analítico de medias o medianas a través de test paramétricos o no paramétircos. El límite de significancia estadísitca fue p<0.05. Se utilizó IBM-SPSS V21®. Resultados. Con un total de 300 pacientes y una media de edad de 65±12.7, en el análisis del AF no existieron diferencias según la fase del estudio (estrés-reposo) [AH (p=0.4), DE (p=0.6), E (p=0.7)], tipo de estrés [AH (p=0.38), DE (p=0.8), E (p=0.84)], dosis utilizada [AH(p=0.19), DE (p=0.05), E (p=0.06)], gammacámara [AH (p=0.02), DE (p=0.06), E (p=0.08)] ni entre antecedente de enfermedad coronaria [AH (p=0.44), DE (p=0.18), E (p=0.17)]. Hubo diferencias según trastornos de conducción [AH (p=0.001), DE (p=0.02), E (p=0.001)], fracción de eyección < o >35% [AH (p=0.001), DE (p=0.001), E (p=0.001)], estudio normal o con necrosis [AH (p=0.001), DE (p=0.001), E (p=0.001)] y género [AH (p=0.002), DE (p=0.006), E (p=0.005)]. Conclusiones. El uso de la nueva herramienta del AF de medicina nuclear es factible. Sus parámetros no se afectaron por el tipo de estrés producido, dosis administrada o fase del estudio por la gammacámara empleada. Por su parte, sí fueron afectados por género, trastornos de conducción interventricular, necrosis y disfunción sistólica.

Strategic evaluation of silent myocardial ischemia in a group of patients with rheumatoid arthritis and traditional cardiovascular risk factors / Evaluación estratégica de la isquemia miocárdica silenciosa en un grupo de pacientes con artritis reumatoide y factores de riesgo cardiovascular tradicionales

Abstract: Introduction: IHD has become an important long-term end point for RA patients independent of traditional CVRF. Therefore, cardiovascular injury and mortality might be due to the presence of a chronic systematic inflammatory response. Nonetheless, there is a gap in its diagnosis since symptoms remain silent until major events occur. Objective: We aimed to evaluate by gated single-photon emission computed tomography (g-SPECT). Myocardial perfusion in asymptomatic Mexican patients with RA and at least one traditional CVRF, and without history of angina. Patients and methods: A prospective study with a total number of 91 patients was conducted. We evaluated CVRF and RA characteristics. We non-invasively assessed them with g-SPECT to reveal ischemia, territories and severity. We calculated relative risks and 95% CI of ischemia given the associated variables. Results: 22 (24.2%) patients presented ischemia, half of them in the LAD territory. Regarding CVRF and disease's characteristics; only smokers and patients under a steroid treatment were at more risk to present ischemia (0.49 [0.24 to 0.98] and 2.04 [1.01 to 4.14], respectively) with a p = 0.046. Conclusion: We have contributed with additional evidence to strategically diagnose IHD in patients with RA even if they have no symptoms and independently of the existence of cardiovascular risk factors to prevent and reduce cardiovascular mortality.

Resumen: Introducción: La IC se ha convertido en un importante punto de partida a largo plazo para los pacientes con AR independientemente de los FRCV tradicionales. Por lo tanto, las lesiones cardiovasculares y la mortalidad podrían deberse a la presencia de una respuesta inflamatoria sistemática crónica. Sin embargo, hay una brecha en su diagnóstico ya que los síntomas permanecen en silencio hasta que ocurren eventos importantes. Objetivo: Evaluar mediante tomografía computarizada de emisión de un solo fotón (g-SPECT). Perfusión miocárdica en pacientes mexicanos asintomáticos con AR y al menos un FRCV tradicional, sin antecedentes de angina. Pacientes y métodos: Se realizó un estudio prospectivo con un número total de 91 pacientes. Se evaluaron las características FRCV y AR. Los evaluamos de forma no invasiva con g-SPECT para revelar isquemia, territorios y severidad. Se calcularon los riesgos relativos la isquemia de 95% dadas las variables asociadas. Resultados: Veintidós (24.2%) pacientes presentaron isquemia, la mitad de ellos en territorio LAD. Respecto a los FRCV y características de la enfermedad; sólo los fumadores y los pacientes sometidos a un tratamiento con esteroides presentaron mayor riesgo de presentar isquemia (0.49 [0.24 a 0.98] y 2.04 [1.01 a 4.14], respectivamente) con p = 0.046. Conclusión: Hemos aportado pruebas adicionales para diagnosticar la isquemia estratégicamente en los pacientes con AR, incluso si no tienen síntomas y con independencia de la existencia de factores de riesgo cardiovascular para prevenir y reducir la mortalidad cardiovascular.

La cardiopatía isquémica en pacientes diabéticos y no diabéticos / Ischemic heart disease in diabetic and non-diabetic patients

Introducción: La cardiopatía isquémica tiene como uno de sus factores de riesgo más importante a la Diabetes mellitus, la cual influye en el pronóstico, tratamiento, severidad, morbilidad y mortalidad de esta enfermedad.Objetivo: Caracterizar la influencia de la Diabetes mellitus en la cardiopatía isquémica. Material y Métodos: Se realizó una revisión bibliográfica sobre la temática. Resultados: La Diabetes mellitus es un factor de riesgo de alta relevancia de la cardiopatía isquémica. Las personas con diabetes corren el mismo riesgo de tener un infarto de miocardio que las personas sin diabetes que ya han tenido uno. Las mujeres diabéticas son más propensas a cardiopatías isquémicas. Existe una mayor frecuencia de Diabetes mellitus en los pacientes portadores de la cardiopatía isquémica con edades entre 45 y 80 años. Conclusiones: La diabetes impone mayor riesgo de padecer cardiopatía isquémica, la hace más precoz, le impone dificultades diagnósticas y mayor riesgo de complicaciones. La diabetes y la cardiopatía isquémica son enfermedades con incidencias y prevalencias que se incrementan con la edad(AU)

Introduction:Ischemic heart disease has Diabetes mellitus as one of its most important factors, because affects the prognosis, treatment, severity, morbidity and mortality of the first one. Objective: To characterize the influence of diabetes mellitus on ischemic heart disease. Material and Methods: A literature review on the subject was conducted. Results: Diabetes mellitus is confirmed as a highly relevant risk factor for ischemic heart disease. People with diabetes are at the same risk of having a myocardial infarction as people without diabetes who have already had one. Diabetic women are more likely to have ischemic heart disease. There is a higher frequency of Diabetes mellitus in patients with ischemic heart disease aged between 45 and 80 years. Conclusions:Diabetes imposes an increased risk of suffering of ischemic heart disease, makes it more precocious, and imposes diagnostic difficulties and greater risk of complications. Diabetes and ischemic heart disease are illnesses with incidence and prevalence that increase with age(AU)

La cardiopatía isquémica en pacientes diabéticos y no diabéticos / Ischemic heart disease in diabetic and non-diabetic patients

Introducción: La cardiopatía isquémica tiene como uno de sus factores de riesgo más importante a la Diabetes mellitus, la cual influye en el pronóstico, tratamiento, severidad, morbilidad y mortalidad de esta enfermedad. Objetivo: Caracterizar la influencia de la Diabetes mellitus en la cardiopatía isquémica. Material y Métodos: Se realizó una revisión bibliográfica sobre la temática. Resultados: La Diabetes mellitus es un factor de riesgo de alta relevancia de la cardiopatía isquémica. Las personas con diabetes corren el mismo riesgo de tener un infarto de miocardio que las personas sin diabetes que ya han tenido uno. Las mujeres diabéticas son más propensas a cardiopatías isquémicas. Existe una mayor frecuencia de Diabetes mellitus en los pacientes portadores de la cardiopatía isquémica con edades entre 45 y 80 años. Conclusiones: La diabetes impone mayor riesgo de padecer cardiopatía isquémica, la hace más precoz, le impone dificultades diagnósticas y mayor riesgo de complicaciones. La diabetes y la cardiopatía isquémica son enfermedades con incidencias y prevalencias que se incrementan con la edad(AU)

Introduction:Ischemic heart disease has Diabetes mellitus as one of its most important factors, because affects the prognosis, treatment, severity, morbidity and mortality of the first one. Objective: To characterize the influence of diabetes mellitus on ischemic heart disease. Material and Methods: A literature review on the subject was conducted. Results: Diabetes mellitus is confirmed as a highly relevant risk factor for ischemic heart disease. People with diabetes are at the same risk of having a myocardial infarction as people without diabetes who have already had one. Diabetic women are more likely to have ischemic heart disease. There is a higher frequency of Diabetes mellitus in patients with ischemic heart disease aged between 45 and 80 years. Conclusions:Diabetes imposes an increased risk of suffering of ischemic heart disease, makes it more precocious, and imposes diagnostic difficulties and greater risk of complications. Diabetes and ischemic heart disease are illnesses with incidence and prevalence that increase with age(AU)

Análisis de fase mediante "Gated-SPECT" de perfusión miocárdica para valorar el sincronismo mecánico del ventrículo / Phase analysis to measure left ventricular dyssynchrony by Gated-SPECT myocardial perfusion imaging showed by two different software

Resumen Introducción y objetivos: El análisis de fase mediante Gated-SPECT de perfusión miocárdica (GS-PMI) es una nueva herramienta para medir la asincronía ventricular izquierda con importantes aplicaciones clínicas futuras en resincronización e insuficiencia cardiaca. Se puede medir mediante dos programas (ECTb o QGS C-S). El objetivo es demostrar su factibilidad y verificar si existen diferencias entre ambos. Metodología: Estudio analítico, observacional y retrospectivo en pacientes con GS-PMI normales. Los parámetros obtenidos fueron: la desviación estándar de la fase (DE) y el ancho de banda de histograma (AH). La evaluación de la diferencia entre los grupos se realizó usando pruebas para muestras independientes después de analizar la distribución de datos. Nivel de significación p<0,05. Se utilizó SPSS IBM V.21®. Resultados: Total pacientes: 193 (104 hombres). Edad media: 64 años (24-89).61/193 procesados con QGS C-S y 132/193 con ECTb. Postestrés: la media de la DE fue 6º±3,7º, con mediana de 5º y rango intercuartílico (IR):3.6º. La media de AH fue 22,7º±10º, con mediana de 18º y IR:11.5º. Postreposo: la media de la DE fue 5,76º±4,82º y la mediana 4,5º con IR: 3.1º. La media de AH fue 21.67º± 14.06º y la mediana 18º, IR:12º. Entre ambos programas se encontraron diferencias significativas en la DE en postestrés (p=0,001) y postreposo (p=0,019), sin diferencias en el AH postestrés (p=0,31) y postreposo (p=0,18). Conclusión: Realizar el análisis fase de análisis por GS-PMI es factible. Sin embargo, la DE mostró diferencias significativas entre los dos programas. Aunque los valores mostrados podrían ser utilizados como valores normales, se recomienda que estos se obtengan y utilicen para cada programa por separado.

Abstract Introduction and objectives:Phase analysis by Gated-SPECT myocardial perfusion imaging (G-MPI) is a new tool to measure left ventricular dyssynchrony with important clinical applications in near future (heart failure and resynchronization) and can be measured by two software (ECTb o QGS C-S). The aim is to show its feasibility and verify whether there is difference between the programs. Methodology: Analytical observational and retrospective study in patients with normal G-MPI. The parameters were the phase standard deviation (SD) and the histogram bandwidth (HB) in post-stress and rest tests. Assessment of the difference between groups was performed using tests for independent samples after analyze the distribution of data. The significance level (p) was 0,05 and the software used was SPSS IBM V.21® Results: Total:193 patients (104 men).64 years old ± (24-89).61/193 processed with QGS C-S and 132/193 with ECTb. Post-stress tests: mean of the SD was 6º±3.7º,the median was 5º,interquartile range (IR):3.6º.The mean of HB was 22.7º±10º and the median was 18º IR:11.5º. Post-rest tests: mean of the SD was 5.76º±4.82º and median was 4.5º IR: 3.1º.The overall mean of HB was 21.67º±14.06º and median was 18º IR: 12º. Between the data from both software, significant differences were found in SD in post-stress(p=0.001)and post-rest tests(p=0.019)and no significant differences were found in HB in post-stress(p= 0.31)or post-rest tests(p=0.18). Conclusion: Phase analysis by G-MPI is feasible. However SD showed significant differences between the two groups. Although the values showed could be used as normal values, it is recommended that these have to be obtained and used for each software separately.