Gender differences in outcome in patients with diabetes mellitus.

BACKGROUND: Diabetes mellitus is an independent risk factor in the development of coronary artery disease (CAD), myocardial infarction (MI), and cardiac death (CD). The major adverse cardiac events (MACEs) between men and women in diabetic patients stratified by CAD (previous MI and/or coronary revascularization, CR) were analyzed. METHODS AND RESULTS: A cohort of 1327 consecutive diabetic patients (age 66.5 ± 9 years) underwent gated SPECT (single-photon emission computed tomography). During a mean follow-up of 4.7 ± 2.2 years post gated SPECT, MACEs (non-fatal MI, CD, and late CR) were evaluated according to gender stratified by CAD. Among diabetic patients without known CAD (N = 731), men had more MACEs (sHR 1.9;95%CI 1.2-3.2) than women. Among diabetic patients with known CAD (N = 596), there was no difference in MACEs in diabetic men and women (sHR 1.15;95%CI 0.73-1.8). Diabetic women with known CAD (n = 143) were the group with the highest risk (sHR 1.7; P = .041) for MACEs (4.5% MACEs/year, [95%CI 3.1%-6.4%]), compared to the remaining diabetic patients (N = 1184) (3% MACEs/year, [95%CI 2.6%-3.5%]). CONCLUSIONS: The prognosis of diabetic patients for MACEs is different in men and women stratified by CAD. The worst prognosis for MACEs occurs in women with known CAD.

A novel clinical risk prediction model for myocardial infarction, coronary revascularization, and cardiac death according to clinical, exercise, and gated SPECT variables (VH-RS).

AIMS: To create a risk score for cardiac events (CE) according to clinical, exercise, and gated SPECT variables. METHODS AND RESULTS: We analysed 5707 consecutive patients; 3181 patients (age 64.2 ± 11 years, male 59.6%) with suspected coronary artery disease (CAD) [without previous myocardial infarction (MI) or coronary revascularization (CR)] and 2526 patients (age 63.3 ± 11 years, male 81.7%) with established CAD (with previous MI or CR). To create the Vall d'Hebron Risk Score (VH-RS), first we analyse the predictors of CE (non-fatal MI, CR, and/or cardiac death), then the probability of CE for every patient according to the predictive variables. According to risk we stratified patients into four risk levels: very low risk (VLR), low risk (LR), moderate risk (MR), and high risk (HRi) using Multiple Cox Regression analysis models. Finally, we validate the VH-RS in another prospective cohort of 734 patients. In patients with suspected CAD; age (P < 0.001); gender (P = 0.001); hyperlipidaemia (P < 0.001); nitrates (P = 0.04); ejection fraction (EF) (P = 0.001); summed stress score (P < 0.001); METs (P < 0.001); exercise angina (P = 0.006); and mm of ST segment depression (P = 0.004) were the independent predictors of CE (C-statistic: 0.8; P < 0.001). In patients with established CAD, EF (P < 0.001); summed difference score (P = 0.001); age (P < 0.001); smoker (P = 0.002); nitrates (P = 0.003); exercise angina (P = 0.001); METs (P < 0.001); and mm of ST segment depression (P = 0.011) were the independent predictors of CE (C-statistic: 0.7; P < 0.001). The risk score obtained from these variables allows the stratification of patients into four risk levels: VLR, LR, MR, and HRi. CONCLUSIONS: The cardiac risk stratification by mean of clinical, exercise, and gated SPECT variables is an objective aid to assessing an individual's cardiac risk.

Reduction of Left Ventricular Dilation Beyond the First Year After Anterior Myocardial Infarction.

BACKGROUND: Reduction of left ventricular (LV) dilation (RD) beyond the first year after ST-segment-elevation myocardial infarction (STEMI) is unknown. We investigated its potential occurrence in comparison with stationary (SD) and progressive (PD) dilation. METHODS AND RESULTS: Perfusion gated SPECT features at 1 and 3 years were evaluated in 168 3-year survivors of a first anterior STEMI. Comparisons were made among patients with RD (≥15% reduction of LV end-systolic volume [LVESV]), SD (<15% reduction or increase), and PD (≥15% increase). There were 35 patients with RD (21%), 84 with SD (50%), and 49 with PD (29%). At 1 year, ejection fraction, wall motion and perfusion scores, and LV volumes were similar. In RD patients, the fall in LVESV, nearly 22%, was apparent in those with frank (>51 mL; P < .001) or little/moderate LV dilation at 1 year (LVESV ≤51 mL; P = .002) and was associated with increased ejection fraction (P values .008 and .009, respectively). In the 3 groups, however, LVESV changes were unrelated to 1-year LV volumes, ejection fraction, or contractility score. CONCLUSIONS: At 3 years following anterior STEMI there is reduction of LV dilation in about 21% of patients associated with increases in ejection fraction in those with or without clearly dilated ventricles at 1year. These findings add to the complexity of LV remodeling and possibly suggest very late changes in infarct size.

Mechanical dyssynchrony according to validated cut-off values using gated SPECT myocardial perfusion imaging.

BACKGROUND: The aim of this study was to establish different degrees of mechanical dyssynchrony according to validated cut-off (CO) values of myocardial perfusion gated SPECT phase analysis parameters (SD, standard deviation; B, bandwidth; S, skewness; K, kurtosis). METHODS: Using Emory Cardiac Toolbox™, we prospectively analyzed 408 patients (mean age 64.1 years, 26.7% female), divided into a control group of 150 normal subjects and a validation group of 258 patients (left bundle branch block: 17.8%, right bundle branch block: 8.9%. atrial fibrillation: 16.3%, coronary revascularization: 30%, dilated cardiomyopathy: 7.4%. valvulopathies: 2.7%, ischemic test: 45.3%) with ischemic and non-ischemic cardiac diseases, by means of phase analysis. RESULTS: Agreement of CO values (SD > 18.4°; B > 51°; S ≤ 3.2; K ≤ 9.3) used to discriminate between normal subjects and patients was strong (c-statistic 0.9; 95% CI 0.98-0.99). Four degrees of dyssynchrony were found according to the number of abnormal phase parameters. All patients with mechanical and electrical criteria for cardiac resynchronization therapy (CCRT) (n: 82) had Grade 2 to 4 (two to four abnormal phase parameters). Agreement of CO values (SD > 40.2°; B > 132°; S ≤ 2.3; K ≤ 4.6) used to discriminate between patients with and without CCRT was strong (c-statistic 0.8; 95% CI 0.79-0.87) but 12% of patients with CCRT did not have any of these abnormal phase parameters. CONCLUSIONS: The discriminatory capacity of gated SPECT phase analysis parameters between normal subjects and patients, and between patients with and without CCRT, is very good, making it possible to define different degrees of mechanical dyssynchrony.

Diagnostic performance of the quantification of myocardium at risk from MPI SPECT/CTA 2G fusion for detecting obstructive coronary disease: A multicenter trial.

BACKGROUND: The effective non-invasive identification of coronary artery disease (CAD) and its proper referral for invasive treatment are still unresolved issues. We evaluated our quantification of myocardium at risk (MAR) from our second generation 3D MPI/CTA fusion framework for the detection and localization of obstructive coronary disease. METHODS: Studies from 48 patients who had rest/stress MPI, CTA, and ICA were analyzed from 3 different institutions. From the CTA, a 3D biventricular surface of the myocardium with superimposed coronaries was extracted and fused to the perfusion distribution. Significant lesions were identified from CTA readings and positioned on the fused display. Three estimates of MAR were computed on the 3D LV surface on the basis of the MPI alone (MARp), the CTA alone (MARa), and the fused information (MARf). The extents of areas at risk were used to generate ROC curves using ICA anatomical findings as reference standard. RESULTS: Areas under the ROC curve (AUC) for CAD detection using MARf was 0.88 (CI = 0.75-0.95) and for MARp and MARa were, respectively 0.82 (CI = 0.69-0.92) and 0.75 (CI = 0.60-0.86) using the ≥70% stenosis criterion. AUCs for CAD localization (all vessels) using MARf showed significantly higher performance than either MARa or MARp or both. CONCLUSIONS: Using ICA as the reference standard, MAR as the quantitative parameter, and AUC to measure diagnostic performance, MPI-CTA fusion imaging provided incremental diagnostic information compared to MPI or CTA alone for the diagnosis and localization of CAD.

Plasma B-type natriuretic peptide levels are poorly related to the occurrence of ischemia or ventricular arrhythmias during symptom-limited exercise in low-risk patients.

INTRODUCTION: The usefulness of B-type natriuretic peptide (BNP) as a marker of ischemia is controversial. BNP levels have predicted arrhythmias in various settings, but it is unknown whether they are related to exercise-induced ischemic ventricular arrhythmias. MATERIAL AND METHODS: We analyzed in 63 patients (64 ±14 years, 65% male, 62% with known coronary disease) undergoing exercise stress single-photon emission computed tomography (SPECT) the association between plasma BNP values (before and 15 min after exercise) and the occurrence of ischemia or ventricular arrhythmias during the test. RESULTS: Exercise test (8.1 ±2.7 min, 7.4 ±8.1 metabolic equivalents, 82 ±12% of maximal predicted heart rate) induced reversible perfusion defects in 23 (36%) patients. Eight (13%) patients presented significant arrhythmias (≥ 7 ventricular premature complexes/min, couplets, or non-sustained ventricular tachycardia during exercise or in the first minute of recovery). Median baseline BNP levels were 17.5 (12.4-66.4) pg/ml in patients developing scintigraphic ischemia and 45.6 (13.2-107.4) pg/ml in those without ischemia (p = 0.137). The BNP levels increased after exercise (34.4 (15.3-65.4)% increment over baseline, p < 0.001), but the magnitude of this increase was not related to SPECT positivity (35.7 (18.8-65.4)% vs. 27.9 (5.6-64.0)% in patients with and without ischemia, respectively, p = 0.304). No significant association was found between BNP values (at baseline or their change during the test) and ventricular arrhythmias. CONCLUSIONS: Plasma BNP values - at baseline or after exercise - were not associated with myocardial ischemia or with ventricular arrhythmia during exercise SPECT. These results highlight the limited usefulness of this biomarker to assess acute ischemia.

Prognostic Value of Infarct size Measured by Gated sPECT scintigraphy / Valor pronóstico del tamaño del infarto de miocardio cuantificado mediante SPECT gatillada

Background: Despite the improved sensitivity and specificity of SPECT myocardial perfusion imagingto detect myocardial involve-ment after acute myocardial infarction (AMI), there is little information about the usefulness of early infarct size (IS) measurement by this method for risk stratification and prognosis. Objectives: The goal of this study was to evaluate the usefulness of quantifying IS by gated SPECT scintigraphy to predict cardio­vascular events in patients with a first AMI. Methods: Patients with a first ST-segment elevation AMI were included from 2009 to 2014. Infarct size was estimated using the Cedars QPS software. The incidence of events (heart failure, ventricular arrhythmias, mortality and a composite of the three events) was evaluated at one year. Results: One-hundred and forty nine patients were included in the study; mean age was 59±11 years and 81.9% were men. Diabetes was present in 16.1% of cases, 9.4% had a history of myocardial revascularization, 84.6% were admitted in Killip and Kimball class A, 43% of AMIs were located in the anterior wall and 69.8% of the patients underwent reperfusion. Left ventricular ejection fraction estimated by gated SPECT scintigraphy was 51%±14%. Follow-up was completed in 95.9% of cases. An IS cutoff point of 22% (ROC curve) was established to predict the composite endpoint at follow-up (sensitivity 92%, specificity 81%, AUC: 0.94%), dividing the sample into two groups: Group I (IS <22%) and Group II (IS ≥22%). The prevalence of the composite endpoint was greater in Group II (2.1% Group I vs. 50% Group II; p<0.001). Infarct size ≥ 22% was the only variable identified as predictor of events during follow-up (OR 1.978; 95% CI 1.887-1.996; p<0.001). Conclusion: Early quantification of IS by gated SPECT scintigraphy is an independent risk predictor at one year that allows risk stratification in patients with a first AMI.

Introducción: Si bien la SPECT de perfusión miocárdica ha mejorado la sensibilidad y la especificidad en la detección del compromiso miocárdico luego de un infarto agudo de miocardio (IAM), aún es escasa la información sobre la determinación precoz del tamaño del infarto (TI) con este método para la estratificación del riesgo y su valor pronóstico. Objetivos: Evaluar la utilidad de la cuantificación del TI estimado por SPECT gatillada en la predicción de complicaciones cardio­vasculares en pacientes con un primer IAM. Material y métodos: Se analizaron los pacientes con IAM con elevación del ST desde 2009 a 2014, excluyéndose aquellos con IAM previo. El cálculo del TI se realizó con el softwareCedars QPS. Se evaluaron eventos al año: insuficiencia cardíaca, arritmias ventri-culares, muerte y la combinación de los tres eventos. Resultados: Se incluyeron 149 pacientes, con edad media de 59±11 años,el 81,9% de sexo masculino. El 16,1% eran diabéticos y el 9,4% presentaban revascularización previa. El 84,6% ingresaron en Killip y Kimball A, el 43% de los IAM fueron de territorio anterior y el 69,8% de los pacientes fueron reperfundidos. La fracción de eyección del ventrículo izquierdo por SPECT gatillada fue del 51% ±14%. Se realizó seguimiento clínico en el 95,9% de los casos. El punto de corte del TI (curva ROC) para predecir eventos combinados al seguimiento se estableció en 22% (sensibilidad: 92%, especificidad: 81%, ABC: 0,94),con el cual la muestra se dividió en dos grupos: Grupo I (TI<22%) y Grupo II (TI≥22%). La prevalencia de eventos combinados fue mayor en el Grupo II (2,1% Grupo Ivs. 50% Grupo II; p<0,001). El TI ≥22% se identificó como la única variable predictora de eventos al seguimiento (OR 1,978; IC 95% 1,887-1,996; p<0,001). Conclusión: La cuantificación precoz del TI mediante SPECT es un predictor independiente de riesgo al año que permite establecer una estratificación del riesgo en pacientes con un primer IAM.

Cut-off values of myocardial perfusion gated-SPECT phase analysis parameters of normal subjects, and conduction and mechanical cardiac diseases.

BACKGROUND: The aim of this study was to determine the cut-off values of gated myocardial perfusion rest SPECT phase analysis parameters of normal subjects, and conduction (CCD) and mechanical cardiac diseases (MCD). METHODS: We prospectively analyzed 455 patients by means of phase analysis using SyncTool™ (Emory Cardiac Toolbox™). Of these, 150 corresponded to the control group (group 1, normal subjects) and 305 corresponded to patients with cardiac diseases (group 2, 63 with only CCD, 121 with only MCD, and 121 with CCD plus MCD). The optimal cut-off (CO) values of the peak phase (P), standard deviation (SD), bandwidth (B), skewness (S), and kurtosis (K) for discriminating between normal and dyssynchrony were obtained. RESULTS: In order to differentiate group 1 from group 2, CO of SD > 18.4 and CO of B > 51 were the most sensitive parameters (75.7%, 95% CI 70.5%-80.4%, and 78.7%, 95% CI 73.7%-83.1%, respectively), and CO of S ≤ 3.2 and CO of K ≤ 9.3 were the most specific (92%, 95% CI 86.4%-95.8%, and 94.7%, 95% CI 89.8%-97.7%, respectively). In order to differentiate patients with CCD and MCD, CO values were SD > 26.1, B > 70, S ≤ 2.89, and K ≤ 10.2. In order to differentiate between patients with (n: 26) and without (n: 216) criteria of cardiac resynchronization therapy, CO values were SD > 40.2, B > 132, S ≤ 2.3, and K ≤ 4.6. CONCLUSIONS: In this pilot study, different CO values of phase histogram parameters were observed between normal subjects and patients with conduction and MCD, and between patients with and without criteria of cardiac resynchronization therapy.

Warranty periods for normal myocardial perfusion stress SPECT.

BACKGROUND: To assess different warranty periods following a normal myocardial perfusion SPECT based on patients' clinical characteristics and the type of stress performed. METHODS AND RESULTS: A study was done of 2,922 consecutive patients (62.9 ± 13 years; 53.4% women) with a normal stress-rest SPECT. The warranty period was defined as the period during which patients remained at a low risk (<1% events/year) of total mortality (TM), or hard events (HE) (cardiac death or non-fatal myocardial infarction). Of these patients, 2,051 were given an exercise myocardial perfusion imaging (Ex-MPI); 461 submaximal exercise plus dipyridamole (Ex+Dipy-MPI); and 410 dipyridamole (Dipy-MPI). During a mean follow-up of 5 ± 3.3 years, a significant reduction (P < .05) of the warranty period for TM (13.5, 9.6 and 8 months) and HE (34.8, 20.5 and 8.2 months) was observed, for Ex-MPI, Ex+Dipy-MPI and Dipy-MPI, respectively. Other warranty period determinants were the clinical variables of age, sex, diabetes and known coronary artery disease. An abnormal left ventricular ejection fraction on gated-SPECT also significantly shortened the warranty period for HE in patients undergoing Ex+Dipy-MPI (P = .001) or Dipy-MPI alone (P = .007). CONCLUSIONS: The warranty period for a normal stress-rest SPECT is highly variable since it is primarily determined by the type of stress, the patient's clinical characteristics and LVEF.

Normal Myocardial Perfusion Gated SPECT and Positive Stress Test: Different Prognoses in Women and Men.

BACKGROUND: The aim of this study was to analyze different prognoses in women and men with normal myocardial perfusion gated SPECT, according to stress test results. METHODS: Differences between women and men in terms of hard events (HE) (non-fatal acute myocardial infarction or cardiac death) and HE plus coronary revascularization (HE + CR) were analyzed in 2,414 consecutive patients (mean age 62.8 ± 13.5 years, 1,438 women) with a normal stress-rest gated SPECT, taking into account their stress test results. RESULTS: Four hundred and seven patients (16.9%) (15.9% women and 17.5% men) had a positive stress test (ST-segment depression ≥1 mm and/or angina). During a follow-up of 5.1 ± 3.4 years, there were more significant HE (6.5% vs 2.3%; P = .005) and HE + CR (11.6% vs 4.8%, P = .001) in men with a positive stress test than in men with a negative stress test. These differences were not observed in women. In multivariate regression models, HE and HE + CR were also more frequent in men with a positive stress test (HR:3.3 [95% CI 1.1% to 9.5%]; HR:4.2 [95% CI 1.8% to 9.9%]; respectively) vs women with a positive stress test. CONCLUSIONS: Although patients with normal gated SPECT studies have a favorable outcome, men with an abnormal stress test have a more adverse prognosis than women.

Update on cardiac imaging techniques 2013.

Cardiac imaging is a cornerstone of diagnosis in heart conditions, and an essential tool for assessing prognosis and establishing treatment decisions. This year, echocardiography stands out as a guide in interventional procedures and in choosing the size of the prosthesis. It is also proving to be a valuable technique in low-flow, low-gradient aortic stenosis. Three-dimensional echocardiography is advancing our knowledge of cardiac anatomy and valvular measurements. The parameters indicating tissue deformation have predictive power in valve disease and in the follow-up of drug-induced cardiotoxicity. Single-photon emission computed tomography and positron emission tomography are proving useful in ischemic heart disease and in the diagnosis of cardiac inflammation and infections. The role of computed tomography has been strengthened in noninvasive coronary angiography, the emergency room management of chest pain, assessment of chronic occlusions, and morphologic study of coronary plaque. Cardiac magnetic resonance imaging remains the gold standard for tissue characterization in ischemic heart disease and cardiomyopathies, and is assuming a greater role in stress studies and in the assessment of myocardial viability.

Novedades en imagen cardiaca 2013 / Update on cardiac imaging techniques 2013

La imagen cardiaca es la piedra angular del diagnóstico en cardiología, así como un instrumento esencial en la valoración pronóstica y las decisiones terapéuticas. Este año, la ecocardiografía destaca como guía en el intervencionismo y en la elección del tamaño de las prótesis. Se consolida la entidad de la estenosis aórtica de bajo flujo y bajo gradiente. El método tridimensional avanza en el conocimiento anatómico y la cuantificación valvular. Los parámetros de deformación muestran su poder predictor en valvulopatías y en el seguimiento en la cardiotoxicidad inducida por fármacos. La tomografía computarizada por emisión monofotónica y la tomografía por emisión positrónica consolidan su utilidad en cardiopatía isquémica y destacan en el diagnóstico de inflamaciones e infecciones cardiacas. La tomografía computarizada cardiaca afianza su papel en la coronariografía no invasiva, el manejo del dolor torácico en urgencias, la valoración de las oclusiones crónicas y el estudio morfológico de la placa. La resonancia magnética cardiaca permanece como técnica de referencia en la caracterización tisular tanto en cardiopatía isquémica como en las miocardiopatías y afianza su papel en el estudio de estrés y la valoración de la viabilidad (AU)

Cardiac imaging is a cornerstone of diagnosis in heart conditions, and an essential tool for assessing prognosis and establishing treatment decisions. This year, echocardiography stands out as a guide in interventional procedures and in choosing the size of the prosthesis. It is also proving to be a valuable technique in low-flow, low-gradient aortic stenosis. Three-dimensional echocardiography is advancing our knowledge of cardiac anatomy and valvular measurements. The parameters indicating tissue deformation have predictive power in valve disease and in the follow-up of drug-induced cardiotoxicity. Single-photon emission computed tomography and positron emission tomography are proving useful in ischemic heart disease and in the diagnosis of cardiac inflammation and infections. The role of computed tomography has been strengthened in noninvasive coronary angiography, the emergency room management of chest pain, assessment of chronic occlusions, and morphologic study of coronary plaque. Cardiac magnetic resonance imaging remains the gold standard for tissue characterization in ischemic heart disease and cardiomyopathies, and is assuming a greater role in stress studies and in the assessment of myocardial viability (AU)

Long-term follow-up assessment after the arterial switch operation for correction of dextro-transposition of the great arteries by means of exercise myocardial perfusion-gated SPECT.

The arterial switch operation (ASO) is the preferred technique for correcting transposition of the great arteries, but translocation and reimplantation of the coronary arteries can produce myocardial ischemia. This report aims to describe the authors' experience with exercise single-photon emission computed tomography (SPECT) used to evaluate myocardial perfusion. Exercise-rest gated-myocardial perfusion SPECT was performed for 69 patients (49 boys; median age, 9 years; 5th percentile [6.4 years] to 95th percentile [15.6 years]), 64 of whom were asymptomatic 9.98 ± 3.20 years after ASO. During exercise testing, the patients reached 9.85 ± 3.05 metabolic equivalents (METs) and a median heart rate of 160 beats per minute (bpm), 5th percentile (106 bpm) to 95th percentile (196 bpm). Whereas 61 patients (88.41 %) had normal myocardial perfusion, 2 patients (2.9 %) had reversible defects, and 6 patients (8.7 %) had fixed defects. All the patients with perioperative ischemic complications (4/4, 100 %) had myocardial perfusion defects, whereas four patients (4/65, 6.15 %) without ischemic complications had abnormal perfusion (p = 0.0005). Age at the time of surgery did not differ significantly (p = 0.234) between the patients with perfusion defects and those with normal study results. No significant difference was observed between the patients who had an A coronary pattern (left coronary artery originating from the left sinus and the right coronary artery originating from the right sinus, n = 47) and those who had a non-A coronary pattern (n = 22) (p = 1). The high rate for normality of exercise myocardial perfusion in our study suggests that myocardial perfusion gated-SPECT should be reserved for patients who have experienced perioperative ischemic complications or those with symptoms, at least during the first 10 years after the surgery.

Gated-SPECT de perfusión miocárdica como técnica complementaria de la resonancia magnética para pacientes con infarto de miocardio crónico / Gated-SPECT myocardial perfusion imaging as a complementary technique to magnetic resonance imaging in chronic myocardial infarction patients

Introducción y objetivos. El objetivo de este estudio es comparar los resultados de la resonancia magnética y la gated-SPECT de perfusión miocárdica en la valoración de la función ventricular y la viabilidad en pacientes con infarto de miocardio en fase crónica. Métodos. Se estudió con resonancia magnética y gated-SPECT a 104 pacientes (media de edad, 61 ± 12 años; el 87,5% varones) con infarto previo. Se correlacionaron los volúmenes y la fracción de eyección del ventrículo izquierdo y los criterios clásicos de viabilidad con realce tardío con gadolino (< 75% de transmuralidad) con los de la SPECT (captación > 50%) en los 17 segmentos del ventrículo izquierdo. Se valoró la motilidad, el engrosamiento y la isquemia en la gated-SPECT de los segmentos no viables o con criterios dudosos con el realce (un 50-75% de transmuralidad). Resultados. Se observó buena correlación entre ambas exploraciones para los volúmenes y la fracción de eyección (p < 0,05) y para la masa necrótica estimada (p < 0,01). De los 264 segmentos con realce > 75%, 82 (31%) tenían captación > 50% en la SPECT. De los 106 segmentos con criterios dudosos de viabilidad (un 50-75% de realce) en la resonancia magnética, en la SPECT 68 (64%) tenían una captación > 50%; 41 (38,7%), motilidad conservada; 46 (43,4%), engrosamiento conservado, y 17 (16%), criterios de isquemia. Conclusiones. Una tercera parte de los segmentos considerados no viables en la resonancia magnética muestran captación > 50% en la SPECT. El análisis de la motilidad, engrosamiento y presencia de isquemia en la gated-SPECT es de utilidad en los segmentos de dudosa viabilidad en la resonancia magnética(AU)

Introduction and objectives. The aim of this study was to compare magnetic resonance and gated-SPECT myocardial perfusion imaging in patients with chronic myocardial infarction. Methods. Magnetic resonance imaging and gated-SPECT were performed in 104 patients (mean age, 61 [12] years; 87.5% male) with a previous infarction. Left ventricular volumes and ejection fraction and classic late gadolinium enhancement viability criteria (<75% transmurality) were correlated with those of gated-SPECT (uptake >50%) in the 17 segments of the left ventricle. Motion, thickening, and ischemia on SPECT were analyzed in segments showing nonviable tissue or equivocal enhancement features (50%-75% transmurality). Results. A good correlation was observed between the 2 techniques for volumes, ejection fraction (P<.05), and estimated necrotic mass (P<.01). In total, 82 of 264 segments (31%) with >75% enhancement had >50% single SPECT uptake. Of the 106 equivocal segments on magnetic resonance imaging, 68 (64%) had >50% uptake, 41 (38.7%) had normal motion, 46 (43.4%) had normal thickening, and 17 (16%) had ischemic criteria on SPECT. Conclusions. A third of nonviable segments on magnetic resonance imaging showed >50% uptake on SPECT. Gated-SPECT can be useful in the analysis of motion, thickening, and ischemic criteria in segments with questionable viability on magnetic resonance imaging(AU)

Usefulness of exercise test and myocardial perfusion-gated single photon emission computed tomography to improve the prediction of major events.

BACKGROUND: The incremental prognostic value of myocardial perfusion-gated single photon emission computed tomography (MPGS) compared with exercise test has not yet been properly evaluated. METHODS AND RESULTS: Five thousand six hundred seventy-two consecutive patients with known or suspected coronary disease undergoing exercise MPGS between 1997 and 2007 were included. Three-year predictive models for total death and death from cardiovascular causes or acute myocardial infarction (ie, major cardiovascular events [MCE]) were built using Cox-regression modeling, including only the clinical information. Then the exercise and MPGS information was sequentially added. The added discriminative ability of exercise test information and MPGS was assessed by net reclassification improvement and integrated discrimination improvement. The increase in predictive ability of exercise information for death and MCE was high as assessed by net reclassification improvement (0.199 and 0.263) and integrated discrimination improvement (0.042 and 0.021). The only variable of MPGS associated with total death was ejection fraction (hazard ratio, 0.84; 95% confidence interval, 0.79-0.89; P<0.001). Global stress ischemic score emerged as an additional variable associated with MCE (hazard ratio, 1.07; 95% confidence interval, 1.02-1.12; P=0.007). Adding MPGS information barely improved the prognostic value for total death (net reclassification improvement, 0.017; integrated discrimination improvement, 0.013), but it increased for MCE (net reclassification improvement, 0.122; integrated discrimination improvement, 0.033). CONCLUSIONS: Adding MPGS information to exercise information does not improve prediction of total death, although it allows a more accurate prediction of MCE.

Acute myocardial infarction: estimation of at-risk and salvaged myocardium at myocardial perfusion SPECT 1 month after infarction.

PURPOSE: To estimate at-risk and salvaged myocardium by using gated single photon emission computed tomography (SPECT) myocardial perfusion imaging after acute myocardial infarction (AMI). MATERIALS AND METHODS: The study was approved by the hospital's Ethical Committee on Clinical Trials (trial register number, PR(HG)36/2000), and all patients gave informed consent. Forty patients (mean age, 61.78 years; eight women) with a first AMI underwent two gated SPECT examinations--one before percutaneous coronary intervention (PCI) and one 4-5 weeks after PCI. Myocardium at risk was estimated by assessing the perfusion defect at the first gated SPECT examination, and salvaged myocardium was estimated by assessing the risk area minus necrosis at the second examination. Myocardium at risk was estimated by determining the discordance between the areas of left ventricular (LV) wall motion and perfusion at the second examination. Concordance between tests was analyzed by means of linear regression analysis, the Pearson correlation, the intraclass correlation coefficient, and Bland-Altman analysis. RESULTS: An improvement in perfusion, wall motion, wall thickening, and LV ejection fraction (P < .001) was observed at 1 month. At 1 month, the area with abnormal wall motion was greater than the area of altered perfusion (35.47 vs 23.1 cm(2); P = .007). The extent of myocardium at risk estimated from this discordance correlated well with myocardium at risk measured at the first gated SPECT examination and with salvaged myocardium between both studies (Pearson correlation: 0.78 and 0.6, respectively). Concordance for correct classification of patients with salvaged myocardium of 50% or greater was 83% (κ = 0.65). CONCLUSION: Myocardial perfusion gated SPECT performed 1 month after early PCI in a first AMI provides potentially useful information on at-risk and salvaged myocardium. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13122324/-/DC1.

Predictive variables for hard cardiac events and coronary revascularization in patients with normal left ventricular myocardial perfusion and systolic function.

BACKGROUND: The objective of this study was to investigate the impact of clinical, electrocardiographic and stress testing variables in predicting hard cardiac events (HE) and coronary revascularization (CR) in patients with normal stress-rest gated SPECT. MATERIALS AND METHODS: Included in the study were 2,004 patients (63.5 ± 12.5 years, 41.6% men) with normal myocardial perfusion and left ventricular ejection fraction (LVEF) >50% on gated SPECT who were followed for HE (cardiovascular death or acute myocardial infarction) and CR. RESULTS: During a follow-up of 4.3 ± 2.4 years, 33 patients (1.6 %; 0.4%/year) had HE and 50 patients (2.5%; 0.6%/year) underwent CR. In a univariate analysis, age ≥65 years, insulin-dependent diabetes mellitus (IDDM), left bundle branch block (LBBB), and pharmacological stress were associated with HE. Independent predictors of HE were age ≥65 years (p < 0.001; HR 6.9), IDDM (p = 0.014; HR 3.4), and LBBB (p = 0.002; HR 4.6). In the univariate analysis, male gender, LVEF, known coronary artery disease (CAD), LBBB, and a positive stress test were associated with CR. Independent predictors of CR were known CAD (p = 0.016; HR 2.1), and a positive stress test (p = 0.006; HR 2.3). CONCLUSION: Age ≥65 years, IDDM, and LBBB are HE-independent predictors in patients with normal myocardial perfusion and normal LVEF on gated SPECT. The presence of known CAD or a positive stress test significantly increases the probability of CR during follow-up.

La distensión de la región isquémica predice una mayor inducibilidad de fibrilación ventricular tras la oclusión coronaria en el modelo porcino / Distension of the ischemic region predicts increased ventricular fibrillation inducibility following coronary occlusion in swine

Introducción y objetivos. La distensión de la región isquémica se ha relacionado con una mayor incidencia de arritmias ventriculares espontáneas tras la oclusión coronaria. Analizamos si la distensión isquémica regional predice una mayor inducibilidad de fibrilación ventricular tras la oclusión coronaria en cerdos. Métodos. En 18 cerdos anestesiados con tórax abierto, se ocluyó la descendente anterior durante 60 min. Se monitorizó la longitud segmentaria en la región isquémica mediante cristales ultrasónicos. Se realizó estimulación programada basal, y después continuamente entre 10 y 60 min tras la oclusión. Resultados. La oclusión coronaria indujo un rápido aumento en la longitud telediastólica en la región isquémica, que alcanzó el 109,4±0,9% de los valores basales a los 10 min (p<0,001). Se completaron 6,6±0,5 protocolos de estimulación, que indujeron 5,4±0,6 episodios de fibrilación ventricular entre 10 y 60 min tras la oclusión. Ni los valores séricos de potasio ni el tamaño del área isquémica se asociaron significativamente con la inducibilidad de fibrilación ventricular. Por el contrario, el aumento en la longitud telediastólica 10 min tras la oclusión coronaria se asoció directamente (r=0,67; p=0,002) con el número de episodios inducidos de fibrilación ventricular e inversamente (r=–0,55; p=0,018) con el número de extraestímulos necesarios para inducir la arritmia. Conclusiones. La distensión regional isquémica predice una mayor inducibilidad de fibrilación ventricular tras la oclusión coronaria. Estos resultados subrayan la influencia potencial de los factores mecánicos, que actúan no sólo sobre los desencadenantes, sino también sobre el sustrato, en la génesis de las arritmias ventriculares malignas durante la isquemia aguda (AU)

Introduction and objectives. Distension of the ischemic region has been related to an increased incidence of spontaneous ventricular arrhythmias following coronary occlusion. This study analyzed whether regional ischemic distension predicts increased ventricular fibrillation inducibility after coronary occlusion in swine. Methods. In 18 anesthetized, open-chest pigs, the left anterior descending coronary artery was ligated for 60min. Myocardial segment length in the ischemic region was monitored by means of ultrasonic crystals. Programmed stimulation was applied at baseline and then continuously between 10 and 60min after coronary occlusion. Results. Coronary occlusion induced a rapid increase in end-diastolic length in the ischemic region, which reached 109.4% (0.9%) of baseline values 10min after occlusion (P<.001). On average, 6.6 (0.5) stimulation protocols were completed and 5.4 (0.6) ventricular fibrillation episodes induced between 10 and 60min of coronary occlusion. Neither baseline serum potassium levels nor the size of the ischemic region were significantly related to ventricular fibrillation inducibility. In contrast, the increase in end-diastolic length 10min after coronary occlusion was associated directly (r=0.67; P=.002) with the number of induced ventricular fibrillation episodes and inversely (r=–0.55; P=.018) with the number of extrastimuli needed for ventricular fibrillation induction. Conclusions. Regional ischemic expansion predicts increased ventricular fibrillation inducibility following coronary occlusion. These results highlight the potential influence of mechanical factors, acting not only on the triggers but also on the substrate, in the genesis of malignant ventricular arrhythmias during acute ischemia (AU)