Integración de los parámetros de remodelado, sincronía y velocidad máxima de vaciado para evaluar la función sistólica del ventrículo izquierdo / Integration of ventricular remodeling, synchrony and filling rate parameters to improve the assessment of left ventricular systolic function

Objetivos El objetivo es estudiar la relación entre los parámetros estructurales, de remodelado, de sincronía y de función sistólica del ventrículo izquierdo (VI) mediante gSPECT. Obtener los valores de corte del VI para el índice de la forma telediastólica (iFTD), el índice de la forma telesistólica (iFTS), el índice de excentricidad (iEX) y la velocidad máxima de vaciado (VMV). Desarrollar un nuevo índice para evaluar diferentes patrones de función sistólica del VI. Material y métodos Analizamos prospectivamente 238 pacientes (edad: 63,4±13 años) estudiados mediante gSPECT de esfuerzo-reposo (grupo-control, n=148; pacientes con infarto de miocardio [IM] previo, n=90). Estudio aprobado por el Comité de Ética del Hospital (PR[AG]168.2010). Resultados En el grupo-control, el índice del volumen telediastólico (iVTD) y el iEX influyeron en el iFTD (r2: 0,52, p<0,001). El iVTD, la VMV, ser varones y el iEX (r2: 0,44; p<0,001) influyeron en el iFTS. El iFTD, iFTS, la fracción de eyección VI (FEVI) y el volumen de eyección sistólica (r2: 0,62; p<0,001) influyeron en el iEX. La FEVI, la frecuencia cardíaca, el ancho de banda (AB) y la desviación estándar influyeron (r2: 0,76; p<0,001) en la VMV. Los valores de corte para iFTD, iFTS, iEX y VMV fueron 0,59, 0,42, 0,87 y −3,3 respectivamente. La VMV, el iFTS y el AB fueron los parámetros mejor relacionados con los pacientes con IM previo (AUC: 0,89), y sumados a la FEVI permitieron obtener distintos patrones de función sistólica (índice PERRS). Conclusiones Los parámetros de remodelado, sincronía y función sistólica del VI deben interpretarse simultáneamente, ya que esto permite obtener distintos patrones de función sistólica del VI (AU)

Introduction and objectives The aim of this study is to assess the relationship between structural, remodeling, synchrony, and systolic left ventricular (LV) function parameters using gated-SPECT myocardial-perfusion-images (gSPECT-MPI). In addition, obtaining the cut-off values for end-diastolic LV-shape-index (EDLVsi), end-systolic LV-shape-index (ESLVsi), ECC (eccentricity-index) and PER, and developing a new index to evaluate different patterns of the LV systolic function. Methods The study was approved by the Hospital's Ethical-Committee (PR[AG]168.2010), and all patients gave their informed consent. We analyzed prospectively 238 patients (age 63.4±13 years) who underwent stress-rest gSPECT-MPI (control-group, n=148; patients with previous myocardial infarction [MI], n=90). Results In the control group, with regard to remodeling parameters: the end-diastolic-volume-index (EDV) and the ECC were the parameters that influenced the EDLVsi (r2: 0.52, P<.001). EDV, PER, men, and the ECC were the parameters (r2: 0.44; P<.001) which influenced the ESLVsi. EDLVsi, ESLVsi, LVEF and the stroke-volume were the parameters (r2: 0.62; P<.001) which influenced the ECC. With regards to PER: LVEF, heart-rate, bandwidth, and the standard-deviation were the influencing parameters (r2: 0.76; P<.001). The cut-off values for EDLVsi, ESLVsi, ECC, and PER were 0.59, 0.42, 0.87, and 3.3, respectively. The PER, the ESLVsi and the bandwidth were the parameters related to patients with previous MI (AUC: 0.89); and they allow the assessment of different patterns of systolic function (PERRS-index: Peak-Emptying-Rate, left ventricular-Remodeling and Synchrony). Conclusions The remodeling, synchrony and the systolic function parameters of the LV should be interpreted together (PERRS-index). In this way, we obtain different patterns of LV systolic function (AU)

Integration of ventricular remodeling, synchrony and filling rate parameters to improve the assessment of left ventricular systolic function.

INTRODUCTION AND OBJECTIVES: The aim of this study is to assess the relationship between structural, remodeling, synchrony, and systolic left ventricular (LV) function parameters using gated-SPECT myocardial-perfusion-images (gSPECT-MPI). In addition, obtaining the cut-off values for end-diastolic LV-shape-index (EDLVsi), end-systolic LV-shape-index (ESLVsi), ECC (eccentricity-index) and PER, and developing a new index to evaluate different patterns of the LV systolic function. METHODS: The study was approved by the Hospital's Ethical-Committee (PR[AG]168.2010), and all patients gave their informed consent. We analyzed prospectively 238 patients (age 63.4 ±â€¯13 years) who underwent stress-rest gSPECT-MPI (control-group, n = 148; patients with previous myocardial infarction [MI], n = 90). RESULTS: In the control group, with regard to remodeling parameters: the end-diastolic-volume-index (EDV) and the ECC were the parameters that influenced the EDLVsi (r2: 0.52, p < 0.001). EDV, PER, men, and the ECC were the parameters (r2: 0.44; p < 0.001) which influenced the ESLVsi. EDLVsi, ESLVsi, LVEF and the stroke-volume were the parameters (r2: 0.62; p < 0.001) which influenced the ECC. With regards to PER: LVEF, heart-rate, bandwidth, and the standard-deviation were the influencing parameters (r2: 0.76; p < 0.001). The cut-off values for EDLVsi, ESLVsi, ECC, and PER were 0.59, 0.42, 0.87, and 3.3, respectively. The PER, the ESLVsi and the bandwidth were the parameters related to patients with previous MI (AUC: 0.89); and they allow the assessment of different patterns of systolic function (PERRS-index: peak-emptying-rate, left ventricular-remodeling and synchrony). CONCLUSIONS: The remodeling, synchrony and the systolic function parameters of the LV should be interpreted together (PERRS-index). In this way, we obtain different patterns of LV systolic function.

Myocardial Perfusion SPECT Imaging Radiomic Features and Machine Learning Algorithms for Cardiac Contractile Pattern Recognition.

A U-shaped contraction pattern was shown to be associated with a better Cardiac resynchronization therapy (CRT) response. The main goal of this study is to automatically recognize left ventricular contractile patterns using machine learning algorithms trained on conventional quantitative features (ConQuaFea) and radiomic features extracted from Gated single-photon emission computed tomography myocardial perfusion imaging (GSPECT MPI). Among 98 patients with standard resting GSPECT MPI included in this study, 29 received CRT therapy and 69 did not (also had CRT inclusion criteria but did not receive treatment yet at the time of data collection, or refused treatment). A total of 69 non-CRT patients were employed for training, and the 29 were employed for testing. The models were built utilizing features from three distinct feature sets (ConQuaFea, radiomics, and ConQuaFea + radiomics (combined)), which were chosen using Recursive feature elimination (RFE) feature selection (FS), and then trained using seven different machine learning (ML) classifiers. In addition, CRT outcome prediction was assessed by different treatment inclusion criteria as the study's final phase. The MLP classifier had the highest performance among ConQuaFea models (AUC, SEN, SPE = 0.80, 0.85, 0.76). RF achieved the best performance in terms of AUC, SEN, and SPE with values of 0.65, 0.62, and 0.68, respectively, among radiomic models. GB and RF approaches achieved the best AUC, SEN, and SPE values of 0.78, 0.92, and 0.63 and 0.74, 0.93, and 0.56, respectively, among the combined models. A promising outcome was obtained when using radiomic and ConQuaFea from GSPECT MPI to detect left ventricular contractile patterns by machine learning.

Could myocardial viability be related to left ventricular dyssynchrony? Simultaneous evaluation by gated SPECT-MPI.

BACKGROUND: Left ventricular contraction dyssynchrony (LVCD) has been related to induced ischemia and transmural scar but the interplay of myocardial viability and dyssynchrony is unknown. The aim of the present study was to establish the role of dyssynchrony in the context of a viability study performed with nitrate augmentation gated single photon emission computed tomography (GSPECT) myocardial perfusion imaging (MPI). METHODS: Fifty-four consecutive patients with ischemic dilated cardiomyopathy (IDC) and depressed left ventricular ejection fraction (LVEF) were included. They underwent a two-day rest/nitroglycerine (NTG) study GSPECT MPI to determine the myocardial viability. Patients with a nitrate-induced uptake increase of > 10% vs baseline, in at least, two consecutive dysfunctional segments were considered viable as well as those who showed no improvement in the uptake but the uptake was > 50% on post NTG study. Patients with no nitrate-induced uptake increase of > 10% and the uptake of < 50% were considered non-viable. Perfusion, function and LVCD were compared in 25 viable patients vs 29 non-viable patients at baseline and after NTG administration. RESULTS: After NTG administration, in the viable group, the LVEF increased (36.44 ± 6.64% vs 39.84 ± 6.39%) and the end-systolic volume decreased significantly (119.28 ± 31.77 mL vs 109.08 ± 33.17 mL) (P < 0.01). These patients also experienced a significant reduction in the LVCD variables: phase standard deviation was reduced in the post NTG study (57.77° ± 19.47° vs 52.02° ± 17.09°) as well as the phase histogram bandwidth (190.20° ± 78.83° vs 178.0° ± 76.14°) (P < 0.05). Functional and LVCD variables remained similar in the non-viable patients (P > 0.05). CONCLUSION: In patients with IDC and depressed LVEF, the myocardial viability detected by rest/ NTG GSPECT MPI, might determine LVCD improvement.