Background: This study aimed to elucidate whether regional left ventricular wall thickening (LVWT) determined by quantitative gated SPECT (QGS) is useful in predicting surgical outcomes for ischemic (ICM) and nonischemic cardiomyopathy (NICM).
Methods and results: The study group comprised 53 patients with either ICM (n=30, left ventricular ejection fraction (LVEF)=24.7±7.1%) or NICM (n=23, LVEF=24.0±6.3%) scheduled for surgical repair underwent preoperative QGS to evaluate regional LV function. LVWT of 20 segments derived from QGS was normalized by being divided by the normal value of each LV level. Normalized values of the segments were summed to be representative of each area. For 16 of the 30 patients with ICM and 17 of the 23 patients with NICM, surgical ventricular restoration and papillary muscle approximation (PMA) were performed for surgical repair and, for the rest, PMA alone was done for both ICM and NICM patients. Adjunctive coronary artery bypass grafting for ICM patients was added when necessary. Mean follow-up periods were 2.5±1.8 years for ICM and 2.2±2.4 years for NICM. Posterior regional LVWT in NICM (normalized sum value <0.61 n=7, ROC: AUC=0.80) predicted cardiac events (chronic heart failure and cardiac-caused death). The one-year cardiac event-free rates were 22.2% and 85.1% and the 2 years rates were 11.1% and 48.6% for the lower posterior WT group and higher posterior WT group respectively (P=0.003).
Conclusions: Posterior LVWT can be a predictor for postoperative cardiac events in patients with NICM.