Predictive value for mortality of left ventricular wall thickness in dilated cardiomyopathy.

ABSTRACT

AIMS: The purpose of this study was to explore the predictive value of wall thickness measured by cardiac magnetic resonance (CMR) for all-cause mortality in dilated cardiomyopathy (DCM) patients. METHODS AND RESULTS: DCM patients who underwent CMR and completed the regular follow-up were included in this study. The left ventricular end-diastolic diameter (LVDd), left ventricular end-diastolic volume (LVEDV), left ventricular posterior wall thickness (PWT), interventricular septum thickness (IVST), left ventricular ejection fraction, and left ventricular mass (LVM) were measured by CMR. The presence and extent of late gadolinium enhancement (LGE) were also assessed. The relative posterior wall thickness (RWTPW ) and relative interventricular septum wall thickness (RWTIVS ) were defined by the following equations RWTPW  = (2 × PWT)/LVDd, and RWTIVS  = (2 × IVST)/LVDd. All patients received regular telephone and outpatient follow-up. The primary endpoint was all-cause mortality. A total of 161 patients were enrolled in this study, including 126 (78.3%) males. The mean age was 52.3 ± 13.6 years. During the median follow-up of 47 months (interquartile range 32-57 months), 41 (24.8%) patients died. Compared with the non-death group, LVDd (75.2 ± 11.9 vs. 70.5 ± 8.8 mm; P = 0.025) was greater in the death group, while PWT [5.2 mm (3.7-6.8) vs. 6.9 mm (5.3-8.6); P < 0.001], IVST [8.2 mm (6.5-9.5) vs. 9.3 mm (7.4-10.5); P = 0.005], RWTPW [0.15 (0.11-0.19) vs. 0.20 (0.15-0.25); P < 0.001], RWTIVS [0.22 (0.17-0.26) vs. 0.26 (0.22-0.31); P < 0.001], and LVM/LVEDV ratio (0.5 ± 0.2 vs. 0.7 ± 0.2 g/mL; P < 0.001) were lower. The presence of LGE [LGE(+)] was more frequent in the death group (75.6% vs. 58.3%; P = 0.048). However, the LGE extent was not significantly different between the two groups [4 (1-7) vs. 2 (0-6); P = 0.096]. Multivariate Cox regression analysis showed that PWT [hazard ratio (HR) 0.086, 95% confidence interval (CI) 0.665-0.976; P < 0.05] and RWTPW (HR 0.001, 95% CI 0.000-0.502; P < 0.05) were independent predictors of all-cause death. In contrast, IVST, RWTIVS , and the presence of LGE were not clearly associated with death. CONCLUSIONS: PWT measured by CMR is an independent predictor of all-cause mortality in DCM patients. However, there was no significant correlation between septum wall thickness and mortality.