Abstract 1996: Left Ventricular Mass Predicts Death and Sudden Death in Patients with CAD Regardless of Ejection Fraction: Data from the Heart & Soul Study
BACKGROUND: Increased left ventricular (LV) mass may lead to electrical heterogeneity and serve as the substrate for ventricular arrhythmias even in patients with normal ejection fraction. We hypothesized that LV mass would predict sudden cardiac death and all-cause mortality.
METHODS & RESULTS: We performed transthoracic echocardiography in 1016 subjects with stable CAD. LV mass was measured using the truncated ellipsoid technique and normalized to body surface area to obtain LV mass index (LVMI). Cox proportional hazards models were used to examine the association of LVMI to death and to sudden or arrhythmic death during a mean follow-up of 3.55 years. The mean LVMI was 98.2 ± 26.5 gm/m2. In 82% of patients, EF was normal (≥ 55%) and accounted for only 42% of the variability (r-squared) of LVMI. EF was normal in 94 of 145 (65%) overall deaths and in 10 of 21 (47%) sudden or arrhythmic deaths. Mortality rate increased stepwise by LVMI quartile (8.3%, 10.6%, 13.4%, 24.4%, p < 0.0001). The rate of sudden or arrhythmic death also increased by LVMI quartile (0.82%, 1.63%, 1.22%, 5.16%, p < 0.05). Among cases of sudden and arrhythmic death with EF > 30% (MADIT-II ineligible), 57% were in the highest quartile of LV mass. After adjustment for cardiovascular risk factors, the highest LVMI quartile was still associated with death (HR 2.15, 95% CI 1.3–3.7, p < 0.005) and sudden or arrhythmic death (HR 5.8, 95% CI 1.2–28.8, p < 0.05). To determine if the effect of LVMI was independent from other echocardiographic measurements, we created a separate model adjusting for ejection fraction, end-systolic and diastolic volume, and septal and posterior wall thickness. In this model, LVMI was the only significant predictor of mortality (HR 1.81, 95% CI 1.1–3.4, p < 0.05).
CONCLUSION: LVMI is a potent independent predictor of death and sudden or arrhythmic death in patients with CAD. LVMI also identified sudden and arrhythmic deaths that would not be have been captured by MADIT-II criteria.