Left Ventricular Mass and the Risk of Sudden Cardiac Death: A Population-Based Study

Background-Left ventricular (LV) mass ascertained using echocardiography may enhance risk stratification for sudden cardiac death. The objective of this study was to assess the association between left ventricular mass and the risk of sudden cardiac death in a population-based cohort and determine its incremental value beyond conventional risk predictors. Methods and Results-Assessment of LV mass was based on echocardiography in a sample of 905 middle-aged men representative of the general population (aged 42 to 61 years). During the follow-up period of 20 years, there were a total of 63 sudden cardiac deaths. In a comparison of the top versus the bottom quartile of LV mass adjusted by body surface area (> 120 versus < 89 g/m(2)), the multivariable adjusted hazard ratio was 2.57 (95% CI 1.24 to 5.31, P = 0.010). Further adjustment for LV function only modestly attenuated the risk of sudden cardiac death among men with LV mass of > 120 g/m(2) (hazard ratio 2.29, 95% CI 1.10 to 4.74, P = 0.026). Addition of LV mass adjusted by body surface area to a conventional risk factor model for sudden cardiac death improved the integrated discrimination index by 0.033 (95% CI 0.009 to 0.057, P = 0.007) and the category-free net reclassification index by 0.501 (95% CI 0.092 to 0.911, P = 0.016). Conclusions-Indexed LV mass by body surface area is an independent predictor of sudden cardiac death and may help improve the risk prediction of sudden cardiac death beyond conventional cardiovascular risk factors.