Racial/ethnic differences in the prognostic utility of left ventricular mass index for incident cardiovascular disease

Background: Evidence exists for racial/ethnic differences in left ventricular mass index (LVMI). How this translates to future cardiovascular disease (CVD) events is unknown. Hypothesis: The impact of racial/ethnic differences in LVMI on incident cardiovascular outcomes could have potential implications for the optimization of risk stratification strategies. Methods: Using the prospectively collected database of the Multi-Ethnic Study of Atherosclerosis (MESA) involving 4 racial/ethnic groups (non-Hispanic Whites, Chinese, Blacks, and Hispanics) free of CVD at baseline, we assessed for racial/ethnic differences in the relationship between LVMI and incident CVD using a Cox model. Results: 5004 participants (mean age, 62 ± 10 years; 48% male) were included in this study. After an average follow-up of 10.2 years, 369 (7.4%) CVD events occurred. Significant racial/ethnic differences existed in the relationship between LVMI and incident CVD (P for interaction = 0.04). Notably, the relationship was strongest for Chinese (HR per 10-unit increase in LVMI: 1.7, 95% CI: 1.1–2.8) and Hispanics (HR per 10-unit increase in LVMI: 1.9, 95% CI: 1.5–2.2). Non-Hispanic Whites demonstrated the lowest relationship (HR: 1.3, 95% CI: 1.1–1.5). LVMI values of 36.9 g/m^2.7, 31.8 g/m^2.7, 39.9 g/m^2.7, and 41.7 g/m^2.7 were identified as optimal cutpoints for defining left ventricular hypertrophy (LVH) for non-Hispanic Whites, Chinese, Blacks, and Hispanics, respectively. In secondary analysis of LVH (vs no LVH) using these optimal cutpoints, we found a similar pattern of association as above (P for interaction = 0.04). For example, compared with those without LVH, Chinese with LVH had HR: 5.3, 95% CI: 1.6–17, whereas non-Hispanic Whites with LVH had HR: 1.6, 95% CI: 1.2–2.1 for CVD events. Conclusions: Among 4 races/ethnicities studied, LVMI has more prognostic utility predicting future CVD events for Chinese and Hispanics and is least significant for non-Hispanic Whites.