Association between elevated left ventricular mass index and increased cardiovascular events in patients with acute coronary syndrome: A sub-analysis of the HIJ-PROPER study.

Aim This study aimed to assess the association between left ventricular mass index (LVMI) and cardiovascular events in patients with acute coronary syndrome (ACS) under standard ACS management. Methods and results This study is the sub-analysis of the HIJ-PROPER study. A total of 299 patients who had echocardiographic LVMI data were included in the current analysis. The participants were divided into four groups according to the LVMI quartile [quartile 1 (Q1), 77 (25.8%); quartile 2 (Q2), 73 (24.4%); quartile 3 (Q3), 74 (24.7%); and quartile 4 (Q4), 75 (25.1%)]. The incidence of cardiovascular events was compared among the four groups. The primary endpoint was defined as the composite endpoint of all-cause death, non-fatal myocardial infarction, non-fatal stroke, and hospitalization for heart failure. Mean LVMI in the four groups was 68.1±8.6, 86.2±3.8, 101.1±4.9, and 126.0±18.5 g/m2 , respectively. The primary endpoint was noted in 4, 4, 7, and 14 patients in Q1, Q2, Q3, and Q4, corresponding to an incidence of 5.2%, 5.5%, 9.5%, and 18.7%, respectively (p = 0.03 for difference among four groups). The cumulative incidence of the primary endpoint was significantly higher in patients in Q4 than in those in Q1 and Q2 [hazard ratio (HR) 3.75; 95% confidence interval (CI), 1.23-11.4; p = 0.02 for Q4 vs Q1; HR 3.43; 95% CI, 1.13-10.4; p = 0.03 for Q4 vs Q2]. This tendency was noted even after adjusting for patient characteristics and echocardiography parameters (p = 0.039 for Q4 vs Q1). Conclusion Elevated LVMI was associated with increased cardiovascular events in patients with ACS under standard management. Adequately powered studies are warranted to validate these findings.