OBJECTIVES: This study sought to understand prognostic implications of increased baseline left ventricular (LV) mass and geometric patterns in a high risk acute myocardial infarction. BACKGROUND: The LV hypertrophy and alterations in LV geometry are associated with an increased risk of adverse cardiovascular events. METHODS: Quantitative echocardiographic analyses were performed at baseline in 603 patients from the VALIANT (VALsartan In Acute myocardial iNfarcTion) echocardiographic study. The left ventricular mass index (LVMi) and relative wall thickness (RWT) were calculated. Patients were classified into 4 mutually exclusive groups based on RWT and LVMi as follows: normal geometry (normal LVMi and normal RWT), concentric remodeling (normal LVMi and increased RWT), eccentric hypertrophy (increased LVMi and normal RWT), and concentric hypertrophy (increased LVMi and increased RWT). Cox proportional hazards models were used to evaluate the relationships among LVMi, RWT, LV geometry, and clinical outcomes. RESULTS: Mean LVMi and RWT were 98.8 +/- 28.4 g/m(2) and 0.38 +/- 0.08. The risk of death or the composite end point of death from cardiovascular causes, reinfarction, heart failure, stroke, or resuscitation after cardiac arrest was lowest for patients with normal geometry, and increased with concentric remodeling (hazard ratio [HR]: 3.0; 95% confidence interval [CI]: 1.9 to 4.9), eccentric hypertrophy (HR: 3.1; 95% CI: 1.9 to 4.8), and concentric hypertrophy (HR: 5.4; 95% CI: 3.4 to 8.5), after adjusting for baseline covariates. Also, baseline LVMi and RWT were associated with increased mortality and nonfatal cardiovascular outcomes (HR: 1.22 per 10 g/m(2) increase in LVMi; 95% CI: 1.20 to 1.30; p < 0.001) (HR: 1.60 per 0.1-U increase in RWT; 95% CI: 1.30 to 1.90; p < 0.001). Increased risk associated with RWT was independent of LVMi. CONCLUSIONS: Increased baseline LV mass and abnormal LV geometry portend an increased risk for morbidity and mortality following high-risk myocardial infarction. Concentric LV hypertrophy carries the greatest risk of adverse cardiovascular events including death. Higher RWT was associated with an increased risk of cardiovascular complications after high-risk myocardial infarction.