High-risk myocardial infarction in the young: The VALsartan In Acute myocardial iNfarcTion (VALIANT) trial

Abstract

Advanced age is a well-established prognostic risk factor after acute myocardial infarction (AMI), yet approximately 10% of MIs occur in patients <45 years. We examined characteristics, cardiovascular outcomes, and the influence of risk factors on outcomes in young survivors of AMI. Fourteen thousand seven hundred three patients enrolled in the VALsartan In Acute myocardial iNfarcTion (VALIANT) trial were divided into 3 age groups: 18 to < 45 (n = 803), 45 to < 65 (n = 6185), > or = 65 years (n = 7715). Multivariate Cox regression was used to compare cardiovascular event rates and assess the impact of risk factors on outcomes. The youngest patients had less diabetes, hypertension, and history of MI and were more likely to be male (18 to < 45 years, 88%; > or = 65 years, 59.1%), nonwhite (18 to < 45 years, 9.6%; > or = 65 years, 5%), current smokers (18 to < 45 years, 73.7%; > or = 65 years, 15.9%), obese (18 to < 45 years, 37.9%; > or = 65 years, 25.1%), and dyslipidemic at randomization (18 to < 45 years, 43.1%; > or = 65 years, 32.7%). Adjusted relative risks of smoking (18 to < 45 years, hazard ratio [HR] 1.6 [95% confidence interval {CI} 1.1-2.5]; > or = 45 years, HR 0.9 [95% CI 0.9-1.1]; P =.014) and hypertension (18 to < 45 years, HR 1.8 [95% CI 1.3-2.6]; > or = 45 years, HR 1.2 [95% CI 1.1-1.3]; P = .044) were higher in the young, with significant interactions observed between age and these risk factors. After AMI, risk factors and outcomes of the young differ substantively from their older counterparts. The influence of hypertension and smoking is more profound in the young, underscoring the need for aggressive risk factor modification post-AMI.