Effect of antecedent hypertension and follow-up blood pressure on outcomes after high-risk myocardial infarction

Abstract

The influence of blood pressure on outcomes after high-risk myocardial infarction is not well characterized. We studied the relationship between blood pressure and the risk of cardiovascular events in 14 703 patients with heart failure, left ventricular systolic dysfunction, or both after acute myocardial infarction in the Valsartan in Myocardial Infarction Trial. We assessed the relationship between antecedent hypertension and outcomes and the association between elevated (systolic: >140 mm Hg) or low blood pressure (systolic: <100 mm Hg) in 2 of 3 follow-up visits during the first 6 months and subsequent cardiovascular events over a median 24.7 months of follow-up. Antecedent hypertension independently increased the risk of heart failure (hazard ratio [HR]: 1.19; 95% CI: 1.08 to 1.32), stroke (HR: 1.27; 95% CI: 1.02 to 1.58), cardiovascular death (HR: 1.11; 95% CI: 1.01 to 1.22), and the composite of death, myocardial infarction, heart failure, stroke, or cardiac arrest (HR: 1.13; 95% CI: 1.06 to 1.21). While low blood pressure in the postmyocardial infarction period was associated with increased risk of adverse events, patients with elevated blood pressure (n=1226) were at significantly higher risk of stroke (adjusted HR: 1.64; 95% CI: 1.17 to 2.29) and combined cardiovascular events (adjusted HR: 1.14; 95% CI: 1.00 to 1.31). Six months after a high-risk myocardial infarction, elevated systolic blood pressure, a potentially modifiable risk factor, is associated with an increased risk of subsequent stroke and cardiovascular events. Whether aggressive antihypertensive treatment can reduce this risk remains unknown.