Antecedent hypertension and the effect of captopril on the risk of adverse cardiovascular outcomes after acute myocardial infarction with left ventricular systolic dysfunction: Insights from the Survival and Ventricular Enlargement Trial.

BACKGROUND

Hypertension is a well-established risk factor for myocardial infarction (MI), but its prognostic importance in survivors of an acute MI is less clear.

METHODS

We used Cox proportional hazards models to examine the risk of any major cardiovascular event (cardiovascular death, heart failure, recurrent MI, or stroke)-combined or individual components-and all-cause death and evaluate the efficacy of captopril in 906 patients with hypertension and 1325 patients without hypertension in the Survival and Ventricular Enlargement (SAVE) clinical trial. All patients had survived an acute MI with resultant left ventricular (LV) systolic dysfunction, but without overt heart failure, and were randomized within 3 to 16 days after the index MI to receive either captopril or placebo. The mean (+/- SD) follow-up period was 42 +/- 10 months.

RESULTS

After adjustment for known risk factors, medication use at enrollment, and baseline systolic blood pressure, patients with hypertension had a significant increase in the risk of experiencing a combined cardiovascular event (47.7% vs 31.3%; hazard ratio [HR], 1.49; 95% CI, 1.28-1.74), cardiovascular death (23.4% vs 15.9%; HR, 1.40; 95% CI, 1.12-1.74), heart failure (27.7% vs 15.5%; HR, 1.64; 95% CI, 1.34-2.02), and all-cause death (27.4 vs 19.3%; HR, 1.25; 95% CI, 1.02-1.53), and a similar but statistically non-significant increase in the risk of non-fatal or fatal recurrent MI (17.4% vs 10.9%; HR, 1.27; 95% CI, 0.98-1.65), and non-fatal or fatal stroke (5.0% vs 3.6%; HR, 1.31; 95% CI, 0.81-2.09). Captopril resulted in similar benefits for both patients with and patients without hypertension. The number of combined cardiovascular events prevented for every 100 patients treated with captopril was 7.0 (95% CI, 0.5-13.5) in patients with hypertension and 7.5 (95% CI, 2.6-12.5) in patients without hypertension.

CONCLUSIONS

In survivors of an acute MI with LV systolic dysfunction, antecedent hypertension was associated with a greater risk of subsequent adverse cardiovascular events, not directly explained by elevated blood pressure levels. Captopril use was beneficial in both patients with and patients without hypertension.