Prevention of heart failure by antihypertensive drug treatment in older persons with isolated systolic hypertension. SHEP Cooperative Research Group.

CONTEXT

Heart failure is often preceded by isolated systolic hypertension, but the effectiveness of antihypertensive treatment in preventing heart failure is not known.

OBJECTIVE

To assess the effect of diuretic-based antihypertensive stepped-care treatment on the occurrence of heart failure in older persons with isolated systolic hypertension.

DESIGN

Analysis of data from a multicenter, randomized, double-blind, placebo-controlled clinical trial.

PARTICIPANTS

A total of 4736 persons aged 60 years and older with systolic blood pressure between 160 and 219 mm Hg and diastolic blood pressure below 90 mm Hg who participated in the Systolic Hypertension in the Elderly Program (SHEP).

INTERVENTION

Stepped-care antihypertensive drug therapy, in which the step 1 drug is chlorthalidone (12.5-25 mg) or matching placebo, and the step 2 drug is atenolol (25-50 mg) or matching placebo.

MAIN OUTCOME MEASURES

Fatal and nonfatal heart failure.

RESULTS

During an average of 4.5 years of follow-up, fatal or nonfatal heart failure occurred in 55 of 2365 patients randomized to active therapy and 105 of the 2371 patients randomized to placebo (relative risk [RR], 0.51; 95% confidence interval [CI], 0.37-0.71; P<.001; number needed to treat to prevent 1 event [NNT], 48). Among patients with a history of or electrocardiographic evidence of prior myocardial infarction (MI), the RR was 0.19 (95% CI, 0.06-0.53; P=.002; NNT, 15). Older patients, men, and those with higher systolic blood pressure or a history of or electrocardiographic evidence of MI at baseline had higher risk of developing heart failure.

CONCLUSION

In older persons with isolated systolic hypertension, stepped-care treatment based on low-dose chlorthalidone exerted a strong protective effect in preventing heart failure. Among patients with prior MI, an 80% risk reduction was observed.