Antihypertensives lower risk for CVD patients without hypertension

In patients who had a clinical history of cardiovascular disease (CVD) but not hypertension, antihypertensive treatment was associated with decreased risk of stroke, congestive heart failure (CHF), composite CVD events and all-cause mortality, according to a meta-analysis.

To evaluate the effect of antihypertensive treatment on secondary prevention, researchers conducted a meta-analysis of 25 randomized, controlled trials reviewing outcomes of stroke, myocardial infarction (MI), CHF, composite CVD outcomes, CVD mortality and all-cause mortality. These studies totaled 64,162 participants (mean age range, 55 to 68 years; 76% men), all with blood pressure less than 140 mm Hg systolic, less than 90 mm Hg diastolic, or no clinical history of hypertension at baseline. Researchers reported results in the March 2 Journal of the American Medical Association.

Compared with controls, participants receiving antihypertensive medications had a pooled relative risk of 0.77 (95% CI, 0.61 to 0.98) for stroke, 0.80 (95% CI, 0.69 to 0.93) for MI, 0.71 (95% CI, 0.65 to 0.77) for CHF, 0.85 (95% CI, 0.80 to 0.90) for composite CVD events, 0.83 (95% CI, 0.69 to 0.99) for CVD mortality, and 0.87 (95% CI, 0.80 to 0.95) for all-cause mortality from random-effects models.

The corresponding absolute risk reductions per 1,000 persons were −7.7 (95% CI, −15.2 to −0.3) for stroke, −13.3 (95% CI, −28.4 to 1.7) for MI, −43.6 (95% CI, −65.2 to −22.0) for CHF events, −27.1 (95% CI, −40.3 to −13.9) for composite CVD events, −15.4 (95% CI, −32.5 to 1.7) for CVD mortality and −13.7 (95% CI, −24.6 to −2.8) for all-cause mortality.

Subgroup analyses showed little difference in the association of antihypertensive treatment among those with clinical history of MI or coronary artery disease, those with preexisting CHF, and those with history of diabetes or according to class of antihypertensive medication. Further, there was little change in the overall effect estimates by clinical history among those with MI or coronary artery disease, those with preexisting CHF, or according to class of antihypertensive medication, with the exception of diabetes. A limited number of trials conducted exclusively in patients with diabetes showed no statistically significant benefit of antihypertensive treatment.

The meta-analysis' strength is that it used only randomized, controlled trials with study characteristics very similar at baseline. Its weakness is that few studies reported outcomes for normotensive and prehypertensive patients.

“The results of this meta-analysis suggest that persons with these compelling indications but without hypertension may also benefit from reduced morbidity and mortality attributable to CVD events when treated with antihypertensive medications,” the authors wrote. “In persons 40 years and older with prehypertension, more than 90% have at least 1 above-optimal risk factor, and more than 68% have at least 1 clinically high risk factor for heart disease or stroke. Although pharmacological treatment for all individuals in this population would not be economically feasible, a more reasonable strategy might be to identify groups within the prehypertensive population who would obtain the greatest benefit from early pharmacological intervention.”