Antihypertensive Treatment and Secondary Prevention of Cardiovascular Disease Events Among Persons Without Hypertension: A Meta-analysis

Abstract

CONTEXT: Cardiovascular disease (CVD) risk increases beginning at systolic blood pressure levels of 115 mm Hg. Use of antihypertensive medications among patients with a history of CVD or diabetes and without hypertension has been debated. OBJECTIVE: To evaluate the effect of antihypertensive treatment on secondary prevention of CVD events and all-cause mortality among persons without clinically defined hypertension. DATA SOURCES: Meta-analysis with systematic search of MEDLINE (1950 to week 3 of January 2011), EMBASE, and the Cochrane Collaboration Central Register of Controlled Clinical Trials and manual examination of references in selected articles and studies. STUDY SELECTION: From 874 potentially relevant publications, 25 trials that fulfilled the predetermined inclusion and exclusion criteria were included in the meta-analysis. DATA EXTRACTION: Information on participant characteristics, trial design and duration, treatment drug, dose, control, and clinical events were extracted using a standardized protocol. Outcomes included stroke, myocardial infarction (MI), congestive heart failure (CHF), composite CVD outcomes, CVD mortality, and all-cause mortality. RESULTS: Compared with controls, participants receiving antihypertensive medications had a pooled relative risk of 0.77 (95% confidence interval [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 1000 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. Results did not differ according to trial characteristics or subgroups defined by clinical history. CONCLUSIONS: Among patients with clinical history of CVD but without hypertension, antihypertensive treatment was associated with decreased risk of stroke, CHF, composite CVD events, and all-cause mortality. Additional randomized trial data are necessary to assess these outcomes in patients without CVD clinical recommendations.