Matchar and colleagues (3) reviewed the comparative effectiveness of ACE inhibitors and ARBs for treating essential hypertension. They identified 61 clinical studies that directly compared ACE inhibitors with ARBs in adults with essential hypertension, reported an outcome of interest, lasted at least 12 weeks, and enrolled at least 20 patients. Forty-seven were randomized, controlled trials (RCTs); 1 was a nonrandomized, controlled trial; 9 were retrospective cohort studies; 2 were prospective cohort studies; 1 was a cross-sectional cohort study; and 1 was a case–control study. Not surprisingly, ACE inhibitors and ARBs had similar long-term effects on blood pressure. Rates of use as monotherapy were similar for the 2 drug classes, and they had similar effects on mortality and cardiovascular events, quality of life, lipid levels, progression to diabetes, measures of left ventricular mass and function, and measures of kidney disease. However, these outcomes were studied infrequently over the long term, and the studies did not report important outcomes or results in patient subgroups.