The health benefits of diuretics and beta blockers are proved. To determine the relative health benefits of six first-line antihypertensive therapies, Psaty and colleagues used a new method of meta-analysis to overcome previous statistical problems in comparing trials.
MEDLINE searches identified studies of antihypertensive effects on cardiovascular morbidity and mortality. The authors identified 42 trials including 192,478 patients who were followed for an average of three to four years. Compared with placebo, any active treatment resulted in risk reductions for all major outcomes. A network meta-analysis showed that the relative risks of low-dosage diuretic therapy were significantly less than placebo for six outcomes: chronic heart disease, congestive heart failure (CHF), stroke, cardiovascular disease events, cardiovascular disease mortality, and total mortality. Compared with beta blockers, low-dosage diuretics were associated with a lower point estimate for events; only the incidence of cardiovascular events was significant. Compared with angiotensin-converting enzyme inhibitors, low-dosage diuretics were associated with a significantly lower risk of CHF, stroke, and cardiovascular disease events; CHF and cardiovascular disease event risks also were significantly lower in patients taking diuretics than in those taking calcium channel blockers.
For all outcomes, the network meta-analysis showed that low-dosage diuretics were superior to placebo; no other therapies were significantly better than diuretics. Beta blockers were inferior to diuretics for all outcomes, although cardiovascular disease events was the only category in which a significant difference was noted. These findings may be related to lower blood pressures achieved by diuretics but, if so, the differences in blood pressures were small. Direct and indirect comparisons from trials indicate that diuretics are the treatment of choice in uncomplicated hypertension.