Background: Results of randomized controlled trials are consistent in showing reduced rates of stroke, heart failure and cardiovascular events in very old patients treated with antihypertensive drugs. However, inconsistencies exist with regard to the effect of these drugs on total mortality.
Methods: We performed a meta-analysis of available data on hypertensive patients 80 years and older by selecting total mortality as the main outcome. Secondary outcomes were coronary events, stroke, cardiovascular events, heart failure and cause-specific mortality. The common relative risk (RR) of active treatment versus placebo or no treatment was assessed using a random-effect model. Linear meta-regression was performed to explore the relationship between intensity of antihypertensive therapy and blood pressure (BP) reduction and the log-transformed value of total mortality odds ratios (ORs).
Results: The overall RR for total mortality was 1.06 (95% confidence interval 0.89-1.25), with significant heterogeneity between hypertension in the very elderly trial (HYVET) and the other trials. This heterogeneity was not explained by differences in the follow-up duration between trials. The meta-regression suggested that a reduction in mortality was achieved in trials with the least BP reductions and the lowest intensity of therapy. Antihypertensive therapy significantly reduced (P < 0.001) the risk of stroke (35%), cardiovascular events (27%) and heart failure (50%). Cause-specific mortality was not different between treated and untreated patients.
Conclusion: Treating hypertension in very old patients reduces stroke and heart failure with no effect on total mortality. The most reasonable strategy is the one associated with significant mortality reduction; thiazides as first-line drugs with a maximum of two drugs.