Cardiovascular Protection with Antihypertensive Drugs in Dialysis Patients: A Systematic Review and Meta-analysis

Abstract

Epidemiological studies demonstrate that a lower blood pressure and decline in blood pressure over months or years are associated with higher mortality in dialysis patients. In contrast, randomized controlled trials lack power to establish benefits of antihypertensive therapy. Patients on long-term dialysis participating in randomized controlled trials and receiving antihypertensive drug therapy were the subject of this meta-analysis. Outcomes assessed were the hazard ratio of cardiovascular events and all-cause mortality in treated group compared to controls. Among 1202 patients we identified in 5 studies, the overall benefit of antihypertensive therapy compared to control or placebo group had a combined hazard ratio for cardiovascular events of 0.69 (95% CI 0.56 to 0.84) using a fixed effects model and 0.62 (95% CI 0.44 to 0.88) using a random effects model. In a sensitivity analysis we found that the hypertensive group had a pooled hazard ratio of 0.49 (95% CI 0.35 to 0.67), but when normotensives were included in the trial lesser cardiovascular protection was seen (pooled hazard ratio of 0.86 (95% CI 0.67 to 1.12)). Test for herterogenity between hypertensive and “normotensive-included” groups was significant (p<0.006). Similar results were seen for risk ratio for death and cardiovascular events. There was evidence of publication bias based on Egger's test and funnel plot. Randomized trials suggest benefit of antihypertensive therapy among hemodialysis patients. Adequately powered randomized trials are required to confirm these observations especially among those with hypertension.