Cardiovascular disease is the leading cause of death in patients receiving maintenance dialysis. In the general population, renin-angiotensin system (RAS) antagonists reduce cardiovascular morbidity and mortality through primary or secondary prevention, as has been summarized in a number of meta-analyses. Two RAS antagonists, angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) have demonstrated efficacy in reducing all-cause mortality and myocardial infarction in people with ischemic heart disease, hypertension, heart failure, and diabetes, as well as preventing kidney failure and cardiovascular events in those with chronic kidney disease. However, whether these findings extend to dialysis patients is less well understood. While both RAS inhibitors share important similarities, they differ pharmacodynamically in important ways. As such, the comparative effectiveness of these agents in specific populations remains an important area of study.
[Photo: Dr. Theresa Shireman]
The purpose of this study, led by Dr. Theresa Shireman, professor of health services, policy and practice, and faculty member in the Center for Gerontology and Healthcare Research, was to determine whether ACE and ARB are differentially associated with reductions in cardiovascular events and mortality in patients receiving maintenance dialysis. To do this, Dr. Shireman and her colleagues conducted a national retrospective cohort study of hypertensive, Medicare-Medicaid eligible patients initiating chronic dialysis between 2000 and 2005. The exposure of interest was new use of either an ACEI or ARB, and outcomes were all-cause mortality and combined cardiovascular hospitalization or death.
The results of the study suggest that, in patients initiating maintenance dialysis, ARBs, compared to ACEIs, were associated with a significant reduction in all-cause mortality of greater than 20 percent. A similar pattern was observed for cardiovascular morbidity and mortality, although the results were not statistically significant. The reasons for this are uncertain, but they suggest that these agents may not be truly equivalent choices for initiation in incident dialysis patients. This important finding sets the stage for a randomized controlled trial to validate the present findings, as does continued work differentiating the relevant pharmacodynamics properties among RAS agents.
This study was published in Kidney & Blood Pressure Research, Volume 41, Issue 6 (ahead of print).
For more information: https://www.ncbi.nlm.nih.gov/pubmed/27871075