In Hemodialysis Patients, Renin-Angiotensin System Inhibitors Reduce All-Cause Mortality Risk

A recent study suggests that renin-angiotensin system (RAS) inhibitors are the preferred antihypertensive agents for patients starting hemodialysis, as it found that drug regimens containing RAS inhibitors are associated with a lower risk of cardiovascular and all-cause deaths among those patients, compared to regimens containing only beta blockers (BBs).

As hypertension is highly prevalent among dialysis patients, antihypertensive medications are commonly prescribed to those patients. However, the optimal antihypertensive treatment regimen for dialysis patients remains unknown, though it’s considered a priority area of research by an Agency for Healthcare Research and Quality (AHRQ) panel of technical experts, providers, and patient advocates.

In an effort to quantify the effect of common antihypertensive regimens prescribed to hemodialysis patients on the risk of death, Tariq Shafi, MBBS, MHS, FACP, FASN, FNKF, an assistant professor of medicine at The Johns Hopkins University in Baltimore, MD, and colleagues reported their findings at Kidney Week 2013, the American Society of Nephrology's annual meeting held November 5-10, 2013, in Atlanta, GA.

Their retrospective study cohort included 33,166 incident in-center patients who began hemodialysis treatment between 2006 and 2008 and were still it after 6 months. At baseline on day 180, 37% of the patients were given medications containing BBs, 19% were given medications containing RAS agents, 26% were given BB+RAS, and 18% were given other drugs.

The researchers assessed blood pressure medication use from Medicare part D claims data that included prescription fill dates and the number of pills prescribed. Patients who discontinued blood pressure medication during follow-up were considered as the study’s 5th group. The authors used discrete time proportional hazards models adjusting for demographic and clinical characteristics and comorbidities in order to assess the association among blood pressure medications, death, and the recorded the cause of death.

According to the investigators, the hazard ratio for the association of antihypertensive medications with cardiovascular and all-cause mortality considered age, sex, race, ethnicity, Medicaid status, body mass index (BMI), end-stage renal disease (ESRD) cause, and serum albumin and hemoglobin. Baseline and time-varying factors such as antihypertensive medication use in the prior month and comorbidities including congestive heart failure (CHF), cardiovascular disease (CVD), diabetes mellitus (DM), and chronic obstructive pulmonary disease (COPD) were also measured.

Of the 9,107 (28%) deaths that occurred during follow-up, 4,521 (50%) were cardiovascular-related, and patients in the BB group were more likely to have CVD and CHF. RAS-based medications were associated with a lower mortality hazard than BB medications without RAS. The hazard ratio for the RAS group was 0.87 for all-cause mortality and 0.84 for cardiovascular mortality, while the hazard ratio for the BB+RAS group was 0.75 for all-cause mortality and 0.77 for cardiovascular mortality.

Across multiple subgroup analyses, medication regimens containing RAS or containing BB+RAS were associated with a lower risk of cardiovascular and all-cause mortality than regimens containing only BBs, the authors concluded.

Shafi disclosed support from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).