RAAS Blockers Linked to Increased Survival in Dialysis Patients

Antihypertensive medications, including renin angiotensin-aldosterone system (RAAS) inhibitors, have a small but significant survival benefit for hemodialysis patients, according to a study in Kidney International.

The researchers analyzed data from the International Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 2 to 5 (2002–2015). The study included data on 11,421 patients with incident hemodialysis, over 120 days or less; and 11,421 with prevalent hemodialysis, over 120 days. The exposure of interest was baseline treatment with RAAS inhibitors: angiotensin-converting enzyme inhibitor, angiotensin-receptor blocker (ARB), aldosterone receptor antagonist, or direct renin inhibitor. The effects of treatment with RAAS inhibitors or other antihypertensive agents on all-cause mortality were estimated by Cox regression analysis.

Overall, 39% of patients were taking a RAAS inhibitor at baseline. More than 95% of these prescriptions were for ACE inhibitors or ARBs. Prescription of RAAS inhibitors varied widely by region, duration of hemodialysis, and diabetes status, but not by history of congestive heart failure or coronary artery disease.

Prescription of a RAAS inhibitor was associated with a significant reduction in all-cause mortality: adjusted hazard ratio 0.89 in incident hemodialysis patients and 0.94 in the prevalent hemodialysis group.

Beta-blockers and calcium channel blockers were also associated with lower mortality. Among patients with a RAAS inhibitor prescription, the survival benefit appeared greater with ARBs versus ACE inhibitors.

Hemodialysis patients are less likely to receive RAAS inhibitor therapy, reflecting mixed data from clinical trials and concerns about hyperkalemia. This analysis of DOPPS data shows significantly lower all-cause mortality in hemodialysis patients receiving a RAAS inhibitor: by 11% in incident and 6% in prevalent hemodialysis patients.

The study shows no interaction between diabetes, coronary artery disease, or congestive heart failure and the survival benefit of RAAS inhibitors. Randomized trials are needed to clarify RAAS inhibitor prescribing criteria in patients receiving hemodialysis, the authors noted [Karaboyas A, et al. DOPPS data suggest a possible survival benefit of renin angiotensin-aldosterone system inhibitors and other antihypertensive medications for hemodialysis patients. Kidney Int 2018; 94:589–598]

October/November 2018 (Vol. 10, Number 10 & 11)