Association between renin-angiotensin system antagonist use and mortality in heart failure with severe renal insufficiency: a prospective propensity score-matched cohort study.

AIMS: In heart failure (HF) with reduced ejection fraction (EF), renin-angiotensin receptor (RAS) antagonists reduce mortality. However, severe renal insufficiency was an exclusion criterion in trials. We tested the hypothesis that RAS antagonists are associated with reduced mortality also in HF with severe renal insufficiency. METHODS AND RESULTS: We studied patients with EF ≤39% registered in the prospective Swedish Heart Failure Registry. In patients with creatinine >221 µmol/L or creatinine clearance <30 mL/min, propensity scores for RAS-antagonist use were derived from 36 variables. The association between RAS antagonist use and all-cause mortality was assessed with Cox regression in a cohort matched 1:1 based on age and propensity score. To assess consistency, we performed the same analysis as a 'positive control' in patients without severe renal insufficiency. Between 2000 and 2013, there were 24 283 patients of which 2410 [age, mean (SD), 82 (9), 45% women] had creatinine >221 µmol/L or creatinine clearance <30 mL/min and were treated (n = 1602) or not treated (n = 808) with RAS antagonists. In the matched cohort of 602 vs. 602 patients [age 83 (8), 42% women], RAS antagonist use was associated with 55% [95% confidence interval (CI) 51-59] vs. 45% (41-49) 1-year survival, P < 0.001, with a hazard ratio (HR) for mortality of 0.76 (95% CI 0.67-0.86, P < 0.001). In positive control patients without severe renal insufficiency [n = 21 873; age 71 (12), 27% women], the matched HR was 0.79 (95% CI 0.72-0.86, P < 0.001). CONCLUSION: In HF with severe renal insufficiency, the use of RAS antagonists was associated with lower all-cause mortality. Prospective randomized trials are needed before these findings can be applied to clinical practice.