β-blocker dialyzability and the risk of mortality and cardiovascular events in patients undergoing hemodialysis

Background β-blocker (BB) dialyzability has been proposed to limit their efficacy among hemodialysis (HD) patients. We attempted to confirm this hypothesis by comparing health outcomes associated with the initiation of dialyzable or nondialyzable BBs in a nationwide cohort of HD patients. Methods We created a prospective cohort study of 15 699 HD patients who initiated dialyzable BBs (atenolol, acebutolol, metoprolol and bisoprolol) and 20 904 hemodialysis patients who initiated nondialyzable BBs (betaxolol, carvedilol and propranolol) between 2004 and 2011 in Taiwan healthcare. We compared the risk of all-cause mortality and major adverse cardiovascular events (MACEs, a composite of the acute coronary syndrome, ischemic stroke and heart failure) between users of dialyzable versus nondialyzable BBs during a 2-year follow-up. Results New users of dialyzable BBs were younger, more often men, with diabetes mellitus, hypertension and hyperlipidemia compared with users of nondialyzable BBs. Compared with nondialyzable BBs, initiation of dialyzable BBs was associated with lower all-cause mortality {hazard ratio [HR] 0.82 [95% confidence interval (CI) 0.75-0.88]} and lower risk of MACEs [HR 0.89 (95% CI 0.84-0.93)]. Results were confirmed in subgroup analyses, censoring at BB discontinuation or switch, after 1:1 propensity score matching, reclassifying bisoprolol or excluding bisoprolol/carvedilol users. Conclusions This study does not offer support for the hypothesis that the dialyzability of BBs reduces their efficacy in HD patients.