Nondialyzable versus Dialyzable β -Blockers in Hemodialysis : A Target Trial Emulation Study.

KEY POINTS: Many major adverse cardiovascular events happen within the first 6 months after hemodialysis initiation. Using nondialyzable β -blockers at hemodialysis initiation was associated with fewer cardiovascular events than dialyzable β -blockers.

BACKGROUND

How β -blocker dialyzability affects cardiovascular outcomes in patients receiving hemodialysis remains unclear. Previous observational studies show conflicting results, and conducting clinical trials in this population has proven challenging. This uncertainty has contributed to substantial variation in β -blocker prescribing patterns across regions and clinicians.

METHODS

Using data from the United States Renal Data System, we identified patients receiving β -blockers on the day of starting hemodialysis and classified them into nondialyzable and dialyzable exposure groups. Geographical variations in nondialyzable and dialyzable β -blocker prescription rates across neighboring regions in each state were leveraged as an instrumental variable. The treatment effect of nondialyzable versus dialyzable β -blockers on major adverse cardiovascular events (MACE) at 6 months, 1 year, and 3 years was evaluated using instrumental variable g -estimation methods for survival outcomes. MACE comprised myocardial infarction, stroke, and all-cause mortality.

RESULTS

The cohort of 40,313 participants from 41 US states experienced 25,720 MACE over the 3-year follow-up period (median years [interquartile range], 1.4 [0.4-3.0]), with more than 42% occurring during the first 6 months after hemodialysis initiation. The instrumental variable met all statistical assumptions. Nondialyzable β -blockers were associated with significantly lower risk of MACE at all three follow-up time points compared with dialyzable β -blockers (hazard ratios [95% confidence intervals], 0.82 [0.74 to 0.90], 0.85 [0.79 to 0.92], and 0.90 [0.85 to 0.96], respectively). Similar patterns were observed for each separate component of MACE.

CONCLUSIONS

The use of nondialyzable β -blockers compared with dialyzable β -blockers was associated with a lower risk of MACE during all time points, including the early, high-risk period in the 6 months following hemodialysis initiation.