Kidney Function and Associated Bleeding Events During Antithrombotic Therapy

In an article in BMC Medicine, investigators “reaffirmed that kidney function affects bleeding events in patients on antithrombotic therapy.” Lead author Kunihiko Matsui and the collaborating researchers advised that “patients on antithrombotic therapy, especially those with decreased kidney function, should receive detailed explanations from their physicians regarding possible bleeding events when continuing antithrombotic therapy.”

These conclusions were based on the investigators’ post-hoc analysis of the randomized Atrial Fibrillation and Ischemic Events with Rivaroxaban in Patients with Stable Coronary Artery Disease (AFIRE) trial. AFIRE stratified 2,092 total participants into high (n = 1,386; 66.3%) and low estimated glomerular filtration rate (eGFR) groups based on a cutoff of 50 mL/min. Matsui and colleagues used a “Cox regression model with multiple failure time data” to specifically analyze recurrent bleeding events in the AFIRE study.

The cumulative incidence of bleeding events per 100 patients at one year was 5.4 in the high eGFR group and 6.2 in the low eGFR group. Notably, the difference increased over time. For the high eGFR group, the hazard ratio was 0.875 for time to first bleeding event (95% confidence interval [CI], 0.701–1.090; p = 0.234) and 0.723 for time to first composite event (95% CI, 0.603–0.867; p = 0.234).

The incidence of recurrent bleeding events per 100 person-years was 11.3 and 15.3 in the high and low eGFR groups, respectively. In both groups, the authors noted that risk of bleeding peaked soon after enrollment; however, the risk remained high in the low eGFR group and decreased over time in the high eGFR group.

In short, the authors concluded that reduced kidney function, via eGFR, was associated with high bleeding event prevalence and continuously high bleeding risk.