Patients treated with dabigatran for nonvalvular atrial fibrillation appeared to be at higher risk for 30-day hospital readmission due to bleeding, according to a population-based, retrospective cohort study.
Use of dabigatran — the first non-vitamin-K antagonist oral anticoagulant to be approved as an alternative treatment to warfarin for non-valvular atrial fibrillation — has increased among hospitals. However, cases of serious bleeds associated with dabigatran therapy have been reported.
“Dabigatran works rapidly following its initiation; hence it may lead to more early-onset bleeds,” Esther W. Chan, BPharm(Hons), MClinPharm, PhD, GradCertPharmEc, PhD, FSHP, associate professor in the department of pharmacology and pharmacy at The University of Hong Kong, and colleagues wrote. “In contrast, warfarin may take weeks to achieve anticoagulation stability following its initiation, resulting in less bleeding.”
Limited information is available regarding the 30-day readmission rates for patients with nonvalvular atrial fibrillation treated with dabigatran or warfarin. Chan and colleagues aimed to address this knowledge gap.
The researchers reviewed population-wide electronic medical records from the Clinical Data Analysis and Reporting System of the Hong Kong Hospital Authority to identify 51,946 patients newly diagnosed with nonvascular atrial fibrillation from 2010 to 2014. Investigators matched 5,160 of these individuals by propensity score (n = 2,580 each for dabigatran and warfarin users).
Chan and colleagues assessed rate of hospital admission with bleeding (mean follow-up, 425 ± 434 days) in association with dabigatran or warfarin therapy.
hospitalization with bleeding occurred in 151 patients who received dabigatran and 172 patients who received warfarin; incidence rates appeared comparable between groups (5 vs. 5.8 per 100 patient-years; incidence rate ratio (IRR): 0.92; 95% CI, 0.66-1.28).
Subgroup analyses showed dabigatran use was associated with higher admission rate with gastrointestinal bleeding (2.9 vs. 2.1 per 100 patient-years; IRR = 2.21; 95% CI, 1.28-3.83) and a lower rate of intracranial hemorrhage (0.5 vs. 1.4 per 100 patient-years; IRR = 0.26; 95% CI, 0.12-0.55).
Post hoc analysis showed an association between dabigatran use and a lower rate of bleeding among patients aged younger than 75 years (IRR = 0.59; 95% CI, 0.35-0.97) compared with those aged 75 years or older (IRR = 1.29; 95% CI, 0.83–2.01).
Results showed 13.5% of dabigatran-treated patients and 5.1% of warfarin-treated patients were readmitted to the hospital with bleeding within 30 days of discharge.
Among patients who were continuously prescribed their initial anticoagulants upon discharge, dabigatran use appeared associated with a higher risk for 30-day readmission with bleeding (HR = 2.87; 95% CI, 1.10-7.43).
Chan and colleagues attributed these associations to dabigatran’s ability to achieve full anticoagulation effect more quickly than warfarin. They also cited limited guidance on prevention of recurrent bleeding with dabigatran.
“Considering that dabigatran achieves full anticoagulation more rapidly compared with warfarin, close early monitoring of patients initiated on anticoagulation following hospital discharge and strategies to reduce recurrence of bleeding with dabigatran are warranted,” Chan and colleagues wrote. – by Kristie L. Kahl
Disclosures: Chan reports research funding from Bristol-Myers Squibb, Hong Kong Research Grants Council, Hong Kong Health and Medical Research Fund, Janssen and Pfizer. Please see the full study for a list of all other researchers’ relevant financial disclosures.