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Direct Oral Anticoagulants in Atrial Fibrillation Patients With Concomitant Hyperthyroidism
Yi-Hsin Chan1,2,3, Lung-Sheng Wu1,2, Lai-Chu See4,5,6
1Division of Cardiology, Chang Gung Memorial Hospital, Linkou, Taiwan.
Insights
Direct oral anticoagulants (DOACs) demonstrated comparable efficacy and reduced bleeding risk compared to warfarin in nonvalvular atrial fibrillation (NVAF) patients with hyperthyroidism. DOACs may be a safer alternative for this population.
Area of Science:
- Cardiology
- Pharmacology
- Internal Medicine
Background:
- Direct oral anticoagulants (DOACs) are increasingly used for stroke prevention in nonvalvular atrial fibrillation (NVAF).
- Patients with hyperthyroidism were excluded from pivotal DOAC trials, leaving a gap in understanding their safety and efficacy in this specific population.
- Hyperthyroidism may influence the risk of thromboembolic events and bleeding in NVAF patients.
Purpose of the Study:
- To compare the effectiveness and safety of DOACs versus warfarin for stroke prevention in NVAF patients with hyperthyroidism.
- To assess the risk of ischemic stroke/systemic embolism (IS/SE) and major bleeding in NVAF patients with and without hyperthyroidism on DOACs or warfarin.
Main Methods:
- Nationwide retrospective cohort study using the Taiwan National Health Insurance Research Database (2012-2017).
- Inclusion of NVAF patients with and without hyperthyroidism, treated with either DOACs or warfarin.
- Propensity score stabilized weights (PSSWs) and 1:4 matching were used to balance covariates and compare outcomes.
Main Results:
- Among hyperthyroid NVAF patients, DOACs showed comparable IS/SE risk and a significantly lower risk of major bleeding (HR 0.65) versus warfarin.
- NVAF patients with hyperthyroidism had comparable risks of IS/SE and major bleeding compared to those without hyperthyroidism when treated with DOACs.
- Warfarin-treated hyperthyroid NVAF patients had a lower risk of IS/SE (HR 0.61) than non-hyperthyroid counterparts.
Conclusions:
- DOACs represent a potentially effective and safer alternative to warfarin for stroke prevention in Asian NVAF patients with hyperthyroidism.
- Thromboprophylaxis with DOACs should be considered for NVAF patients with hyperthyroidism.
- Further prospective studies are warranted to validate these findings.
Objective:
Patients with hyperthyroidism were excluded from the randomized clinical trials of direct oral anticoagulants (DOACs) for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF).
Methods:
We performed a nationwide retrospective cohort study using data from the Taiwan National Health Insurance Research Database. We enrolled 3213 and 1181 NVAF patients with hyperthyroidism who were taking DOACs and warfarin, respectively, from June 1, 2012 to December 31, 2017. We also enrolled 53 591 and 16 564 NVAF patients without hyperthyroidism, taking DOACs and warfarin, respectively. We used propensity score stabilized weights (PSSWs) to balance covariates across the study groups. We also used 1:4 matching on both taking DOACs, with (n = 3213) and without hyperthyroidism (n = 12 852); and both taking warfarin, with (n = 1181) and without hyperthyroidism (n = 4724).
Results:
After PSSW, DOAC had a comparable risk of ischemic stroke/systemic embolism (IS/SE) and a lower risk of major bleeding (hazard ratio [HR] 0.65; 95% confidential interval [CI], 0.44-0.96; P = 0.0295) than warfarin among patients with hyperthyroidism. There were comparable risks of IS/SE and major bleeding between those patients with and without hyperthyroidism. However, among patients taking warfarin, those with hyperthyroidism had a lower risk of IS/SE than those without hyperthyroidism (HR 0.61; 95% CI, 0.43-0.86; P = 0.0050).
Conclusion:
Among NVAF Asian patients with concomitant hyperthyroidism, DOACs may be an effective and safer alternative to warfarin. Thromboprophylaxis with DOACs may be considered for such patients, and it is important to validate this finding in further prospective study.
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