DOAC Effect on Cardiovascular Outcomes in Patients with Peripheral Arterial Disease

Introduction: Peripheral arterial disease (PAD) increases cardiovascular (CV) morbidity and mortality, but remains underdiagnosed and undertreated. Several trials support low-dose rivaroxaban in PAD treatment, although this has yet to be widely adopted in clinical practice. The effect of warfarin and direct oral anticoagulants (DOACs) on comprehensive PAD outcomes warrants further study. Hypothesis: Anticoagulant therapy, particularly DOACs, improves CV outcomes in PAD. Methods: We conducted a retrospective study of patients who underwent ankle-brachial index testing (ABI) from 1996 – 2020 at Mayo Clinic. We included patients with PAD defined by abnormal ABI (<1.0 or >/=1.4). Prolonged (>6 months) DOAC or warfarin use was compared to no anticoagulant therapy. Multivariable (MV) regression, controlling for baseline CV risk factors, was used. Results: 21,891 patients had abnormal ABI readings; 3,093 were on warfarin and 267 were on DOAC for any indication. Anticoagulation improved mortality, with DOACs superior to warfarin. DOACs improved critical limb ischemia (CLI)/amputation in univariate analysis, although this was not significant in MV. Patients with poorly compressible vessels (ABI >/=1.4) had increased limb outcomes compared to reduced ABI (<1.0). Ischemic stroke and myocardial infarction occurred more frequently in those on anticoagulation, but the risk was less for DOACs vs. warfarin. Notably, both anticoagulant groups had greater baseline comorbidity than the non-anticoagulant group; the DOAC and warfarin groups were similar. Major bleeding (6.7%) was increased in both anticoagulant groups, but less so with DOACs and this was similar to the bleeding risk seen with aspirin (HR 1.20). Conclusion: Anticoagulant therapy improved mortality in a large cohort of PAD patients. The risk of limb events appears improved in those on DOACs. DOACs showed improved risk profiles compared to warfarin regarding CV and bleeding outcomes.