Outcomes of Oral Anticoagulation in Atrial Fibrillation Patients with or without Comorbid Vascular Disease: Insights from the GARFIELD-AF Registry

BACKGROUND: Many patients with atrial fibrillation suffer from comorbid vascular disease. The comparative efficacy and safety of different types of oral anticoagulation (OAC) in this patient group have not been widely studied. METHODS: Adults with newly-diagnosed atrial fibrillation were recruited into the prospective observational registry, GARFIELD-AF, and followed for 24 months. Associations of vascular disease with clinical outcomes were analysed using adjusted hazard ratios (HR), obtained via Cox proportional-hazard modelling. Outcomes of OAC vs no OAC, and of non-vitamin K antagonist OAC (NOAC) vs vitamin K antagonist (VKA) treatment, were compared by overlap propensity weighted Cox proportional-hazard models. RESULTS: Of 51,574 atrial fibrillation patients, 25.9% had vascular disease. Among eligible atrial fibrillation patients, those with vascular disease received OAC less frequently than those without (63% vs 73%). Over 2-years follow-up, patients with vascular disease showed a higher risk of all-cause mortality (HR [95% CI]: 1.30 [1.16-1.47]) and cardiovascular mortality (1.59 [1.28-1.97]). OAC was associated with a significant decrease in all-cause mortality and non-haemorrhagic stroke, and increased risk of major bleeding in non-vascular disease. In vascular disease, similar but non-significant trends existed for stroke and major bleeding. A significantly lower risk of all-cause mortality (0.74 [0.61-0.90]) and major bleeding (0.45 [0.29-0.70]) was observed in vascular disease patients treated with NOACs compared to VKAs. CONCLUSIONS: Atrial fibrillation patients with a history of vascular disease have worse long-term outcomes than those without. The association of NOACs vs VKA with clinical outcomes was more evident in atrial fibrillation patients with vascular disease.