Lewis, Basil S.

BackgroundThe optimal anticoagulation strategy for patients with atrial fibrillation (AF) and bioprosthetic valve (BPV) replacement or native valve repair remains uncertain.HypothesisWe evaluated the safety and efficacy of apixaban vs warfarin in patients with AF and a history of BPV replacement or native valve repair.MethodsUsing data from Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) (n = 18 201), a randomized trial comparing apixaban with warfarin in patients with AF, we analyzed the subgroup of patients (n = 251) with prior valve surgery. We contacted sites by telephone to obtain additional data about prior valve surgery. Full data were available for 156 patients. The primary efficacy endpoint was stroke/systemic embolism. The primary safety endpoint was major bleeding. Treatment groups were compared using a Cox regression model.ResultsIn ARISTOTLE, 104 (0.6%) patients had a history of BPV replacement (n = 73 [aortic], n = 26 [mitral], n = 5 [mitral and aortic]) and 52 (0.3%) had a history of valve repair (n = 50 [mitral], n = 2 [aortic]). Among patients with BPVs, 55 were randomized to apixaban and 49 to warfarin. Among those with a history of native valve repair, 32 were randomized to apixaban and 20 to warfarin. Overall clinical event rates were low, with no significant differences between apixaban and warfarin for any outcomes.ConclusionsIn patients with AF and a history of BPV replacement or repair, the safety and efficacy of apixaban compared with warfarin was consistent with results from ARISTOTLE. These data suggest that apixaban may be reasonable for patients with BPVs or prior valve repair, though future larger randomized trials are needed.ClinicalTrials.govNCT00412984.

Background Patients with atrial fibrillation ( AF ) and hypertension are at high risk for stroke. Previous studies have shown elevated risk of stroke in patients with AF who have a history of hypertension (regardless of blood pressure [ BP ] control) and in patients with elevated BP . We assessed the association of hypertension and BP control on clinical outcomes. Methods and Results In ARISTOTLE (n=18 201), BP was evaluated as history of hypertension requiring treatment and elevated BP (systolic ≥140 and/or diastolic ≥90 mm Hg) at study entry and any point during the trial. Hazard ratios ( HR s) were derived from Cox proportional hazards models including BP as a time‐dependent covariate. A total of 15 916 (87.5%) patients had a history of hypertension requiring treatment. In patients with elevated BP measurement at any point during the trial, the rate of stroke or systemic embolism was significantly higher ( HR , 1.53; 95% confidence interval [ CI ], 1.25–1.86), as was hemorrhagic stroke ( HR 1.85; 95% CI , 1.26–2.72) and ischemic stroke ( HR , 1.50; 95% CI , 1.18–1.90). Rates of major bleeding were lower in patients with a history of hypertension ( HR , 0.80; 95% CI , 0.66–0.98) and nonsignificantly lower in patients with elevated BP at study entry ( HR , 0.89; 95% CI , 0.77–1.03). The benefit of apixaban versus warfarin on preventing stroke or systemic embolism was consistent among patients with and without a history of hypertension ( P interaction=0.27), BP control at baseline ( P interaction=0.43), and BP control during the trial ( P interaction=0.97). Conclusions High BP measurement at any point during the trial was independently associated with a substantially higher risk of stroke or systemic embolism. These results strongly support efforts to treat elevated BP as an important strategy to optimally lower risk of stroke in patients with AF . Clinical Trial Registration URL : https://ClinicalTrials.gov/ . Unique identifier: NCT 00412984.