Apixaban compared with parenteral heparin and/or vitamin K antagonist in patients with nonvalvular atrial fibrillation undergoing cardioversion: Rationale and design of the EMANATE trial

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• 作者：Michael D. Ezekowitz ; MBChB ; DPhil^a ; ^b ; ^{michael.ezekowitz@comcast.net" class="auth_mail" title="E-mail the corresponding author} ; Charles V. Pollack ; MD ; MA^c ; Paul Sanders ; PhD^d ; Jonathan L. Halperin ; MD^e ; Judith Spahr ; MPH ; MEd^f ; Nilo Cater ; MD^g ; William Petkun ; MD^h ; Andrei Breazna ; PhD^g ; Paulus Kirchhof ; MDⁱ ; ^j ; Jonas Oldgren ; MD ; PhD^k
• 刊名：American Heart Journal
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：179
• 期：Complete
• 页码：59-68
• 全文大小：504 K

文摘

Stroke prevention in anticoagulation-naïve patients with atrial fibrillation undergoing cardioversion has not been systematically studied.

Objective

To determine outcomes in anticoagulation-naïve patients (defined as those receiving an anticoagulant for <48 hours during the index episode of atrial fibrillation) scheduled for cardioversion.

Methods

This is a randomized, prospective, open-label, real-world study comparing apixaban to heparin plus warfarin. Early image-guided cardioversion is encouraged. For apixaban, the usual dose is 5 mg BID with a dose reduction to 2.5 mg BID if 2 of the following are present: age >80 years, weight <60 kg, or serum creatinine >1.5 mg/dL. If cardioversion is immediate, a single starting dose of 10 mg (or 5 mg if the dose is down-titrated) of apixaban is administered. Cardioversion may be attempted up to 90 days after randomization. Patients are followed up for 30 days after cardioversion or 90 days postrandomization if cardioversion is not performed within that timeframe. Outcomes are stroke, systemic embolization, major bleeds, clinically relevant nonmajor bleeding, and death, all adjudication-blinded.

Statistics

The warfarin-naive cohort from the ARISTOTLE study was considered the closest data set to the patients being recruited into this study. The predicted incidence of stroke, systemic embolism, and major bleeding within 30 days after randomization was approximately 0.75%. To adequately power for a noninferiority trial, approximately 48,000 participants would be needed, a number in excess of feasibility. The figure of 1,500 patients was considered clinically meaningful and achievable.

Clinical context

This first prospective cardioversion study of a novel anticoagulant in anticoagulation-naïve patients should influence clinical practice.