Five to 8% of people undergoing percutaneous coronary intervention (PCI) also have atrial fibrillation (AF).  The optimal antiplatelet / anticoagulant regimen in these individuals remains unclear as stroke and stent thrombosis prevention need to be balanced against the risks of major bleeding.  The PIONEER AF-PCI trial (Open-Label, Randomized, Controlled, Multicenter Study Exploring Two Treatment Strategies of Rivaroxaban and a Dose-Adjusted Oral Vitamin K Antagonist Treatment Strategy in Subjects with Atrial Fibrillation who Undergo Percutaneous Coronary Intervention) randomized 2124 patients with AF who had undergone PCI to 1 of 3 arms: 15mg rivaroxaban + a P2Y12 inhibitor alone for 12 months, 2.5mg of twice daily rivaroxaban + a P2Y12 inhibitor and aspirin (DAPT) for 1, 6 or 12 months or warfarin + DAPT for 1, 6 or 12 months.  The predominant P2Y12 inhibitor was clopidogrel (approx. 90%). The primary endpoint was clinically significant bleeding while efficacy – both myocardial infarction and stroke were secondary end-points.  Both rivaroxaban arms demonstrated significant reductions in major bleeding relative to the warfarin arm (16.8% vs. 18.0% vs. 26.7%; P<0.001).  Furthermore, overall rates of stroke and myocardial infarction were similarly low across all sub-groups.

Conclusions

PIONEER-AF demonstrated significantly lower rates of major bleeding events in patients with AF undergoing PCI when treated with a rivaroxaban-based strategy instead of warfarin and DAPT. The trial, however, suffers from lack of consistency in antiplatelet strategy across the randomization arms. There is mounting observational data that ‘triple therapy’, as was mandated in the warfarin arm but not in the full dose rivaroxaban arm, maybe associated with increased bleeding in the absence of additional thromboembolic benefit. The Rivaroxaban strategies do appear to have reasonable safety and efficacy profiles. It is unclear if warfarin + P2Y12 inhibitor alone could match these findings.

Gibson CM, Mehran R, Bode C, Halperin J, Verheugt FW, Wildgoose P, Birmingham M, Ianus J, Burton P, van Eickels M, Korjian S, Daaboul Y, Lip GYH, Cohen M, Husted S, Peterson ED and Fox KA. Prevention of Bleeding in Patients with Atrial Fibrillation Undergoing PCI. N Engl J Med. 2016 Dec 22;375(25):2423-2434.

Hussain Contractor and James M. McCabe