Dr Roxana Mehran Discusses the Outcomes of the PIONEER AF Study

The PIONEER AF-PCI trial studied bleeding in patients with atrial fibrillation undergoing percutaneous coronary intervention with 3 different treatments. The study found that a rivaroxaban (Xarelto)-based strategy had a significant reduction of bleeding complications, explained Roxana Mehran, MD, FACC, FACP, professor of medicine and director of Interventional Cardiovascular Research and Clinical Trials at the Zena and Michael A. Weiner Cardiovascular Institute at Mount Sinai School of Medicine.

Transcript (slightly modified)

What was the point of the PIONEER AF-PCI study and what was the population being studied?

The PIONEER AF study was a study that was much needed in our literature. We have patients with atrial fibrillation undergoing PCI (percutaneous coronary intervention), and, frankly, we have a very, very difficult time in understanding how to treat these patients, on what kind of pharmacotherapy should these patients be on. Typically, there's this combination of warfarin—vitamin K antagonist warfarin—aspirin and clopidogrel, but, really, we know that stacking those therapies together increases the patient's risk for bleeding complications. And those bleeding complications can be quite significant.

So the alternative has been: can we drop aspirin? What about the novel anticoagulants? We really had no idea what to do and how to incorporate these approved agents that many patients with atrial fibrillation are already on and do not want to switch back to coumadin (warfarin). We really had no idea what to do with those patients, and so I think for the very first study with the novel anticoagulant, the PIONEER AF was very much needed. And now we really have some way to treat these patients.

PIONEER AF-PCI included 3 arms: 2 arms included rivaroxaban and the third arm was the current standard treatment. What were the outcomes of the study and what can you determine about the safety and efficacy of rivaroxaban?

What the PIONEER study showed was that a strategy that had a rivaroxaban-based strategy, the arm 1 and arm 2, had significant reduction of bleeding complications. These were clinically signficant bleeding requiring medical attention—most of them were that—or severe bleeding. And, in fact, there was a reduction in intracranial hemorrhage in the patients who received rivaroxaban therapy compared to a coumadin-based therapy or a vitamin k antagonist-based therapy. So the reduction in bleeding, which was the primary endpoint, was met.

Regarding the ischemic endpoints—stroke, stent thrombosis—we were not powered for those endpoints. You'd need 20,000 patients to show that. And so what we could say about the safety and efficacy—if you look at the safety profile regarding bleeding, we absolutely showed that. In fact, it was a superior safety profile in bleeding. But regarding the efficacy and reduction of stroke, the objective of the PIONEER study was not to look at that. What we were looking for was any kind of a signal and we didn't find one. Wide confidence intervals, no differences between stroke, stent thrombosis, ischemic complications.

So I think it's a profound study in showing a major reduction in bleeding when you avoid the triple therapy and you go with a novel anticoagulant during that period of time in the peri-PCI period of time of 6 to 12 months.