Ischemic, Bleeding Risks Matter in DAPT… But One Matters More

Bleeding risk outweighs ischemic risk in determining the duration of dual antiplatelet therapy (DAPT) after coronary stenting, a study suggested.

Patients getting percutaneous coronary intervention (PCI) had fewer ischemic events (composite of myocardial infarction, stent thrombosis, stroke, and target vessel revascularization) over 2 years with long-term DAPT only among those without high bleeding risk.

The results were as follows:

• Benefit for non-high bleeding risk patients getting complex PCI: absolute risk difference -3.86% (P=0.05)
• Benefit for non-high bleeding risk patients getting non-complex PCI: -1.14% (P=0.04)
• No benefit for high-bleeding risk patients getting complex PCI: +1.30% (P=0.76)
• No benefit for high-bleeding risk patients getting non-complex PCI: +1.45% (P=0.39)

That the group who underwent complex PCI, associated with high ischemic risk, benefited from long-term DAPT of 12-24 months only if high bleeding risk features weren’t present supports the idea that “risk of bleeding should be considered more strongly than ischemic risk in determining the duration of DAPT after PCI,” said Marco Valgimigli, MD, PhD, of Bern University Hospital in Switzerland, and colleagues.

“Against previous evidence that ACS [acute coronary syndrome] at presentation is a major treatment modifier with respect to DAPT duration, we also analyzed the acuity of presentation (i.e., ACS vs non-ACS) as an additional high ischemic risk feature, with or without complex PCI criteria,” the team wrote online in the Journal of the American College of Cardiology. “We consistently observed no evidence that HBR [high bleeding risk] patients, even if they underwent complex intervention due to ACS, derived benefit from long-term DAPT.”

The PRECISE-DAPT score was used to determine who was and who wasn’t at high bleeding risk, the researchers explained. The score considers five variables — age, creatinine clearance, hemoglobin, white blood cell count, and previous spontaneous bleeding — and was endorsed by the 2017 European guidelines on DAPT.

Valgimigli’s group performed an analysis of eight randomized trials (n=14,963) in which 3,118 patients underwent complex PCI. Of those, over a quarter were considered to be at high bleeding risk.

Patients mostly got second-generation drug-eluting stents in those trials.

Long-term DAPT was tied to an excess of bleeding in patients with HBR regardless of PCI complexity, with a significant increase of major or minor bleeding in those getting non-complex PCI and a similar but non-significant increase among complex cases, the researchers said. “In contrast, among patients without HBR, long-term DAPT was not associated with higher bleeding liability, regardless of PCI complexity.”

The investigators acknowledged that their study was subject to the original limitations of the trials included, and that elements that made up complex PCI were not checked by a central core lab.

Their work is “nonetheless a major signal for interventional cardiologists willing to individualize post-PCI DAPT duration,” said Denis Angoulvant, MD, PhD, of France’s Hôpital Trousseau in Tours, and colleagues, writing in an accompanying editorial.

The cohort with high bleeding risk scored greater in all components of the CHA₂DS₂-VASc score. “This might be of importance because the CHA₂DS₂-VASc score, which was developed to estimate stroke risk in nonvalvular atrial fibrillation patients, was also shown to be a predictor of cerebrovascular events in coronary artery disease patients without atrial fibrillation,” Angoulvant and co-authors said.

The question now, the editorial continued, is whether antithrombotics may be better than antiplatelets to prevent ischemic events in those with high ischemic and high bleeding risk. They cited the COMPASS trial that showed fewer ischemic strokes with rivaroxaban added to aspirin therapy in patients with atherosclerotic cardiovascular disease.

In any case, the DAPT strategy proposed by Valgimigli et al “deserves to be tested in a prospective randomized trial,” the editorialists concluded.