Research evaluating the effects of high bleeding risk (HBR) and complex percutaneous coronary intervention (PCI) on one month versus 12 months of dual antiplatelet therapy (DAPT) has found that the effects of clopidogrel monotherapy after short DAPT relative to prolonged DAPT were consistent regardless of HBR and complex PCI.
The study team have also reported that the absolute benefit of one-month DAPT in reducing bleeding was numerically greater in patients with HBR than in those without, and have concluded that complex PCI may not be an appropriate determinant of DAPT duration after PCI.
A six-to-12-month course of DAPT with aspirin and a P2Y12 inhibitor is typically prescribed to mitigate the risk of thrombotic complications post-PCI, but a risk of bleeding is one of the potential drawbacks. Patients at high risk of bleeding may therefore benefit from a shorter DAPT regime.
Writing in JACC: Asia, Ko Yamamoto (Kyoto University Graduate School of Medicine, Kyoto, Japan) and colleagues, on behalf of the STOPDAPT-2 investigators, note that in real clinical practice, HBR and complex PCI are the major determinants of whether shorter or longer DAPT duration is adopted.
Shorter DAPT duration is preferred in patients with HBR due to concerns surrounding higher rates of major bleeding events with prolonged DAPT, they write, while longer DAPT duration is preferred in patients undergoing complex PCI, as prolonged DAPT has been reported to reduce the risk for ischaemic events after PCI.
“The influence of HBR and complex PCI on the effects of short versus prolonged DAPT for ischaemic and bleeding events after PCI has not been fully addressed and remains controversial,” Yamamoto and colleagues note. Their study seeks to evaluate the effects of HBR and complex PCI on the safety and efficacy of clopidogrel monotherapy after one-month DAPT relative to 12-month DAPT using a pooled population of patients from the STOPDAPT-2 total cohort. In this trial, patients receiving clopidogrel monotherapy after one month of DAPT post-PCI were randomly compared to those receiving 12-month DAPT with aspirin and clopidogrel.
The present study includes two primary endpoints, a composite endpoint of cardiovascular death, myocardial infarction (MI), definite stent thrombosis or stroke, or bleeding, defined as Thrombolysis in Myocardial Infarction (TIMI) major or minor bleeding endpoints at one year, with secondary endpoints including the cardiovascular and bleeding components of the primary endpoint.
The analysis includes data from 5,997 patients in total. In the analysis for HBR, 1,893 patients (31.6%) counted as HBR patients—912 receiving one-month DAPT, and 981 receiving 12-month DAPT, with the remaining 4,104 non-HBR patients. In the non-HBR group, 2,081 patients received one-month DAPT and 2023 patients received 12-month DAPT. In the analysis set for complex PCI, 999 patients (16.7%) underwent complex PCI—481 receiving one-month DAPT, and 518 12-month DAPT, with the remaining 4,998 patients classed as having undergone non-complex PCI. In the non-complex PCI group, 2,512 patients received one-month DAPT and 2,486 received 12-month DAPT.
The investigators report that the risk of one-month DAPT followed by clopidogrel monotherapy relative to 12-month DAPT with aspirin and clopidogrel was not significant for the primary and major secondary cardiovascular endpoints, but was significantly lower for the major secondary bleeding endpoint, which was consistent regardless of HBR or non-HBR and complex or non-complex subgroups.
“In the present study, the magnitude of relative risk reduction for major bleeding with one-month DAPT was consistent regardless of HBR or non-HBR subgroup,” the authors write. “However, the absolute benefit of one-month DAPT relative to 12-month DAPT in reducing major bleeding was greater in patients with HBR than in those without HBR.”
In an editorial accompanying the study in JACC: Asia, Antonio Greco and Davide Capodanno (both University of Catania and G Rodolico-San Marco, Catania, Italy) describe the research as “important as it raises awareness on the role of HBR and PCI complexity in risk stratification, and suggests that HBR should be prioritised regardless of PCI complexity to guide decision making on DAPT duration”.