The treatment of patients with dual antiplatelet therapy (DAPT) after a percutaneous coronary intervention (PCI) for acute coronary syndrome was found to be associated with a reduction in de novo atherothrombotic ischemic events, according to a study published in the Journal of the American College of Cardiology.
The aim of this study was to assess the effect of DAPT on the etiology and timing of cardiovascular death and myocardial infarction in patients who had undergone PCI for ACS.
In this Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition With Prasugrel-Thrombolysis In Myocardial Infarction 38 study (TRITON-TIMI 38; ClinicalTrials.gov identifier: NCT00097591), 12,844 patients with ACS (ie, unstable angina/non-ST-segment elevation myocardial infarction [NSTEMI] or STEMI) who had received ≥1 stent were enrolled and randomly assigned to receive prasugrel or clopidogrel.
The study’s primary outcome was a composite of cardiovascular deaths, myocardial infarctions and stroke (follow-up, 6-15 months post- discharge).
In this cohort, there were 1149 myocardial infarctions and 254 cardiovascular deaths during follow-up. Of the 1306 first events, 46% were procedural, 14% were stent-related, and 39% were spontaneous. Of the myocardial infarctions that occurred, 25% were STEMI and 75% were NSTEMI.
A total of 846 events (65% of total events) occurred during the first 30 days 69% were procedural, 15% were stent-related, and 16% were spontaneous. In the late phase (ie, >30 days), 468 occurred, of which 5% were procedural, 13% were stent-related, and 82% were spontaneous. Spontaneous events were significantly more prevalent in the late (>30 days post- discharge) vs early phase (P <.001).
In participants treated with prasugrel vs clopidogrel, the incidence of myocardial infarctions and cardiovascular deaths were reduced, both for those related to stent thrombosis (1.0% vs 2.1%, respectively; n=186; hazard ratio [HR], 0.47; 95% CI, 0.35-0.65), and those that were spontaneous (3.9% vs 4.8%, respectively; n=514; HR, 0.90; 95% CI, 0.67-0.95). Procedure-related had a rate of 4.4% in the prasugrel cohort and 5.1% in the clopidogrel cohort (hazard ratio [HR], 0.87; 95% CI, 0.74-1.02; P =.078). A separate analysis of a longer follow-up time frame indicated that spontaneous events are more frequent than procedural or stent-related events.
Participants receiving prasugrel vs clopidogrel experienced few procedural, stent-related, and spontaneous STEMI and unstable angina/NSTEMI.
The most common thrombolysis in myocardial infarction major bleeding episodes unrelated to coronary artery bypass graft surgery were spontaneous (60.2%), followed by procedure-related (CABG; 31.1%), and trauma-related (8.4%), with the spontaneous and procedure-related bleeding events most frequently occurring in the late and early phase post-discharge, respectively. Prasugrel was found to increase the risk for spontaneous major bleeding in non-CABG thrombolysis in myocardial infarction in the first 30 days (HR, 1.50; 95% CI, 0.87-2.57; P =.14) and after the first 30 days (HR, 1.44; 95% CI, 0.96-2.17; P =.078).
Limitations of this study include a classification of events based on clinical assessment rather than angiography or autopsy, and the use of early-generation stents in the majority of the procedures, rather than the newer technology currently used to reduce thrombotic events.
The researchers concluded, “Extended, high-potency DAPT improves cardiovascular outcomes after ACS in patients treated with PCI, predominantly by reducing de novo atherothrombotic events in these high-risk patients. Further studies are needed to identify patients treated with PCI likely to derive the greatest benefit of extended-duration DAPT following ACS.”
Disclosure: This clinical trial was supported by Daiichi-Sankyo and Eli Lilly. Several study authors declared affiliations with the pharmaceutical industry.
Scirica BM, Bergmark BA, Morrow DA, et al. Nonculprit Lesion Myocardial Infarction Following Percutaneous Coronary Intervention in Patients With Acute Coronary Syndrome. J Am Coll Cardiol. 2020;75(10):1095-1106.