IMPORTANCE De-escalation of dual-antiplatelet therapy through dose reduction of prasugrel improved net adverse clinical events after acute coronary syndrome (ACS), mainly through the reduction of bleeding without an increase in ischemic outcomes. However, whether such benefits are similarly observed in those receiving complex procedures is unknown.

OBJECTIVE To investigate whether the benefits of prasugrel dose de-escalation therapy are maintained in the complex percutaneous coronary intervention (PCI) subgroup.

DESIGN, SETTING, AND PARTICIPANTS This was a post hoc analysis of the HOST-REDUCE-POLYTECH-ACS trial, a randomized, open-label, adjudicator-blinded, multicenter trial performed at 35 hospitals in South Korea. Study participants included patients with ACS who were receiving PCI. Data were collected from September 30, 2014, to December 18, 2015, and analyzed from September 17, 2020, to June 15, 2021.

INTERVENTIONS AND EXPOSURES Patients were randomized to a prasugrel dose de-escalation (5 mg daily) at 1 month post-PCI group or a conventional (10 mg daily) group. Complex PCI was defined as having at least 1 of the following features: 3 or more stents implanted, 3 or more lesions treated, bifurcation PCI, total stent length 60 mm or larger, left main PCI, or heavy calcification.

MAIN OUTCOMES AND MEASURES The main analysis end points were MACE (major adverse cardiac event, a composite of cardiovascular death, nonfatal myocardial infarction, stent thrombosis, and repeat revascularization) at 1 year for ischemic outcomes, and BARC (Bleeding Academic Research Consortium) class 2 or higher bleeding events at 1 year for bleeding outcomes.

RESULTS Of 2271 patients (mean [SD] age, 58.9 [9.0] years; 2024 [89%] male patients) for whom full procedural data were available, 705 patients received complex PCI, and 1566 patients received noncomplex PCI. Complex PCI was associated with higher rates of ischemic outcomes but not with bleeding outcomes. Prasugrel dose de-escalation did not increase the risk of MACE (hazard ratio [HR], 0.88; 95% CI, 0.47-1.66; P = .70 in complex PCI; HR, 0.81; 95% CI, 0.45-1.46; P = .48 in noncomplex PCI; P for interaction = .84) but decreased BARC class 2 or higher bleeding events (HR, 0.25; 95% CI, 0.10-0.61; P = .002 in complex PCI; HR, 0.62; 95% CI, 0.38-1.00; P = .05 in noncomplex PCI; P for interaction = .08), albeit with wide 95% CIs.

CONCLUSIONS AND RELEVANCE In this post hoc analysis of patients with ACS, prasugrel dose de-escalation compared with conventional therapy was not associated with an increased risk of ischemic outcomes but may reduce the risk of minor bleeding events at 1 year, irrespective of PCI complexity.

TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02193971.