Dual Antiplatelet Therapy for 3 or 12 Months in Patients with Non-ST-elevation MI/Unstable Angina or ST-elevation MI: Analysis of the REDUCE Trial

Background: The aim of this subanalysis of the REDUCE (Short-term Dual Antiplatelet Therapy in Patients with ACS Treated with the COMBO Dual-therapy Stent) trial was to evaluate differences between non-ST-elevation MI/unstable angina (NSTEMI/UA) patients and ST-elevation MI (STEMI) patients in terms of patient characteristics, procedures and outcomes. Methods: In the REDUCE trial, 1,496 acute coronary syndrome patients undergoing successful COMBO stent implantation were randomised to 3 or 12 months of dual antiplatelet therapy (DAPT) treatment. In total, 789 (52.8%) patients had NSTEMI/UA and 706 (47.2%) had STEMI. For this analysis, NSTEMI/UA patients (n=789) were compared with STEMI patients (n=706). Results: In the analysis of the NSTEMI/UA and STEMI cohorts comparing 3-month DAPT (751 patients) and 12-month DAPT treatment (745 patients) there were no statistically significant differences in the primary endpoints of all-cause mortality, MI, stent thrombosis, stroke, target vessel revascularisation or bleeding (Bleeding Academic Research Consortium [BARC] II, III, V) at 360 and 720 days between the two cohorts. Comparing the overall primary endpoints in the NSTEMI/UA cohort, 3-month DAPT was better than 12-month DAPT (9.6% versus 10.0% at 360 days and 12.1% versus 15.0% at 720 days). In the STEMI cohort, 12-month DAPT was better than 3-month DAPT (8.4% versus 11.0% at 720 days). Conclusion: For NSTEMI/UA patients, a numerically lower occurrence of outcomes was observed with 3-month DAPT at 360 and 720 days, whereas for STEMI patients, 12-month DAPT appeared to be better at 720 days. NSTEMI patients seemed to have less favourable long-term outcomes than STEMI patients in this subanalysis. Further adequately powered randomised trials are needed to confirm the findings.