Guideline Recommendations for Non-Culprit Lesion Intervention in Stemi: When to Go Beyond the Culprit

Background: Non-culprit coronary lesion management of patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease remains a controversial topic in interventional cardiology. Earlier practice concentrated on the culprit vessel only but emerging evidence indicates that the timing of intervention of non-culprit lesions of immediate, early-staged or delayed demonstrations of intervention determine a decisive position on patient prognosis. Purpose: To compare clinical outcomes of immediate, early-staged, and delayed non-culprit percutaneous coronary intervention (PCI) in STEMI patients with multivessel disease, as per the existing guidelines. Methods: The study is a prospective observational study that was undertaken at the Fellow Interventional Cardiology, Armed Forces Institute of Cardiology (AFIC), Rawalpindi in the duration from 22nd July, 2025 to 22nd October, 2025. One hundred and twenty-five patients with multivessel disease who had angiographically confirmed disease were included in the study of STEMI. After culprit PCI patients were allocated to four groups. Group A: Immediate non-culprit PCI (same sitting). Group B: PCI at an early stage (3-4 days later) in the same admission. Group C: PCI delayed (more than 2 weeks). Group D: Non-significant lesions (<70%): Medical management. The main outcomes were recurrent ischemia, heart failure, arrhythmias, complications during the procedure, and in-hospital mortality. Findings: PCI at the earliest possible stages (Group B) was the most successful in clinical results, as the rate of repeat ischemia was 6.9 and the rate of complications related to the procedure was the lowest (3%). The immediate PCI (Group A) also had a little more risks (13.6% ischemia) and delayed PCI (Group C) obtained stable yet slower recovery. Medical management (Group D) had higher recurrence (18%), whilst no in-hospital death was reported in all the groups. Conclusion: Early-staged non-culprit PCI during the identical hospital stay is the most desirable balance between safety and effectiveness of STEMI patients who are hemodynamically stable. It is recommended to medically treat non-significant lesions in accordance with the existing guidelines.