Prophylactic IABP in Delayed-Presentation Anterior STEMI

Overview

PROACTIVE-AMI is a prospective, multicenter, randomized, open-label trial with blinded endpoint adjudication evaluating whether prophylactic intra-aortic balloon counterpulsation (IABP) initiated before primary percutaneous coronary intervention (PPCI) improves clinical outcomes in patients with delayed-presentation acute anterior ST-segment elevation myocardial infarction (STEMI). Eligible patients are adults aged ≥18 years who present 4 to 12 hours after symptom onset, have electrocardiographic evidence of anterior STEMI with proximal left anterior descending artery total occlusion (TIMI flow 0), and are planned for PPCI. Participants will be randomized 1:1 to pre-PPCI IABP plus standard PPCI or standard PPCI alone. The primary endpoint is 180-day major adverse cardiovascular events (MACE), defined as a composite of all-cause death, cardiogenic shock, and new or worsening heart failure. Secondary outcomes include individual MACE components, cardiac death, length of stay, NT-proBNP, left ventricular ejection fraction, and left ventricular end-diastolic volume. Safety outcomes include major bleeding, vascular complications, thrombocytopenia, and stroke.

This is a prospective, multicenter, randomized, open-label, parallel-group, controlled clinical trial with blinded endpoint adjudication. The study is designed to evaluate whether prophylactic intra-aortic balloon counterpulsation (IABP) before primary percutaneous coronary intervention (PPCI) can improve outcomes in patients with delayed-presentation acute anterior ST-segment elevation myocardial infarction (STEMI). Eligible patients are adults aged ≥18 years with symptom onset to presentation between 4 and 12 hours, electrocardiographic evidence of anterior STEMI (≥2 mm ST elevation in contiguous anterior leads or sum ≥4 mm), and angiographically confirmed proximal left anterior descending artery occlusion with TIMI flow 0. After informed consent and coronary angiography confirming eligibility, participants are randomized in a 1:1 ratio to one of two groups: (1) prophylactic IABP before infarct-related artery opening plus standard PPCI, or (2) standard PPCI alone. In the intervention group, IABP will be inserted before PCI, operated at a 1:1 counterpulsation ratio for at least 24 hours and up to 72 hours as clinically appropriate. In the control group, prophylactic mechanical circulatory support will not be routinely used; rescue IABP may be initiated if predefined hemodynamic deterioration or complications occur. All participants receive guideline-directed medical therapy for ST-segment elevation myocardial infarction. The primary endpoint is major adverse cardiovascular events (MACE) within 180 days after randomization, defined as a composite of all-cause death, cardiogenic shock, and new or worsening heart failure. Secondary endpoints include individual components of the primary composite endpoint, cardiac death, length of hospital stay, NT-proBNP at 90 and 180 days, left ventricular ejection fraction and left ventricular end-diastolic volume at 90 and 180 days. Safety outcomes include major bleeding (BARC 3-5), vascular complications, thrombocytopenia, and stroke within 30 days. Follow-up assessments will be performed during hospitalization and at 30, 90, and 180 days after randomization. Endpoint adjudication will be performed by an independent clinical events committee blinded to treatment assignment.