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.