Conventional moderate-intensity continuous training (MICT) has certain shortcomings in enhancing peak oxygen consumption (VO ₂ peak) and recovery of left ventricular function in post-percutaneous coronary intervention (PCI) acute myocardial infarction (AMI) patients, while high-intensity interval training (HIIT) raises safety concerns despite evidence of its effectiveness.

To assess the efficacy and safety of combined HIIT and MICT training compared to single training modalities in post-PCI AMI patients.

This single-center, three-arm parallel, assessor-blinded randomized controlled trial enrolled 204 clinically stable post-PCI AMI patients, who were randomized 1:1:1 to combined training (HIIT+MICT, n = 68), MICT alone ( n = 68), or HIIT alone ( n = 68) groups for 12-week supervised cardiac rehabilitation. The primary outcome was the change in VO ₂ peak; secondary outcomes included left ventricular ejection fraction (LVEF), N-terminal pro-B-type natriuretic peptide (NT-proBNP), exercise capacity, and major adverse cardiovascular events (MACE).

Combined training showed superior improvement in VO ₂ peak (5.6 ± 2.3 mL/kg/min) compared with MICT alone (2.7 ± 1.9 mL/kg/min, P < .001) and HIIT alone (4.2 ± 1.8 mL/kg/min, P = .003), with 76.7% reaching clinically meaningful improvement (≥3 mL/kg/min). In the combined training group, LVEF increased 8.6 ± 3.2% and NT-proBNP decreased -706 pg/mL. Incidence of MACE remained low at 2.9%, without significant inter-group differences, P = .85.

Combined HIIT and MICT training produces synergistic effects, superior to single modalities, in improving cardiopulmonary function and cardiac remodeling in post-PCI AMI patients, with comparable safety profile, providing evidence-based optimization strategy for cardiac rehabilitation.

Chinese Clinical Trial Registry (ChiCTR); Registration No. ChiCTR2000031251; showproj.html?proj=31251 .