Prognostic value of cardiac magnetic resonance pulmonary transit time and myocardial strain across different stages of ST-elevation myocardial infarction

Background: This study evaluated the prognostic value of pulmonary transit time (PTT) and myocardial strain in ST-elevation myocardial infarction (STEMI) patients stratified by the Canadian Cardiovascular Society (CCS) classification. Material and methods: A total of 521 STEMI patients underwent 3.0-T cardiac magnetic resonance (CMR) imaging between January 2017 and December 2025. PTT was measured as the number of cardiac cycles for contrast to travel from the right to left ventricle during first-pass perfusion. Global myocardial strain (longitudinal, circumferential, radial) was assessed via CMR feature tracking. Cox regression analyses were used to evaluate associations of PTT, normalized PTT (nPTT), wall motion score index (WMSI), and global longitudinal strain (GLS) with major adverse cardiac events (MACE: death, re-infarction, heart failure). Results: < 0.01). Conclusion: Elevated PTT correlates with severe myocardial injury and adverse outcomes. PBVI, nPTT, PTT, GLS, and WMSI are independent prognostic indicators, providing valuable risk stratification across CCS stages.