Left ventricular diastolic function and left atrial remodelling early after STEMI: insights from multiparametric CMR tissue mapping

Abstract Background Left ventricular (LV) diastolic dysfunction and left atrial (LA) remodeling frequently follow ST-elevation myocardial infarction (STEMI), contributing to adverse outcomes. However, their relationship with early myocardial tissue alterations remains unclear. This study aimed to assess the association between echocardiographic markers of LV diastolic function and LA mechanics, and CMR-derived native T1 tissue characteristics one week after primary percutaneous coronary intervention (pPCI) Methods We included 36 patients with STEMI (mean age 58 ± 11 years, 81% male), all treated with successful pPCI. Echocardiography and cardiac magnetic resonance were performed on day 6–8 post-pPCI. Echocardiographic analysis included tissue Doppler parameters (E’ lat, E’ med), transmitral flow (E/A), E/E’, LA volume (LAVi), LA strain (PALS), conduit (LA CD), contraction (LA CT), and LA ejection fraction. CMR parameters (CVI42) included infarct size (IS), area at risk (AAR), myocardial salvage (MS), myocardial salvage index (MSI), and native T1 mapping in infarct, remote, and global LV zones. Spearman correlations were used. Results Key findings are summarized in Tables 1, 2, and 3. CMR-derived native T1 in the remote myocardium correlated significantly with echocardiographic markers of impaired LV relaxation and LA remodelling. Additionally, PALS showed a significant inverse correlation with T1 in the infarct zone (r = –0.334, p < 0.05). LA remodelling also correlated with infarct burden: higher IS and AAR were associated with reduced LA EF and PALS; greater MS correlated with impaired Eprim lateral. Conclusion Early after STEMI, myocardial tissue alterations assessed by native T1 mapping correlate with markers of LV diastolic dysfunction and LA remodelling. Remote myocardial T1 prolongation was associated with impaired relaxation and altered LA conduit function, suggesting diffuse interstitial involvement may contribute to diastolic dysfunction beyond the infarct zone. These results underscore the importance of integrative assessment combining echocardiographic mechanics and CMR tissue characterization to understand LV–LA interaction in post-infarction remodelling.