The hidden impact of diabetes mellitus on myocardial function: unveiling left ventricular and left atrial dysfunction in STEMI patients post-PCI

Abstract Background Diabetes mellitus (DM) is a well-recognized risk factor that may contribute to worse post-STEMI outcomes. Beyond standard measures such as left ventricular (LV) ejection fraction (EF), advanced echocardiographic techniques, including strain and myocardial work analysis, provide a more comprehensive assessment of subclinical LV and left atrial (LA) dysfunction in this high-risk population. Objective To evaluate the impact of DM diagnosis (known and de-novo) on LV and LA structure and function in STEMI patients successfully treated with primary percutaneous coronary intervention (pPCI), using conventional and advanced echocardiographic techniques. Methods This prospective study included STEMI patients, categorized by DM status (without DM vs with DM) . Echocardiographic assessment was performed at discharge (Vivid E95i, EchoPAC v206) following EACVI guidelines. LV structure and function were assessed using LV end-diastolic volume index (EDVi), LV end-systolic volume index (ESVi), LV mass index (LVMi), LV EF, global longitudinal strain (LV GLS), and myocardial work indices: global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE). Diastolic function was evaluated via E/E′ avg, while LA structure and function were assessed using LA volume index (LAVi), and LA strain indices (LAS-r, LAS-cd, LAS-c). Results A total of 399 STEMI patients were analyzed, including 85 patients (21.3%) with a previous or de novo DM diagnosis. Key findings are in Table 1. LV structural parameters differed significantly between groups, with lower EDVi in diabetic patients (p = 0.002), while ESVi and LVMi were similar (p = ns). LV EF showed a trend toward lower values in the DM group (p = 0.050). Diabetic patients had more pronounced LV diastolic dysfunction, reflected by a higher E/E′ avg (p = 0.016), suggesting elevated LV filling pressures. LV systolic function was also impaired, with significantly lower LV GLS (p = 0.039), indicating subclinical myocardial dysfunction. Additionally, diabetic patients exhibited significantly lower myocardial work indices, including LV GWI (p = 0.022) and LV GCW (p = 0.040), while LV GWW and LV GWE were similar between groups (p = ns). LA function showed selective impairment in diabetic patients, with reduced LAS-cd (p = 0.040), suggesting compromised LA conduit function. However, LA volume (LAVi), LAS-r, and LAS-c did not differ significantly between groups (p = ns). Conclusion Diabetes mellitus in STEMI patients is associated with impaired LV systolic and diastolic function, evidenced by lower LV GLS, reduced myocardial work indices and increased LV filling pressures. Despite similar LA volume, diabetic patients showed impaired LA conduit function. These findings highlight the importance of myocardial work analysis and LA strain assessment in identifying subclinical myocardial dysfunction in diabetic STEMI patients, which may guide more tailored post-infarction management strategies.