Guideline-Directed Medical Therapy Intensity, Ventricular Remodeling, and Clinical Outcomes After Acute Myocardial Infarction: A Single-Center Real-World Retrospective Cohort Study

Background: Guideline-directed medical therapy (GDMT) is recommended after acute myocardial infarction (AMI), particularly in patients with left ventricular systolic dysfunction, yet real-world implementation remains suboptimal. Whether greater early GDMT intensity is associated with post-infarction ventricular remodeling has not been fully established. We aimed to quantify the guideline-to-practice gap and evaluate the association between GDMT intensity, cardiac remodeling, and clinical outcomes after AMI. Methods: In this single-center retrospective cohort study, 186 consecutive patients hospitalized for AMI who underwent successful percutaneous coronary intervention and had baseline plus follow-up transthoracic echocardiography were included. GDMT intensity was defined as the number of prescribed foundational therapy classes at discharge (renin–angiotensin system inhibitors, beta-blockers, mineralocorticoid receptor antagonists, and sodium–glucose cotransporter 2 inhibitors; range 0–4). The primary endpoint was change in left ventricular end-diastolic diameter (ΔLVEDD). Secondary endpoints included changes in left ventricular ejection fraction, left ventricular end-diastolic volume, left ventricular mass, and heart failure rehospitalization. Multivariable models adjusted for relevant clinical covariates were applied. Results: Only 18.8% of the overall cohort and 26.2% of patients with baseline left ventricular ejection fraction ≤ 40% received all four GDMT pillars. A graded association was observed between higher GDMT intensity and more favorable remodeling. In adjusted analyses, each additional GDMT pillar was associated with a greater reduction in LVEDD (β = 0.120 cm, p = 0.004). In the prespecified reduced-ejection-fraction subgroup, the association was stronger (β = 0.204 cm, p < 0.001). Higher GDMT intensity was also associated with lower odds of heart failure rehospitalization (odds ratio 0.384, 95% CI 0.195–0.754; p = 0.006). Conclusions: In this real-world post-AMI cohort, broader implementation of foundational GDMT at discharge was associated with more favorable early ventricular reverse remodeling and lower odds of heart failure rehospitalization. These findings highlight a persistent implementation gap and support prospective studies evaluating rapid comprehensive GDMT initiation after AMI.