Comparison of real-time contrast echocardiography and low-dose dobutamine stress echocardiography in predicting the left ventricular functional recovery in patients after acute myocardial infarction under different therapeutic intervention

Background: Early prediction of left ventricular (LV) functional recovery after acute myocardial infarction (AMI) remains challenging. This prospective study aims to compare real-time myocardial contrast echocardiography (MCE) with low-dose dobutamine stress echocardiography (LDDSE) in predicting the LV functional recovery in patients after AMI who underwent different therapeutic interventions. Methods: Ninety-two patients with AMI were divided into 3 groups: primary coronary intervention group (n=34), thrombolysis group (n=30) and conservative therapy group (n=28). MCE was performed 2.3±0.7 days after chest pain onset. LDDSE was done within 2 days of MCE study. Follow-up echocardiography was performed 4 months later. Results: Patients treated by primary coronary intervention or thrombolysis had significantly lower regional perfusion score (0.65±0.53 vs. 1.01±0.49, p=0.008; 0.78±0.55 vs. 1.01±0.49, p=0.03), better contractile reserve (regional dobutamine Δwall motion score -1.12±0.39 vs. -0.80±0.43, p=0.01; -0.99±0.50 vs. -0.80±0.43, p=0.08) and LV function recovery (regional Δwall motion score -1.67±0.53 vs. -1.02±0.46, p=0.003; -1.42±0.58 vs. -1.02±0.46, p=0.03) than those of conservative therapy group. MCE and LDDSE showed good concordance for predicting LV functional recovery (kappa=0.63, p<0.001). Perfusion score index had a good correlation with LV functional recovery (r=-0.75, p<0.001). Conclusions: This study demonstrates that perfusion score index obtained from real-time MCE is comparable to LDDSE in predicting the LV functional recovery even under different therapeutic interventions. Revascularization results in better preservation of myocardial microvascular integrity, regional contractile reserve and LV functional recovery.