Objective: This study attempted to determine the optimal interpretation method of intravenous myocardial contrast echocardiography (MCE) for predicting myocardial functional recovery in patients with acute myocardial infarction.
Background: Assessment of the myocardial contrast effect is subjective and there is currently no universal agreement on the pulsing interval (PI) for imaging.
Methods: Twenty-nine patients underwent percutaneous transluminal coronary angioplasty (PTCA) 4.8 +/- 1.9 days after acute myocardial infarction and intravenous MCE before and 24 hours after PTCA by using intermittent harmonic angioimaging at a series of PIs of 4, 8, 12, and 16 cardiac cycles. Adequate contrast enhancement was defined by homogeneous (MCEhomo score) and heterogeneous patterns (MCEheter score), and by a combination of intensity threshold and computed planimetry (MCEcom score). Adequate contrast enhancement at a shorter PI defined a higher MCE score (1 vs 5). The regional wall motion in the risk area was assessed before PTCA and 2 months after PTCA to evaluate functional recovery.
Results: A significant improvement after PTCA was noted in the MCEhomo score (3.2 +/- 1.7 vs 3.6 +/- 1.7, P =.008) and the MCEcom score (2.9 +/- 1.6 vs 3.3 +/- 1.5, P <.0001), but not in the MCEheter score (4.3 +/- 1.3 vs 4.5 +/- 1.1, P =.058). Twenty-four hours after PTCA, segments with functional recovery had a higher MCEheter score (4.9 +/- 0.5 vs 3.8 +/- 1.6, P =.002), MCEhomo score (4.2 +/- 1.4 vs 2.6 +/- 1.9, P <.0001), and MCEcom score (3.8 +/- 1.2 vs 2.1 +/- 1.4, P <.0001) than those without. For the prediction of function recovery, MCEheter generally had a higher sensitivity but a lower specificity and accuracy than did MCEhomo and MCEcom. MCEcom had the best accuracy (83%) with a sensitivity of 95% and specificity of 61% at a PI of 16 cardiac cycles.
Conclusion: Using a combination of intensity threshold and computed planimetry for interpreting myocardial contrast enhancement at a long PI can optimize the value of MCE in predicting functional recovery after PTCA in patients with acute myocardial infarction.