Comparative analysis of cardiac magnetic resonance viability indexes to predict functional recovery after successful percutaneous coronary intervention in acute myocardial infarction.

The aim of this study was to examine the relative value and the influence of the association of 4 cardiac magnetic resonance (CMR) viability indexes for predicting segmental functional recovery after optimal pharmacologic therapies and early percutaneous coronary intervention in acute myocardial infarction (AMI). CMR has been shown to predict functional recovery after AMI. The relative predictive value of CMR viability indexes remains disputed and has not been described in AMI reperfused within the first 12 hours. Sixty-nine patients with a first reperfused (<12 hours) Thrombolysis In Myocardial Infarction grade 3 AMI (61 men, 57.6 +/- 12.6 years) were studied on day 5 +/- 2. Low-dose (10 microg/kg/min) dobutamine response (DOB), microvascular obstruction (MVO), relative delayed enhancement extent (DE), and transmural DE pattern (TMDE) were assessed in each of the 17 left ventricular segments. Segmental functional outcome was assessed by CMR at 3 months. Logistic regression and Bayesian probabilities evaluated the association between viability indexes and functional segmental outcome. At rest, 27% of segments (314 of 1,173) were dysfunctional of which 53% (165 of 314) recovered at follow-up. Odd ratios for dobutamine response, MVO, DE, and TMDE were 15.8, 5.9, 2.6, and 2.5 respectively. The probability of segmental recovery was 0.84 when dobutamine response was positive and increased successively to 0.91 when adding MVO absence, 0.94 when adding TMDE absence, and 0.97 when adding DE absence. In conclusion, contractile response to low-dose dobutamine is the best predictive factor of segmental recovery after Thrombolysis In Myocardial Infarction grade 3 early reperfused AMI. Its value is further increased by other CMR viability indexes.