Usefulness of a comprehensive cardiovascular magnetic resonance imaging assessment for predicting recovery of left ventricular wall motion in the setting of myocardial stunning.

Abstract

We sought to evaluate the usefulness of a comprehensive assessment of four cardiovascular magnetic resonance imaging (CMR)-derived myocardial viability indexes in the setting of myocardial stunning. Cardiovascular magnetic resonance imaging allows the simultaneous assessment of several viability indexes. We studied 40 patients with a first ST-segment elevation myocardial infarction (MI) and an open infarct-related artery. At the first week, using CMR, wall motion (WM), and four viability indexes were determined: wall thickness, WM improvement with low-dose dobutamine, perfusion, and transmural extent of necrosis. We created a comprehensive score based on the presence and the relative power of these viability indexes for predicting normal WM at the sixth month. Of 153 dysfunctional segments at the first week, 59 (39%) exhibited normal WM at the sixth month. According to the odds ratio of viability indexes for predicting normal WM, we developed a five-level predictive score. The proportions of segments showing normal WM at sixth month were as follows; Level 1 (0 indexes): 0 of 13 (0%); Level 2 (normal thickness and/or perfusion): 14 of 82 (17%); Level 3 (dobutamine response): 5 of 11 (45%); Level 4 (non-transmural necrosis): 20 of 26 (77%); Level 5 (non-transmural necrosis and dobutamine response): 20 of 21 (95%), p < 0.0001 for the trend. These proportions were similar in a matched prospective validation group comprising 16 patients (0%, 18%, 62%, 77%, and 90% for levels 1 to 5, respectively, p < 0.0001 for the trend). A comprehensive analysis of the four more widely used CMR-derived viability indexes is useful for predicting late systolic function after myocardial infarction.