Ischemic cardiomyopathy: value of different MRI techniques for prediction of functional recovery after...

The purpose of this study was to compare the value of different MRI techniques for the assessment of myocardial viability. SUBJECTS AND METHODS. Eighteen infarct patients (mean age +/- SD, 62 +/- 8 years) with myocardial ischemia were examined using MRI before and after revascularization. The MRI study before treatment consisted of an evaluation of first-pass perfusion, contractile function at rest and during dobutamine stress, and delayed hyperenhancement. Findings were correlated with segmental and global cardiac function after revascularization.

In initially dysfunctional segments, the likelihood of functional recovery after revascularization was 91% for segments without delayed hyperenhancement, 43% for segments with delayed hyperenhancement with transmural extent of 75% or less, and 8% for segments with delayed hyperenhancement with transmural extent of more than 75% (p < 0.05). Improved function at dobutamine stress MRI indicated functional recovery in 87%, whereas functional recovery was observed in only 30% of segments not responding at dobutamine stress MRI (p < 0.05). No significant correlation was found between the results of first-pass perfusion MRI and functional recovery. The ejection fraction after revascularization was best predicted by the MRI-derived infarct volume (p < 0.001, R(2) = 0.63).

A simple protocol consisting of baseline contractility and delayed enhancement MRI studies is adequate to differentiate dysfunctional but viable from nonviable myocardium. Dobutamine stress and perfusion MRI studies offer little or no additional information.