Purpose: Previous studies demonstrated that low-dose dobutamine stress cine magnetic resonance imaging (MRI) and delayed contrast-enhanced MRI can provide assessments of myocardial viability. The purpose of this study was to evaluate the comparative diagnostic values of dobutamine cine MRI and delayed contrast-enhanced MRI for predicting functional recovery of myocardial contraction in patients with acute reperfused myocardial infarction.
Methods: Twenty-three patients with myocardial infarction after percutaneous coronary interventions were studied. All patients underwent steady-state cine MRI covering the entire left ventricle at rest and during low-dose dobutamine stress (10 micrograms/kg/min). Delayed contrast-enhanced MR images were acquired to determine transmural extent of hyperenhancement. Second cine MR images in the resting state were obtained 3 to 11 months after revascularization.
Results: On the first cine MR images in the resting state, 278 (20%) of 1380 segments demonstrated abnormal, regional contraction (systolic wall thickening < 40%). Of the 175 segments showing functional recovery on the following cine MRI, 156 (89%) segments were recognized as reversible by dobutamine cine MRI and 146 (83%) segments by delayed contrast-enhanced MRI. The sensitivity, specificity, and accuracy of dobutamine stress cine MRI was 89%, 80%, and 86%, respectively. These values of contrast-enhanced MRI were 83%, 72%, and 79%, respectively. The area under the receiver operating curve (ROC) was 0.87 by dobutamine cine MRI and 0.78 by delayed contrast-enhanced MRI (p < 0.05).
Conclusions: The current results using quantitative segmental analysis indicated that low-dose dobutamine stress cine MRI can predict recovery of myocardial contractility with significantly higher diagnostic performance in comparison with contrast-enhanced MRI in patients with myocardial infarction who underwent revascularization.