Dobutamine induced myocardial perfusion reserve index with cardiovascular MR in patients with coronary artery disease.

Currently, adenosine or dipyridamole is commonly used for the assessment of perfusion reserve. With intolerance to these agents, dobutamine can be used alternatively or it can be used for a combined examination of wall motion and perfusion. The aim of the study was to analyze the feasibility of cardiovascular magnetic resonance (CMR) to assess perfusion reserve with dobutamine. Alterations of myocardial perfusion were noninvasively assessed in 23 patients with and 4 without significant coronary artery disease by calculation of a myocardial perfusion reserve index from the upslope of the signal intensity curves of a first pass gadolinium bolus before and during dobutamine infusion (20 micrograms/min/kg). An ischemic threshold value of perfusion reserve index was determined from patients without significant coronary artery disease. Significant differences were found between ischemic and remote to ischemic segments in patients with single vessel disease (0.90 +/- 0.18 vs. 1.73 +/- 0.32, p < 0.0001). Differences between nonischemic segments in patients without and ischemic segments in patients with coronary artery disease were significant (2.0 +/- 0.39 vs. 0.97 +/- 0.20, p < 0.001). A cut-off value for myocardial perfusion reserve index of 1.22 for the detection of significant coronary artery stenosis yielded a sensitivity, specificity, and diagnostic accuracy of 81, 73, and 77%, respectively. Dobutamine MR is feasible in the evaluation of myocardial perfusion and can be used for the detection of myocardial ischemia alternatively to adenosine or dipyridamole in patients with coronary artery disease.