Assessment of myocardial viability in a porcine model of chronic coronary artery stenosis with dual dose dobutamine magnetic resonance imaging.

In a non-surgical porcine coronary stenosis model resulting in chronic left ventricle dysfunction, we aimed in this study to evaluate the potential of magnetic resonance imaging (MRI) to distinguish dysfunctional but viable from necrotic myocardium by using multiple levels of dobutamine inotropic stimulation during a cine MRI protocol (F.P. van Rugge et al. Circulation 1994; 90: 127-138). We compared our results with histopathology. We were able to demonstrate a biphasic effect at increasing doses of dobutamine in a subgroup of animals with a high-grade coronary stenosis, while in another subgroup the coronary stenosis produced a chronic myocardial infarction, in which no functional recovery could be obtained. In this experimental protocol, dual dose dobutamine MRI proved to be an accurate and reproducible technique to perform viability studies in chronic obstructive coronary artery disease. It permits distinguishing chronic ischemic, but viable myocardium from infarcted tissue. The detection of chronically underperfused but potentially salvageable myocardium is of significant clinical importance since it may aid in determining which patients are eligible for revascularization.