Magnetic Resonance Imaging of Reverse Remodeling After Coronary Revascularization in Ischemic Heart Disease - Morphologic Evaluation

Background: Coronary revascularization has been shown to induce left ventricular (LV) reverse remodeling (RR). The serial morphologic changes in enhanced necrotic tissue during RR on cardiac magnetic resonance imaging (CMR) have not been investigated. Methods and Results: This retrospective study included 26 patients with severe LV systolic dysfunction (ejection fraction [EF], <35% on echocardiography) who underwent CMR before and >6 months after surgical revascularization. Of 26 patients, 20 had a reduction of >= 10% in end-diastolic and end-systolic volumes (classified as RR group). The RR group had improvement in EF after revascularization (28.8 +/- 6.6% vs. 40.6 +/- 7.8%, P<0.0001), and no change in absolute infarct mass (17.3 +/- 10.9 g vs. 17.5 +/- 10.4 g, P=0.8), but an increase in relative infarct mass (21.0 +/- 13.7% vs. 26.5 +/- 19.4%, P=0.01) due to reduction of myocardial mass after revascularization. Significant increase in regional transmural extent (30.3 +/- 21.6 vs. 42.6 +/- 22.8, P<0.0001) and in thickness of enhanced tissue (4.2 +/- 1.5 mm vs. 5.9 +/- 1.8 mm, P<0.0001) was found in the RR group. No significant differences were observed in any of the variables in the non-RR group. Conclusions: In patients with chronic myocardial ischemic dysfunction, significant volume reduction after revascularization led to significant increase in regional transmural extent of the enhanced area without a change in absolute infarct mass, on CMR.