Objectives: We studied the effect of drug-eluting stent implantation for chronic total coronary occlusion (CTO) on left ventricular volumes and function and assessed the predictive value of magnetic resonance imaging (MRI) performed before revascularization.
Background: The effect of recanalization of CTO on long-term left ventricular function and the value of myocardial viability assessment with MRI is incompletely understood.
Methods: Twenty-seven patients underwent contrast-enhanced MRI before and five months after successful drug-eluting stent implantation for CTO. A CTO was defined as a complete occlusion of a major epicardial coronary artery existing for at least six weeks (mean, 7 +/- 5 months). Myocardial wall thickening and left ventricular volumes were quantified on cine-images, and the transmural extent of infarction (TEI) was scored on delayed-enhancement images.
Results: A significant decrease in mean end-systolic volume index (34 +/- 13 ml/m2 to 31 +/- 13 ml/m2; p = 0.02) and mean end-diastolic volume index (84 +/- 15 ml/m2 to 79 +/- 15 ml/m2; p < 0.002) was observed, whereas the mean ejection fraction did not change significantly (61 +/- 9% to 62 +/- 11%; p = 0.54). The extent of the left ventricle that was dysfunctional but viable before revascularization was related to improvement in end-systolic volume index (R = 0.46; p = 0.01) and ejection fraction (R = 0.49; p = 0.01) but not to the end-diastolic volume index (R = 0.10; p = 0.53). Segmental wall thickening improved significantly in segments with <25% TEI (21 +/- 15% to 35 +/- 25%; p < 0.001), tended to improve in segments with 25% to 75% TEI (18 +/- 22% to 27 +/- 22%; p = 0.10), whereas segments with >75% TEI did not improve (4 +/- 14% to -9 +/- 14%; p = 0.54).
Conclusions: Drug-eluting stent implantation for a CTO has a beneficial effect on left ventricular volumes and function that can be predicted by performing MRI before revascularization.