Prediction of left ventricular function after drug-eluting stent implantation for chronic total coronary occlusions

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.