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/m(2) to 31 +/- 13 ml/m(2); p = 0.02) and mean end-diastolic volume index (84 +/- 15 ml/m(2) to 79 +/- 15 ml/m(2); 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 +/- 1.5% to 35 +/- 25%; p < 0.001), tended to improve in segments with 25% to 75% TEI (18 22% to 27 +/- 22%; 1) = 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.