Clinical, electrocardiographic, and procedural characteristics of patients with coronary chronic total occlusions

Background and Objectives: Percutaneous coronary intervention for chronic total occlusion lesions is technically difficult despite equipment advances. Changes in electrocardiographic patterns, such as Q and T waves, during chronic total occlusion can provide information about procedural success and myocardial viability. In this study, we investigated clinical, electrocardiographic, and procedural characteristics of chronic total occlusions. Subjects and Methods: Patients (2,635) who underwent coronary angiography between January 2006 and July 2007 at six Catholic University Hospitals were identified using a dedicated Internet database. Results: A total of 195 patients had total occlusion lesions (7.4%). Percutaneous coronary interventions were attempted in 136 total occlusion lesions (66.0%) in 134 patients. Successful recanalization with stent implantation was accomplished in 89 lesions, with a procedural success rate of 66.4%. One procedure-related death occurred because of no-reflow phenomenon. After excluding 8 patients with bundle branch block, Q and T wave inversions were observed in 60 (32.1%) and 78 patients (41.7%), respectively. The presence of Q waves was associated with severe angina, decreased left ventricular ejection fraction, regional wall motion abnormality, and T wave inversion, but was not related to procedural success. Conclusion: Percutaneous coronary intervention is a safe and useful procedure for the revascularization of coronary chronic total occlusion lesions. The procedural success rate was not related to the presence of pathologic Q waves, which were associated with severe angina and decreased left ventricular function.