Impact of successful recanalisation of chronically occluded coronary arteries on clinical outcomes in patients with coronary artery disease

Background. Chronically occluded coronary arteries (CTO) are a common finding in coronary angiography. The technical success rate of endovascular recanalisation of CTO is high; however, the effect of technical success on long-term clinical results remains unclear. Aim. To evaluate long-term outcomes of CTO recanalisation according to technical success of the procedure. Methods. We evaluated 1073 patients who underwent endovascular recanalisation of CTO from 2013 to 2019. Assessment of clinical results was performed via phone call or follow-up visit at years 1, 2, 3, 4 and 5. Survival was evaluated using the Kaplan-Meier method and compared between the technical success and technical failure groups using the log-rank test. The initial clinical and angiographic characteristics and procedural results of recanalisation were included as probable predictors of adverse cardiovascular events in uni- and multivariate regression analyses. Results. Mean follow-up was 2.7 ± 1.9 years. The incidence of adverse cardiovascular events, including death from all causes, nonfatal myocardial infarction, stroke and unplanned myocardial revascularisation was 11.4% in the technical success group and 24 % in the technical failure group (p = 0.0001). The difference was mainly due to the higher prevalence of repeat revascularisation in the technical failure group (6.7 % vs. 18.1 %, p = 0.0001). Differences in mortality (2.7 % vs. 3.8 %, p = 0.38), stroke (0.6 % vs. 0.4 %, p = 0.99) and myocardial infarction (2 % vs. 4 %, p = 0.13) were not observed. Multivariate regression analysis found that ejection fraction of the left ventricle, calcification of the coronary arteries and technical success were independent predictors of adverse events. Conclusion. Successful recanalisation of CTO is associated with fewer adverse cardiovascular events over the long term. Technical failure, calcification and low ejection fraction are independent predictors of adverse events.