Impact Of Target Vessel And Percutaneous Coronary Intervention On Long-Term Clinical Outcomes For Chronic Total Occlusions

Background:This study sought to investigate the long-term clinical outcomes of patients with successful percutaneous coronary intervention (PCI) for chronic total occlusions (CTO). It was also aimed to estimate whether there is a differential prognostic effect according to the target vessel where CTO is located in.Methods:Between September2006and December2011, a total of209patients who underwent PCI for at least one CTO in the Department of Cardiology, Sir Run Run Shaw hospital were enrolled. Patients with acute myocardial infarction (MI) within1month pre-procedure, a CTO in the left main stem or bypass graft, and those with more than one CTO lesions in multiple target vessels have been excluded. Of the209patients, a total of183were followed up for as least36months. The combining endpoint was the occurrence of major adverse cardiovascular events (MACE), which was a composite of all-cause death (including fatal MI, fatal stroke and others), non-fatal MI and urgent target vessel revascularization (TVR). MACE-free survival and the need for repeat revascularization were compared between patients with successful vs. unsuccessful CTO-PCI.Results:Among the209patients, right coronary artery (RCA) was the target vessel in101(48.3%), left anterior descending (LAD) in62(29.7%), and left circumflex (LCX) in46(22.0%) individuals. Hypertension and prior PCI were significantly more common in the RCA group, while male gender and current smoking were more common in LAD patients. RCA CTO was associated with significantly more triple-vessel diseases (80.2%vs.29.0%vs.66.0%, P<0.001) and collateralization (72.2%vs.59.7%vs.42.0%, P=0.001) compared with LAD or LCX group. The overall angiographic success rates and procedural success rates were79.4%and75.4%, respectively. There were no differences in angiographic/procedural success across groups stratified by target vessel. The mean follow-up duration was44.6months. Procedural success compared with failure was associated with improved MACE-free survival in the entire population (P<0.001). In the comparison of subgroups, survival benefit was only statistically significant in successful vs. unsuccessful LAD (P<0.001), but not in the non RCA group (P=0.053). In multivariable analysis, CTO PCI success in the RCA group remained associated with decreased MACE risk (HR3.30,95%CI:1.30-8.39, P=0.012).Conclusion:The results from this contemporary cohort suggested successful CTO-PCI was associated with improved long-term MACE-free survival. The improvement was only statistically significant in the RCA, but not the LAD or LCX. This information may assist in selecting patients for attempted CTO-PCI.