Long-term outcomes post chronic total occlusion interventionimplications of completeness of revascularization

BackgroundLong term clinical outcomes post chronic total occlusion (CTO) intervention may depend not only on CTO success/failure alone but also on Completeness of revascularization. ObjectivesTo determine long term outcomes post CTO intervention and relate them to both success versus failure and Complete Revascularization (CR) versus Incomplete Revascularization (IR). MethodsConsecutive patients taken up for CTO intervention with at-least one CTO vessel between Jan 2006 to Dec 2015 were included. Clinical, procedural and follow up details were recorded in a pre-specified custom made software. Primary endpoint of the study was survival free of major adverse event individual, death, myocardial infarction (MI), repeat revascularisation (percutaneous coronary intervention [PCI], or coronary artery bypass grafting (CABG) and recurrent or continued angina. Each individual adverse event was considered as a secondary end point. ResultsA total of 632 patients were enrolled in study with follow up data available in 549 (86%) constituting the study group with 490 (89.3%) success and 59 (11.7%) failure. Complete revascularization (CR) was obtained in 410 (74.7%). Follow up was median 2.9 years with inter-quartile range 1.1-4.8 years. Kaplan Meier survival analysis showed a better EFS with both CTO success versus failure (P=0.03)and CR versus IR (P=0.017). Individual adverse outcomes however were not significantly different in CTO success versus failure group but significantly better when analyzed with respect to CR versus IR including death (P=0.049) and recurrent angina (P=0.024). Repeat intervention and MI were not different by either analysis. ConclusionsSuccessful CTO PCI results in a better long term event free survival but the difference between the groups is more if analyzed with respect to completeness of revascularization rather than CTO success/failure alone.