Prognostic significance of occlusion length in recanalized chronic total occlusion lesion: a retrospective cohort study with 5-year follow-up

OBJECTIVES: This study sought to investigate the relationship between occlusion length and long-term outcomes of patients with recanalised chronic total occlusion (CTO) lesion. DESIGN: A retrospective cohort study. SETTING: Fuwai Hospital, National Center for Cardiovascular Disease, Beijing, China PARTICIPANTS: Consecutive patients with successfully recanalised CTO were included from January 2010 to December 2013. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary endpoint of the present study was a composite event of all-cause death and myocardial infarction (MI). The secondary endpoints included target lesion revascularisation (TLR) and target vessel revascularisation (TVR). RESULTS: A total of 1987 patients were included and 1801 (90.6%) subjects completed 5-year follow-up in this study. Based on occlusion length, the patients were divided equally into two groups: short (length <15 mm, n=957) and long (length ≥15 mm, n=1030) CTO group. Kaplan-Meier survival curve showed no significant difference in the risk of the composite primary endpoint between short and long CTO groups (p=0.242). Receiver operating characteristic curve analysis also established occlusion length ≥15 mm as a cut-off value for predicting TLR and TVR, with an area under the curve of 0.604 (95% CI: 0.569 to 0.638, p<0.001) and 0.605 (95% CI: 0.572 to 0.638; p<0.001). Kaplan-Meier analysis revealed that the risks for TLR (p=0.002) and TVR (p=0.002) were higher in a patient with long CTO lesion. Multivariate Cox analysis also identified long CTO lesion as an independent predictor of TLR (HR: 1.539, 95% CI: 1.033 to 2.293; p=0.034) and TVR (HR: 1.476, 95% CI: 1.012 to 2.151; p=0.043). CONCLUSION: Patients with long CTO lesion did not show a higher risk of death and MI after recanalisation, but had higher risks of TLR and TVR. Lesion with occlusion length ≥15 mm should be under close surveillance for restenosis after recanalisation.