Impact of Residual Chronic Total Occlusion of Right Coronary Artery on the Long-term Outcome in Patients Treated for Unprotected Left Main Disease The Milan and New-Tokyo Registry

Background-The presence of chronic total occlusion of the right coronary artery (CTO-RCA) in patients undergoing percutaneous interventions for unprotected left main (ULM) disease may affect the prognosis. In this study, we evaluated the immediate results and follow-up of patients with ULM-percutaneous interventions and with or without associated CTO-RCA. Methods and Results-Between March 2002 and December 2008, a total of 568 consecutive patients with ULM stenosis treated with drug-eluting stent were included in this analysis. The mean EuroScore and SYNTAX scores were 4.05+/-2.62 and 28.12+/-10.82, respectively. Of these, 522 had ULM lesions without residual CTO-RCA (493 ULM without CTO-RCA+29 ULM with treated CTO-RCA), and 46 patients had residual CTO-RCA. At 1466 days (interquartile range, 1150-1917) follow-up, the cardiac-death occurred in 41 patients (7.2%). Cardiac-death was more frequently observed in patients with ULM and residual CTO-RCA as compared with those without residual CTO-RCA (adjusted hazard ratios, 2.163 [95% confidence interval, 1.018-4.597]; P=0.045). However, target lesion revascularization occurred less frequently in patients with residual CTO-RCA (adjusted hazard ratios, 0.321 [95% confidence interval, 0.13-0.794]; P=0.014), resulting in the similar major adverse cardiovascular events rates between the 2 groups. When we analyzed patients with concomitant ULM and CTO-RCA, cardiac-death was significantly higher in patients with residual as compared with treated CTO-RCA (log-rank P=0.01) despite no difference in baseline characteristics. Conclusions-Cardiac-death occurred more frequently in patients with residual CTO-RCA as compared with those without residual CTO-RCA. These findings suggest that recanalization of CTO-RCA has significant impact on the long-term cardiac-mortality in patients undergoing ULM-percutaneous interventions probably by offering reserve coronary circulation, if in-stent restenosis were to occur in the treated left main.