Left Main Coronary Artery Disease and Outcomes after Percutaneous Coronary Intervention for Chronic Total Occlusions.

Background: Concomitant left main coronary artery (LMCA) disease in patients with chronic total occlusions (CTO) commonly results in referral for coronary artery bypass grafting, although the impact of LMCA in CTO patients remains largely unknown. Nevertheless, patient selection for percutaneous coronary intervention of CTOs (CTO-PCI) or alternative revascularization strategies should be based on precise evaluation of the coronary anatomy to anticipate those patients that most likely benefit from a procedure and not on strict adherence to perpetual clinical practice. Therefore, the aim of this study was to assess the impact of LMCA disease on long-term outcomes in patients undergoing percutaneous coronary intervention for CTO. Methods: We enrolled 3860 consecutive patients undergoing PCI for at least one CTO lesion and investigated the predictive value of concomitant LMCA disease. All-cause mortality was defined as the primary study endpoint. Results: We observed that LMCA disease is significantly associated with mortality. In the Cox regression analysis, we observed a crude hazard ratio (HR) 1.59 (95% confidence interval (CI) 1.23–2.04, p < 0.001) for patients with LMCA disease as compared to patients without. Results remained unchanged after bootstrap- or clinical confounder-based adjustment. Conclusion: LMCA disease is associated with excess mortality in CTO patients. Specifically, anatomical features such as CTO of the circumflex artery represent a high risk patient population.