The impact of right coronary artery support on the outcomes of patients with unprotected left main disease undergoing percutaneous coronary intervention.

ABSTRACT Background: Many operators are discouraged from performing left main (LM) percutaneous coronary interventions (PCI) in the absence of right coronary artery (RCA) support due to the increased procedure risk. Aims: We aimed to assess the absent functional RCA impact on prognostic implications in patients undergoing unprotected LM PCI. Methods: 613 patients underwent LM PCI in our department between 2015 and 2019. Consecutive 385 patients with unprotected LM and at least 1-year follow-up were included in the study. The study group consisted of 272 patients with unprotected left main coronary artery disease (ULMCAD) with dominant RCA without any significant lesions (Group 1) and 113 ULMCAD patients and with lack of RCA support (Group 2). Results: In Group 2, 32.7% patients had a significant RCA stenosis, 48.7% chronic total occlusion (CTO) of RCA and 18.6% recessive RCA. Patients in Group 2 were older and had higher prevalence of COPD. SYNTAX Score (median (IQR) 26.0 (20.0-33.0) vs. 19.0 (13.0-25.5); P < 0.001) was higher and left ventricular ejection fraction was lower (median (IQR) 50.0 (40.0-60.0) vs. 55.0 (45.0-60.0); P = 0.01) in this group. All periprocedural complications did not differ among the groups. Long-term all-cause mortality at a median follow-up of 1149 days did not differ significantly (23% vs. 20%; P = 0.37). The long-term mortality in CTO-RCA group was also not significantly different. Conclusions: Patients with ULMCAD who have undergone LM PCI with absent RCA support, compared with patients with ULMCAD with RCA support, differed neither in the frequency of periprocedural complications nor in long-term all-cause mortality.