Left main disease: Percutaneous coronary intervention vs. coronary artery bypass grafting vs. deferring. A West Denmark Heart Registry Study

Background Societal treatment guidelines recommend unprotected left main (LM) disease revascularized by either percutaneous intervention (PCI) or coronary artery bypass grafting (CABG). Revascularization vs. deferring is unlikely to be assessed in a randomized trial. Purpose To compare patients with isolated LM lesions who underwent PCI, CABG or deferred treatment, in a real-world setting. Methods We included patients with isolated LM lesion by invasive coronary angiography on the indication chronic coronary syndrome between January 2002 and January 2021, registered in the Western Denmark Heart Registry. Patients were divided into four groups: Defer with diameter stenosis (DS)<=50%, defer with DS>50%, PCI or CABG. Patients were included after 90-days event free survival. Outcomes were: Acute coronary syndrome (ACS), revascularization, stroke and all-cause mortality within 5 years. Adjusted absolute 5-year risks were derived using multivariate cox models and g-formula methods. Models were adjusted for cardiovascular risk factors including diabetes and year of angiography. Results A total of 16,565 patients were identified. Of these, 6,703 patients underwent PCI, 6,460 CABG, 1,834 were in the defer group with <=50% stenosis, and 1,568 in the >50% group. Median LM diameter stenosis; PCI: 80%(Interquartile Range [IQR] 60-90%), CABG: 70%(IQR 60-90%), defer<=50%: 40%(IQR 30-50%) and defer>50%: 80%(IQR 66-99%) (p<0.0005). For diabetes; PCI: 17.5%, CABG: 21.4%, defer<=50%: 17.4% and defer>50% 22.7%(p<0.0005). Survival probability was 84.8 % for patients receiving PCI, 89.0% for CABG, 85.0% for defer<=50% and 75.9% for defer>50%(p< 0.0005%)(Figure 1). Cumulative incidence of ACS was 10.8% for patients receiving PCI, 4.7% for CABG, 7.6% for defer<=50% and 12.4% for defer>50%(p< 0.0005%)(Figure 1). For revascularization, the numbers were 17.5%, 9.2%, 13.8% and 19.2%(p<0.0005) and for stroke 3.9%, 3.8%, 3.9% and 5.4%,(p<0.005). Adjusted absolute risks of all-cause mortality were; PCI: 12.7%(95% confidence interval [CI] 12.0-13.4%), CABG: 11.6%(95%CI 11.0-12.2%), defer<=50%: 13.2%(95%CI 12.2-14.3%) and defer>50%: 15.4%(95%CI 14.2-16.5%)(Figure 2). For ACS; 10.7%(95%CI 9.9-11.5%) for PCI, 5.2%(95%CI 4.8-5.8%) for CABG, 8.3%(95%CI 7.2-9.5%) for defer<=50% and 12.2%(95%CI 10.7-13.6%) for defer>50%. For revascularization; PCI: 18.6%(95%CI 17.6-19.6%), CABG: 9.4%(95%CI 8.7-10.1%), defer<=50%: 14.9%(95%CI 13.3-16.4%) and defer>50%: 19.5%(95%CI 17.5-21.4%). For stroke; PCI: 4.1%(95%CI 3.6-4.6%), CABG: 4.4%(95%CI 3.9-4.8%), defer<=50%: 4.1%(95%CI 3.4-4.9%) and defer>50%: 4.8%(95%CI 3.9-5.7%). Conclusions Real-world data on revascularization of isolated significant LM stenosis with CABG or PCI showed superior survival versus deferred treatment. PCI was associated with a higher rate of non-fatal ACS and revascularization than CABG but comparable to the deferred group. Deferred revascularization of LM (DS> 50%) stenosis was associated with worst outcomes.