Twelve‐year trends in unprotected left main coronary artery occlusion: insights from a real‐world multicentre study

Abstract

Abstract Aims Acute myocardial infarction (AMI) resulting from unprotected left main coronary artery (LMCA) occlusion and subtotal occlusion is a life‐threatening condition. Although AMI management has improved in the past two decades, there is limited information on recent trends in patient characteristics, management, and outcomes for acute unprotected LMCA‐related AMI. This study aims to assess such trends over a 12 year period. Methods and results This retrospective multicentre study includes patients with unprotected LMCA occlusion/subtotal occlusion admitted to three tertiary hospitals between 2008 and 2020. The patients were divided into two groups based on the chronology of presentation: a ‘past group’ (January 2008 to December 2014) and a ‘contemporary group’ (January 2015 to December 2020). The study compares clinical characteristics, management approaches, and outcomes between the two groups. The study includes 128 patients, with 51 (40%) in the ‘past group’ and 77 (60%) in the ‘contemporary group’. Baseline risk factors did not show statistically significant differences between the two groups, except for hypertension (49% vs. 74%; P = 0.005). Chest pain was more frequent in the ‘past group’ (98% vs. 89%; P = 0.014), and a trend towards more cardiac arrests was observed in the ‘contemporary group’ (18% vs. 31%; P = 0.087). Revascularization type did not differ significantly (P = 0.419), but manual thrombectomy was less frequently used (41% vs. 23%; P = 0.032) and stent implantation showed a trend towards higher rates (66% vs. 78%; P = 0.150) in the ‘contemporary cohort’. There was a gradual shift from bare‐metal to drug‐eluting stents, with a significantly higher percentage of ticagrelor/prasugrel loading in the ‘contemporary cohort’ (5% vs. 79%; P < 0.001). The use of mechanical circulatory support (MCS), although not statistically significant, was higher among patients in the ‘past group’ (67% vs. 51%; P = 0.073). The type of MCS differed significantly between groups, with a decrease in intra‐aortic balloon pump use (67% vs. 42%; P = 0.005) and an increase in veno‐arterial extracorporeal membrane oxygenation (4% vs. 22%; P = 0.005) and Impella system (0% vs. 3%) over time. Survival analysis showed no significant differences (P = 0.599; log‐rank test) in all‐cause mortality between the different time groups, with the long‐term survival rate being approximately 30%. Conclusions In our real‐world population, despite the progressive use of newer drugs and more advanced devices over time, patients with unprotected LMCA occlusion/subtotal occlusion remain a subpopulation with poor prognosis.

Keywords

• Unprotected left main coronary artery occlusion/subtotal occlusion
• Acute coronary syndrome
• Mechanical circulatory support
• Real‐world multicentre study