Trends in Unprotected Left Main Percutaneous Coronary Intervention and Clinical Outcomes

Area of Science:

• Cardiology
• Interventional Cardiology
• Public Health

Background:

• Unprotected left main percutaneous coronary intervention (LM PCI) is a recognized treatment for coronary artery disease of low anatomic complexity.
• Recent trends in LM PCI procedural volume, patient demographics, techniques, and outcomes require description to confirm its contemporary safety.

Purpose of the Study:

• To examine temporal trends in the utilization and in-hospital outcomes of unprotected LM PCI in Japan.
• To assess the safety and effectiveness of LM PCI in current clinical practice.

Main Methods:

• A retrospective cohort study utilizing prospectively collected data from the Japanese Percutaneous Coronary Intervention registry (2019-2023).
• Analysis included approximately 1100 PCI-capable institutions, focusing on patients undergoing unprotected LM PCI.
• In-hospital mortality was the primary outcome, analyzed using multivariable logistic regression to adjust for patient and procedural characteristics.

Main Results:

• Unprotected LM PCI constituted approximately 5.2% of all PCI procedures between 2019 and 2023.
• The mean patient age increased, and the prevalence of heart failure among patients undergoing LM PCI rose during the study period.
• While unadjusted in-hospital mortality showed a modest increase, risk-adjusted analysis revealed no significant change in mortality rates over time, even after accounting for increased use of radial access and mechanical circulatory support.

Conclusions:

• Unprotected LM PCI represents a consistent proportion of percutaneous coronary interventions in Japan.
• Increasing patient complexity was associated with a slight rise in unadjusted mortality, but risk-adjusted outcomes remained stable.
• These findings support the continued role of LM PCI as a safe revascularization strategy in contemporary practice.