Outcomes With Intermediate Left Main Disease: Analysis From the ISCHEMIA Trial

Area of Science:

• Cardiology
• Interventional Cardiology
• Clinical Trials

Background:

• Significant left main disease (LMD) (≥50% stenosis) poses a high cardiovascular risk, necessitating revascularization.
• The clinical impact of intermediate LMD (25%-49% stenosis) on patient outcomes remains incompletely understood.

Purpose of the Study:

• To investigate the outcomes of patients with and without intermediate left main disease (LMD) within the ISCHEMIA trial.
• To assess the impact of an invasive revascularization strategy on these outcomes, considering the presence of intermediate LMD.

Main Methods:

• Analysis of patients from the ISCHEMIA trial who underwent baseline coronary computed tomography angiography.
• Categorization of patients into groups with intermediate LMD (25%-49%) and without (<25%) LMD.
• Comparison of primary composite outcomes (cardiovascular death, MI, hospitalization) and quality of life (Seattle Angina Questionnaire score) between groups and treatment strategies.

Main Results:

• 26% of participants had intermediate LMD; 7% of those with intermediate LMD on CT angiography had significant LMD on invasive angiography.
• Patients with intermediate LMD showed a higher unadjusted risk of cardiovascular events, but this was not significant after full adjustment.
• An invasive strategy increased procedural MI but decreased nonprocedural MI, with no significant difference in the primary endpoint. A significant interaction was observed for nonprocedural MI, with a greater reduction in the intermediate LMD group.

Conclusions:

• The ISCHEMIA trial found no significant heterogeneity in the treatment benefit of an invasive strategy based on intermediate LMD status, except for a greater reduction in nonprocedural MI.
• An invasive strategy in patients with intermediate LMD increased procedural MI, reduced nonprocedural MI, and improved angina-related quality of life.
• These findings suggest that intermediate LMD does not preclude the benefits of an invasive approach, particularly regarding nonprocedural MI reduction and quality of life improvements.