Safety of Revascularization Deferral of Left Main Stenosis Based on Instantaneous Wave-Free Ratio Evaluation

Area of Science:

• Cardiovascular Medicine
• Interventional Cardiology
• Clinical Outcomes Research

Background:

• The instantaneous wave-free ratio (iFR) is established for guiding revascularization in stable coronary artery disease.
• Safety data for deferring left main (LM) coronary artery stenosis treatment based on iFR is lacking.
• LM stenosis requires careful consideration due to its critical location and potential for severe outcomes.

Purpose of the Study:

• To evaluate the long-term clinical outcomes of patients with left main (LM) coronary artery stenosis.
• To assess the safety of deferring revascularization based on the instantaneous wave-free ratio (iFR) in LM stenosis.
• To compare outcomes between deferred and revascularized LM stenosis guided by iFR.

Main Methods:

• Multicenter observational study of 314 patients with LM stenosis.
• Patients were divided into deferred (n=163) or revascularized (n=151) groups based on iFR cutoff ≤0.89.
• Primary endpoint: composite of all-cause death, nonfatal myocardial infarction, and ischemia-driven target lesion revascularization over a median 30-month follow-up.

Main Results:

• No significant difference in the primary endpoint between deferred (9.2%) and revascularized (14.6%) groups (p=0.26).
• Similar rates for secondary endpoints including all-cause death, cardiac death, nonfatal myocardial infarction, and target lesion revascularization between groups (p>0.05 for all).
• Hazard ratio for the primary endpoint was 1.45 (95% CI: 0.75 to 2.81) favoring the deferred group.

Conclusions:

• Deferral of revascularization for LM stenosis guided by iFR appears safe.
• Long-term clinical outcomes are comparable to those undergoing revascularization based on iFR values.
• iFR is a reliable physiological index for guiding management decisions in LM coronary artery stenosis.