Instantaneous wave-free ratio cutoff values for nonculprit stenosis classification in patients with ST-segment...

Area of Science:

• Cardiology
• Interventional Cardiology
• Physiology

Background:

• The instantaneous wave-free ratio (iFR) is a validated metric for assessing coronary stenosis hemodynamic significance in stable patients.
• Its utility in evaluating nonculprit lesions in the acute phase of ST-segment elevation myocardial infarction (STEMI) requires further investigation.

Purpose of the Study:

• To evaluate different instantaneous wave-free ratio (iFR) cutoff values for determining the hemodynamic significance of nonculprit coronary stenoses in patients with STEMI.
• To assess the diagnostic performance of acute iFR measurements compared to follow-up iFR in this patient population.

Main Methods:

• Instantaneous wave-free ratio (iFR) was measured in nonculprit stenoses of 120 STEMI patients during the acute phase and at follow-up.
• 157 nonculprit stenoses were analyzed, with 147 completing follow-up in 113 patients.
• Diagnostic performance metrics (positive and negative predictive values) were calculated for various acute iFR cutoffs against follow-up iFR as the reference standard.

Main Results:

• The prevalence of hemodynamically significant nonculprit stenoses was 52% acutely and 41% at follow-up.
• An acute iFR cutoff of <0.90 showed the highest agreement between acute and follow-up assessments.
• An acute iFR cutoff >0.93 yielded a 100% negative predictive value, while cutoffs <0.86 and <0.83 had positive predictive values of 71% and 77%, respectively.

Conclusions:

• In STEMI patients, an acute instantaneous wave-free ratio (iFR) cutoff of <0.90 is optimal for evaluating nonculprit stenoses.
• This cutoff demonstrates a high negative predictive value and moderate positive predictive value for identifying hemodynamically significant lesions.