Immediate or Deferred Nonculprit-Lesion PCI in Myocardial Infarction

The preferred timing of treatment of nonculprit lesions in patients with ST-segment elevation myocardial infarction (STEMI) remains uncertain. A comparison of immediate percutaneous coronary intervention (PCI) guided by instantaneous wave-free ratio (iFR) and deferred PCI guided by cardiac stress magnetic resonance imaging (MRI) in patients with STEMI and multivessel disease is warranted.

In this international, investigator-initiated, open-label, randomized, controlled trial, patients with STEMI and at least one nonculprit lesion who had undergone successful primary PCI were randomly assigned in a 1:1 ratio to immediate iFR-guided PCI (in lesions with >50% stenosis and an iFR of ≤0.89 [normal value, >0.89]) or deferred cardiac stress MRI-guided PCI within 6 weeks after randomization. The primary end point was a composite of death from any cause, recurrent myocardial infarction, or hospitalization for heart failure at 3-year follow-up.

The trial included 1146 patients (558 in the iFR group and 588 in the MRI group) with a mean (±SD) age of 63±11 years; 78% were men. A total of 237 of 556 patients (42.6%) in the iFR group and 110 of 587 patients (18.7%) in the MRI group underwent nonculprit-lesion coronary-artery PCI. A primary-end-point event occurred in 50 patients (9.3%) in the iFR group and in 55 patients (9.8%) in the MRI group (hazard ratio, 0.95; 95% confidence interval, 0.65 to 1.40; P = 0.81). Serious adverse events occurred in 145 patients in the iFR group and in 181 in the MRI group.

Among patients with STEMI who have undergone successful primary PCI, immediate iFR-guided PCI was not superior to deferred cardiac stress MRI-guided PCI of nonculprit coronary-artery lesions with respect to death from any cause, recurrent myocardial infarction, or hospitalization for heart failure at 3 years. (Funded by Philips Volcano and others; iMODERN ClinicalTrials.gov number, NCT03298659.).