Plaque Characterization to Inform the Prediction and Prevention of Periprocedural Myocardial Infarction During Percutaneous Coronary Intervention: The CANARY Trial (Coronary Assessment by Near-infrared of Atherosclerotic Rupture-prone Yellow).

OBJECTIVES: This study sought to determine whether pre-percutaneous coronary intervention (PCI) plaque characterization using near-infrared spectroscopy identifies lipid-rich plaques at risk of periprocedural myonecrosis and whether these events may be prevented by the use of a distal protection filter during PCI.

BACKGROUND: Lipid-rich plaques may be prone to distal embolization and periprocedural myocardial infarction (MI) in patients undergoing PCI.

METHODS: Patients undergoing stent implantation of a single native coronary lesion were enrolled in a multicenter, prospective trial. Near-infrared spectroscopy and intravascular ultrasound were performed at baseline, and lesions with a maximal lipid core burden index over any 4-mm length (maxLCBI4mm) ≥600 were randomized to PCI with versus without a distal protection filter. The primary endpoint was periprocedural MI, defined as troponin or a creatine kinase-myocardial band increase to 3 or more times the upper limit of normal.

RESULTS: Eighty-five patients were enrolled at 9 U.S. sites. The median (interquartile range) maxLCBI4mm was 448.4 (274.8 to 654.4) pre-PCI and decreased to 156.0 (75.6 to 312.6) post-PCI (p < 0.0001). Periprocedural MI developed in 21 patients (24.7%). The maxLCBI4mm was higher in patients with versus without MI (481.5 [425.6 to 679.6] vs. 371.5 [228.9 to 611.6], p = 0.05). Among 31 randomized lesions with maxLCBI4mm ≥600, there was no difference in the rates of periprocedural MI with versus without the use of a distal protection filter (35.7% vs. 23.5%, respectively; relative risk: 1.52; 95% confidence interval: 0.50 to 4.60, p = 0.69).

CONCLUSIONS: Plaque characterization by near-infrared spectroscopy identifies lipid-rich lesions with an increased likelihood of periprocedural MI after stent implantation, presumably due to distal embolization. However, in this pilot randomized trial, the use of a distal protection filter did not prevent myonecrosis after PCI of lipid-rich plaques.