HAWKEYE Study Demonstrates Prognostic Value of Quantitative Flow Ratio Measured After PCI

October 28, 2019—Findings from the international, multicenter, prospective HAWKEYE study of angio-based fractional flow reserve to predict adverse events after stent implantation were published by Simone Biscaglia, MD, et al in Journal of the American College of Cardiology (JACC): Cardiovascular Interventions (2019;12:2079–2088).

The aim of this study was to investigate the potential role of post–percutaneous coronary intervention (PCI) quantitative flow ratio (QFR) measurements to predict clinical outcomes in patients with successful PCI. The HAWKEYE investigators concluded that lower values of QFR after complete and successful revascularization predict subsequent adverse events.

As summarized in JACC: Cardiovascular Interventions, patients undergoing complete revascularization with successful PCI and stent implantation were eligible for acquisition of projections for QFR computation. At the end of the procedure, investigators acquired two angiographic projections for each vessel treated with PCI. Computation of QFR was performed offline by an independent core laboratory.

The study’s primary outcome was the vessel-oriented composite endpoint, defined as vessel-related cardiovascular death, vessel-related myocardial infarction, and ischemia-driven target vessel revascularization. The investigators analyzed 751 vessels in 602 patients. The median value of post-PCI QFR was 0.97 (interquartile range, 0.92–0.99).

In JACC: Cardiovascular Interventions, the investigators reported that predictors of lower post-PCI QFR included lesion location in the left anterior descending coronary artery, baseline SYNTAX score, lesion length, and post-PCI diameter stenosis. Altogether, 77 events were detected in 53 treated vessels (7%).

Additionally, the HAWKEYE study showed the following:

• Post-PCI QFR was significantly lower in vessels with the vessel-oriented composite endpoint during follow-up, compared with those without it (0.88 [interquartile range, 0.81–0.99] versus 0.97 [interquartile range, 0.93–0.99], respectively; P < .001).
• Receiver-operating characteristic curve analysis identified a post-PCI QFR best cutoff of ≤ 0.89 (area under the curve, 0.77; 95% confidence interval [CI], 0.74–0.80; P < .001).
• After correction for potential confounding factors, post-PCI QFR ≤ 0.89 was associated with a threefold increase in risk for the vessel-oriented composite endpoint (hazard ratio, 2.91; 95% CI, 1.63–5.19; P < .001).