Quantitative flow ratio predicts outcomes in complex PCI
SAN FRANCISCO — Among patients with three-vessel disease who underwent PCI, achievement of a quantitative flow ratio of at least 0.91 in all treated vessels was associated with improved vessel-related outcomes, according to findings presented at TCT 2019.
The researchers retrospectively analyzed the quantitative flow ratio (QFR) of all vessels treated in the SYNTAX II trial. A valid QFR was obtained in 771 vessels. Norihiro Kogame, MD, cardiologist at Amsterdam University Medical Center and Toho University Medical Center Ohashi Hospital, Tokyo, presented the results, which were simultaneously published in JACC: Cardiovascular Interventions.
Unlike fractional flow reserve, QFR does not require a pressure wire or adenosine, Kogame said during a presentation, but noted that until this study, “the clinical implications of post-PCI QFR in patients with complex coronary artery disease were not yet investigated.”
The primary outcome was a vessel-oriented composite endpoint at 2 years, defined as vessel-related cardiac death, vessel-related MI and target vessel revascularization.
Among the cohort, the mean QFR was 0.91 and 6.7% experienced a vessel-oriented composite endpoint, Kogame said during his presentation.
The researchers determined that QFR moderately predicted the vessel-oriented composite endpoint (area under the curve, 0.702; 95% CI, 0.633-0.772).
Kogame said the optimal cutoff value for predicting the vessel-oriented composite endpoint was 0.91 (sensitivity, 0.652; specificity, 0.635).
Vessels with a QFR of less than 0.91 after PCI were more than three times as likely than those with a QFR of at least 0.91 to be the culprit of a vessel-oriented composite endpoint at 2 years (12% vs. 3.7%; HR = 3.37; 95% CI, 1.91-5.97), driven by TVR, according to the researchers.
Those with lower QFR after PCI were more likely to have prior MI, serial lesions, left atrial descending artery stenosis, lower preprocedural QFR and lower minimum stent area compared with those with higher QFR after PCI, according to the researchers.
“Higher post-PCI QFR value is associated with improved vessel-related clinical outcomes in patients with three-vessel disease treated with state-of-the-art PCI,” Kogame said during the presentation. “Operators should aim for a post-PCI QFR value above 0.91. These findings require confirmation in future prospective trials.”
In a related editorial published in JACC: Cardiovascular Interventions, Abdul Hakeem, MD, interventional cardiologist at Rutgers Robert Wood Johnson Medical School, and Barry F. Uretsky, MD, clinical professor of medicine, director of interventional cardiology and director of the interventional cardiology fellowship program at the University of Arkansas for Medical Sciences and the Central Arkansas VA Medical Center, wrote that “if QFR can be performed rapidly and in real time, it holds practical appeal,” but the study findings have to be validated prospectively.
“Using QFR as part of an ideal PCI algorithm may be part of the solution to equalizing long-term outcomes of PCI with bypass surgery (functionally complete revascularization), particularly if it is shown in a randomized trial that use of functional evaluation post-PCI (with any measure) is superior to pre-PCI functional evaluation alone,” they concluded. – by Erik Swain
Kogame N, et al. Physiologic Guidance: Hyperemic, Basal and Angiographic Studies. Presented at: TCT Scientific Symposium; Sept. 25-29, 2019; San Francisco.
Disclosures: Kogame, Hakeem and Uretsky report no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.