TY - JOUR JO - EuroIntervention TI - Reproducibility of quantitative flow ratio: the QREP study AB - <p><strong>Background:</strong> Quantitative flow ratio (QFR) is a tool for physiological lesion assessment based on invasive coronary angiography.</p> <p><strong>Aims:</strong> We aimed to assess the reproducibility of QFR computed from the same angiograms as assessed by multiple observers from different, international sites.</p> <p><strong>Methods:</strong> We included 50 patients previously enrolled in dedicated QFR studies. QFR was computed twice, one month apart by five blinded observers. The main analysis was the coefficient of variation (CV) as a measure of intra- and inter-observer reproducibility. Key secondary analysis was the identification of clinical and procedural characteristics predicting reproducibility.</p> <p><strong>Results:</strong> The intra-observer CV ranged from 2.3% (1.5-2.8) to 10.2% (6.6-12.0) among the observers. The inter-observer CV was 9.4% (8.0-10.5). The QFR observer, low angiographic quality, and low fractional flow reserve (FFR) were independent predictors of a large absolute difference between repeated QFR measurements defined as a difference larger than the median difference (&gt;0.03).</p> <p><strong>Conclusions:</strong> The inter- and intra-observer reproducibility for QFR computed from the same angiograms ranged from high to poor among multiple observers from different sites with an average agreement of 0.01&plusmn;0.08 for repeated measurements. The reproducibility was dependent on the observer, angiographic quality and the coronary artery stenosis severity as assessed by FFR.</p> AU - Westra Jelmer AU - Sejr-Hansen Martin AU - Koltowski Lukasz AU - Mejía-Rentería Hernán AU - Tu Shengxian AU - Kochman Janusz AU - Zhang Yimin AU - Liu Tommy AU - Campo Gianluca AU - Hjort Jakob AU - Mogensen Lone Juul Hune AU - Erriquez Andrea AU - Andersen Krogsgaard Birgitte AU - Eftekhari Ashkan AU - Escaned Javier AU - Christiansen Høj Evald AU - Holm Ramsing Niels VL - 17 IS - 15 Y1 - 18/02/2022 Y1 - 2022 DOI - 10.4244/EIJ-D-21-00425 SP - 1252 EP - 1259 KW - fractional flow reserve KW - qca KW - stable angina PB - Europa Digital & Publishing SE - Coronary interventions - Mini focus on Coronary Physiology UR - https://eurointervention.pcronline.com/article/reproducibility-of-quantitative-flow-ratio-the-qrep-study SN - 1774-024X ER -