Author + information
- Jelmer Westra1,
- Shengxian Tu2,
- Louise Nissen3,
- Mai-Britt Vestergaard4,
- Birgitte Krogsgaard Andersen4,
- Emil Holck5,
- Lene Nyhus Andreasen4,
- Yimin zhang2,
- Steen Dalby Kristensen4,
- Lars Romer Krussell4,
- Christian Terkelsen6,
- Johan Reiber7 and
- Jens Flensted Lassen8
- 1Aarhus Universitetshospital, Skejby, Aarhus, Denmark
- 2Shanghai Jiao Tong University, Shanghai, China
- 3Hospital Unit West, Herning, Denmark
- 4Aarhus University Hospital, Skejby, Aarhus, Denmark
- 5Aarhus University Hospital, Skejby, Viby J, Denmark
- 6Aarhus University Hospital, Aarhus, Denmark
- 7Leiden University Medical Center, Leiden, Netherlands
- 8The Heart Centre, Rigshospitalet, Copenhagen, Denmark
Pressure wire based fractional flow reserve (FFR) may be used for functional testing of stenosis-mediated ischemia. To further expand the use of physiological lesion assesment, quantitative flow ratio (QFR) based on computation of coronary angiography was recently developed. This is the first adequately powered, prospective study to evaluate the off-line feasibility and diagnostic performance of QFR.
WIFI-II was a sub study to the DAN-NiCAD study (NCT02264717), referring 360 patients with positive coronary CT-scans for diagnostic coronary angiography (CAG). FFR was measured as gold standard in 290 lesions with 30-90% diameter stenosis. Blinded observers calculated QFR with Medis Suite (Medis, the Netherlands) for comparison with FFR. QFR computation is based on three-dimensional coronary angiography reconstruction and flow modeling using contrast-flow velocity in standard diagnostic angiography.
The first 106 patients with 162 lesions interrogated with FFR were analyzed pr. 06/25/16. Thirteen (8%) and 22 lesions (14 %) were excluded due to predefined FFR and angiographic core-lab criteria, respectively. QFR was successfully computed for 117 out of 127 lesions (92 %) with a mean diameter stenosis of 48±14 %. Mean difference between FFR and QFR was 0.01±0.08. Mean flow velocity at rest was 0.19±0.08 m/s. QFR correctly classified 83 % of the lesions using FFR<0.80 as reference standard. The area under the receiver-operating characteristic curve (AUC) was 0.89 (95% CI: 0.83-0.95) with a sensitivity, specificity, negative predictive value and positive predictive value of 77%, 87%, 85% and 80%, respectively. Accuracy and AUC increased to 90% and 0.92 for FFR values <0.77 and >0.83.
QFR is a safe and cheap modality for coronary stenosis evaluation showing good agreement to FFR and therefore has the potential to improve the global adaption of physiological lesion assessment pending in-procedure validation. Inclusion was finalized May 8th 2016. Analysis is finalized this August and final results can be presented at TCT 2016.
IMAGING: FFR and Physiologic Lesion Assessment