Feasibility of Quantitative Flow Ratio Virtual Stenting for Guidance of Serial Coronary Lesions Intervention

Background Coronary physiology measurement in serial coronary lesions with multiple stenoses is challenging. Therefore, we evaluated the feasibility of Murray fractal law-based quantitative flow ratio (mu QFR) virtual stenting for guidance of serial coronary lesions intervention. Methods and Results Patients who underwent elective coronary angiography and had 2 serial de novo coronary lesions of 30% to 90% diameter stenosis by visual estimation were prospectively enrolled. mu QFR and fractional flow reserve (FFR) were assessed after coronary angiography. In vessels with an FFR <= 0.80, the lesion with the larger pressure gradient was considered to be the primary lesion and treated firstly, followed by FFR measurement. The second lesion was stented when FFR <= 0.80. All mu QFR and predicted mu QFR after stenting were calculated from diagnostic coronary angiography before interventions, with the analysts masked to the FFR data. A total of 54 patients with 61 target vessels were interrogated. Percutaneous coronary intervention was performed in 44 vessels with FFR <= 0.80. After stenting the primary lesions, 14 nonprimary lesions had FFR <= 0.80 and a second drug-eluting stent was implanted. There was excellent correlation (r=0.97, P<0.001) and good agreement (mean difference: 0.00 +/- 0.03) between baseline mu QFR and FFR in identifying flow-limiting lesions. Per-vessel diagnostic accuracy of mu QFR on de novo lesions was 96.7% (95% CI, 88.7%-99.6%). mu QFR and FFR are highly consistent (93.2%) in identifying the primary lesion requiring revascularization. After stenting the primary lesions, per-vessel diagnostic accuracy of predicted mu QFR for identifying the significance of the nonprimary lesion was 90.9%. Predicted residual mu QFR with virtual stenting was higher than final FFR (mean difference: 0.05 +/- 0.06). Conclusions In vessels with serial coronary lesions, virtual stenting by mu QFR can identify the primary flow-limiting lesion for revascularization.