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 (μQFR) 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. μQFR 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 μQFR and predicted μQFR 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 (=0.97, <0.001) and good agreement (mean difference: 0.00±0.03) between baseline μQFR and FFR in identifying flow-limiting lesions. Per-vessel diagnostic accuracy of μQFR on de novo lesions was 96.7% (95% CI, 88.7%-99.6%). μQFR 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 μQFR for identifying the significance of the nonprimary lesion was 90.9%. Predicted residual μQFR with virtual stenting was higher than final FFR (mean difference: 0.05±0.06). Conclusions In vessels with serial coronary lesions, virtual stenting by μQFR can identify the primary flow-limiting lesion for revascularization.