Residual Quantitative Flow Ratio to Estimate Post‐Percutaneous Coronary Intervention Fractional Flow Reserve

Figure 5

Case examples of true positive and true negative residual QFR results. Case 1 demonstrates a case of a successfully treated proximal LAD lesion with a suboptimal post-PCI FFR (1a-b). Residual QFR estimated a post-PCI FFR of 0.85 (1c–e). The suboptimal result was caused by a pressure drop due to an additional lesion in the mid-LAD (1d). In case 2, residual QFR was 0.86 and FFR after treating the proximal LAD lesion was 0.80 (2a–e). QFR analyses revealed diffuse disease without a focal pressure drop to be the potential cause of the suboptimal result (2D). The last case demonstrates a case of a true negative result; the lesion in the proximal LAD was successfully treated, and there were no additional lesions or diffuse disease which led to a concordant residual QFR and post-PCI FFR ≥ 0.90 (3a–e). FFR, fractional flow reserve; PCI, percutaneous coronary intervention; QFR, quantitative flow ratio; LAD, left anterior descending artery.