Department of Cardiology, Hospital Clínico San Carlos IDISSC and Universidad Complutense de Madrid, Madrid, Spain.
Servicio de Cardiología de Adultos, Hospital Ramon y Cajal, Madrid, Spain.
Catheter Cardiovasc Interv. 2023 May;101(6):1045-1052. doi: 10.1002/ccd.30633. Epub 2023 Mar 19.
We aimed to evaluate the diagnostic accuracy of quantitative flow ratio (QFR) in left main (LM) coronary stenoses, using Fractional Flow Reserve (FFR) as reference.
QFR has demonstrated a high accuracy in determining the functional relevance of coronary stenoses in non-LM. However, there is an important paucity of data regarding its diagnostic value in the specific anatomical subset of LM disease.
This is a retrospective, observational, multicenter, international, and blinded study including patients with LM stenoses. Cases with significant ostial LM disease were excluded. QFR was calculated from conventional angiograms at blinded fashion with respect to FFR.
Sixty-seven patients with LM stenoses were analyzed. Overall, LM had intermediate severity, both from angiographic (diameter stenosis [%DS] 43.8 ± 11.1%) and functional perspective (FFR 0.756 ± 0.105). Mean QFR was 0.733 ± 0.159. Correlation between QFR and FFR was moderate (r = 0.590). Positive and negative predictive value, sensitivity and specificity were 85.4%, 64%, 85.4%, and 69.6% respectively. Classification agreement of QFR and FFR in terms of functional stenosis severity was 78.1%. Area under the receiver operating characteristics of QFR using FFR as reference was 0.82 [95% confidence interval [CI], 0.71-0.93], and significantly better than angiographic evaluation including %DS (area under the receiver-operating characteristic curve [AUC] 0.45 [95% CI, 0.32-0.58], p < 0.001) and minimum lumen diameter (AUC 0.60 [95% CI, 0.47-0.74], p < 0.001).
Compared with FFR, QFR has acceptable diagnostic performance in determining the functional relevance of LM stenosis, being better than conventional angiographic assessment. Nonetheless, caution should be taken when applying functional angiography techniques for the assessment of LM stenosis given its particular anatomical characteristics.
本研究旨在评估定量血流比（QFR）在左主干（LM）狭窄病变中的诊断准确性，以血流储备分数（FFR）为参考标准。
QFR 已被证实可准确评估非 LM 狭窄病变的功能相关性。然而，关于其在 LM 疾病特定解剖亚组中的诊断价值的数据尚十分有限。
这是一项回顾性、观察性、多中心、国际性、盲法研究，纳入了 LM 狭窄病变患者。排除了开口部 LM 病变严重的病例。以盲法方式根据 FFR 计算 QFR。
共分析了 67 例 LM 狭窄病变患者。从血管造影（直径狭窄率 [%DS] 43.8±11.1%）和功能角度（FFR 0.756±0.105）来看，LM 病变狭窄均处于中度严重程度。平均 QFR 为 0.733±0.159。QFR 与 FFR 之间存在中度相关性（r=0.590）。QFR 的阳性预测值、阴性预测值、敏感度和特异度分别为 85.4%、64%、85.4%和 69.6%。QFR 和 FFR 在功能狭窄严重程度方面的分类一致性为 78.1%。以 FFR 为参考时，QFR 的受试者工作特征曲线下面积为 0.82[95%置信区间（CI），0.71-0.93]，明显优于包括 %DS（受试者工作特征曲线下面积 0.45[95%CI，0.32-0.58]，p<0.001）和最小管腔直径（AUC 0.60[95%CI，0.47-0.74]，p<0.001）的血管造影评估。
与 FFR 相比，QFR 在确定 LM 狭窄病变的功能相关性方面具有可接受的诊断性能，优于传统血管造影评估。然而，鉴于 LM 解剖结构的特殊性，在评估 LM 狭窄时应谨慎应用功能血管造影技术。
