Weatherhead PET Center, Division of Cardiology, Department of Medicine, McGovern Medical School at UTHealth and Memorial Hermann Hospital, Houston, Texas.
Division of Cardiovascular Medicine, Stony Brook University Medical Center, Stony Brook, New York; Cardiovascular Research Foundation (CRF), New York, New York.
JACC Cardiovasc Interv. 2016 Apr 25;9(8):757-767. doi: 10.1016/j.jcin.2015.12.273.
This study compared the diagnostic performance with adenosine-derived fractional flow reserve (FFR) ≤0.8 of contrast-based FFR (cFFR), resting distal pressure (Pd)/aortic pressure (Pa), and the instantaneous wave-free ratio (iFR).
FFR objectively identifies lesions that benefit from medical therapy versus revascularization. However, FFR requires maximal vasodilation, usually achieved with adenosine. Radiographic contrast injection causes submaximal coronary hyperemia. Therefore, intracoronary contrast could provide an easy and inexpensive tool for predicting FFR.
We recruited patients undergoing routine FFR assessment and made paired, repeated measurements of all physiology metrics (Pd/Pa, iFR, cFFR, and FFR). Contrast medium and dose were per local practice, as was the dose of intracoronary adenosine. Operators were encouraged to perform both intracoronary and intravenous adenosine assessments and a final drift check to assess wire calibration. A central core lab analyzed blinded pressure tracings in a standardized fashion.
A total of 763 subjects were enrolled from 12 international centers. Contrast volume was 8 ± 2 ml per measurement, and 8 different contrast media were used. Repeated measurements of each metric showed a bias <0.005, but a lower SD (less variability) for cFFR than resting indexes. Although Pd/Pa and iFR demonstrated equivalent performance against FFR ≤0.8 (78.5% vs. 79.9% accuracy; p = 0.78; area under the receiver-operating characteristic curve: 0.875 vs. 0.881; p = 0.35), cFFR improved both metrics (85.8% accuracy and 0.930 area; p < 0.001 for each) with an optimal binary threshold of 0.83. A hybrid decision-making strategy using cFFR required adenosine less often than when based on either Pd/Pa or iFR.
cFFR provides diagnostic performance superior to that of Pd/Pa or iFR for predicting FFR. For clinical scenarios or health care systems in which adenosine is contraindicated or prohibitively expensive, cFFR offers a universal technique to simplify invasive coronary physiological assessments. Yet FFR remains the reference standard for diagnostic certainty as even cFFR reached only ∼85% agreement.
本研究比较了基于腺苷的血流储备分数（FFR）≤0.8 的对比 FFR（cFFR）、静息远端压力（Pd）/主动脉压力（Pa）和瞬时无波比（iFR）的诊断性能。
FFR 客观地确定了从药物治疗中获益的病变与血运重建。然而，FFR 需要最大程度的血管扩张，通常通过腺苷来实现。造影剂注射会导致冠状动脉次最大程度的充血。因此，冠状动脉内造影剂可能提供一种简单且廉价的预测 FFR 的工具。
我们招募了接受常规 FFR 评估的患者，并对所有生理学指标（Pd/Pa、iFR、cFFR 和 FFR）进行了配对、重复测量。造影剂的剂量和给药方法均遵循当地的惯例，冠状动脉内腺苷的剂量也是如此。操作者被鼓励同时进行冠状动脉内和静脉内腺苷评估，并进行最终漂移检查以评估导丝校准。一个核心实验室以标准化的方式分析了盲压迹。
共从 12 个国际中心招募了 763 名患者。每次测量的造影剂体积为 8±2ml，使用了 8 种不同的造影剂。每个指标的重复测量显示出 <0.005 的偏差，但 cFFR 的标准差（变异性较小）低于静息指数。虽然 Pd/Pa 和 iFR 与 FFR≤0.8 的准确性相当（78.5%与 79.9%；p=0.78；接受者操作特征曲线下面积：0.875 与 0.881；p=0.35），但 cFFR 提高了这两个指标的准确性（85.8%和 0.930 面积；p<0.001），最佳二值阈值为 0.83。使用 cFFR 的混合决策策略比基于 Pd/Pa 或 iFR 的策略使用腺苷的频率更低。
cFFR 提供的诊断性能优于 Pd/Pa 或 iFR，可用于预测 FFR。对于腺苷禁忌或过于昂贵的临床情况或医疗保健系统，cFFR 提供了一种简化有创冠状动脉生理评估的通用技术。然而，即使 cFFR 仅达到约 85%的一致性，FFR 仍然是诊断确定性的参考标准。
