Department of Cardiology, Thoraxcenter, Erasmus Medical Center, Rotterdam, the Netherlands.
Circ Cardiovasc Interv. 2018 Dec;11(12):e006911. doi: 10.1161/CIRCINTERVENTIONS.118.006911.
Instantaneous wave-free ratio (iFR) offers a reliable non-hyperemic assessment of coronary physiology but requires dedicated proprietary software with a fully automated algorithm. We hypothesized that dPR (diastolic pressure ratio), calculated with novel universal software, has a strong correlation with iFR, similar diagnostic accuracy relative to resting distal coronary artery pressure/aortic pressure and fractional flow reserve (FFR).
The dPR study is an observational, retrospective, single-center cohort study including patients who underwent iFR or FFR. Dedicated software was used to calculate the dPR from Digital Imaging and Communications in Medicine (DICOM) pressure waveforms. The flat period on the pressure difference between sample (dP) to the time difference between the same sample points (dt) signal was used to detect automatically the period, where the resistance is low and constant, and to calculate the dPR, which is an average over 5 consecutive heartbeats. The software was validated by correlating iFR results with dPR. Software validation was done by comparing 78 iFR measurements in 44 patients who underwent iFR. Mean iFR and dPR were 0.91±0.10 and 0.92±0.10, respectively, with a significant linear correlation ( R=0.997; P<0.001). Diagnostic accuracy was tested in 100 patients who underwent FFR. Mean FFR, resting distal coronary artery pressure/aortic pressure, and dPR were 0.85±0.09, 0.94±0.05, and 0.93±0.07, respectively. There was a significant linear correlation between dPR and FFR ( R=0.77; P<0.001). Both distal coronary artery pressure/aortic pressure and dPR had good diagnostic accuracy in the identification of lesions with an FFR ≤0.80 (area under the curve, 0.84; 95% CI, 0.76-0.92 and 0.86; 95% CI, 0.78-0.93, respectively).
dPR, calculated by a novel validated software tool, showed a strong linear correlation with iFR. dPR correlated well with FFR with a good diagnostic accuracy to identify positive FFR.
瞬时无波比（iFR）可提供可靠的非充血性冠状动脉生理学评估，但需要专用的专有软件和完全自动化的算法。我们假设，用新型通用软件计算的舒张压力比（dPR）与 iFR 具有很强的相关性，相对于静息远端冠状动脉压力/主动脉压力和血流储备分数（FFR）具有相似的诊断准确性。
dPR 研究是一项观察性、回顾性、单中心队列研究，包括接受 iFR 或 FFR 检查的患者。专用软件用于从数字成像和通信（DICOM）压力波形中计算 dPR。在样本（dP）与同一样本点（dt）信号之间的压力差的平期间期，用于自动检测阻力低且恒定的时期，并计算 dPR，它是 5 个连续心跳的平均值。通过将 iFR 结果与 dPR 进行相关来验证软件。通过比较 44 名接受 iFR 检查的患者的 78 次 iFR 测量值来验证软件。平均 iFR 和 dPR 分别为 0.91±0.10 和 0.92±0.10，具有显著的线性相关性（R=0.997；P<0.001）。在 100 名接受 FFR 检查的患者中测试了诊断准确性。平均 FFR、静息远端冠状动脉压力/主动脉压力和 dPR 分别为 0.85±0.09、0.94±0.05 和 0.93±0.07。dPR 与 FFR 之间存在显著的线性相关性（R=0.77；P<0.001）。在识别 FFR≤0.80 的病变时，远端冠状动脉压力/主动脉压力和 dPR 的诊断准确性均较好（曲线下面积分别为 0.84、0.76-0.92 和 0.86、0.78-0.93）。
通过新型验证软件工具计算的 dPR 与 iFR 具有很强的线性相关性。dPR 与 FFR 相关性良好，具有较高的诊断准确性，可识别阳性 FFR。
