Di Molfetta A, Cusimano V, Cesario M, Mollo P, Di Ruzza G, Menichelli M
Catheterization Laboratory - Ospedale Fabrizio Spaziani, Italy.
IASI-Italian National Research Council, Italy.
Cardiovasc Revasc Med. 2025 Mar;72:44-51. doi: 10.1016/j.carrev.2024.09.004. Epub 2024 Sep 19.
Literature reports a 20 % discordance between hyperemic (FFR) and non-hyperemic indexes (NHi) of coronary stenosis lesions. This work aims to develop and test clinically, a formula relating FFR and NHi (including iFR, RFR and Pd/Pa) to study their discordance.
We conducted a prospective, single-center, clinical study enrolling all patients undergoing full coronary physiology assessment with Coroventis CoroFlow Cardiovascular System (Abbott Vascular, St. Paul, Minnesota) to validate the developed formula: [Formula: see text] where IMR(BMR) is the hyperemic (basal) microvascular resistance and HSR(BSR) is the hyperemic (basal) stenosis resistance.
A total of 51 patients were enrolled, 72 % male, average age 67.4 ± 8.9. Mean hemodynamic data were: FFR 0.87 ± 0.07, iFR 0.93 ± 0.05, RFR 0.91 ± 0.05, Pd/Pa 0.92 ± 0.05, BMR 76.6 ± 51.6 mmHgs, IMR 28.4 ± 22.8 mmHgs, BSR 5.5 ± 4.7 mmHg, HSR 3.8 ± 2.9 mmHg*s, coronary flow reserve (CFR) 2.9 ± 1.6, resistive reserve ratio (RRR) 3.3 ± 2.0. Lin's Concordance and Bland Altman analysis showed an optimal correlation between measured and estimated data. Sensitivity analysis showed that: (1) FFR can underestimate epicardial stenosis severity leading to FFR- vs NHi + discordance in case of elevated IMR, (2) NHi can overestimate epicardial stenosis severity leading to FFR- vs NHi + in the case of low BMR, (3) if BSR > HSR, FFR- vs NHi + discordance can occur, while if BSR < HSR, FFR+ vs NHi- discordance can occur.
(1) NHi can be more reliable in case of elevated IMR; (2) FFR-CFR combination can be more reliable for low BMR occurring to compensate an epicardial stenosis; (3) NHi-CFR combination can be more reliable when BSR > HSR, while FFR-CFR combination can be more reliable when BSR < HSR. The combination between pressure and flow indexes (FFR-CFR or NHi-CFR) is more reliable when compensatory mechanisms occur.
文献报道冠状动脉狭窄病变的充血（FFR）和非充血指标（NHi，包括iFR、RFR和Pd/Pa）之间存在20%的不一致性。本研究旨在开发并在临床上测试一个将FFR与NHi相关联的公式，以研究它们之间的不一致性。
我们进行了一项前瞻性、单中心临床研究，纳入所有使用Coroventis CoroFlow心血管系统（雅培血管，明尼苏达州圣保罗）进行全面冠状动脉生理学评估的患者，以验证所开发的公式：[公式：见正文]，其中IMR（BMR）是充血（基础）微血管阻力，HSR（BSR）是充血（基础）狭窄阻力。
共纳入51例患者，男性占72%，平均年龄67.4±8.9岁。平均血流动力学数据为：FFR 0.87±0.07，iFR 0.93±0.05，RFR 0.91±0.05，Pd/Pa 0.92±0.05，BMR 76.6±51.6 mmHgs，IMR 28.4±22.8 mmHgs，BSR 5.5±4.7 mmHg，HSR 3.8±2.9 mmHg*s，冠状动脉血流储备（CFR）2.9±1.6，阻力储备比（RRR）3.3±2.0。林氏一致性分析和布兰德 - 奥特曼分析显示测量数据与估计数据之间具有最佳相关性。敏感性分析表明：（1）在IMR升高的情况下，FFR可能低估心外膜狭窄严重程度，导致FFR-与NHi+不一致；（2）在BMR较低的情况下，NHi可能高估心外膜狭窄严重程度，导致FFR-与NHi+不一致；（3）如果BSR>HSR，可能出现FFR-与NHi+不一致，而如果BSR<HSR，则可能出现FFR+与NHi-不一致。
（1）在IMR升高的情况下，NHi可能更可靠；（2）对于因补偿心外膜狭窄而出现的低BMR，FFR-CFR组合可能更可靠；（3）当BSR>HSR时，NHi-CFR组合可能更可靠，而当BSR<HSR时，FFR-CFR组合可能更可靠。当出现代偿机制时，压力和流量指标（FFR-CFR或NHi-CFR）的组合更可靠。
