Demir Ozan M, Sinha Aish, Rahman Haseeb, Ryan Matthew, O'Gallagher Kevin, Ellis Howard, Li Kam Wa Matthew, Saraf Smriti, Alfakih Khaled, Webb Ian, Melikian Narbeh, De Silva Kalpa, Chiribiri Amedeo, Plein Sven, Perera Divaka
British Heart Foundation Center of Excellence and National Institute for Health Research Biomedical Research Center at the School of Cardiovascular Medicine and Sciences, King's College London, United Kingdom (O.M.D., A.S., H.R., M.R., K.O.G., H.E., M.L.K.W., K.A., I.W., N.M., K.D.S., A.C., S.P., D.P.).
Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom (O.M.D., A.S., H.R., H.E., M.L.K.W., K.D.S., A.C., D.P.).
Circ Cardiovasc Interv. 2025 Jul;18(7):e015320. doi: 10.1161/CIRCINTERVENTIONS.125.015320. Epub 2025 May 12.
Pressure-based physiological evaluation of coronary artery disease is well established, but its application is limited in left main coronary artery (LMCA) disease. Our aim was to investigate whether pressure-based indices are comparable in the left anterior descending (LAD) and left circumflex artery (LCx) branches of the LMCA, and if discordance is due to differences in microvascular function in these territories.
Simultaneous measurements of coronary pressure and flow were made in patients with (1) isolated LMCA disease and (2) unobstructed coronary arteries. Fractional flow reserve, instantaneous wave-free ratio, and microvascular resistance reserve values in the LAD were compared with those of the LCx.
A total of 80 patients were enrolled (mean age 65±10 years, 56% male). In those with isolated LMCA disease, fractional flow reserve in the LAD was lower than in the LCx (0.74±0.11 versus 0.81±0.11; <0.0001). Instantaneous wave-free ratio was also lower in the LAD (0.89 [0.76-0.92] versus 0.94 [0.88-0.97]; <0.0001). The misclassification rates of functionally significant coronary disease, when these indices were measured in the LCx, were 21% for fractional flow reserve and 28% for instantaneous wave-free ratio. Microvascular resistance reserve was higher in the LAD than the LCx, in cohorts with diseased (3.57±1.40 versus 2.50±0.81; <0.0001) or unobstructed LMCA (3.40±0.78 versus 2.47±0.68; <0.0001). Microvascular resistance reserve in the LAD territory was similar regardless of whether the LMCA was obstructed or not (=0.56). Similarly, microvascular resistance reserve in the LCx territory was comparable between cohorts (=0.88).
Microvascular resistance in the LAD is lower than in the LCx territory. Consequently, fractional flow reserve and nonhyperemic pressure-derived indices are lower in the LAD than the LCx. These findings have important implications for how LMCA atheroma should be assessed in clinical practice and also suggest the need for territory-specific thresholds for defining abnormal microvascular function and epicardial conductance.
基于压力的冠状动脉疾病生理评估已得到充分确立，但其在左主干冠状动脉（LMCA）疾病中的应用有限。我们的目的是研究基于压力的指标在LMCA的左前降支（LAD）和左旋支（LCx）分支中是否具有可比性，以及不一致是否是由于这些区域微血管功能的差异所致。
对患有（1）孤立性LMCA疾病和（2）冠状动脉通畅的患者同时进行冠状动脉压力和血流测量。比较LAD和LCx的血流储备分数、瞬时无波比值和微血管阻力储备值。
共纳入80例患者（平均年龄65±10岁，男性占56%）。在患有孤立性LMCA疾病的患者中，LAD的血流储备分数低于LCx（0.74±0.11对0.81±0.11；<0.0001）。LAD的瞬时无波比值也较低（0.89[0.76 - 0.92]对0.94[0.88 - 0.97]；<0.0001）。当在LCx中测量这些指标时，功能上显著的冠状动脉疾病的误诊率，血流储备分数为21%，瞬时无波比值为28%。在患有LMCA疾病（3.57±1.40对2.50±0.81；<0.0001）或LMCA通畅（3.40±0.78对2.47±0.68；<0.0001）的队列中，LAD的微血管阻力储备高于LCx。无论LMCA是否阻塞，LAD区域的微血管阻力储备相似（=0.56）。同样，LCx区域的微血管阻力储备在各队列之间具有可比性（=0.88）。
LAD的微血管阻力低于LCx区域。因此，LAD的血流储备分数和非充血压力衍生指标低于LCx。这些发现对临床实践中如何评估LMCA粥样硬化具有重要意义，也表明需要针对特定区域设定定义异常微血管功能和心外膜传导的阈值。
