Department of Radiology, Universitair Ziekenhuis Brussel, Brussels, Belgium.
Department of Cardiology, National Defense Medical College Hospital, Tokorozawa, Japan.
Echocardiography. 2023 Feb;40(2):103-112. doi: 10.1111/echo.15526. Epub 2023 Jan 6.
The ramus artery contributes to the development of turbulence, which may influence computed tomography (CT) derived fractional flow reserve (FFR ) even without coronary artery disease (CAD). The relationship between ramus-induced turbulence and FFR is unclear.
A total of 120 patients with <20% coronary stenosis assessed by both FFR and invasive coronary angiography were evaluated. The patients were divided into three groups: absent-ramus (n = 72), small-ramus that could not be analyzed by FFR (n = 18), and large-ramus that could be analyzed by FFR (n = 30). FFR measurements were performed at the proximal and distal segments of the left anterior descending (LAD), left circumflex (LCX), and ramus artery. With absent-ramus and small-absent ramus groups, FFR was measured at the distal end of the left main trunk at the same level for the proximal segments of the LAD and LCX. In absent-ramus group, proximal FFR showed no significant differences between three vessels (LAD = .96 ± .02; MID = .97 ± .02; LCX = .97 ± .02). However, in small and large-ramus groups, proximal FFR was significantly higher in the ramus artery than LAD and LCX (small-ramus, LAD = .95 ± .03, Ramus = .97 ± .02, LCX = .95 ± .03; large-ramus: LAD = .95 ± .03, Ramus = .98 ± .01; LCX = .96 ± .03; p < .05). A large ramus was associated with a higher prevalence of a distal FFR ≤.80 (odds ratio 7.0, 95% CI 1.2-40.1, p = .03). A proximal ramus diameter predicted distal FFR ≤.80 (cut-off 2.1 mm, AUC .76, sensitivity 100%, specificity 52%, 95% CI .61-.90).
The presence of a large-ramus artery may cause an FFR decline in no apparent CAD.
分出动脉导致的血流紊乱可能会影响到计算机断层扫描（CT）得到的血流储备分数（FFR），即使患者不存在冠状动脉疾病（CAD）。但分出动脉导致的血流紊乱和 FFR 之间的关系尚不明确。
共有 120 名接受了 FFR 和有创性冠状动脉造影检查且狭窄程度均<20%的患者参与研究。这些患者被分为三组：无分出动脉组（n=72）、小分出动脉组（FFR 无法分析分出动脉，n=18）和大分出动脉组（FFR 可分析分出动脉，n=30）。FFR 测量在左前降支（LAD）、左回旋支（LCX）和分出动脉的近端和远端进行。在无分出动脉组和小无分出动脉组中，LAD 和 LCX 的近端在左主干的远端进行测量。在无分出动脉组中，三支血管的近端 FFR 无显著差异（LAD=0.96±0.02；MID=0.97±0.02；LCX=0.97±0.02）。但是，在小和大分出动脉组中，分出动脉的近端 FFR 明显高于 LAD 和 LCX（小分出动脉：LAD=0.95±0.03，Ramus=0.97±0.02，LCX=0.95±0.03；大分出动脉：LAD=0.95±0.03，Ramus=0.98±0.01，LCX=0.96±0.03；p<0.05）。大分出动脉与远端 FFR≤0.80 的发生率较高相关（比值比 7.0，95%置信区间 1.2-40.1，p=0.03）。分出动脉的近端直径可预测远端 FFR≤0.80（截断值 2.1mm，AUC 0.76，敏感度 100%，特异性 52%，95%置信区间 0.61-0.90）。
即使不存在明显的 CAD，大分出动脉的存在也可能导致 FFR 下降。
