Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Am J Cardiol. 2011 Jun 15;107(12):1787-93. doi: 10.1016/j.amjcard.2011.02.323. Epub 2011 Apr 18.
A single stent crossover technique is the most common approach to treating bifurcation lesions. In 90 bifurcation lesions with side branch (SB) angiographic diameter stenosis <75%, we assessed preintervention intravascular ultrasound (IVUS; of main branch [MB] and SB) predictors for SB compromise (fractional flow reserve [FFR] <0.80) after a single stent crossover. Minimal lumen area (MLA) was measured within each of 4 segments (MB just distal to the carina, polygon of confluence, MB just proximal to polygon of confluence, and SB ostium). All lesions showed Thrombolysis In Myocardial Infarction grade 3 flow in the SB after MB stenting. Although angiographic diameter stenosis at the SB ostium increased from 26 ± 15% before the procedure to 36 ± 21% after stenting (p = 0.001), FFR <0.80 was observed in only 16 patients (18%). Negative remodeling (remodeling index <1) was seen in 83 (92%) lesions but did not correlate with FFR after stenting. Independent predictors for FFR after stenting were maximal balloon pressure (p = 0.002) and MLA of SB ostium before percutaneous coronary intervention (p <0.001), MLA within the MB just distal to the carina (p = 0.025), and plaque burden at the SB ostium before percutaneous coronary intervention (p = 0.005), but not angiographic poststenting diameter stenosis or minimal lumen diameter. For prediction of FFR <0.80 after percutaneous coronary intervention, the best cutoff of MLA within the SB ostium before percutaneous coronary intervention was 2.4 mm(2) (sensitivity 94%, specificity 69%). Also, the cutoff of plaque burden within the SB ostium before percutaneous coronary intervention was ≥51% (sensitivity 75%, specificity 71%). In 67 lesions with an MLA ≥2.4 mm(2) or plaque burden <50% before percutaneous coronary intervention, 63 (94%) showed FFR ≥0.80. However, FFR <0.80 was seen in only 12 (52%) of 23 lesions with an MLA <2.4 mm(2) and plaque burden ≥50%. In conclusion, there do not appear to be reliable IVUS predictors of functional SB compromise after crossover stenting.
单支架对吻技术是治疗分叉病变最常用的方法。在 90 例分叉病变患者中，侧支（SB）的血管造影狭窄率<75%，我们评估了单支架对吻技术后 SB 狭窄（血流储备分数[FFR] <0.80）的术前血管内超声（IVUS；主支[MB]和 SB）预测因子。在 MB 支架置入术前后，对 4 个节段（MB 在嵴部远端、汇合处多边形、MB 在汇合处近端和 SB 开口）内的每个节段进行最小管腔面积（MLA）测量。所有病变在 MB 支架置入后 SB 内均显示心肌梗死溶栓治疗（TIMI）血流 3 级。尽管 SB 开口处的血管造影狭窄程度从术前的 26±15%增加到支架置入后的 36±21%（p=0.001），但仅 16 例（18%）患者出现 FFR <0.80。83 例（92%）病变出现负性重构（重构指数<1），但与支架置入后的 FFR 无关。支架置入后 FFR 的独立预测因子是最大球囊压力（p=0.002）和 SB 开口处的 SB 置入前 MLA（p<0.001）、MB 在嵴部远端的 MLA（p=0.025）和 SB 开口处的斑块负荷（p=0.005），但与支架置入后的血管造影狭窄程度或最小管腔直径无关。对于预测 SB 介入治疗后 FFR <0.80，SB 开口处 SB 介入治疗前 MLA 的最佳截断值为 2.4mm²（敏感性 94%，特异性 69%）。此外，SB 开口处 SB 介入治疗前斑块负荷的截断值≥51%（敏感性 75%，特异性 71%）。在 67 例 SB 介入治疗前 MLA≥2.4mm²或斑块负荷<50%的病变中，63 例（94%）FFR≥0.80。然而，在 23 例 MLA<2.4mm²和斑块负荷≥50%的病变中，仅 12 例（52%）出现 FFR<0.80。总之，在交叉支架置入后，似乎没有可靠的 IVUS 预测功能性 SB 狭窄的指标。
