血管内超声指导急性冠脉综合征临界病变介入治疗临床研究

目的探讨血管内超声指导下急性冠脉综合征（ACS）临界病变介入治疗疗效,评价血管内超声（IVUS）在急性冠脉综合征临界病变介入治疗中的作用。方法ACS经冠状动脉造影显示狭窄程度在40%～70%的临界病变患者,根据IVUS测定的罪犯病变最小血管腔面积小于4mm2作为介入干预的标准,31例行介入干预的患者作为病例组。测量该组患者支架扩张前、扩张后和高压球囊再次扩张后的最小管腔直径、最小管腔面积、总截面积、斑块面积和面积狭窄率,观察扩张后支架是否贴壁。同期未行IVUS检查而行介入干预的临界病变患者31例作为对照组。所有入选患者于入选后的第1、3、6和12月给予临床随访,记录患者不良事件（再发心绞痛、心肌梗死、再次血运重建、死亡）情况。于第10～12月行CAG和IVUS检查,观察支架内膜增生情况及有否支架内血栓征象。以CAG或IVUS显示支架置入成功并随访期间无心血管事件（心肌梗死、靶病变再次冠脉成形术以及心衰或死亡）发生为手术成功。结果病例组31例患者的32处靶病变支架植入成功后行IVUS检查提示28处（87.5%）支架存在贴壁不完全。再次以更高的压力（18～20atm）或换用另一高压球囊扩张,最终均达到了IVUS支架植入理想标准。术中未见与冠脉介入和IVUS相关的并发症。术后10～12个月病例组22例患者行CAG和IVUS复查,CAG结果无一例患者出现支架内再狭窄。IVUS结果未发现局部支架内血栓征象,支架内均有不同程度的内膜增生,增生内膜负荷量无统计学差异。最小支架内管腔面积与第一次植入支架相比差异亦无统计学意义[（10.12±1.15）mm2vs（8.98±2.12）mm2,P〉0.05]。对照组31例支架植入后CAG提示贴壁良好。术后3～6月3例患者临床出现心绞痛,CAG结果提示3例患者出现再狭窄,IVUS检测结果这3例患者均存在支架贴壁不良。结论IVUS比CAG能更有效地指导ACS临界病变支架的植入和实时评价手术效果;在IVUS指导下的高压力（18～20atm）球囊后扩张可使87.5%贴壁不良的病变进一步得到改善。IVUS指导的ACS临界病变支架植入获得较高的即时成功率和远期成功率。

Intravascular ultrasound-guided interventional therapy for borderline lesions in patients with acute coronary syndrome

Objective To assess the efficacy and safety of intravascular ultrasound (IVUS)-guided interventional therapy for borderline lesions in patients with acute coronary syndrome (ASC). Methods Thirty-one ASC patients with borderline lesions (coronary artery stenosis between 40%-70% confirmed by coronary arteriography [CAG]) and a minimal lumen area (MLA) of the infarction related artery(IRA) ≤4.0 mm~2 shown by IVUS underwent percutaneous coronary intervention (PCD. Another 31 PCI cases without IVUS were also enrolled as the control group. The minimal luminal diameter, cross section luminal area, total cross section, plaque area and area stenosis rate were measured before and after stent deployment at a conventional or higher pressure in the IVUS group. All the patients were followed up for 10-12 months and clinically evaluated 1, 3, 6 month and 12 months after the procedure to collect the data of angina recurrence, myocardial infarction and revascularization. Results All the 31 cases were successfully stented with satisfied CAG results (with residual stenosis <0, TIMI flow grade Ⅲ) and without dissection or any related complications. Among the 32 stents, 28 showed insufficient adherence or underexpansion (stem malapposition) to require 18-20 atm dilation or another high pressure balloon to attain the adequate IVUS results. CAG and IVUS were repeated in 22 patients (70.97%) of the IVUS group during the 10 to 12 months of follow up. No stent restenosis occurred with the in-stent diameter late loss >50%, nor was in-stent thrombns found by IVUS. Endomembrane proliferation was found but without any significant difference. Minimal stent lumen area were not significantly different from the immediate results after PCI (10.12±1.15 mm~2 vs 8.98±2.12 mm~2, P>0.05). The 31 patients in the control group were successfully stented with satisactory CAG results, but 3 suffered angina at 3-6 months who showed stent restenosis and insufficient stent adherence. Conclusions IVUS can more effectively guide the interventional therapy for ACS borderline lesions and assess the immediate efficacy of therapy than CAG. Post-dilation with higher pressure (16-20 atm) guided by IVUS can further improve the procedural results. IVUS-guided PCI for ACS borderline lesions ensures high immediate and long-term success rate.