Airoldi Flavio, Di Mario Carlo, Presbitero Patrizia, Maiello Luigi, Carcagnì Addolorata, Bortone Alessandro, Cremonesi Alberto, Castriota Fausto, Frasheri Arian, Rubino Antonio, Pernice Vincenzo, Rubartelli Paolo, Reimers Bernhard, Colombo Antonio
Interventional Cardiology Unit, San Raffaele Hospital, Milan.
Ital Heart J. 2002 Jul;3(7):406-11.
The role of stent implantation in small coronary arteries is still controversial. The MICROSCOPE study (Ministenting in small coronary arteries, a prospective evaluation) is a multicenter registry addressed to prospectively evaluate the immediate and mid-term clinical and angiographic results of elective stenting of lesions located in coronary arteries with an angiographic reference diameter < or = 2.75 mm.
A total of 146 patients (160 lesions) were included in the study. The percentage of complex lesions (B2 and C lesions) was 49.3%. The clinical indications for stent implantation were: stable angina (55.0%), unstable angina (24.6%), and clinical evidence of myocardial ischemia in asymptomatic patients (20.4%); 60% of patients had multivessel disease. Stent deployment could be performed in 96.2% of lesions. The baseline reference diameter was 2.12 +/- 0.36 mm. In all cases the Ministent (Cordis, a J&J Company, Miami, FL, USA), specifically designed for small coronary arteries, was employed. The stent was pre-mounted on low profile balloons available in three different diameters (2.25, 2.50 and 2.75 mm) and three different lengths (11, 15 e 26 mm).
The primary endpoint of successful stent-assisted angioplasty in all study vessels without major adverse cardiac events was achieved in 95.8% of the patients. The minimal lumen diameter increased from 0.64 +/- 0.24 to 2.02 +/- 0.43 mm and the dimensions of the stenosis (expressed as a percentage of the diameter of the coronary vessel) decreased from 68.6 +/- 10.8 to 16.2 +/- 10.7% (< 30% standard deviation in all cases). After the procedure all the patients received double antiplatelet therapy for 4 weeks. Post-procedural complications were limited to 2 patients (1.3%) who had a non-Q wave myocardial infarction at 6 months of follow-up; 13 patients (11%) required target lesion revascularization. No patient died following the procedure. Angiographic control was performed in 44% of lesions. The minimal lumen diameter decreased to 1.12 +/- 0.47 mm and the percent stenosis increased to 45.9 +/- 23.2%. The incidence of binary restenosis (stenosis > or = 50%) was 41%.
Elective stenting of small coronary arteries with the Ministent can be safely performed and is associated with a low incidence of acute or subacute stent thrombosis. The mid-term results indicate a high rate of angiographic restenosis but a low need of target vessel revascularization. These data suggest that stenting cannot be considered the treatment of choice for unselected lesions located in coronary arteries with a small reference diameter, but represents a safe solution if unsatisfactory results are obtained with balloon angioplasty alone.
冠状动脉支架植入术在小冠状动脉中的作用仍存在争议。MICROSCOPE研究（小冠状动脉最小支架植入术，一项前瞻性评估）是一项多中心注册研究，旨在前瞻性评估造影参考直径≤2.75mm的冠状动脉病变择期支架植入的即刻及中期临床和血管造影结果。
本研究共纳入146例患者（160处病变）。复杂病变（B2和C型病变）的比例为49.3%。支架植入的临床指征为：稳定型心绞痛（55.0%）、不稳定型心绞痛（24.6%）以及无症状患者的心肌缺血临床证据（20.4%）；60%的患者有多支血管病变。96.2%的病变可进行支架置入。基线参考直径为2.12±0.36mm。所有病例均采用专门为小冠状动脉设计的Ministent支架（美国佛罗里达州迈阿密市强生公司旗下的Cordis公司生产）。该支架预先安装在三种不同直径（2.25、2.50和2.75mm）和三种不同长度（11、15和26mm）的低轮廓球囊上。
所有研究血管中成功进行支架辅助血管成形术且无主要不良心脏事件的主要终点在95.8%的患者中实现。最小管腔直径从0.64±0.24mm增加到2.02±0.43mm，狭窄程度（以冠状动脉直径的百分比表示）从68.6±10.8%降至16.2±10.7%（所有病例标准差均<30%）。术后所有患者接受4周双联抗血小板治疗。术后并发症仅限于2例患者（1.3%）在随访6个月时发生非Q波心肌梗死；13例患者（11%）需要进行靶病变血管重建。术后无患者死亡。44%的病变进行了血管造影复查。最小管腔直径降至1.12±0.47mm，狭窄百分比增至45.9±23.2%。二元再狭窄（狭窄≥50%）的发生率为41%。
使用Ministent支架对小冠状动脉进行择期支架植入术可安全进行，且急性或亚急性支架血栓形成的发生率较低。中期结果表明血管造影再狭窄率较高，但靶血管重建的需求较低。这些数据表明，对于造影参考直径较小的冠状动脉中未经选择的病变，支架植入术不能被视为首选治疗方法，但如果单纯球囊血管成形术效果不理想，支架植入术是一种安全的解决方案。
