Metropolitan Heart and Vascular Institute, Mercy Hospital, Minneapolis, Minnesota.
Central Florida Heart Center, Ocala, Florida.
JACC Cardiovasc Interv. 2014 May;7(5):510-8. doi: 10.1016/j.jcin.2014.01.158.
The ORBIT II (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) trial evaluated the safety and efficacy of the coronary Orbital Atherectomy System (OAS) to prepare de novo, severely calcified coronary lesions for stent placement.
Despite advances in interventional techniques, treatment of calcified coronary lesions remains a challenge. Stent placement in these lesions may result in stent underexpansion, malapposition, and procedural complications.
ORBIT II is a prospective, multicenter, nonblinded clinical trial that enrolled 443 consecutive patients with severely calcified coronary lesions at 49 U.S. sites from May 25, 2010, to November 26, 2012. Investigators used the centrifugal action of the OAS diamond-coated crown to modify calcified lesions prior to stent placement.
The pre-procedure mean minimal lumen diameter of 0.5 mm increased to 2.9 mm after the procedure. The primary safety endpoint was 89.6% freedom from 30-day major adverse cardiac events compared with the performance goal of 83%. The primary efficacy endpoint (residual stenosis <50% post-stent without in-hospital major adverse cardiac events) was 88.9% compared with the performance goal of 82%. Stent delivery occurred successfully in 97.7% of cases with <50% stenosis in 98.6% of subjects. Low rates of in-hospital Q-wave myocardial infarction (0.7%), cardiac death (0.2%), and target vessel revascularization (0.7%) were reported.
The ORBIT II coronary OAS trial met both the primary safety and efficacy endpoints by significant margins. Preparation of severely calcified plaque with the OAS not only helped facilitate stent delivery, but improved both acute and 30-day clinical outcomes compared with the outcomes of historic control subjects in this difficult-to-treat patient population. (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions [ORBIT II]; NCT01092416).
ORBIT II（评估 Orbital 冠状动脉旋磨系统治疗严重钙化冠状动脉病变的安全性和疗效）试验评估了冠状动脉 Orbital 冠状动脉旋磨系统（OAS）治疗新出现的严重钙化冠状动脉病变以准备支架置入的安全性和疗效。
尽管介入技术取得了进步，但钙化冠状动脉病变的治疗仍然是一个挑战。在这些病变中放置支架可能导致支架扩张不足、贴壁不良和程序并发症。
ORBIT II 是一项前瞻性、多中心、非盲临床研究，于 2010 年 5 月 25 日至 2012 年 11 月 26 日在美国 49 个地点连续纳入 443 例严重钙化冠状动脉病变患者。研究人员在支架置入前使用 OAS 金刚石冠的离心作用来修饰钙化病变。
术前平均最小管腔直径 0.5mm 在术后增加至 2.9mm。主要安全性终点为 30 天主要不良心脏事件发生率为 89.6%，优于 83%的目标值。主要疗效终点（支架置入后残余狭窄<50%，且无院内主要不良心脏事件）为 88.9%，优于 82%的目标值。97.7%的病例成功置入支架，狭窄<50%的比例为 98.6%。报告的院内 Q 波心肌梗死发生率（0.7%）、心脏死亡率（0.2%）和靶血管血运重建率（0.7%）较低。
ORBIT II 冠状动脉 OAS 试验以显著的优势达到了主要安全性和疗效终点。使用 OAS 对严重钙化斑块进行预处理不仅有助于支架输送，而且与该治疗难度较大的患者人群中的历史对照受试者的结果相比，还改善了急性和 30 天临床结局。（评估 Orbital 冠状动脉旋磨系统治疗严重钙化冠状动脉病变的安全性和疗效[ORBIT II]；NCT01092416）。
