Long-term safety and performance of the orbital atherectomy system for treating calcified coronary artery lesions: 5-Year follow-up in the ORBIT I trial.

Background/purpose: The ORBIT I trial, a first-in-man study, was conducted to evaluate the safety and performance of the orbital atherectomy system (OAS) in treating de novo calcified coronary lesions.

Methods/materials: Fifty patients were enrolled between May and July 2008 based on several criteria, and were treated with the OAS followed by stent placement. The safety and performance of the OAS were evaluated by procedural success, device success, and overall major adverse cardiovascular event (MACE) rates, including cardiac death, myocardial infarction (MI) and need for target lesion revascularization (TLR). Our institution enrolled and treated 33 of the 50 patients and continued follow-up for 5 years.

Results: Average age was 54 years and 91% were males. Mean lesion length was 15.9 mm. Device success was 100%, and average number of orbital atherectomy devices (OAD) used per patient was 1.3. Stents were placed directly after OAS in 31/32 patients (96.9%). All stents (average stent per lesion 1.1) were successfully deployed with 0.3% residual stenosis. The overall cumulative MACE rate was 6.1% in-hospital, 9.1% at 30 days, 12.1% at 6 months, 15.2% at 2 years, 18.2% at 3 years and 21.2% at 5 years (4 total cardiac deaths). None of the patients had Q-wave MIs. Angiographic complications were observed in 5 patients. No flow/slow flow due to distal embolization was observed.

Conclusions: The ORBIT I trial suggests that OAS treatment continues to offer a safe and effective method to change compliance of calcified coronary lesions to facilitate optimal stent placement in these difficult-to-treat patients.