San Diego, California — After two years, patients treated with orbital atherectomy, a device that sands away severly calcified plaque in the coronary arteries prior to stenting, continued to show positive results, according to new data from the ORBIT II trial presented today as a late-breaking clinical trial at the Society for Cardiovascular Angiography and Interventions (SCAI) 2015 Scientific Sessions.

ORBIT II is the first atherectomy study to exclusively investigate severely calcified lesions. It included patients who are usually excluded from large clinical trials, such as patients on hemodialysis or with low left ventricular ejection fraction (<25 percent). In patients treated with percutaneous coronary intervention (PCI), calcified lesions may prevent the stent from fully expanding in the artery and patients may need a repeat coronary intervention or coronary artery bypass graft surgery (CABG).

For the clinical trial, investigators enrolled 443 patients at 49 U.S. sites. The Diamondback 360 Orbital Atherectomy System (OAS) catheter was used to treat severely calcified lesions prior to stent placement. The device’s eccentric crown creates an elliptical orbit in the artery to sand the calcified portion of the plaque into minuscule particles. The device received FDA approval in October 2013 and demonstrated favorable safety outcomes in hospital, at 30 days and at one year.

The new data followed patients to two years after their procedure. Results showed 19.4 percent of patients experienced a major adverse cardiac event (MACE), including cardiac death (4.3 percent) and the need for a repeat procedure to open the target vessel (8.1 percent).

"ORBIT II includes some of the most high-risk PCI patients," said Jeffrey Chambers, MD, FSCAI, director of the Cardiac Catheterization Laboratory, Mercy Hospital, Minneapolis, and the study’s principal investigator. "We found that preparing the artery prior to stent placement with orbital atherectomy is associated with low complication rates and may allow many of these patients to avoid more invasive surgery."

Further, the study found similar rates of MACE in both diabetic and non-diabetic patients, even though diabetics typically have higher rates of MACE than non-diabetics post-PCI.

A cost analysis presented by study investigators found OAS is a cost-effective treatment at one year. Total cost savings were projected to be up to $4,913. When the cost of the orbital atherectomy device ($3,795) was taken into account, there was still a potential cost savings of up to 1,118 dollars.

Dr. Chambers receives consulting fees/honoraria from Cardiovascular Systems, Inc.

Dr. Chambers presented "Orbital Atherectomy Treatment of Severely Calcified Coronary Lesions: Two Year Results of the ORBIT II Trial and Long-Term Economic Analysis," on Thursday, May 7, at 11:30 a.m. (Pacific Time).