Orbital Atherectomy of Severely Calcified Arteries Studied in Patients With Left Ventricular Systolic Dysfunction

July 17, 2017—One-year outcomes from the ORBIT II study of orbital atherectomy treatment of severely calcified coronary lesions in patients with impaired left ventricular ejection fraction (LVEF) were published by Michael S. Lee, MD, et al online in EuroIntervention.

The ORBIT II study evaluated the safety and efficacy of the Diamondback 360 coronary orbital atherectomy system (Cardiovascular Systems, Inc.) in treating patients with de novo severely calcified coronary lesions.

The investigators noted that percutaneous coronary intervention (PCI) of severe coronary artery calcification (CAC) is challenging. The ORBIT II study demonstrated the safety and efficacy of orbital atherectomy in patients with severe CAC but showed that microparticulate liberated during orbital atherectomy may disturb the coronary microcirculation.

In the present study, this treatment was evaluated in patients with left ventricular systolic dysfunction.

As summarized in EuroIntervention, patients were grouped by LVEF: 26% to 40% (n = 33), 41% to 50% (n = 90), and > 50% (n = 314). Procedural success was similar in all groups (LVEF 26%–40%, 90.9%; LVEF 41%–50%, 88.9%; and LVEF > 50%, 88.4%). Rates of major adverse cardiac events (MACEs), defined as cardiac death, myocardial infarction, and target vessel revascularization, were also similar among all of the groups at 30 days (9.1%, 7.8%, and 11.5%, respectively) and 1 year (18.2%, 19.1%, and 16.0%, respectively). Although the 30-day cardiac death rate was 0% in patients with left ventricular dysfunction, 1-year cardiac death was higher compared with patients with preserved left ventricular systolic function.

The investigators concluded that no patient with left ventricular systolic dysfunction experienced cardiac death at 30 days, suggesting that orbital atherectomy was well tolerated without hemodynamic complications. However, 1-year cardiac death was higher in patients with left ventricular systolic dysfunction, consistent with previous studies demonstrating the association between reduced left ventricular function and increased mortality after PCI, advised the investigators in EuroIntervention.