Orbital atherectomy for treating de novo, severely calcified coronary lesions: 3-year results of the pivotal ORBIT II trial.
OBJECTIVE
The presence of heavy coronary artery calcification increases the complexity of percutaneous coronary intervention (PCI) and increases the incidence of major adverse cardiac events (MACE): death, myocardial infarction (MI), target vessel revascularization (TVR), and stent thrombosis. The ORBIT II (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) trial reported low rates of procedural, 30-day, 1-year, and 2-year ischemic complications after treatment of de novo, severely calcified lesions with the Diamondback 360° Coronary Orbital Atherectomy System (OAS) (Cardiovascular Systems, Inc.).


METHODS
ORBIT II was a single-arm trial that enrolled 443 patients at 49U.S. sites; in this study, de novo, severely calcified coronary lesions were treated with OAS prior to stenting. The primary safety endpoint was 30-day MACE: the composite of cardiac death, MI, and TVR (inclusive of target lesion revascularization (TLR)). The primary efficacy endpoint was procedural success: stent delivery with a residual stenosis of <50% without the occurrence of in-hospital MACE.The present analysis reports the final, 3-year follow-up results from ORBIT II.


RESULTS
The majority of subjects (88.2%) underwent PCI with drug-eluting stents after orbital atherectomy. There were 360 (81.3%) subjects who completed the protocol-mandated 3-year visit.The overall cumulative rate of 3-year MACE was 23.5%, including cardiac death (6.7%), MI (11.2%), and TVR (10.2%). The 3-year target lesion revascularization rate was 7.8%.


CONCLUSIONS
In the final 3-year analysis of the ORBIT II trial, orbital atherectomy of severely calcified coronary lesions followed by stenting resulted in a low rate of adverse ischemic events compared with historical controls.Orbital atherectomy represents a safe and effective revascularization strategy for patients with severely calcified coronary lesions.


CONCLUSIONS
The ORBIT II trial enrolled 443 subjects to study orbital atherectomy followed by stenting for de novo severely calcified coronary lesions. The overall cumulative 3-year MACE rate was 23.5%, including cardiac death (6.7%), MI (11.2%), and TVR (10.2%); the 3-year target lesion revascularization rate was 7.8%. Orbital atherectomy of heavily calcified coronary lesions followed by stenting results in a low rate of adverse ischemic events compared with historical controls; it represents a reasonable revascularization strategy for patients with severely calcified coronary lesions.
UCLA Medical Center, Los Angeles, CA, United States. Electronic address: mslee@mednet.ucla.edu.
Michael
M
Lee
Columbia University Medical Center, New York City, NY, United States; Cardiovascular Research Foundation, New York City, NY, United States; Hôpital du Sacré-Coeur de Montréal, Université de Montréal, Montréal, Québec, Canada; Morristown Medical Center, NJ, United States.
Philippe
P
Généreux
St. Francis Hospital-The Heart Center, Roslyn, NY, United States.
Richard
R
Shlofmitz
UCLA Medical Center, Los Angeles, CA, United States.
Daniel
D
Phillipson
Cardiovascular Systems, Inc. (CSI), St. Paul, MN, United States.
Bynthia M
BM
Anose
Cardiovascular Systems, Inc. (CSI), St. Paul, MN, United States.
Brad J
BJ
Martinsen
The Stern Cardiovascular Center, Memphis, TN, United States.
Stevan I
SI
Himmelstein
Metropolitan Heart and Vascular Institute, Mercy Hospital, Minneapolis, MN, United States.
Jeff W
JW
Chambers
D000368:Aged; D017225:Atherectomy, Coronary / Q000009:adverse effects / Q000401:mortality; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D018579:Patient Selection; D062645:Percutaneous Coronary Intervention; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*
Atherectomy; Coronary calcification; Percutaneous coronary intervention