Pivotal trial to evaluate the safety and efficacy of the orbital atherectomy system in treating de novo, severely calcified coronary lesions (ORBIT II).
OBJECTIVE
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.


BACKGROUND
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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).
Metropolitan Heart and Vascular Institute, Mercy Hospital, Minneapolis, Minnesota. Electronic address: J.Chambers@mhvi.com.
Jeffrey W
JW
Chambers
Central Florida Heart Center, Ocala, Florida.
Robert L
RL
Feldman
The Stern Cardiovascular Center, Memphis, Tennessee.
Stevan I
SI
Himmelstein
Florida Heart Group, Orlando, Florida.
Rohit
R
Bhatheja
Palm Beach Cardiovascular Clinic, Jupiter, Florida.
Augusto E
AE
Villa
The Texas Heart Institute, Houston, Texas.
Neil E
NE
Strickman
St. Francis Hospital-The Heart Center, Roslyn, New York.
Richard A
RA
Shlofmitz
Metropolitan Heart and Vascular Institute, Mercy Hospital, Minneapolis, Minnesota.
Daniel D
DD
Dulas
Florida Hospital Memorial Medical Center, Daytona Beach, Florida.
Dinesh
D
Arab
Desert Cardiology Center, Rancho Mirage, California.
Puneet K
PK
Khanna
The Cardiac and Vascular Institute, Gainesville, Florida.
Arthur C
AC
Lee
Iowa Heart Center, Des Moines, Iowa.
Magdi G H
MG
Ghali
Comprehensive Cardiology Consultants, Langhorne, Pennsylvania.
Rakesh R
RR
Shah
Eastlake Cardiovascular Associates, St. Clair Shores, Michigan.
Thomas P
TP
Davis
Utah Cardiology, Layton, Utah.
Christopher Y
CY
Kim
Gessler Clinic, Winter Haven, Florida.
Zaheed
Z
Tai
Cardiology and Vascular Associates, Bloomfield Hills, Michigan.
Kirit C
KC
Patel
Lenox Hill Heart and Vascular Institute of New York, New York, New York.
Joseph A
JA
Puma
Cardiology Associates of Northwest Indiana, Munster, Indiana.
Prakash
P
Makam
Cardiology Associates of North Mississippi, Tupelo, Mississippi.
Barry D
BD
Bertolet
Premier Cardiovascular Center, Chandler, Arizona.
Georges Y
GY
Nseir
D000368:Aged; D017225:Atherectomy, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D023921:Coronary Stenosis / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000209:etiology / Q000401:mortality; D062645:Percutaneous Coronary Intervention / Q000295:instrumentation; D011446:Prospective Studies; D012720:Severity of Illness Index; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States; D061205:Vascular Calcification / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*
atherectomy; calcification; cardiovascular intervention; clinical trial; coronary