Optimal Atherectomy Restenosis Study - OARS


Optimal atherectomy for angiographic restenosis in CAD.


More aggressive "optimal" atherectomy could be performed safely to produce larger initial lumen diameters and a lower late restenosis rate.

Study Design

Study Design:

Patients Screened: 781
Patients Enrolled: 216
Mean Follow Up: 1 year
Mean Patient Age: 58
Female: 24
Mean Ejection Fraction: 54%

Patient Populations:

18 to 80 years old
Angina or a positive functional study due to obstructive native coronary artery disease
Target vessel reference diameter of &ge 3.0 mm and ≤ 4.5 mm
One or more culprit lesions (same vessel) of ≥ 60% and <100% diameter stenosis and ≤ 15 mm in length; )
Mild to moderate vessel tortuosity and no more than mild target lesion calcification


Aspirin allergy
Adjacent nontreated lesions in the target vessel of > 40%
MI with CK > 3 times normal within 5 days of treatment
History of bleeding diathesis
Transient ischemic neurological attacks within the past year;
Women of child-bearing potential

Primary Endpoints:

6-month angiographic restenosis rate (defined as percent diameter stenosis > 50%), 1-year target vessel failure rate (initial procedure failure, target vessel revascularization, Q-wave MI, or death).

Drug/Procedures Used:

Directional Atherectomy (DCA)

Principal Findings:

Optimal DCA was defined as using a 7F atherectomy device and adjunctive PTCA if necessary to achieve a < 15% residual stenosis. A total of 199 patients with 213 lesions met eligibility criteria for enrollment.

Short-term procedural success was achieved in 97.5%, with a major complication rate (death, emergency bypass surgery, or Q-wave myocardial infarction) of 2.5%. There were no early deaths.

Mean diameter stenosis was reduced from 63.5% to a final stenosis of 7%.

Late 1-year clinical follow-up revealed one cardiac death and a target lesion revascularization rate of 17.8%.

The angiographic restenosis rate at 6 months was 28.9%


The achievement of a 7% post-treatment residual diameter stenosis was lower than that seen in two previous randomized trials of DCA, CAVEAT (29%) and CCAT (32%).Compared with the results of the DCA arm in the previous major randomized study, CAVEAT, the present results were promising. However, the actual impact of DCA on late restenosis and repeat revascularization cannot be definitively determined by this registry. The general assumption that the technique can be widely applied is confounded by the results being drawn from four centers with a high level of DCA experience.


1. Circulation. 1998;97:332-339 Final results

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Atherosclerotic Disease (CAD/PAD), Aortic Surgery, Interventions and Coronary Artery Disease

Keywords: Coronary Artery Disease, Myocardial Infarction, Follow-Up Studies, Atherectomy, Coronary, Constriction, Pathologic, Angioplasty, Balloon, Coronary

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