Coronary Flow Reserve Following Orbital Atherectomy

Coronary artery disease (CAD) affects over 16 million subjects in the United States, making
it the most common form of heart disease. The American Heart Association 2010 Update on
Heart Disease and Stroke Statistics reported that in 2006 an estimated 1,313,000 inpatient
percutaneous coronary intervention (PCI) procedures were performed in the United Sates.
Despite advances in interventional equipment and techniques, there are still patient
populations who remain challenging to treat. One of those patient subsets consists of
individuals with lesions that have calcium deposits. Up to 50% of stents deployed in
calcified lesions were found to have asymmetric stent expansion. Research has also shown
that an increased amount of calcium deposits leads to a higher incidence of major adverse
cardiac events (MACE) when compared to non-calcified lesions.In addition, lesion
calcification has been shown to be associated with vessel dissection during PCI, failure to
deliver a stent, balloon ruptures, and un-dilatable lesions. Unlike PTCA and stenting
procedures where the calcified lesion is cracked and the stenotic lesion materials are
crushed into the arterial walls, atherectomy procedures remove the stenotic lesion
materials, especially the calcified portion of the lesion. Removing, as opposed to
displacing, stenotic material may potentially lead to reduced acute vascular traumas, lessen
the stimulus for neointimal hyperplasia that is commonly associated with in- stent
restenosis, and facilitate stent delivery and expansion. Adequate plaque preparation or
modification may improve both acute and long term outcomes in subjects with complex lesions,
especially heavily calcified lesions.

Measurement of coronary flow reserve (CFR) using the Volcano FloWire can assess
physiological changes in the distal vascular bed. The primary endpoint of this study will
evaluate coronary flow reserve after successful treatment of severely calcified coronary
lesions using OAS and stent deployment. The secondary endpoint will measure the occurrence
of post-procedural Major Adverse Cardiac Events (MACE), including Cardiac death, acute
myocardial infarction (Q wave or non-Q wave), or target vessel revascularization.

Inclusion Criteria:

Subjects will be enrolled and treated in the study if ALL of the following conditions are
met:

1. Subjects must be at least 18 years of age.

2. Subjects must be scheduled for percutaneous coronary intervention involving stent
deployment in de novo coronary lesions.

3. The target vessel must be a de-novo coronary artery with a severely calcified lesion.

4. The target vessel reference diameter must be ≥ 2.0mm and ≤ 4.0 mm.

5. The lesion length must not exceed 40 mm.

6. The target vessel must have a TIMI flow 3 at baseline.

7. The lesion must be crossable with the ViperWire Advance® coronary guide wire.

8. Successful revascularization using OAS and stent deployment as demonstrated by no
evidence of stent dissection and no more than 50% stenosis proximal to the stent.

Exclusion Criteria:

General Exclusion Criteria - subjects will not be eligible to participate in the study if
any of the following conditions are present in the subject:

1. Inability to understand the study or a history of non-compliance with medical advice.

2. Unwilling or unable to sign the ICF.

3. History of any cognitive or mental health status that would interfere with study
participation.

4. Currently enrolled in any pre-approval investigational study. Note: This does not
apply to long-term post-market studies unless these studies might clinically
interfere with the current study endpoints.

5. Female subjects who are pregnant or planning to become pregnant within the study
period.

6. Previous myocardial infarction of the target vessel.

7. Known sensitivity to contrast media, which cannot be adequately pre-medicated.

8. Diagnosed with chronic renal failure or has a serum creatinine level > 2.5 mg/dl.

9. History of a stroke or transient ischemic attack (TIA) within six (6) months of the
procedure.

10. Active peptic ulcer or upper gastrointestinal (GI) bleeding within six (6) months of
the procedure.

11. Wall motion abnormality in the intended vessel target zone.

12. Severe chronic obstructive pulmonary disease (COPD), asthma or current use of the
medication: aminophylline.

13. 2nd or 3rd degree atrioventricular (AV) block.

14. Evidence of current left ventricular ejection fraction (LVEF) ≤45% (where current is
defined as the latest LVEF measurement completed within the last 6 months).

15. NYHA class III or IV heart failure.

16. Previous coronary artery bypass surgery.

17. Known allergy to atherectomy lubricant components such as soybean oil, egg yolk
phospholipids, glycerin and sodium hydroxide.

18. Severe aortic stenosis.

19. Severe left ventricular hypertrophy.

Angiographic Exclusion Criteria - subjects will not be enrolled in the study if any of the
following conditions are present in the subject:

1. Subject with angiographically confirmed evidence of more than 1 lesion requiring
intervention.

2. Target vessel has other lesions with greater than 50% diameter stenosis based on
visual estimate or on-line QCA.

3. Target vessel has angiographically visible or suspected thrombus.

4. Target vessel has a stent from previous PCI unless:

1. The stent was implanted greater than 30 days prior to the treatment, and

2. The stent has no higher than 30% in-stent stenosis, and

3. The stent is on a different branch than the target lesion.

5. Target vessel is excessively tortuous.

6. Target lesion is an ostial location (within 5 mm of ostium) or an unprotected left
main lesion.

7. Target lesion is a bifurcation.

8. Target lesion has a ≥ 1.5 mm side branch.

9. Angiographic evidence of a dissection prior to initiation of OAD.

10. Angiographic evidence of MACE during procedure.