Indications and Technology for Renal Intervention James P. Zidar, M.D., F.A.C.C., F.S.C.A.I Clinical Professor of Medicine UNC Health Systems Corporate Chief of Cardiology, Rex Healthcare President, Rex Heart and Vascular Specialists Raleigh, North Carolina

James P. Zidar, MD Honoraria: Medtronic Core Valve

Clinical Clues to Suggest Renal Artery Stenosis Unexplained or accelerated azotemia Azotemia after starting ACE inhibitor Atrophic kidney or asymmetrical size Presence of atherosclerosis elsewhere PAD coupled with HTN and/or renal insufficiency and/or pulm edema

RAS: Access and Arteriography Femoral artery – 6 Fr short sheath IV heparin bolus(40u/kg) (ACT > 200) Flush aortogram – 5 Fr Pigtail (30 cc’s) (AP) Bilateral selective renal arteriography: IMA or RDC-1 20-30 degrees ipsilateral oblique and AP Define ostia, disease location and severity Characterize distal perfusion Assess pressure gradient IVUS indeterminate disease (50-60% stenosis)

RAS: Guide Catheter Selection and Engagement 6 or 7 Fr Guide catheter selection based on angle of take-off: Horizontal RDC, JR, HS Inferior RDC, IMA,SOS, Cobra Severe Inferior RDC-1, IMA,VB-1, or brachial approach-MP Guide catheter engagement If ostium severely diseased and angle difficult, use “telescoping” 5 Fr IMA diagnostic catheter or Cook C2 to engage (5Fr catheter through 7 Fr IMA guide)

Renal Artery Stenting: Tips Keep it simple and safe! When in doubt, undersize! Recommend pre-dilate Finesse procedure (avoid big balloons and .035” wires) Support is generated by dynamics of guide catheter (not super stiff guidewire) Keep your eye on the guidewire and maintain a proximal wire position Guide, balloon and stent manipulation similar to coronary intervention

Should we use distal protection? Distal protection has a powerful effect on adverse events during SVG intervention1 Preliminary data suggests that distal protection may prevent renal insufficiency after renal intervention2 Anatomy may limit utility in renal application Baim DS. Circulation 2002;105:1285-1290. Henry M. J Endovasc Ther 2001;8:227-237.

Renal Stent Trials Boston Sci Express SD RENAISSANCE Cordis Genesis Palmaz Blue GREAT ASPIRE -2 Abbott Vascular HercuLink Elite HERCULES Medtronic RACER SOAR Cook Formula 414 REFORM --Renal indication

Renal Stent Trials – with renal indication Boston Sci Cook Abbott Trial name RENAISSANCE REFORM HERCULES Stent Express SD Formula 414 Herculink Elite Pts enrolled 100 202 Restenosis 21.3% 8.3% 10.5% Freedom from TLR at 9 mo 91.6% 97.8% 97.0% Statistical reduction in systolic BP at 24 mo. Yes N/A

CMS Coverage Proposal – 2007 CMS had concerns re: Growth of renal intervention in US- 400% increase in dx of RAS from 1992 to 2004 PTA for 1/6 pts – 390% increase in claims by cardiologists Made aware of the slow enrollment rate of the NIH supported CORAL trial Asked for comment period to review the data on renal intervention Focus on quality of data and not quantitty Suggest renal intervention only performed as an alternative to surgical bypass, and not simply as an adjunct to medical therapy MEDCAC mtgs - no change in coverage last 5 years

CORAL Trial Cardiovascular Outcomes in Renal Atherosclerotic Lesions 1080 pts with ≥ 60% RAS, SBP ≥155 mm Hg and ≥ 2 antiHTN meds Stent w/EDP+medical therapy Medical therapy alone Follow-up 3.5-5 years 1° Endpoint: cardiovascular or renal death, stroke, MI, CHF hospitalization, decline in renal function, need for dialysis

Renal Artery Stent Restenosis Cryoplasty and cutting balloon do not work Balloon with a 2nd stent may work for larger vessels (> 5.5 mm) DES for smaller vessels (< 5 mm) Drug Eluting balloons ? Consider ICAST covered stent Downsides – larger profile and significant recoil

Atherosclerotic Renal Artery Stenosis Indications for Intervention Refractory hypertension (BP >160/90 on >3 meds and unilateral/bilateral >75% RAS Recurrent flash pulmonary edema and/or unstable angina without cardiac cause, with documented >75% RAS to entire functioning renal mass Significant arterial pressure gradient  10 mm Hg peak systolic pressure  5 mm Hg mean arterial pressure Asymmetrical renal size Length difference of  1.5 cms Documented decrease in > 1 cm Renal Guidelines- JACC 3/06

Renal Artery Stenosis When Not to Intervene Incidentally identified RAS* in the presence of No significant pressure gradient Normal renal size and function Normal or well-controlled BP on 1-2 anti-hypertensive medications Follow for at 6-month intervals Intervene only when changes observed * Especially in an elderly patient

Renal Artery Intervention: Closing Thoughts Can you justify the intervention? If anatomy is extremely complex, reconsider Is your strategy sound? Imagine worst-case scenario and have a plan If access is a struggle, regroup Stage bilateral disease (esp in renal impaired pt) Monitor BP and renal function frequently post procedure Consider distal protection