1. Renal Artery Angioplasty and Stenting
Ehtisham Mahmud, MD, FACC
Chief of Cardiovascular Medicine
Co-Director, Sulpizio Cardiovascular Center
University of California, San Diego

2. Ehtisham Mahmud, MD
Consulting: St. Jude Medical, Inc.
Grant Support: Sanofi-Aventis, Abbott Vascular and Boston Scientific Corporation.
Honoraria: Medtronic, Inc., Accumetrics, Inc., Eli Lilly and Company and Boston Scientific Corporation. Off-Label: Thienopyridine use after peripheral stenting. Treatment of antiplatelets based on platelet function testing. Use of DES in acute MI and various non FDA approved but commonly used indications/situations.

3. Renal Artery Revascularization
Hypertension management
Renal function preservation
Renal artery angioplasty
-fibromuscular dysplasia
-otherwise replaced by aorto-ostial stenting
Renal stenting
-predictors of response

4. Renal Fibromuscular Dysplasia: IVUS Evaluation
Prasad et al; Cath Cardiovasc Intv 2009;74:260-4

5. Fibromuscular Dysplasia
Mahmud et al; Catheter Cardiovasc Intv 2006; 67:434-7

6. Renal Stenting Technique
Always perform abdominal aortogram prior to selective renal angiography
Accessory renal arteries seen in 25% of cases
Balloon expandable stent with ” compatible system
Stent back to OSTIUM requires oblique views

7. Uncontrolled HTN and unilateral RAS
90% stenosis
Stents back to ostia
61 year old man with uncontrolled hypertension (BP 165/100 mm Hg despite
3 antihypertensives)
Mahmud et al; JACC 2007;473-90

8. Blood Pressure
Zeller at al. Circulation 2003;108:2244-9

9. ASPIRE 2 Study N=208; multicenter
20 mm Hg systolic BP reduction at 12 and 24 mos
Stable creatinine
Restenosis: 17.4%
39% non-responders!!
Rocha-Singh et al; JACC 2005; 46:
Mahmud JACC 2005; 46:

10. Blood Pressure Response in Unilateral Renal Artery Stenosis
Mahmud et al; JACC Intv 2008;1:286-92
Whitlow; JACC Intv 2008;1:

11. Renal Frame Count Control group BP>140/90 mmHg; 2 meds
No renal artery stenosis
Study group
BP>140/90 mmHg; 2 meds
Renal artery stenosis >70%
Mahmud et al; JACC Intv 2008;1:286-92

12. Renal Blush Grade Control group BP>140/90 mmHg; 2 meds
No renal artery stenosis
Study group
BP>140/90 mmHg; 2 meds
Renal artery stenosis >70%
Mahmud et al; JACC Intv 2008;1:286-92

13. Renal Frame Count Reduction Predicts Clinical Response to Renal Stenting
Mahmud et al; JACC Intv 2008;1:286-92

14. Representative RAS lesion. (A) Without VH, (B) With VH
Prasad et al; J Invasive Cardiol 2011;23:227-31

15. Change in RFC and Segment Plaque Composition
Decreased Perfusion
Improved Perfusion
r=0.582, p=0.029
r=-0.449, p=0.093
Prasad et al; J Invasive Cardiol 2011;23:227-31

16. ASTRAL: Blood Pressure
ASTRAL Investigators; NEJM 2009;361:

17. Recent Randomized Trials
STAR
Bax et al; Ann Intern Med 2009:840-48
ASTRAL
Astral Invest; NEJM 2009;361:

18. De Bruyne, B. et al. J Am Coll Cardiol 2006;48:1851-1855
Example of mean pressure tracings obtained simultaneously in the aorta and distal to the artificial renal stenoses induced by incremental balloon inflations
De Bruyne, B. et al. J Am Coll Cardiol 2006;48:
Copyright ©2006 American College of Cardiology Foundation. Restrictions may apply.

19. Relationship between stenosis (Pd/Pa) and lesion gradients
De Bruyne, B. et al. J Am Coll Cardiol 2006;48:
Copyright ©2006 American College of Cardiology Foundation. Restrictions may apply.

20. De Bruyne, B. et al. J Am Coll Cardiol 2006;48:1851-1855
Effects of a balloon-induced, unilateral, controlled, graded stenosis and renin production
De Bruyne, B. et al. J Am Coll Cardiol 2006;48:
Copyright ©2006 American College of Cardiology Foundation. Restrictions may apply.

21. Fractional Flow Reserve and Clinical Response to Renal Stenting
Group I: FFR<0.80
Group II: FFR>0.80
N=17
Papaverine for dilation
Mitchell et al; Catheter Cardiovasc Interv.
2007;69(5):685-9

22. Leesar, M. A. et al. J Am Coll Cardiol 2009;53:2363-2371
Receiver-Operating Characteristic Curves of HSG, FFR, IVUS, and Diameter Stenosis for Hypertension Improvement
Leesar, M. A. et al. J Am Coll Cardiol 2009;53:
Copyright ©2009 American College of Cardiology Foundation. Restrictions may apply.

23. Blood Pressure Response after Renal Stenting:
HSG >=21 Versus <21 mm Hg
Leesar, M. A. et al. J Am Coll Cardiol 2009;53:
Copyright ©2009 American College of Cardiology Foundation. Restrictions may apply.

24. Leesar, M. A. et al. J Am Coll Cardiol 2009;53:2363-2371
Number of Antihypertensive Medications and Serum Creatinine After Renal Stenting: HSG >=21 vs <21 mm Hg
Leesar, M. A. et al. J Am Coll Cardiol 2009;53:
Copyright ©2009 American College of Cardiology Foundation. Restrictions may apply.

25. Stenting: Salvage Renal Function
N=51 patients
42 bilateral RAS
We assessed the long-term effect of successful renal artery stent revascularization on renal function, blood pressure control, and survival in patients with progressive renal dysfunction due to ischemic nephropathy. Ischemic nephropathy presents a potentially serious risk of complete loss of renal function. Surgical renal revascularization is associated with significant risk of mortality/morbidity in this patient population. The potential role and long-term effect of renal artery stent revascularization in this patient population is not well defined. A cohort of 51 patients (mean age, 72 years; 52.9% men) with progressive azotemia, defined as a preprocedure serum creatinine (Scr) value of mg/dl and a negative slope of the reciprocal 1/Scr curve during the 12 months preceding revascularization, underwent successful primary stent deployment in 93 atherosclerotic renal artery lesions (42 bilateral, 9 solitary kidneys). Estimated glomerular filtration rate (EGFR) and serum creatinine values, blood pressure, antihypertensive medication requirements, and survival rates were monitored over a mean of 30-month follow-up. Renal artery duplex Doppler or renal angiography were performed at a mean of 13 months (range, 7-15 months) to assess stent patency. Stent implantation was successful in 92/93 (98.9%) stenotic renal arteries (mean preprocedure serum creatinine 2.3 ± 0.9 mg/dl; range, mg/dl). Forty-seven patients were eligible for 30-month follow-up of the procedural effect on renal function, blood pressure control, number of antihypertensive medications, and survival. At 1-year follow-up, the slope of the 1/Scr curve increased and the EGFR values significantly improved compared to preprocedure values (19.9 ± 6.2 to 26.8 ± 10.1 ml/min; P < ), serum creatinine decreased from the mean preprocedure value to 1.75 ± 0.69 mg/dl (P < 0.001), with renal function improvement or stabilization observed in 94% of patients; three patients (7.3%) required permanent hemodialysis during the 30-month follow-up period. Systolic and diastolic blood pressure significantly decreased (from 177 ± 28 to 148 ± 25 mm Hg and from 92 ± 15 to 78 ± 14 mm Hg, respectively; P < 0.001) with fewer antihypertensive medications required to control blood pressure (3.5 ± 0.9 vs. 1.9 ± 1.3; P < 0.001). The patient survival rate after 30-month follow-up was 87%, with three deaths related to end-stage renal failure. Renal artery stent revascularization reversed progressive renal dysfunction within the first 12 months and maintained the improved level of renal function at 30-month follow-up while improving blood pressure control and reducing the number of antihypertensive medication requirements. Renal stent revascularization should be considered a valid therapeutic option for the long-term treatment of ischemic nephropathy. Cathet Cardiovasc Intervent 2002;57:
Rocha-Singh et al; Cath Cardio Interv 2002;57:135-41

26. ASTRAL: Renal function
ASTRAL Investigators; NEJM 2009;361:

27. Renal Artery Stenosis Ostial in nature
Site not specific to renal, includes aorta
Predominantly fibrous and fibrocalcific plaque
Angioplasty with stent placement is the preferred revascularization approach
Surgical approach limited
-- mortality 2-5%
-- consider with concomitant AAA
DES may have a role as restenosis with BMS=15-20%

28. Renal Artery Stenosis: Treatment
Indications for treatment:
Renovascular hypertension (BP ≥140/90 mm Hg; ≥2 antihypertensives)
Progressive renal insufficiency
Recurrent pulmonary edema
Renal transplant arterial stenosis or bypass stenosis producing hypertension, azotemia or both
Key is to identify likely clinical responders:
Kidney >8 cm and RI<0.8
Angiographic diameter stenosis >70% by QRA
IVUS CSA stenosis >80%
Mean Pd:Pa <0.80 (renal FFR)
Hyperemic systolic gradient ≥ 21 mm Hg
Increased baseline renal frame count (>25) and RBG≥1
Decreased RFC after renal stenting
Renovascular Hypertension: correction of a stenosis > 50%, resting pressure gradient >10mm Hg or occlusion that is associated with refractory hypertension or documentation of renovascular hypertension
Renal Insufficiency: Deterioration of renal function of asymmetric decrease in renal size, and renal artery stenosis >50%
Recurrent PE: due to bilateral renal artery stenosis