Current Role of Renal Artery Stenting in Patients with Renal Artery Stenosis

Transcription

1 Current Role of Renal Artery Stenting in Patients with Renal Artery Stenosis Young-Guk Ko, M.D. Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea

2 Etiology Fibromuscular dysplasia Atherosclerosis Arteritis Aortic disease Complication

3 Fibromuscular Dysplasia Uncommon disease of unknown etiology Typically occurs in women <30 yrs of age Often affects the renal, carotid, & femoral a. arteries. Commonly associated with renovascular HTN Renal failure is unusual.

4 Atherosclerotic RAS Affecting 7% of patients older than age 65 years and 60% of patients with HTN, CAD or PAD, and renal insufficiency. ARAS rarely causes renovascular hypertension but is commonly associated with renal dysfunction.

5 Renal Ischemia

6 Clinical Manifestations Hypertension - age <30 yrs (FMD) or >55 yrs (ARAS) - resistant, accelerated, or malignant Cardiovascular manifestations - Flash pulmonary edema associated with severe HTN (not explained by other causes) Renal ischemia - acute: Cr within 14 days of initiation of ACEI or ARB - chronic ischemic nephropathy: primary cause of ESRD in 5~15%

7 Rena Artery Intervention for FMD Balloon angioplasty is the intervention of choice, and stenting is used for bail-out indications. Restenosis occurs in 10% within 10 years. Renal angioplasty is better in discrete lesions in major renal arteries and worse in diffuse FMD in small segmental, arcuate, and interlobar vessels. Renal arteriography is not reliable for assessment of FMD stenosis. Assessment using pressure wire and intravascular ultrasound may be more appropriate.

8 Rena Artery Intervention for Atherosclerotic RAS Success rate: 95%~100% Residual diameter stenosis: <10% Major complication: <2% Restenosis rate: 10%~15%

9 Balloon vs. Stent Van den Ven PJ et al. Lancet 1999;353:

10 Hypertension & Renal Function after Renal Artery Stenting - Metaanalysis - Leertouwer TC. Radiology 2000;216:78 85

11 Hypertension Response Meta-Analysis of Renal Stents Leertouwer TC, et al. Radiology 2000;216:78-85.

12 Effect on Renal Function Pooled 10 renal stent studies Isles CG, Quart J Med 1999;92:

13 Change in Serum Cr after RAS Zeller T. et al. Circulation 2003;108:

14 Change in BP after RAS Zeller T. et al. Circulation 2003;108:

15 Predictors of Improved Renal Function and BP Control after RAS Improved Creatinine Improved BP * * * * * * PPR=parenchymal/pelvic ratio Zeller T. et al. Circulation 2003;108:

16 Revascularization versus Medical Therapy for Renal-Artery Stenosis The ASTRAL Trial N Engl J Med 2009;361: Multicenter, randomized, unblinded clinical trial N=806, atherosclerotic renovascular disease RAS vs. medical therapy alone Primary outcome: renal function Secondary outcomes: - BP, time to renal and major cardiovascular events, & mortality. The median follow-up: 34 months Inclusion criteria: - Clinical Ix: uncontrolled or refractory HTN or unexplained renal dysfunction - Imaging findings: - substantial stenosis

17 Baseline Characteristics (2.0 mg/dl) N Engl J Med 2009;361:

18 Baseline Characteristics N Engl J Med 2009;361:

19 Serum Creatinine Systolic BP Diastolic BP N Engl J Med 2009;361:

20 Time to Clinical Events First Renal Event First Cardiovascular Event N Engl J Med 2009;361:

21 Critics on ASTRAL Trial 1. Enrollment criteria: - not following guidelines => many patients no severe HTN, relatively preserve renal Fx => 40% of enrolled patients stenosis <70% 2. Inexperience of investigators: patients at 57 centers in 7 years => on average, 2 patients per center per year - Technical success 79%, complication 8% (literature: technical success ~98%, complication ~2%) 3. Primary outcome: renal function - 25% of the patients enrolled had normal renal Fx.

22 Angiographic RAS Assessment Subramanian R. Cathet Cardiovasc Interv 2005;64:480-6.

23 Renal Function Improvement after RAS according to Resistance Index Retrospective study, N=138 Resistance index (RI) =[1-(V min V max )]*100 by renal Duplex ultrasound => RRI >80 = parenchymal Dz Radermacher J. N Engl J Med 2001;344:410-7.

24 Blood Pressure Response after RAS according to RI Radermacher J. N Engl J Med 2001;344:410-7

25 Uncertainty in the Measurement of RI Zeller T.

26 Improvement of BP & Renal Function independent of RI Zeller T. Catheter Cardiovasc Interv. 2003;58:

27 Prediction of BP reduction N=62 1) Pressure wire: - rest PG - hyperemic PG - FFR - mean PG 2) IVUS: - Lumen area 3) Angiography: - diameter stenosis Lessar MA. J Am Coll Cardiol 2009;53:

28 Hyperemic Systolic PG Sensitivity 82% Specificity 84% Accuracy 84% Lessar MA. J Am Coll Cardiol 2009;53:

29 Change in BP & Cr according to HSG Lessar MA. J Am Coll Cardiol 2009;53:2363

30 Atheroembolism during Renal Artery Intervention Baseline Post-stent

31 Atheroembolism during Renal Artery Intervention Emboli detected in 65%~100% using protection device Henri M. Catheter Cardiovasc Interv. 2003;60:299 Holden A. J Vasc Surg. 2003;38:962 Most of embolization occur during stenting. Kawarada O. Catheter Cardiovasc Interv 2007;70:784-8.

32 Change in Renal Function after RAS Control Protection device GP IIb/IIIa Inhibitor GP IIb/IIIa Inhibitor + Protection device Cooper CJ etal. Circulation 2008;117:

33 Change in GFR after RAS Cooper CJ etal. Circulation 2008;117:

34 Distal Protection Device

35 Coral Study Multicenter randomized clinical trial N=1080 Stent + Embolic protection device vs Medical Tx Results will be presented in 2010! Cooper CJ et al. Am Heart J 2006;152:59-66

36 Techniques to Avoid Renal Artery Injury Catheter-in-catheter No-touch

37 ACC/AHA Guidelines 2005 Clinical indications for evaluation for RAS Hypertension manifestations Level of evidence Class - HTN onset age <30 yrs (FMD) - HTN onset age >55 yrs (ARAS) - Resistant HTN - Accelerated HTN - Malignant HTN Renal manifestations - Acute renal failure after ACEI/ARB - Unexplained small kidney - Asymmetry in renal dimensions (>1.5 cm diff) - Unexplained chronic renal failure - New dialysis Cardiovascular manifestations - Unexplained pulmonary edema - Multivessel CAD alone - PAD alone - Unexplained CHF - Refractory angina B B C C C B B B B B B B B C C I I I I I I I I IIA IIA I IIB IIB IIB IIB

38 Definitions Accelerated HTN: - sudden and persistent worsening of previously controlled HTN Resistant HTN: - failure to achieve goal BP despite full doses of an appropriate 3-drug regimen that includes a diuretic. Malignant HTN: - HTN with acute end-organ damage (ARF, acutely decompensated CHF, new visual or neurological disturbance, and/or advanced [grade III to IV] retinopathy.

39 Clinical Evaluation of Renal Artery Perfusion and Renal Ischemia Diagnosis of RAS: Duplex US, MRI, CT, catheter angiography Noninvasive assessment of renal blood flow I-Iothalamate GFR (Total GFR) - 99M Tc-DTPA (split renal function and single-kidney GFR) Invasive assessment of significance of RAS - Visual estimates or quantitative angiography - Translesional pressure gradient (TLG > 20 mmhg) - Fractional flow reserve (FFR<0.8) - Intravascular ultrasound - Renal frame counts - Renal blush score

40 ACC/AHA Guidelines 2005 Indications for Revascularization - ARAS and unexplained pulmonary edema B I - ARAS and unexplained recurrent CHF - RAS and Class I indications for RAS evaluation - RAS and intolerance to medication - Bilateral ARAS and progressive renal dysfunction - Solitary ARAS and progressive renal dysfunction - ARAS and unstable angina - Asymptomatic bilateral ARAS - Asymptomatic solitary ARAS - Asymptomatic unilateral ARAS - Unilateral ARAS and chronic renal dysfunction Level of evidence B B B B B B B B C C C C Class I I IIA IIA IIA IIA IIA IIA IIB IIB IIB IIB

41 Renal Ischemia & Nephropathy Safian RD. JACC Intv 2009;2: 61 74

42 Algorithm for the Evaluation & Treatment of RAS no no RAS none Extensive parenchymal Dz. Clinical indications for evaluation of RAS Screening tests to evaluate RAS Establish relations between RAS & vital-organ injury Evaluate renal parenchymal Dz. & renal perfusion yes yes yes yes Revascularization Safian RD. JACC Intv 2009;2: Medical Tx Access causes of post-procedural renal failure

43 Take Home Messages Medical therapies, particularly antihypertensive drug therapy and therapies to limit ARAS, are the primary therapies for all patients with RAS. The benefits and risks of renal revascularization will be improved by careful patient selection. Decisions on renal revascularization must be made based on an assessment of the severity and functional significance of RAS. Appropriately designed randomized clinical trials are essential to define the role of renal revascularization.

44 Thank You for Your Attention! Renovation & Expansion of Severance Cardiovascular Hospital

45 Relationship Between GFR and Serum Creatinine Concentration