Harvard Medical School

Duane S. Pinto, M.D.Duane S. Pinto, M.D.

Director Peripheral Angiographic Core Laboratory,

TIMI Data Coordinating Center

Director, Cardiology Fellowship Training Program

Interventional Cardiologist Beth Israel Deaconess Medical Center

Assistant Professor of Medicine, Harvard Medical School

Renal Artery Stenosis:Renal Artery Stenosis:Diagnosis and Indications for Diagnosis and Indications for

RevascularizationRevascularization

Harvard Medical School

Clinical Clues for RASClinical Clues for RASClinical Clues for RASClinical Clues for RAS

Onset of HTN after 55 yrs Exacerbation of well-controlled HTN Malignant or resistant HTN Epigastric bruit Unexplained azotemia Azotemia while on ACE or ARB Atrophic kidney or size discrepancy Recurrent CHF or “flash” pulmonary edema Atheroscerosis elsewhere

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Making the Diagnosis of RAS: Imaging Making the Diagnosis of RAS: Imaging RequirementsRequirements

Making the Diagnosis of RAS: Imaging Making the Diagnosis of RAS: Imaging RequirementsRequirements

1. Identify main and accessory renal arteries

2. Localize site of stenosis or disease

3. Provide hemodynamic significance of disease

4. Identify associated pathology

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Making the Diagnosis of RAS: Imaging Making the Diagnosis of RAS: Imaging OptionsOptions

Making the Diagnosis of RAS: Imaging Making the Diagnosis of RAS: Imaging OptionsOptions

Renal arteriographyDuplex ultrasoundMRACTANuclear PerfusionRenal Vein Renin Sampling

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Renal ArteriographyRenal ArteriographyRenal ArteriographyRenal Arteriography

Advantages Meets all 4 criteria Can size RA and intervene

at the same time of diagnosis

Sensitivity and Specificity are Gold Standard

Disadvantages Expense Risks: Atheroembolis, CIN Oculostenotic

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Renal Arteriography Can Distinguish Integrity of Renal Arteriography Can Distinguish Integrity of Main, Accessory, and Branch VesselsMain, Accessory, and Branch Vessels

Renal Arteriography Can Distinguish Integrity of Renal Arteriography Can Distinguish Integrity of Main, Accessory, and Branch VesselsMain, Accessory, and Branch Vessels

Nonatherosclerotic forms of Renovascular Disease FMD Misc: Spontaneous dissection, aneurysmal disease,

William’s Syndrome, neurofibromatosis, trauma

Atherosclerotic Disease Unilateral or Bilateral ostial disease (75%) Nonostial disease (<20%) Isolated branch disease or segmental disease (5%)

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Hemodynamic AssessmentHemodynamic AssessmentHemodynamic AssessmentHemodynamic Assessment

Hemodynamic Assesment confirms visual estimate

60% stenosis diameter stenosis correlates with 84% CSA reduction to create a pressure drop

Magic number is 20 mm Hg

Gross, et al. Radiology 2001. 220:751-756Gross, et al. Radiology 2001. 220:751-756Haimovici, et al. J Cardiovasc Surg. 1962; 3: 259-62Haimovici, et al. J Cardiovasc Surg. 1962; 3: 259-62

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Duplex UltrasoundDuplex UltrasoundDuplex UltrasoundDuplex Ultrasound

Meets 3 or 4 criteria Least expensive Predict whether stenting will

be effective Sensitivity 84-88% Specificity 62-99%

Accessory arteries missed Limited imaging in obese,

gaseous patients Technician dependent

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Renal Resistive IndexRenal Resistive IndexRenal Resistive IndexRenal Resistive Index

Offers prognosis for intervention

Avoid Compression and Valsalva which increase RI

RI= PSV-EDV/PSV RI=(1-[Vmin/Vmax]) Multiply by 100

Radermacher J., et al. Hypertension. 2002; 39: 699-703)Radermacher J., et al. Hypertension. 2002; 39: 699-703)

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RRI: PrognosisRRI: PrognosisRRI: PrognosisRRI: Prognosis

RI >80 is a strong predictor of death, dialysis or progressive disease

Seen with or without RAS Found to be similar with

GFR <40 and Proteinuria However, data only based

on 25 patients with RI >80

Radermacher J., et al. Hypertension. 2002; 39: 699-703)Radermacher J., et al. Hypertension. 2002; 39: 699-703)

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Outcomes: 215 patients with Outcomes: 215 patients with ≥≥70% RAS 70% RAS treated with stentingtreated with stenting

Outcomes: 215 patients with Outcomes: 215 patients with ≥≥70% RAS 70% RAS treated with stentingtreated with stenting

In 52% (99/191) of the patients, Cr decreased during 1-year follow-up

1.21 mg/dL (quartiles: 0.92, 1.60 mg/dL) to 1.10 mg/dL (quartiles: 0.88, 1.50 mg/dL) (P=0.047)

MAP decreased from 102±12 mm Hg (mean±SD) at baseline to 92±10 mm Hg (P<0.001)

Independent predictors of improved renal function were:

Baseline serum Cr (odds ratio [95% CI], 2.58 [1.35 to 4.94], P=0.004)

LV function (OR 1.51 [1.04 to 2.21], P=0.032)

Zeller. Circulation. 2003;108:2244.

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Outcomes: 215 patients with Outcomes: 215 patients with ≥≥70% RAS 70% RAS treated with stentingtreated with stenting

Outcomes: 215 patients with Outcomes: 215 patients with ≥≥70% RAS 70% RAS treated with stentingtreated with stenting

Female sex, high baseline mean blood pressure, and normal renal parenchymal thickness were independent predictors for decreased mean blood pressure.

1yr mortality was approximately 7.5% CHF or MI (73%) Stroke (13.5%)

7 patients hospitalized with flash pulmonary edema and/or acute renal failure requiring acute hemodialysis could be withdrawn from the chronic hemodialysis program

Zeller. Circulation. 2003;108:2244.

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MRA of the RenalsMRA of the RenalsMRA of the RenalsMRA of the Renals

3 of the 4 requirements No radiation or

nephrotoxins Short duration scans Sensitivity 90-100% Specificity 76-94%

Expensive Claustrophobia May miss FMD Overcalls Stenoses Stent Artificact

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CTA of the RenalsCTA of the RenalsCTA of the RenalsCTA of the Renals

3 of the 4 requirements Widely available Visualize stents No Flow Artifact Short duration scans Sensitivity 89-100% Specificity 82-100%

Expensive Radiation Contrast Claustrophobia

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Indications for Continued Medical Indications for Continued Medical TreatmentTreatment

Indications for Continued Medical Indications for Continued Medical TreatmentTreatment

Mild HTNControlled BP on MedsStable and Good renal functionAdvanced Age Anatomic/Technical Considerations

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Indications for Renal RevascularizationIndications for Renal RevascularizationIndications for Renal RevascularizationIndications for Renal Revascularization

Hypertensive Control Reasonable Likelihood of Improvement

Recent escalation on top of essential HTN Refractory, accelerated or malignant HTN

Renal Salvage Unexplained Azotemia or ACE induced Loss of renal mass over time Progression of RAS

Cardiac disturbance USA, “Flash Pulmonary Edema”, CHF

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Predictors of SuccessPredictors of SuccessPredictors of SuccessPredictors of Success

Female Gender (p=0.032)MAP at baseline (p<0.001)Renal Failure

More improvement if moderate dysfunction (1.5 mg/dl) vs. severe (p=0.025)

LV function normal (p=0.032)

Neutral: DM an nephrosclerosis

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Case Selection: Should You ?Case Selection: Should You ?Case Selection: Should You ?Case Selection: Should You ?

BP 148/94 2 Antihypertensive

Meds 12 mm Hg gradient

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Case Selection: Should You ?Case Selection: Should You ?Case Selection: Should You ?Case Selection: Should You ?

“Drive-by Aortogram” BP 148/94 Atenolol only Creatinine 1.9

NO!NO!

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Case Selection: Should You ?Case Selection: Should You ?Case Selection: Should You ?Case Selection: Should You ?

28 y/o nurse BP 209/119 mm Hg Meds: None Creat 0.9 LRA normal

YES!YES!

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Case Selection: Should You ?Case Selection: Should You ?Case Selection: Should You ?Case Selection: Should You ?

YES!!!YES!!!

BP 196/104BP 196/104

Prinivil, HCTZ, MetoprololPrinivil, HCTZ, Metoprolol

71 mm gradient71 mm gradient

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What about the incidentalomas?What about the incidentalomas?Normal BP, No Meds, Normal GFRNormal BP, No Meds, Normal GFR

What about the incidentalomas?What about the incidentalomas?Normal BP, No Meds, Normal GFRNormal BP, No Meds, Normal GFR

Pro Prevent renal injury Treat before it occludes

Con ?Data Complications Cost

I say, No.I say, No.

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SummarySummarySummarySummary

Evaluate patient for clues suggesting RASPerform imaging if patient is a candidate for

revascularizationCombine imaging studies if necessary Intervene on those who have reasonable life

expectancy and potential to benefit from revascularization