Renovascular Hypertension
Staci Smith DO
Case Presentation
• CC: dizziness
• HPI:62 yo WM presented to GVH w/
complaints of SOB and dizziness for the
past three days. Dizziness occurs
w/standing up. No LOC, numbness, or
tingling. Positive for history of CVA with
right sided upper extremity weakness. Pt’s
wife has noticed that bp has been
fluctuating.
Case Presentation
Case Presentation
• PMHx:
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HTN x 20yrs
CKD 4-5
CVA
PVD
AAA
CAD
L Subclavian stenosis
DMT2 (IR)
L DVT
• PSHx:
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GFF
Heart cath
CABG x 4v
IVC filter
Cervical diskectomy
EGD / colonoscopy
Medications
• Aggrenox 200/25 mg two
b.i.d
• Allopurinol 100 mg b.i.d
• Carvedilol 12.5 mg b.i.d
• Clonidine 0.2 mg t.i.d
• Ferrous sulfate 325 mg
daily
• Finasteride 5 mg daily hs
• Flomax 0.4 mg daily hs
• Furosemide 80 mg daily
• Glyburide 5 mg b.i.d
• Hydralazine 25 mg two
tablets t.i.d
• Isosorbide 60 mg daily
• Levemir at bedtime
• Nexium 40 mg daily
• Plavix 75 mg daily
• Simvastatin 20 mg q.h.s
Secondary Causes of HTN
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Renal Artery Stenosis
Obstructive Sleep Apnea / Obesity
Pheochromocytoma
Thyroid Disease
Cushing’s Syndrome
Hyperaldosteronism
Primary hyperparathyroidism
Congenital Adrenal Hyperplasia
Birth Control
Drugs of Abuse
Caffeine and Diet
Clues to Secondary Causes of Hypertension
• Severe or refractory hypertension
• Acute rise in blood pressure over a previously
stable value
• Proven age of onset before puberty
• Age less than 30 years
– non-obese, non-black patients with a
confirmed negative family history of
hypertension
When to Suspect Renal Artery Stenosis
• Hypertension before the age of 30 years
– negative family history and no other risk
factors
• Onset of severe or stage II hypertension after
age 55 yo
• Refractory or resistant hypertension
– three agents including a diuretic
• Acute rise in blood pressure over a previously
stable baseline in patients
When to Suspect Renal Artery Stenosis
• Unexpected rise in Cr after starting ACE/ ARB
• Atrophic kidney size
• Flash pulmonary edema or unexplained heart
failure
• An abdominal bruit that lateralizes to one side
Causes of Renal Artery Stenosis
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Atherosclerosis
Fibromuscular dysplasia
Cholesterol embolic disease
Acute arterial thrombosis or embolism
Aortic dissection
Renal arterial trauma or aneurysm
Arteriovenous malformation of the renal artery
Vasculitides
Fibromuscular Dysplasia Vs. Atherosclerosis
Pathophysiology
• clinical consequence of renin-angiotensinaldosterone activation
• occlusion of the renal artery causes ischemia
– renin release elevates bp
– increased renin levels help in the conversion of
angiotensin I to angiotensin II
– causing severe vasoconstriction and aldosterone
release
• presence of a functioning contralateral kidney
– determines ultimate cascade of events
Pathophysiology
Pathophysiology
• Two kidneys are out of sync:
– ischemic stenotic kidney produces excessive
renin and retains sodium
– the comparatively normal kidney continues to
excrete sodium and water to maintain normal
volume levels
• End result is systemic hypertension that is
renin and angiotensin mediated
Screening and Diagnostic Testing
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Gold standard-renal angiography
Magnetic resonance angiography
Computed tomographic angiography
Duplex Doppler ultrasonography
Screening and Diagnostic Testing
• MR Angiography:
– increasingly used as the first-line screening
test
– gadolinium during MR imaging
• nephrogenic systemic fibrosis
• estimated glomerular filtration rate less than 30
mL/min, avoid gadolinium
MRA of Aorta and Renal Arteries
• Gadolinium enhanced
MRA
• Bilateral RAS
Unilateral Renal Artery Stenosis
Fibromuscular Dysplasia
• Beads on a string
• Females > Males
Fibromuscular Dysplasia
If GFR less than 30
• risk of radiocontrast nephropathy
– Bicarbonate infusion
– Mucomyst
– IVF
• either spiral CT or arteriography can be
performed
– preferably digital subtraction arteriography
with iodinated contrast
Clinical Significance
• arteriographic finding of greater than a 75
percent stenosis
– in one or both renal arteries
– or a 50 percent stenosis with poststenotic
dilatation