A 75-year-old man comes to the office for hypertension follow-up. The patient has been taking chlorthalidone since being diagnosed with hypertension 15 years ago, and he was started on metoprolol 4 years ago after he had a non-ST elevation myocardial infarction. Over the last 2 years, his blood pressure measurements have ranged from 160/80 mm Hg to 180/100 mm Hg, and amlodipine was added to his medical regimen 6 months ago. The patient has had no chest pain, dyspnea, palpitation, headache, or subjective neurological deficits. His medical history includes hyperlipidemia and peripheral vascular disease, and other medications are aspirin and atorvastatin. The patient is a former smoker with a 30-pack-year history and does not use alcohol or illicit drugs.
Today, blood pressure is 165/86 mm Hg and pulse is 68/min. Physical examination is notable for an abdominal bruit.
Serum creatinine is 1.2 mg/dL, and duplex Doppler ultrasonography reveals 60% stenosis of bilateral renal arteries.
Which of the following is the most appropriate next step in management of this patient?

Question

A 75-year-old man comes to the office for hypertension follow-up.  The patient has been taking chlorthalidone since being diagnosed with hypertension 15 years ago, and he was started on metoprolol 4 years ago after he had a non-ST elevation myocardial infarction.  Over the last 2 years, his blood pressure measurements have ranged from 160/80 mm Hg to 180/100 mm Hg, and amlodipine was added to his medical regimen 6 months ago.  The patient has had no chest pain, dyspnea, palpitation, headache, or subjective neurological deficits.  His medical history includes hyperlipidemia and peripheral vascular disease, and other medications are aspirin and atorvastatin.  The patient is a former smoker with a 30-pack-year history and does not use alcohol or illicit drugs.
Today, blood pressure is 165/86 mm Hg and pulse is 68/min.  Physical examination is notable for an abdominal bruit.
Serum creatinine is 1.2 mg/dL, and duplex Doppler ultrasonography reveals >60% stenosis of bilateral renal arteries.
Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

This elderly patient who has uncontrolled hypertension despite multidrug therapy and is found to have high-grade bilateral renal artery stenosis should be treated with an ACE inhibitor. Bilateral renal ischemia (caused by limited blood supply to the poststenotic kidney) induces the activation of the renin-angiotensin-aldosterone system (RAAS), which leads to sodium retention and volume expansion. As the RAAS is involved, a combination of a diuretic with an ACE inhibitor or angiotensin receptor blocker (ARB) is the preferred initial treatment. ACE inhibitors have been shown to decrease mortality, rate of myocardial infarction, progression to end-stage renal disease, and stroke and are equally as effective as angioplasty in most patients. Patients with bilateral renal artery stenosis are at increased risk of development of acute kidney injury; however, ACE inhibitors and ARBs are no longer thought to be contraindicated in this population as most patients only experience a small decline in glomerular filtration rate. More marked declines are usually reversible with dose reduction or elimination of the diuretic; patients should be monitored closely while on these medications. Other antihypertensive agents and statins, as well as antiplatelet therapy should be added when appropriate along with lifestyle changes. Patients who fail optimal medical therapy (eg, refractory hypertension, inability to tolerate medications, progressive renal insufficiency) or those with recurrent flash pulmonary edema or heart failure should undergo revascularization with stenting (Choice D). (Choice B) Although invasive renal angiography is considered the gold standard for diagnosis of renal artery stenosis, less invasive imaging (eg, ultrasound, MRI, CT scan) is preferred due to the risk of complications associated with angiography (eg, contrast load, cholesterol embolization). (Choice C) Plasma renin activity (PRA) measurements are useful to distinguish between primary and secondary hyperaldosteronism in patients with refractory hypertension. PRA is expected to be low in patients with primary hyperaldosteronism and elevated in patients with renovascular hypertension. However, up to 50% of patients with renovascular hypertension do not have an elevated PRA, and levels are suppressed by antihypertensives, high sodium diet, and bilateral renal artery disease, limiting the practical use of PRA measurement. (Choice E) Surgery is recommended for patients who have early primary branching of the main renal artery or multiple small renal arteries, have failed prior stenting, or require aortic reconstruction for other reasons (eg, aneurysm, aorto-iliac disease). Educational objective: Patients with bilateral renal artery stenosis should first be treated with medical therapy (eg, a diuretic and either ACE inhibitor or angiotensin receptor blocker) as it is as efficacious as angioplasty or surgery. Patients who fail optimal medical therapy (eg, progressive renal insufficiency) or those with recurrent flash pulmonary edema or heart failure should be considered for angioplasty. __________ References: Revascularization versus medical therapy for renal-artery stenosis. (http://www.ncbi.nlm.nih.gov/pubmed/19907042) Renal artery stenosis: a common, treatable cause of renal failure? (http://www.ncbi.nlm.nih.gov/pubmed/11160787)

A 75-Year-Old Man Comes to the Office for Hypertension Follow-Up