A 67-year-old man with hypertension comes to the office for follow-up. Despite escalations in his antihypertensive therapy, he has persistently elevated blood pressure readings at home and in the office. The patient has occasional headaches but no chest pain, shortness of breath, or syncope. His other medical conditions include type 2 diabetes mellitus, coronary artery disease, and an ischemic stroke with residual left-sided weakness. The patient underwent coronary artery bypass surgery 7 years ago and carotid endarterectomy 5 years ago. His current antihypertensive regimen includes lisinopril, chlorthalidone, amlodipine, and carvedilol. Blood pressure is 184/120 mm Hg in the left arm and 170/112 mm Hg in the right arm, and pulse is 65/min. Physical examination shows an upper abdominal systolic-diastolic bruit. This finding is best explained by which of the following?
Clinical clues to renovascular disease | |
HTN-related symptoms |
|
Supportive evidence | Physical examination
Laboratory results
Imaging results
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ARBs = angiotensin II receptor blockers; HTN = hypertension. | |
This patient with resistant hypertension—persistent hypertension despite the use of ≥3 antihypertensive agents of different classes—should be evaluated for secondary causes of hypertension. The most common and correctable cause of secondary hypertension is renovascular hypertension.
Renal artery stenosis (RAS) is present in ~1% of patients with mild hypertension but is seen more frequently in those with severe or resistant hypertension or widespread atherosclerotic disease (suggested by this patient's surgical history and upper extremity blood pressure discrepancy). A systolic-diastolic abdominal bruit lateralizing to one side can be heard in ~40% of patients; this finding has very high specificity for RAS.
Other clinical clues include an unexplained atrophic kidney, recurrent flash pulmonary edema, or an unexplained rise in creatinine (>30%) after starting an ACE inhibitor or angiotensin receptor blocker. The diagnosis is confirmed by noninvasive assessment with renal duplex Doppler ultrasonography, CT angiography, or MR angiography.
(Choice A) Most patients with an abdominal aortic aneurysm are initially asymptomatic; the aneurysm is often discovered incidentally on imaging for an unrelated cause. It is not associated with resistant hypertension, and an abdominal bruit is not typically present. Abdominal palpation may reveal a pulsatile mass in some (<50%) patients.
(Choice B) Coarctation of the aorta classically presents with upper extremity hypertension and lower extremity hypotension, diminished or delayed femoral pulses, and a continuous machinery murmur best heard over the back. Patients with coarctation proximal to the left subclavian artery may have higher blood pressure measurements in the right arm compared to the left arm. In contrast, this patient's slightly higher systolic blood pressure measurement in the left arm compared to the right arm is likely due to upper extremity atherosclerotic disease.
(Choice C) Acute aortic dissection typically presents with sudden onset of tearing chest or back pain in the setting of severe hypertension. Upper extremity pulse deficits or differential blood pressure measurements are important clinical signs but are present only in a minority of patients; the absence of pain makes this diagnosis highly unlikely.
(Choice D) Aortoenteric fistula is an abnormal connection between the aortoiliac vessels and the gastrointestinal tract; it usually presents with abdominal pain, gastrointestinal bleeding, and hypotension.
Educational objective:
Renovascular hypertension is the most common and correctable cause of secondary hypertension and should be suspected in patients with diffuse atherosclerosis and resistant hypertension. The presence of a systolic-diastolic abdominal bruit has high specificity for the presence of renal artery stenosis.