A 65-year-old man is brought to the hospital due to sudden-onset shortness of breath. He could not lie flat due to breathing difficulty. There is no associated chest pain. Six months ago, the patient was hospitalized with similar symptoms and responded well to diuretic therapy. Medical history is significant for hypertension, coronary artery disease, and transient ischemic attacks. The patient has undergone several percutaneous coronary interventions for stable angina in the past and had a right carotid endarterectomy 2 years ago. He has good adherence to his daily medication regimen but smokes a pack of cigarettes daily. Blood pressure is 210/100 mm Hg, pulse is 104/min and regular, and respirations are 22/min. Oxygen saturation is 86% on room air. Examination shows distended neck veins and bilateral lung crackles. The abdomen is soft, obese, and nontender. The extremities have no edema. Laboratory results are as follows: Cardiac troponin I levels are not elevated. ECG shows sinus tachycardia with left ventricular (LV) hypertrophy. Echocardiogram reveals LV hypertrophy, preserved LV ejection fraction, and no regional wall motion abnormalities. The patient improves markedly with diuresis and antihypertensive therapy. Which of the following is the next best step in management?

Question

A 65-year-old man is brought to the hospital due to sudden-onset shortness of breath.  He could not lie flat due to breathing difficulty.  There is no associated chest pain.  Six months ago, the patient was hospitalized with similar symptoms and responded well to diuretic therapy.  Medical history is significant for hypertension, coronary artery disease, and transient ischemic attacks.  The patient has undergone several percutaneous coronary interventions for stable angina in the past and had a right carotid endarterectomy 2 years ago.  He has good adherence to his daily medication regimen but smokes a pack of cigarettes daily.  Blood pressure is 210/100 mm Hg, pulse is 104/min and regular, and respirations are 22/min.  Oxygen saturation is 86% on room air.  Examination shows distended neck veins and bilateral lung crackles.  The abdomen is soft, obese, and nontender.  The extremities have no edema.  Laboratory results are as follows:  Cardiac troponin I levels are not elevated.  ECG shows sinus tachycardia with left ventricular (LV) hypertrophy.  Echocardiogram reveals LV hypertrophy, preserved LV ejection fraction, and no regional wall motion abnormalities.  The patient improves markedly with diuresis and antihypertensive therapy.  Which of the following is the next best step in management?

Quizplus · Accepted Answer

11ec25c8_d88f_9cb3_bc81_f704fd1cc690_MD0003_00 This older patient with diffuse atherosclerosis (coronary intervention, carotid intervention) has recurrent flash pulmonary edema (eg, pulmonary crackles, distended neck veins, no lower extremity edema) despite a normal ejection fraction. In association with severe hypertension, this presentation suggests renal artery stenosis (RAS). Renal ischemia (caused by limited blood supply to the poststenotic kidney) induces the activation of the renin-angiotensin-aldosterone system, resulting in sodium and water retention, generalized vasoconstriction, and hypertension. Laboratory abnormalities reflect secondary hyperaldosteronism (ie, hypokalemia, elevated serum bicarbonate). Unlike unilateral RAS, in which the unaffected kidney can typically compensate and the creatinine remains relatively normal, bilateral RAS can result in chronic kidney disease (CKD). Urinalysis is typically bland. renin-angiotensin-aldosterone system The diagnosis is confirmed with renal imaging (eg, renal ultrasound with Doppler, CT/MR angiography). Management includes blood pressure control, aggressive treatment of atherosclerotic disease (eg, statins, smoking cessation), and ACE inhibitors (with close monitoring of renal function) or revascularization. (Choice A) The dexamethasone suppression test is used to identify Cushing syndrome, which can cause hypertension but is typically associated with abnormal glucose tolerance, striae, easy bruising, obesity, and an enlarged dorsal fat pad; pulmonary edema is unexpected. (Choice B) Kidney biopsy is indicated in a variety of diseases including many nephritic and nephrotic syndromes and unexplained acute renal failure. Although biopsy could be considered if further workup is unrevealing, this patient has bland urinary sediment (suggesting against nephritic/nephrotic syndrome), and noninvasive diagnostic tests should be performed first. (Choice C) Plasma metanephrines are indicated to diagnose pheochromocytoma, which results in paroxysms of headache, tachycardia, sweating, and hypertension. Recurrent pulmonary edema is unexpected, and RAS is more likely in this elderly patient with diffuse atherosclerosis. (Choice E) Patients with CKD are at risk for secondary hyperparathyroidism, and serum parathyroid hormone levels are routinely checked in patients with advanced disease. However, this patient does not have hypercalcemia or urinary crystals that would suggest that hypercalcemia is contributing to his renal failure. (Choice F) A urine light chain assay tests for multiple myeloma, which causes CKD but is associated with hypercalcemia, bone pain, and anemia; in addition, a paraprotein gap (serum protein − serum albumin >4) is expected. Educational objective: Severe hypertension and recurrent flash pulmonary edema in the setting of diffuse atherosclerosis suggests renal artery stenosis. Associated findings can include chronic kidney disease and evidence of secondary hyperaldosteronism (hypokalemia, elevated serum bicarbonate); urinalysis is typically bland. The diagnosis is confirmed with renal imaging (eg, renal ultrasound with Doppler).

A 65-Year-Old Man Is Brought to the Hospital Due to Sudden-Onset