Renal artery stenosis.

Atherosclerotic renal artery stenosis (RAS) is the single largest cause of secondary hypertension; it is associated with progressive renal insufficiency and causes cardiovascular complications such as refractory heart failure and flash pulmonary edema. Medical therapy, including risk factor modification, renin-angiotensin-aldosterone system antagonists, lipid-lowering agents, and antiplatelet therapy, is advised in all patients. Patients with uncontrolled renovascular hypertension despite optimal medical therapy, ischemic nephropathy, and cardiac destabilization syndromes who have severe RAS are likely to benefit from renal artery revascularization. Screening for RAS can be done with Doppler ultrasonography, CT angiography, and magnetic resonance angiography.