Acute renal thrombosis induced by angiotensin-converting enzyme inhibitors in patients with renovascular hypertension.

Acute reversible renal failure is a widely recognized potential complication of angiotensin-converting enzyme inhibitor (ACEI) administration in renovascular hypertension, particularly in bilateral artery stenosis or stenosis involving a solitary kidney. We report herein 2 cases of a rare but severe complication, i.e., acute renal artery thrombosis. Whereas marked hypotension does not seem to be necessary to trigger acute renal failure following ACE inhibition, by contrast, the fall in blood pressure could play an important role in our patients. Since single-dose ACEI has been advocated in order to improve the predictive value of renal scintigraphy or plasma renin activity measurements in the diagnosis of renovascular hypertension, the potential risk of this approach should be stressed.