Angiotensin-converting enzyme inhibitor-induced renal failure: causes, consequences, and diagnostic uses

Angiotensin-converting enzyme inhibitor-induced renal failure is now a well-recognized phenomenon that appears to occur almost exclusively in patients with a preexisting reduction in renal perfusion pressure, especially those with renovascular disease. In the latter group of patients, renal failure probably results from some combination of reduced poststenotic renal perfusion pressure and a unique disturbance in the autoregulation of glomerular filtration rate. Although traditionally regarded as functional and reversible, recent animal studies suggest that angiotensin-converting enzyme inhibitor-induced reductions of glomerular filtration rate may lead to progressive renal atrophy, an observation that raises concerns about the long-term safety of these agents in patients with renovascular disease. On the other hand, the deleterious consequences of angiotensin-converting enzyme inhibition in renovascular disease have been exploited as aids in the diagnosis of this disorder. Whether the adjunctive use of angiotensin-converting enzyme inhibitors will prove to be useful in screening large populations of hypertensive patients for renovascular hypertension remains to be determined. However, such adjunctive tests appear to be useful in judging the functional significance of angiographically documented renal artery stenosis.