Do you discontinue an ACE inhibitor in a patient with CKD and well-controlled hypertension who is incidentally found to have bilateral renal artery stenosis on imaging, given stable kidney function on current therapy?

In the circumstances described, i.e., good BP control and stable kidney function, I would continue the ACE inhibitor. There is not a great correlation between the extent of stenosis seen on imaging and the hemodynamic functional significance, and the relation depends on the imaging modality used. So I would be reassured that the stenoses are not functionally significant. However, I would be especially alert in such a patient for future changes in kidney function due to volume depletion, concurrent hypotension, or progression of the stenosis.

There is no question that I would continue the therapy. I believe the benefits of such therapy outweigh the risks.

It is only starting therapy in such a setting that might make nephrologists a bit uneasy, though guidelines support doing so (with appropriate follow-up of renal function).

I would caution patients to temporarily stop therapy during any volume-depleting episodes such as GI illness.

I would also closely follow a patient if diuretic therapy is initiated. Finally, NSAID therapy would, in my mind, be contraindicated.