A review of captopril renal scintigraphy and its effect on patient management

Renal artery stenosis is an important and potentially curable cause of hypertension. Captopril renography is now recognized to have a high sensitivity and specificity in its diagnosis. Ultimately, however, the result is of little benefit if it does not lead to a change in patient management. To assess how patient management was changed following the result of a captopril renogram, we reviewed the notes of 95 patients who had undergone this test over a 5 year period to identify renal artery stenosis. Of these patients, significant renal artery stenosis was suggested in 16 (17%), of whom only 9 (56%) underwent a change in management (7 proceeding to angiography with or without angioplasty, 2 having alterations in medication). In the 67 patients who had a negative renogram, 16 (24%) had an alteration in management (13 angiography, 3 altered drug treatment). Finally, of the 12 patients who had a non-diagnostic renogram, 7 (60%) had a management change (3 angiography, 4 altered drug therapy). Our results suggest that, despite evidence from the literature that captopril renography is both sensitive and specific for renal artery stenosis, clinicians still rely on other factors when determining who has significant stenosis and, therefore, who should proceed to a further investigation or have a change in medication. Ultimately, this reduces the clinical value of the test at present.