Angioplasty of atherosclerotic and fibromuscular renal artery stenosis: Time course and predicting factors of the effects on renal function

The effects of percutaneous transluminal renal angioplasty (PTRA) on the re nal function of stenotic kidneys are usually assessed by evaluating the cha nges in serum creatinine, which is quite a rough indicator of glomerular fi ltration rate (GFR). In 27 hypertensive patients with 19 atherosclerotic an d II fibromuscular significant renal artery stenoses, we investigated with renal scintigraphy the short-term (5 days) and long-term (10 months) effect s of a technically successful PTRA (in seven cases combined with a stent im plantation) on GFR of the stenotic and contralateral kidneys; these measure ments were combined with those of plasma renin activity (PRA) and of angiot ensin II (AII). We found that in short-term studies after PTRA. GFR rose fr om 29.7 +/- 3.5 to 34.6 +/- 3.1 mL/ min and from 36.9 +/- 4.0 to 45.1 +/- 4 .3 mL/min, respectively, in atherosclerotic and fibromuscular poststenotic kidneys. In long-term studies GFR further and significantly increased, to 3 7.8 +/- 3.2 mL/min in the former group, whereas it stabilized in the latter group (46.0 +/- 3.6 mL/min). In patients with fibromuscular stenosis these changes in GFR were associated with clear-cut reductions in blood pressure (BP), PRA, and AII; these decrements also occurred in patients with athero sclerotic stenosis but to a much lesser extent. We also found that in short - and long-term studies the percent of PTRA-induced increments of GFR in th e poststenotic kidneys were inversely correlated with the baseline values o f GFR. In addition, the absolute and percent increments of GFR were positiv ely correlated with the basal levels of All. Thus the time course of the im provement in GFR after angioplasty may differ in kidneys, depending on the etiology of the stenosis, in that in those with fibromuscular stenosis it w as entirely apparent within a few days whereas in those with atheroscleroti c stenosis it required several months to be fully expressed. Also, it appea rs that the more compromised kidneys are those that benefit most from the d ilatation and that AII levels are useful indicators of the possibility that the stenotic kidney will have a favorable functional outcome in terms of r estoration of renal blood flow. Am J Hypertens 2000;13:1210-1217 (C) 2000 A merican Journal of Hypertension, Ltd.