[Hypertension and stenosis of the graft artery: effects of conversion enzyme inhibition].

The use of angiotensin converting enzyme inhibitors may lead to reversible renal insufficiency in transplant patients with transplant renal artery stenosis (TRAS). We assessed acute effects of captopril (50 mg, p. os) in 7 cadaver kidney recipients (mean age: 35.6 +/- 4 yrs) with TRAS, 9 to 46 mo after transplantation. All patients were treated by prednisolone and azathioprine. After captopril administration, mean arterial pressure decreased from 127 +/- 6 to 119 +/- 7 mmHg, effective renal plasma flow from 152 +/- 19 to 118 +/- 19 ml/min/1.73 m2, glomerular filtration rate from 59 +/- 8 to 39 +/- 10 ml/min/1.73 m2 and filtration fraction from 0.39 +/- 0.02 to 0.32 +/- 0.07. Among the 7 patients, 2 developed immediate and transient anuria; 4 presented a net decrease of GFR, only one had stable GFR. This patient was chronically treated by captopril; as BP was not controlled, furosemide (40 mg p. os) was added. Serum creatinine increased from 180 to 250 mumol/l. Percutaneous angioplasty was done without decrease in BP; however, treatment by captopril and furosemide could be reinstitued without deterioration in renal function. We conclude that: acute renal failure in kidney graft recipients with TRAS is frequent, but not mandatory; sodium depletion induced by diuretics enhances the fall in GFR; acute effect of captopril must be assessed in patients with TRAS before the use of this product as long term antihypertensive treatment.