ACE inhibitor versus beta-blocker for the treatment of hypertension in renal allograft recipients

Angiotensin-converting enzyme (ACE) inhibitors have been shown to slow the progression of chronic renal failure. However, the value of ACE inhibitors for the treatment of hypertension in renal allograft recipients has not bee n established. ACE inhibitors dilate the efferent glomerular arteriole, an effect that may aggravate the decrease in glomerular filtration rate result ing from cyclosporine-induced vasoconstriction at the afferent glomerular a rteriole. Therefore, the goal of this double-blind, randomized study was to compare the antihypertensive and renal effects of the ACE inhibitor quinap ril with those of the beta-blocker atenolol in renal allograft recipients i n whom hypertension developed 6 to 12 weeks after transplantation. All pati ents received cyclosporine as an immunosuppressant and had stable graft fun ction (serum creatinine concentration, <220 mu mol/L) at entry into the stu dy. Twenty-nine patients who received quinapril (daily dose titrated betwee n 2.5 and 20 mg) and 30 patients who received atenolol (daily dose titrated between 12.5 and 100 mg) completed the 24-month study. The two groups did not differ in age, sex ratio, height, and weight before entry into the stud y. Quinapril decreased diastolic blood pressure from 96+/-1 to 84+/-1 mm Hg (average throughout treatment period), and atenolol decreased diastolic bl ood pressure from 96+/-1 to 83+/-1 mm Hg. The serum creatinine concentratio n did not change significantly in either group after 24 months (129+/-8 mu mol/L at entry and 148+/-19 mu mol/L after 24 months in the quinapril group and 131+/-6 mu mol/L at entry and 152+/-15 mu mol/L after 24 months in the atenolol group; P=NS for both groups). After 23 months, the change in urin ary albumin excretion from baseline was -10+/-15 mg/d in the quinapril grou p and 52+/-32 mg/d in the atenolol group (P = 0.03). These results show tha t quinapril and atenolol are effective antihypertensive drugs when used aft er renal transplantation. Moreover, compared with atenolol, quinapril has n o adverse effects on graft function. The relative reduction in albuminuria observed with quinapril as compared with atenolol could indicate a benefici al effect of quinapril on long-term graft function.