The effects of an ACE inhibitor and a calcium antagonist on the progression of renal disease: the Nephros Study

Background. The renoprotective effect of ACE inhibition in chronic renal di sease is well established but the studies on effects of calcium antagonists on progression of renal disease and on proteinuria have given varying resu lts. Methods. We conducted an open long-term randomized prospective multi-centre study comparing the combination of ramipril (R) and felodipine ER (F) with either drug alone in non-diabetic renal disease. Included were patients wi th uncontrolled hypertension (diastolic blood pressure (DBP)) greater than or equal to 95 mmHg on treatment with a diuretic and a beta-blocker. Fifty- one patients received the combination of R and F. 54 patients R, and 53 pat ients F. The treatment goal was a DBP <90 mmHg and a similar BP reduction i n the three groups. Mean doses at the last visit were 5 + 5, 10 and 9 mg, r espectively, after a mean treatment time of nearly 2 years. The progression of renal impairment was Studied by serial measurements of serum creatinine . iohexol clearance, and albuminuria. Results. The reduction in supine systolic (S) BP and DBP expressed as media n values were -19.0 -14.5, -14.3 -15.0 and -13.5 -13.3 mmHg in the R + F. R , and F groups, respectively. There was no significant difference between t he groups. When correction for the acute drug effect was performed the R F group had a slower progression rate of the renal disease (loss of glomeru lar filtration rate (GFR) ml/min/year) compared with the F group (P < 0.05) but not to the R group (P > 0.20). There was a rise in albuminuria after 2 years in the F group (P < 0.05), but no significant change was found in th e other groups. Conclusions. In patients with non-diabetic renal disease the combination of an ACE inhibitor and a calcium antagonist in reduced doses used in additio n to baseline therapy with beta-blockers and diuretics, tended to cause a b etter BP reduction as each drug per se. The R + F treatment also caused a s lower progression of the renal disease compared with F alone. The combinati on treatment seems to afford better BP control and appears to be a favourab le therapeutic option in patients with renal disease and hypertension.