RACIAL-DIFFERENCES IN THE RENAL RESPONSE TO BLOOD-PRESSURE-LOWERING DURING CHRONIC ANGIOTENSIN-CONVERTING ENZYME-INHIBITION - A PROSPECTIVEDOUBLE-BLIND RANDOMIZED COMPARISON OF FOSINOPRIL AND LISINOPRIL IN OLDER HYPERTENSIVE PATIENTS WITH CHRONIC RENAL-INSUFFICIENCY

This study was undertaken to compare the effects of chronic angiotensi n-converting enzyme (ACE) inhibition on blood pressure (BP) and renal hemodynamics in older black and nonblack hypertensive patients with ch ronic renal insufficiency, A multicenter, placebo lead-in double-blind , parallel group study was performed to compare the antihypertensive e fficacy and renal hemodynamic response to the once-daily ACE inhibitor s fosinopril (n = 14) and lisinopril (n = 13) over a 22-week period. T he study goal was to lower diastolic blood pressure (DBP) to 90 mm Hg or less. Furosemide was added after 6 weeks if blood pressure goal was not achieved. At outpatient clinics at university medical centers, 27 older hypertensive patients (greater than or equal to 45 years; 12 bl acks, 15 nonblacks; 19 male, eight female) with DBP of 95 mm Hg or hig her and 4-hour creatinine clearance 20 to 70 mL/min/1.73 m(2) were stu died, Changes (Delta) from baseline in BP, glomerular filtration rate (GFR), and renal plasma flow (RPF) were measured, Mean systolic blood pressure (SEP) and DBP decreased significantly and to a similar extent in randomized groups: fosinopril (mean +/- SEM) Delta DBP at 6 weeks was -13 +/- 2 (P < 0.0001; 95% CI, -16 to -9) and at 22 weeks was -12 +/- 2 (P < 0.0001; 95% CI, -16 to -9); lisinopril Delta DBP at 6 weeks was -14 +/- 6 (P < 0.0001; 95% CI, -10 to -18) and at 22 weeks was -1 6 +/- 2 (P < 0.0001; 95% CI, -12 to -21). GFR and RPF did not change s ignificantly in either group. BP was significantly reduced and to a si milar extent in blacks and nonblacks: for blacks, Delta DBP at 6 weeks was -11 +/- 3 (P < 0.05; 95% CI, -0.01 to -9) and at 22 weeks was -16 +/- 2 (P < 0.0001; 95% CI, -11 to -20); for nonblacks, Delta DBP at 6 weeks was -14 +/- 1 (P < 0.0001; 95% CI, -12 to -17) and at 22 weeks was -12 +/- 2 (P < 0.0001; 95% CI, -16 to -8). Eight patients (five bl acks and three nonblacks) required an addition of furosemide after 6 w eeks to reach the DBP goal of less than or equal to 90 mm Hg at 22 wee ks. GFR was not significantly altered for either racial group at 6 wee ks; however, at 22 weeks, GFR decreased significantly in blacks (Delta GFR, -16 +/- 5; P < 0.006; 95% CI, -26 to -5) and tended to increase in nonblacks (Delta GFR, 7 +/- 6; P > 0.25), Delta GFR correlated dire ctly with the Delta RPF (Delta GFR = 0.0811Delta RPF -2.35 +; r = 0.6 6; P < 0.003). There was no correlation between Delta MAP and Delta GF R or Delta RPF in blacks or nonblacks. We conclude that chronic ACE in hibition with fosinopril and lisinopril alone or in combination with f urosemide lowers BP in older blacks and nonblacks with hypertension an d chronic renal insufficiency, Racial differences in the renal hemodyn amic response to chronic ACE inhibition were noted and appear to be in dependent of diuretic use and the magnitude of BP lowering. (C) 1997 b y the National Kidney Foundation, Inc.