BLOOD-PRESSURE INDEPENDENT EFFECTS OF NITRENDIPINE ON CARDIAC STRUCTURE IN PATIENTS AFTER RENAL-TRANSPLANTATION

Left ventricular hypertrophy is well established as a blood pressure i ndependent cardiovascular risk factor in patients on renal replacement therapy. The effects of antihypertensive treatment on myocardial stru cture and function in renal transplant recipients have been so far onl y rarely investigated. In a double-blind, placebo-controlled study pat ients were randomized to the calcium channel blocker nitrendipine or p lacebo if the transplanted kidney had developed a stable phase. Normot ensive patients received nitrendipine 2 x 5 mg daily or placebo, hyper tensive patients received 2 x 10 mg up to 2 x 20 mg nitrendipine daily or placebo. To achieve adequate blood pressure control, all patients with still elevated blood pressure on study medication received antihy pertensive drugs other than calcium channels blockers. Ambulatory bloo d pressure recording and 2D-guided M-mode echocardiography were perfor med at baseline and upon completion of the study. In addition, laborat ory workup (including serum creatinine and lipids) was done, and serum aldosterone, plasma renin activity, plasma angiotensin II and blood g lucose levels were measured in all patients at baseline and after at l east 12 months of therapy. Ambulatory blood pressure was almost identi cal between both groups at study baseline and follow-up. In renal tran splant patients on nitrendipine, posterior wall thickness (-0.10 +/- 1 .77 mm) and septal wall thickness (-0.83 +/- 2.23 mm) did not change s ignificantly from baseline. In contrast, posterior wall thickness (0.7 1 +/- 0.92 mm, P < 0.01) and septal wall thickness (0.97 +/- 2.20 mm, P < 0.05) increased in patients on placebo, which differed from the ob served changes on nitrendipine (ANOVA: P = 0.093 and P = 0.048, respec tively). Relative wall thickness, a parameter for concentric left vent ricular hypertrophy, became numerically smaller on nitrendipine therap y from 0.46 +/- 0.07 to 0.44 +/- 0.09 (-0.02 +/- 0.09, NS) but increas ed from 0.42 +/- 0.08 to 0.48 +/- 0.08 in the placebo arm (+0.04 +/- 0 .08, P < 0.02), which was also significant between the two groups (ANO VA: P = 0.036). Endocrine parameters, lipids and blood glucose were no t different between the two groups. We conclude from these data that t he calcium channel blocker nitrendipine exerted beneficial effects on cardiac structure in patients after renal transplantation independent of blood pressure.