Blood pressure independent effects of nitrendipine on cardiac structure in patients after renal transplantation

Left ventricular hypertrophy is well established as a blood pressureindependent cardiovascular risk factor in patients on renal replacementtherapy. The effects of antihypertensive treatment on myocardial structureand function in renal transplant recipients have been so far only rarelyinvestigated. In a double-blind, placebo-controlled study patients wererandomized to the calcium channel blocker nitrendipine or placebo if thetransplanted kidney had developed a stable phase. Normotensive patientsreceived nitrendipine 2 x 5 mg daily or placebo, hypertensive patientsreceived 2 x 10 mg up to 2 x 20 mg nitrendipine daily or placebo. Toachieve adequate blood pressure control, all patients with still elevatedblood pressure on study medication received antihypertensive drugs otherthan calcium channels blockers. Ambulatory blood pressure recording and2D-guided M-mode echocardiography were performed at baseline and uponcompletion of the study. In addition, laboratory workup (including serumcreatinine and lipids) was done, and serum aldosterone, plasma reninactivity, plasma angiotensin II and blood glucose levels were measured inall patients at baseline and after at least 12 months of therapy.Ambulatory blood pressure was almost identical between both groups at studybaseline and follow-up. In renal transplant patients on nitrendipine,posterior wall thickness (-0.10 +/- 1.77 mm) and septal wall thickness(-0.83 +/- 2.23 mm) did not change significantly from baseline. Incontrast, posterior wall thickness (0.71 +/- 0.92 mm, P < 0.01) andseptal wall thickness (0.97 +/- 2.20 mm, P < 0.05) increased in patientson placebo, which differed from the observed changes on nitrendipine(ANOVA: P = 0.093 and P = 0.048, respectively). Relative wall thickness, aparameter for concentric left ventricular hypertrophy, became numericallysmaller on nitrendipine therapy from 0.46 +/- 0.07 to 0.44 +/- 0.09 (-0.02+/- 0.09, NS) but increased from 0.42 +/- 0.08 to 0.48 +/- 0.08 in theplacebo arm (+0.04 +/- 0.08, P < 0.02), which was also significantbetween the two groups (ANOVA: P = 0.036). Endocrine parameters, lipids andblood glucose were not different between the two groups. We conclude fromthese data that the calcium channel blocker nitrendipine exerted beneficialeffects on cardiac structure in patients after renal transplantationindependent of blood pressure.