June 18, 2007 – Milan, Italy – Cilnidipine, a blocker of the L and N calcium channels, was more effective than amlodipine in preventing renal disease in patients with hypertension already treated with inhibitors of the renin angiotensin system (RAS). The results of the Cilnidipine versus Amlodipine Randomized Trial for Evaluation in Renal Disease (CARTER) study was presented by Dr. T. Fujita, University of Tokyo School of Medicine, Japan, at the 17th European Meeting on Hypertension, held in Milan from June 15-19, 2007.
A total of 339 patients with hypertension and a urinary protein:creatinine ratio >/=300 mg/g and serum creatinine ≤ 3.0 mg/dL were randomized to either cilnidipine (5-20 mg; n=179) or amlodipine (2.5-7.5 mg; n=160). The primary endpoint was changes in the urinary protein:creatinine ratio from baseline and the secondary endpoint was cardiovascular events. The patients were 59 years old and about 36% were women. At baseline, 38% had diabetic nephropathy, 32% of cilnidipine and 38% of amlodipine groups had primary renal disease, and 44% had diabetes. Blood pressure levels were 152/88 mmHg, urine protein 1921 mg/gCr in the cilnidipine and 1711 mg/gCr in the amlodipine groups.
Blood pressure reductions were similar in both groups and were 134.5/77.9 mmHg cilnidipine and 133.1/75.6 mmHg amlodipine at study end (p<0.05). A significant reduction in the urinary protein:creatinine ratio was achieved in the cilnidipine group compared to the amlodipine group (-14.4 vs +13.9). Further, greater reductions in urinary protein were found in women, in persons above and below 65 years old, in persons with different levels of baseline urinary protein:creatinine ratios, primary renal disease at baseline, and diabetic nephropathy. Notably, even in persons with achieved blood pressure <130/85 mmHg, cilnidipine was superior to amlodipine, suggesting cilnidipine has pleiotropic effects. Although the number of secondary events was higher in the amlodipine group, there was an insufficient number to show a significant difference.
In patients with hypertension and proteinuric nephropathies being treated with RAS inhibition, the addition of cilnidpine better reduced proteinuria compared to amlodipine for the same level of blood pressure reduction. The combination of cilnidipine and a RAS inhibitor may be efficacious for patients with hypertension and renal disease.