Improved outcome of cadaveric renal transplantation due to calcium channel blockers

Calcium channel blockers (CCB) administerd to recipients of cadaveric renal transplants have been shown to improve graft function, decrease the incidence of delayed function, prevent acute cyclosporine toxicity, and lessen the number of rejection episodes in the first several weeks posttransplant. In order to determine whether CCB provide a similar long-term benefit, a retrospective analysis of 83 first cadaveric renal transplants performed in 1987 and 1988 was performed. The clinical course of 17 patients who were discharged and maintained on CCB therapy for 1 year was compared with that of 24 patients who never received CCB during the same 1-year period. The remaining 42 patients were excluded for failing to meet these inclusion criteria. The two groups were similar with respect to age, sex, cold ischemia time, degree of sensitization, HLA matching, DR matching, and DR mismatching. The no CCB group did receive a significantly greater number of pretransplant transfusions. In the 1 year of follow-up, graft loss in the CCB group was less than in the no CCB group (1/17, 5.9% vs. 6/24, 25%). There was a striking decrease in the percentage of first rejection episodes in the CCB group as compared with no CCB therapy (35% vs. 83%, P<0.005). In addition, a similar decrease in second rejection episodes was found in the CCB group (18% vs. 33%, P<0.05). The two groups also were compared with respect to graft function. Despite similar serum creatinine levels at 1 month (CCB 1.8 mg% vs. no CCB 2.2 mg%, P= 0.37) and 1 year (CCB 1.7 mg% vs. no CCB 2.4 mg%, P=0.19), the CCB group had a significantly higher glomerular filtration rate at 1 month (53.9 vs. 38.7, P<0.05) and 1 year (57.0 vs. 35.0, P<0.001) as measured by clearance of radiolabeled iothalamate. These results suggest that the short-term improvements noted in both graft function and rejection episodes with CCB are maintained for the first year posttransplant. More importantly, CCB use results in improved 1-year graft survival.