Prevention of osteoporosis in heart transplant recipients: A comparison ofcalcitriol with calcitonin and pamidronate

Bone loss and osteoporotic fractures are common in cardiac transplant recip ients. To compare two prophylactic medical regimens after heart transplanta tion, 26 consecutive heart transplant recipients were randomized to receive either continuous oral calcitriol (0.5 mu g/day) combined with nasal salmo n calcitonin (200 U/day) for the first 3 months (group A) or intermittent i ntravenous pamidronate (0.5 mg/kg body weight) every third month (group B). Bone mineral density (BMD) and biochemical indices of bone turnover were m easured at baseline and 3, 6, 12, and 18 months after transplantation. The mean pretransplant BMD, measured by dual energy X-ray absorptiometry (DXA) was significantly lower in the patients compared with age-matched healthy c ontrols. During the first year of treatment, rates of bone loss at the lumb ar spine and femoral neck were slightly but significantly slower in the pat ients treated with pamidronate, but there was no longer a significant diffe rence between the two groups after 18 months of heart transplantation. Irre spective of the mode of osteoporosis prevention, osteocalcin levels increas ed whereas urinary deoxypyridinoline decreased after transplantation, and s ignificant bone loss was observed in both treatment groups. We found no rel ationship between initial BMD, markers of bone turnover, cumulative glucoco rticoid dose, or cyclosporine levels and the rate of bone loss after cardia c transplantation. In summary, we found that the rapid and severe bone loss following heart transplantation could be attenuated by two preventive meas ures, pamidronate or calcitriol with calcitonin.