Intravenous pamidronate as treatment for osteoporosis after heart transplantation: A prospective study

Fractures due to osteoporosis are one of the major complications after hear t transplantation, occurring mostly during the first 6 months after the gra ft, with an incidence ranging from 18% to 50% for vertebral fractures. Bone mineral density (BMD) decreases dramatically following the graft, at trabe cular sites as well as cortical sites. This is explained by the relatively high doses of glucocorticoids used during the months following the graft, a nd by a long-term increase of bone turnover which is probably due to cyclos porine. There is some evidence for a beneficial effect on BMD of antiresorp tive treatments after heart transplantation. The aim of this study was to a ssess prospectively the effect on BMD of a 3-year treatment of quarterly in fusions of 60 mg of pamidronate, combined with 1 g calcium and 1000 U vitam in D per day, in osteoporotic heart transplant recipients, and that of a tr eatment with calcium and vitamin D in heart transplant recipients with no o steoporosis. BMD of the lumbar spine and the femoral neck was measured by d ual-energy X-ray absorptiometry in all patients every 6 months for 2 years and after 3 years. Seventeen patients, (1 woman, 16 men) aged 46 +/- 4 year s (mean +/- SEM) received only calcium and vitamin D. A significant decreas e in BMD was observed after 6 months following the graft, at the lumbar spi ne (-6.6%) as well as at the femoral neck (-7.8%). After 2 years, BMD tende d to recover at the lumbar spine, whereas the loss persisted after 3 years at the femoral neck. Eleven patients (1 woman and 10 men) aged 46 +/- 4 yea rs (mean +/- SEM) started treatment with pamidronate on average 6 months af ter the graft, because they had osteoporosis of the lumbar spine and/or fem oral neck (BMD T-score below -2.5 SD). Over the whole treatment period, a c ontinuous increase in BMD at the lumbar spine was noticed, reaching 18.3% a fter 3 years (14.3% compared with the BMD at the time of the graft). BMD at the femoral neck was lowered in the first year by -3.4%, but recovered tot ally after 3 years of treatment. In conclusion, a 3-year study of treatment with pamidronate given every 3 months to patients with existing osteoporos is led to a significant increase in lumbar spine BMD and prevented loss at the femoral neck. However, since some of these patients were treated up to 14 months after the transplant, they may already have passed through the ph ase of most rapid bone loss. In patients who were not osteoporotic at basel ine, treatment with calcium and vitamin D alone was not able to prevent the rapid bone loss that occurs immediately after transplantation.