“Recipients of heart transplantation (HT) require immunosuppression to prevent organ rejection,” explains Eveline Löfdahl, MD, PhD candidate. “Unfortunately, osteoporosis—a well-documented adverse effect of immunosuppression—increases risk for bone fractures, which, in turn, increases morbidity and mortality rates. Furthermore, chronic kidney disease (CKD) is frequently found in the HT patient population and may also arise as a side-effect of the immunosuppressive therapy.” To better understand the association between CKD, osteoporosis, and HT, Dr. Löfdahl and colleagues conducted a study that was published in Transplantation Direct.
The study team investigated bone mineral density (BMD) progression and incidence of osteoporosis in conjunction with CKD in patients who underwent HT, following patients for up to 10 years (median, 6.1 years). Data from pre-operative transplantation assessments and post-operative annual checkups were used, including dual-energy X-ray absorptiometry (DXA) measurements from the lumbar spine and femoral neck to assess BMD.
Before HT, only 14% of the patients had normal kidney function, while 34% had CKD stage 2, 41% had stage 3, 5% had stage 4, and 0.6% had stage 5. Patients with CKD stage 1-2 or normal kidney function before HT experienced more than twice the lumbar spine BMD loss as patients with CKD stage 3-5 in the first year after HT. Patients with CKD stage 3-5 gained a mean lumbar BMD of 2.1% during the second postoperative year, while patients with CKD stage 1-2 or normal kidney function lost a mean lumbar BMD of 3.7%. In the femoral neck, all included patients exhibited a mean BMD loss at the first postoperative year, which was not reversed up to 10 years after HT. There was, however, no difference between the groups.
“Our study implies that pre-operative advanced stages of CKD are not associated with osteoporosis in HT patients, suggesting that patients with CKD should not be disqualified for HT based on the risk of impaired bone health,” notes Dr. Löfdahl. “However, evidence is limited due to the retrospective design and lack of data on fractures. Further studies on the relationship between CKD and postoperative bone strength, including fracture data, in larger patient cohorts and prospective study design are highly encouraged.”