Abstract 13707: Increased Bone Turnover and Resorption in Patients with Advanced Heart Failure is Corrected by Hemodynamic Improvement Through Ventricular Assist Device Implantation
Background: Abnormal bone metabolism and progressive demineralization have been described in patients with advanced heart failure (HF). We hypothesized that mechanical unloading through implantation of a ventricular assist device (VAD) with subsequent hemodynamic improvement would correct bone metabolism in patients with advanced HF.
Methods: Serum was collected from 19 controls (age 44.3±10.4 yrs, BMI 27.8±6.9 kg/m²), 34 patients with advanced HF (age 53.1±11.2 yrs, BMI 27±5.5 kg/m²) undergoing VAD implantation and 31 patients at the time of VAD explantation (mean duration: 169±125 days). Serum levels of the bone formation markers procollagen-1 N-terminal peptide (P1NP) and osteocalcin (OC), the bone resorption markers crosslinked C- and N-telopeptide of type 1 collagen (CTX and NTX) and the calciotropic hormones parathyroid hormone (PTH) and 25-hydroxyvitamin D (25OHD) were measured by ELISA and chemiluminescence immunoassay (ECLIA). Clinical data was obtained from medical records.
Results: Compared with controls, HF patients showed increased PTH (44±26 pg/mL vs 117±117 pg/mL in HF; p<0.05) with decreased 25OHD (29±12 ng/mL vs 21±11 ng/mL in HF; p<0.05). While P1NP and OC were similar, NTX and CTX both increased in HF (NTX: 14±4 ng/mL vs 20±11 ng/mL; p<0.05; CTX: 0.31±0.13 ng/mL vs 1.05±0.15 ng/mL; p<0.05 for controls and HF, respectively). Compared with HF, P1NP was strongly increased after VAD implantation (49±37 vs 121±62 ng/mL; p<0.01) with a mild decrease in CTX and NTX levels indicating a shift towards anabolic bone formation. Serum PTH correlated with eGFR (r=-0.51; p<0.001). Renal function is impaired in HF patients (eGFR: 71±15.8 vs 52.1±33.5 mL/min/1.73 m2; p=NS) and improves with LVAD implantation (eGFR: 69.2±26.6 mL/min/1.73 m2; p<0.05 vs pre-LVAD).
Conclusion: Our data from this cross-sectional study suggest that advanced HF is characterized by increased bone resorption potentially as a result of secondary hyperparathyroidism and worsening renal function. Hemodynamic improvement and mechanical unloading after VAD implantation leads to correction of bone resorption markers and increased bone formation in these patients suggesting that altered bone turnover is modified by hemodynamic correction through VAD implantation.
- © 2011 by American Heart Association, Inc.