Vitamin D metabolites and fibroblast growth factor-23 in patients with left ventricular assist device implants: association with stroke and mortality risk

Stroke and mortality risk in patients with left ventricular assist device (LVAD) implants continue to be high. Whether nonclassical cardiovascular risk markers such as vitamin D metabolites and fibroblast growth factor (FGF)-23 contribute to this risk remains to be studied, and this was the objective of our work. In 154 LVAD patients (91 HeartWare and 63 HeartMate II implants), we measured circulating 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D-3 (1,25[OH](2)D-3), parathyroid hormone (PTH) and FGF-23 shortly before LVAD implantation and investigated their association with stroke and mortality risk during 1-year follow-up. Of the study cohort, 34.4 and 92.2 %, respectively, had deficient 25OHD (< 25 nmol/l) and 1,25(OH)(2)D-3 (< 41 pmol/l) values, whereas 42.6 and 98.7 %, respectively, had elevated PTH levels (> 6.7 pmol/l) and FGF-23 values above the reference range (100 RU/ml). One-year freedom from stroke was 80.9 %, and 1-year survival was 64.3 %. The multivariable-adjusted hazard ratio of stroke was 2.44 (95 % CI: 1.09-5.45; P = 0.03) for the subgroup of 25OHD levels < 25 nmol/l (reference group: 25OHD levels a parts per thousand yen25 nmol/l). The multivariable-adjusted hazard ratio of 1-year mortality was 2.78 (95 % CI: 1.52-5.09; P = 0.001) for patients with 25OHD levels < 25 nmol/l compared with patients with 25OHD levels a parts per thousand yen25 nmol/l. PTH, FGF-23 and 1,25(OH)(2)D-3 were not associated with stroke or mortality risk. In LVAD patients, deficient 25OHD levels are independently associated with high stroke and mortality risk. If confirmed in randomized controlled trials, preoperative correction of deficient vitamin D status could be a promising measure to reduce stroke and mortality risk in LVAD patients.