Aims: Immune activation and disturbances of vitamin D metabolism are frequently encountered in patients
with heart failure. Elevated fibroblast growth factor 23 (FGF23) levels as well as immune activation have
been associated with a worse outcome in patients with heart failure. We evaluated the relationship of vitamin
D metabolism and FGF23 levels with immune activation and its association with cardiac function and
outcome in patients with heart failure.
Methods and Results: In 149 patients with heart failure caused by nonischaemic cardiomyopathy,
parameters of vitamin D metabolism (vitamin D, parathormone, phosphate, C-terminal FGF23, calcium),
inflammation (hsCRP, neopterin) and cardiac function were investigated. Patients with elevated
inflammatory parameters had significantly higher Ct-FGF23 levels (37.33 RU/mL vs. 17.60 RU/mL, p <
0.001). The highest Ct-FGF23 and phosphate levels were found in patients with elevated neopterin and
hsCRP levels as well as in in patients with progressive heart failure. Patients with high Ct-FGF23 and
neopterin levels (Ct-FGF23 > 22.60 RU/mL, neopterin > 6.90 nmol/L) had a significantly higher risk for
adverse events compared to patients with low Ct-FGF23 and neopterin levels (HR 7.386, [95%CI 2.543 –
21.447], p < 0.001).
Conclusions: Our study indicates a strong relationship of vitamin D metabolism, especially FGF23, with
Th1 immune activation in patients with heart failure. Elevated Ct-FGF23 and neopterin levels are additive
predictors for adverse cardiovascular events in patients with heart failure.