Background: Vitamin D receptor knockout mice develop typical signs of congestive heart failure (CHF). In approximately 20% of stable CHF patients, frankly low concentrations of the vitamin D hormone calcitriol are found.
Aims: We investigated whether serum calcitriol concentrations predict clinical outcome in end-stage CHF.
Methods and results: We collected blood samples in 383 end-stage CHF patients who were on a waiting list for cardiac transplantation. We assessed associations of calcitriol with disease severity and freedom from event (death or cardiac transplantation) during 1-year follow-up. In electively listed patients (n=325), 31% had deficient calcitriol levels (<43 pmol/l) compared to 47% in urgently/high urgently listed patients (n=58; P<0.001). As determined by multivariable logistic regression, calcitriol was an independent predictor of the listing status 'urgent/high urgent' (P<0.001). Calcitriol concentrations were also significantly lower in patients with an event (n=233) compared to those who survived on the waiting list (P<0.001). Cox regression analysis revealed that patients in the highest calcitriol tertile had a hazard ratio (95% CI) for an event of 0.506 (0.334-0.767) compared with patients in the lowest calcitriol tertile (P=0.005), after adjustment for potential confounders.
Conclusion: Data indicate that low serum calcitriol concentrations are independently associated with poor clinical outcome in end-stage CHF.