New research identified the ratio of calcitriol (a vitamin D metabolite 1,25-dihydroxyvitamin D (1,25(OH)2D)) to parathyroid hormone (PTH 1-84) as a new predictor of the risk of death by chronic heart failure. The results discovered by a research team at the Department of Laboratory Medicine at Cliniques Universitaires Saint Luc in Brussels were presented at the 2015 Annual Meeting of the Endocrine Society in San Diego.
The authors studied 170 chronic heart failure patients (the mean age was 67 years old and the majority of patients were male  with only 36 females) and determined calcitriol and its ratio to PTH (1-84) as a tool to predict death by chronic heart failure. The cause for heart failure was both a restriction in blood supply (ischemia) and dilated cardiomyopathy, in 119 and 51 patients, respectively. The team measured the levels of calcitriol and PTH (1-84) and discovered a correlation between calcitriol and PTH(1-84) with heart failure severity, observing calcitriol levels in the blood sharply decreased upon serious and threatening heart failure.
The team performed an 8-year follow-up study that established calcitriol levels, together with the ratio of calcitriol to PTH (1-84), as a predictor of death in 106 patients who succumbed to cardiovascular causes. Currently, the team is developing a large study to determine how supplementing calcitriol to cardiac patients can benefit their outcomes.
Damien Gruson, PhD, professor and associated laboratory director in the Department of Laboratory Medicine at Cliniques Universitaires Saint Luc, Brussels, Belgium commented in a press release, “This study is important as it identifies and provides physicians with biomarkers that strongly predict cardiovascular death in heart failure and allows them to more intensively and aggressively manage their patients. We hope that our data can contribute to the more personalized tailored care of heart failure patients.” He added, “We were surprised by the strong predictive power of 1,25(OH)2D and its ratio to 1-84 PTH. It is noteworthy that In this study the 1,25(OH)2D was measured by a novel extraction-free, fully automated assay based on an unique murine monoclonal antibody which recognizes the conformational change induced by the binding of the 1,25(OH)2D to a recombinant fusion protein. Our results can provide physicians with a new tool – the 1,25(OH)2D to PTH ratio — to risk stratify heart failure patients. According to the relation between lower ratio values and increased mortality, physicians can try to modulate the ratio by increasing 1,25(OH)2D levels with more supplementation with calcitriol/analogs or by decreasing PTH with aldosterone blockers, for example.”