Parathormone levels add prognostic ability to N-terminal pro-brain natriuretic peptide in stable coronary patients.

Abstract

AimsThere are controversial data on the ability of the components of mineral metabolism (vitamin D, phosphate, parathormone [PTH], fibroblast growth factor‐23 [FGF23], and klotho) to predict cardiovascular events. In addition, it is unknown whether they add any prognostic value to other well‐known biomarkers.Methods and resultsIn 969 stable coronary patients, we determined plasma levels of all the aforementioned components of mineral metabolism with a complete set of clinical and biochemical variables, including N‐terminal pro‐brain natriuretic peptide (NT‐proBNP), high‐sensitivity troponin I (hs‐TnI), and high‐sensitivity C‐reactive protein. Secondary outcomes were ischaemic events (any acute coronary syndrome, stroke, or transient ischaemic attack) and heart failure or death. The primary outcome was a composite of the secondary outcomes. Median follow‐up was 5.39 years. Age was 60 (52–72) years. Median glomerular filtration rate was 80.4 (65.3–93.1) mL/min/1.73 m2. One‐hundred and eighty‐five patients developed the primary outcome. FGF23, PTH, hs‐TnI, and NT‐proBNP were directly related with the primary outcome on univariate Cox analysis, while Klotho and calcidiol were inversely related. On multivariate analysis, only PTH (HR 1.058 [CI 1.021–1.097]; P = 0.002) and NT‐proBNP (HR 1.020 [CI 1.012–1.028]; P < 0.001) were independent predictors of the primary outcome but also for the secondary outcome of heart failure or death (HR 1.066 [CI 1.016–1.119]; P = 0.009 and HR 1.024 [CI 1.014–1.034]; P < 0.001, respectively). PTH was the only biomarker that predicted ischaemic events (HR 1.052 [1.010–1.096]; P = 0.016). Patients were divided in two subgroups according to FGF23 plasma levels. PTH retained its prognostic value only in patients with FGF23 levels above the median (>85.5 RU/mL) (P < 0.001) but not in patients with low FGF23 levels (P = 0.551). There was a significant interaction between FGF23 and PTH (P = 0.002). However, there was no significant interaction between PTH and both klotho and calcidiol levels.ConclusionsParathormone is an independent predictor of cardiovascular events in coronary patients, adding complimentary prognostic information to NT‐proBNP plasma levels. This predictive value is restricted to patients with high FGF23 plasma levels. This should be considered in the design of future studies in this field.