Serum phosphate is an independent predictor of the total aortic calcification volume in non-hemodialysis patients undergoing cardiovascular surgery

J Cardiol. 2016 Oct;68(4):308-15. doi: 10.1016/j.jjcc.2015.10.005. Epub 2015 Nov 11.

Abstract

Background: A high serum phosphate level is a well-known risk factor for vascular calcification (VC) in patients on hemodialysis (HD). However, the association between the serum phosphate level and VC in non-HD patients is unclear. Our aim was to assess the impact of serum phosphate level on aortic calcification (AC) volume in non-HD patients undergoing cardiovascular surgery.

Methods: A total of 117 patients who underwent thoracoabdominal computed tomography as a preoperative general evaluation before cardiovascular surgery were enrolled. The total AC volume was quantified using the volume-rendering method by extracting the area ≥130HU within the entire aorta. The total AC volume index (AC-VI) was estimated as the total AC volume divided by the body surface area.

Results: In the 117 patients (64.7±13.1 years, 39% women), the median total AC-VI was 1.23mL/m(2). The mean estimated glomerular filtration rate (eGFR), adjusted serum calcium levels, and serum phosphate levels were 63.8±19.9mL/min/1.73m(2), 9.1±0.4mg/dL, and 3.6±0.6mg/dL, respectively. When the patients were classified into four quartiles based on their total AC-VI value, the serum phosphate level showed a positive correlation with a probability of being in the highest AC-VI quartile (R(2)=0.0146, p=0.0383) whereas the adjusted serum calcium level did not show a significant correlation (R(2)=0.0040, p=0.2615). A similar relationship between the serum phosphate level, adjusted serum calcium level, and AC-VI was confirmed when the total AC-VI was divided into the thoracic AC-VI and abdominal AC-VI. Multivariate analysis indicated that the serum phosphate level was an independent positive predictor of higher total AC-VI quartiles (β=0.8013, p=0.0160).

Conclusions: An increase in serum phosphate level was associated with an increased AC burden in non-HD patients undergoing cardiovascular surgery.

Keywords: Aortic calcification; Computed tomography; Non-hemodialysis patients; Serum phosphate; Vascular calcification.

MeSH terms

  • Aged
  • Aortic Diseases / diagnostic imaging*
  • Biomarkers / blood
  • Female
  • Humans
  • Imaging, Three-Dimensional
  • Male
  • Middle Aged
  • Multidetector Computed Tomography
  • Phosphates / blood*
  • Severity of Illness Index
  • Vascular Calcification / diagnostic imaging*

Substances

  • Biomarkers
  • Phosphates