Mitsuo Kinugasa1, Shumpei Mori2, Tomofumi Takaya3, Tatsuro Ito2, Hidekazu Tanaka2, Seimi Satomi-Kobayashi2, Sei Fujiwara2, Tatsuya Nishii4, Atsushi K Kono4, Yutaka Okita5, Ken-Ichi Hirata2. 1. Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Cardiology, National Hospital Organization Kobe Medical Center, Kobe, Japan. 2. Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan. 3. Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: toto54@hotmail.com. 4. Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan. 5. Division of Cardiovascular Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
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.
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-HDpatients is unclear. Our aim was to assess the impact of serum phosphate level on aortic calcification (AC) volume in non-HDpatients 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-HDpatients undergoing cardiovascular surgery.