Impact of high coronary artery calcification score (CACS) on survival in patients on chronic hemodialysis

Background

Electron-beam computed tomography (EBCT) is a noninvasive measure of coronary artery calcification and, therefore, could be a marker of developing cardiovascular disease. Whether the coronary artery calcification score (CACS) is a prognostic marker in chronic dialysis patients is not known.

Methods

In the present study, the mortality rate was observed in relation to the baseline CACS. EBCT was performed in 104 chronic hemodialysis patients (62 men and 42 women) in one dialysis unit. The mean (SD) duration of hemodialysis was 48.7 (62.6) months at the time of EBCT. The mean (SD) age at EBCT was 55.9 (13.6) years, ranging from 23 to 88 years. The duration of follow-up was 43.8 (19.3) months after the EBCT. Cox proportional hazard analysis was performed to examine the impact of CACS on survival after adjusting for age, sex, duration of dialysis, diabetes mellitus, hypertension, serum albumin, and dyslipidemia.

Results

The CACS was distributed from zero to 5896, with a median of 200. During the study period, 24 patients (15 men and 9 women) died, 7 in the low CACS group (≪200) and 17 in the high CACS group (≧200). The 5-year cumulative survival rate was 84.2% in the low CACS group and 67.9% in the high CACS group. The adjusted relative risk (95% confidence interval) of death was 1.001 (1.000–1.002); P = 0.0003, for the absolute value of CACS.

Conclusions

The present study suggested that CACS was an independent predictor of death in patients on chronic hemodialysis. Patients with a high CACS should be carefully monitored and evaluated for reversible prognostic factors such as dyslipidemia and, probably, hyperphosphatemia and a high value for the calcium × phosphate product.