Background: Vascular calcification is a feature of arteriosclerosis. In hemodialysis (HD) patients, vascular calcification progresses rapidly. This study used the aortic calcification area index (ACAI), an index of vascular calcification, to evaluate vascular calcification factors in HD patients, to investigate correlations between ACAI and long-term prognosis and to assess correlations between various factors and long-term prognosis.
Methods: Subjects comprised 137 patients on maintenance HD. ACAI was measured as an index of vascular calcification as measured by abdominal plain computed tomography. The patients were divided into a high ACAI (H) group and a low ACAI (L) group according to whether the ACAI was below or above the mean value (21.4%) of ACAI, and long-term all-cause death and cardiovascular death rates were compared between groups. Risk factors for all-cause death and cardiovascular death were examined by Cox hazard analysis.
Results: During follow-up (mean follow-up period 95.3 ± 50.3 months), 76 patients died, including 46 cardiovascular deaths. Deaths included 51 of 70 patients (67.1%) in Group H and 25 of 67 patients (37.3%) in Group L. Cardiovascular death rates were 51.4 and 14.9%, respectively. On Kaplan-Meier analysis, the number of all-cause deaths was significantly higher in Group H (P < 0.001, log-rank test). Similarly, the number of cardiovascular deaths was significantly higher in Group H. Multivariate Cox proportional hazards analysis showed that ACAI (%) was a significant prognostic indicator for cardiovascular death (hazard ratio 1.03; 95% confidence interval 1.00-1.06, P = 0.03).
Conclusion: High ACAI was clearly correlated with mortality rate in HD patients, particularly cardiovascular mortality rate. ACAI was a useful long-term prognostic indicator in HD patients.