Ialysis is a significant predictor for all-cause and cardiovascular MedChemExpress PHCCC mortality in a relatively large number of incident PD patients. In addition, AoAC progression was found to be associated with patient outcome, irrespective of the presence of AoAC at baseline. Accumulating evidence has shown that vascular calcification is highly prevalent in ESRD patients [6,7] and that it is associated with increased vascular stiffness and decreased vascular compli-Table 3. All-cause and cardiovascular death rates according to the presence of aortic arch calcification (AoAC) at baseline and progression of AoAC.No. of events /No. of patients All-cause death Baseline AoAC present group (n = 140) Progression (+) Progression (2) Baseline AoAC HIV-RT inhibitor 1 supplier absent group (n = 223) Progression (+) Progression (2) Cardiovascular death Baseline AoAC present group (n = 140) Progression (+) Progression (2) Baseline AoAC absent group (n = 223) Progression (+) Progression (2) doi:10.1371/journal.pone.0048793.t003 2/12 6/211 15/90 4/50 5/12 19/211 27/90 9/Follow-up, No. of Person-YearsEvent rate per 100 Person-Years136.3 104.19.8 8.45.0 863.11.1 2.136.3 105.11.0 3.45.4 998.4.4 0.Progression of Aortic Arch Calcification in PDFigure 2. Kaplan-Meier analysis of aortic arch calcification (AoAC) progression for all-cause and cardiovascular mortality according to baseline AoAC subgroups. In baseline AoAC present group, patients with AoAC progression 
showed significantly higher all-cause (A) and cardiovascular (B) mortality (log-rank test, P = 0.002 and P = 0.016, respectively). Patients with AoAC progression in baseline AoAC absent group also showed significantly higher all-cause (C) and cardiovascular (D) mortality (P,0.001 and P = 0.003, respectively). doi:10.1371/journal.pone.0048793.gance, resulting in left ventricular (LV) hypertrophy and LV diastolic dysfunction [21,22]. Furthermore, arterial stiffness leads to a decrease in diastolic blood pressure, 15755315 which can compromise coronary perfusion to increase LV mass, irrespective of preexisting coronary artery disease [23,24]. Based on these findings, some investigators have suggested that vascular calcification may contribute in part to significantly high cardiovascular mortality in ESRD. In accordance with most previous studies, this study showed AoAC presence at the start of PD was a significant independent predictor of all-cause and cardiovascular mortality in incident PD patients [3,11,18]. The prevalence of AoAC at baseline was 40.7 in this study, which was much lower than that of most previous studies from Western countries [2,3,13,14,25]. In the study by Ogawa et al [11], however, only 50.6 of 401 prevalent HD patients with dialysis duration of more than 8 years had AoAC. A study on 184 Korean incident dialysis patients also showed that AoAC was present in 41.3 before initial dialysis, which is comparable with the results of our study [26]. Taken together, the prevalence of vascular calcification in ESRD patients seems to be highly variable depending on not only the screening technique but also the studiedpopulation, such as ethnicity and BMI. Meanwhile, the proportion of smokers was significantly lower in patients with AoAC at baseline in this study. Most previous studies demonstrated that smoking was a significant risk factor for AoAC and that a doseresponse relationship was observed between the amount of smoking and AoAC [27,28]. Moreover, several studies revealed that smoking cessation decreased the risk of AoAC in some l.Ialysis is a significant predictor for all-cause and cardiovascular mortality in a relatively large number of incident PD patients. In addition, AoAC progression was found to be associated with patient outcome, irrespective of the presence of AoAC at baseline. Accumulating evidence has shown that vascular calcification is highly prevalent in ESRD patients [6,7] and that it is associated with increased vascular stiffness and decreased vascular compli-Table 3. All-cause and cardiovascular death rates according to the presence of aortic arch calcification (AoAC) at baseline and progression of AoAC.No. of events /No. of patients All-cause death Baseline AoAC present group (n = 140) Progression (+) Progression (2) Baseline AoAC absent group (n = 223) Progression (+) Progression (2) Cardiovascular death Baseline AoAC present group (n = 140) Progression (+) Progression (2) Baseline AoAC absent group (n = 223) Progression (+) Progression (2) doi:10.1371/journal.pone.0048793.t003 2/12 6/211 15/90 4/50 5/12 19/211 27/90 9/Follow-up, No. of 
Person-YearsEvent rate per 100 Person-Years136.3 104.19.8 8.45.0 863.11.1 2.136.3 105.11.0 3.45.4 998.4.4 0.Progression of Aortic Arch Calcification in PDFigure 2. Kaplan-Meier analysis of aortic arch calcification (AoAC) progression for all-cause and cardiovascular mortality according to baseline AoAC subgroups. In baseline AoAC present group, patients with AoAC progression showed significantly higher all-cause (A) and cardiovascular (B) mortality (log-rank test, P = 0.002 and P = 0.016, respectively). Patients with AoAC progression in baseline AoAC absent group also showed significantly higher all-cause (C) and cardiovascular (D) mortality (P,0.001 and P = 0.003, respectively). doi:10.1371/journal.pone.0048793.gance, resulting in left ventricular (LV) hypertrophy and LV diastolic dysfunction [21,22]. Furthermore, arterial stiffness leads to a decrease in diastolic blood pressure, 15755315 which can compromise coronary perfusion to increase LV mass, irrespective of preexisting coronary artery disease [23,24]. Based on these findings, some investigators have suggested that vascular calcification may contribute in part to significantly high cardiovascular mortality in ESRD. In accordance with most previous studies, this study showed AoAC presence at the start of PD was a significant independent predictor of all-cause and cardiovascular mortality in incident PD patients [3,11,18]. The prevalence of AoAC at baseline was 40.7 in this study, which was much lower than that of most previous studies from Western countries [2,3,13,14,25]. In the study by Ogawa et al [11], however, only 50.6 of 401 prevalent HD patients with dialysis duration of more than 8 years had AoAC. A study on 184 Korean incident dialysis patients also showed that AoAC was present in 41.3 before initial dialysis, which is comparable with the results of our study [26]. Taken together, the prevalence of vascular calcification in ESRD patients seems to be highly variable depending on not only the screening technique but also the studiedpopulation, such as ethnicity and BMI. Meanwhile, the proportion of smokers was significantly lower in patients with AoAC at baseline in this study. Most previous studies demonstrated that smoking was a significant risk factor for AoAC and that a doseresponse relationship was observed between the amount of smoking and AoAC [27,28]. Moreover, several studies revealed that smoking cessation decreased the risk of AoAC in some l.
