Radial augmentation index may be an effective predictor of vascular calcification in patients on peritoneal dialysis

Abstract

Vascular calcification (VC) is an important promoter of cardiovascular disease (CVD) in patients undergoing peritoneal dialysis (PD). Several indices can be used to evaluate VC, including the abdominal aortic calcification index (AACI) and carotid artery intima-media thickness (IMT); however, simpler and lesser expensive predictors, such as the radial augmentation index (RAI), should be investigated. A total of 101 patients undergoing PD were recruited to measure RAI, AACI, and carotid artery IMT and perform echocardiography. Fifty healthy controls (HCs) were recruited to undergo RAI measurement. RAI in patients undergoing PD was significantly higher than the RAI in HCs (86.25%±8.39% vs. 76.05%±9.81%, p < 0.05). Patients undergoing PD and who suffer with diabetic mellitus, hypertension, and CVD had more severe VC than those without the abovementioned diseases. In patients with PD, RAI was positively correlated with AACI (r = 0.671, p < 0.05) and carotid artery IMT (r = 0.596, p < 0.05). RAI was positively correlated with left ventricular end-diastolic dimensions (LVDd; r = 0.678, p < 0.05), left ventricular mass index (r = 0.595, p < 0.05), and negatively correlated with early-diastolic mitral inflow velocity/late-diastolic mitral inflow velocity (r = -0.342, p < 0.05) and left ventricular ejection fraction (r= -0.497, p < 0.05). Multiple linear regression analysis showed that RAI was associated with AACI, LVDd, age, and serum phosphate (p < 0.05). RAI might be an effective predictor of VC and cardiac structural/functional abnormalities in patients undergoing PD.

Keywords: Radial augmentation index; abdominal aortic calcification index; intima–media thickness; peritoneal dialysis.

Figure 1.

Histogram of radial augmentation index (RAI) in patients undergoing peritoneal dialysis (PD) and in healthy controls. RAI (86.25 ± 8.39%) in patients undergoing PD was significantly higher compared with healthy controls (76.05 ± 9.81%; p < 0.05).

Figure 2.

Correlation between abdominal aortic calcification index (AACI) and carotid artery intima–media thickness (IMT), and the correlation between radial augmentation index (RAI) and indices of vascular assessment (AACI and carotid artery IMT) in patients undergoing PD. AACI was positively correlated with carotid artery IMT, and RAI was positively correlated with AACI and carotid artery IMT.

Figure 3.

Correlation between RAI and echocardiography cardiac parameters. RAI was positively correlated with left ventricular end-diastolic dimensions (LVDd) and left ventricular mass index (LVMI), and negatively correlated with early-diastolic mitral inflow velocity/late-diastolic mitral inflow velocity (E/A ratio) and left ventricular ejection fraction (LVEF).