Association of Abdominal Arterial Calcification Score with Patients' Survival and Kidney Allograft Function after Kidney Transplant

Abstract

Background: Abdominal arterial calcification (AAC) is common among candidates for kidney transplant. The aim of this study is to correlate AAC score value with post-kidney transplant outcomes.

Methods: We modified the coronary calcium score by changing the intake data points and used it to quantitate the AAC. We conducted a retrospective clinical study of all adult patients who were transplanted at our center, between 2010 and 2013, and had abdominal computed tomography scan done before transplantation. Outcomes included mortality, pulse pressure (PP) measured by 24 h ambulatory blood pressure monitoring system, and kidney allograft function measured by iothalamate clearance.

Results: For each 1000 increase of AAC score value, there is an associated 1.05 increase in the risk of death (95% CI 1.02, 1.08) (p < 0.001). Overall median AAC value for all patients was 1784; Kaplan-Meier curve showed reduced survival of all-cause mortality for patients with AAC score value above median and reduced survival among patients with cardiac related mortality. The iothalamate clearance was lower among patients with total AAC score value above the median. Patients with abnormal PP (< 40 or > 60 mmHg) had an elevated median AAC score value at 4319.3 (IQR 1210.4, 11097.1) compared to patients with normal PP with AAC score value at 595.9 (IQR 9.9, 2959.9) (p < 0.001).

Conclusion: We showed an association of AAC with patients' survival and kidney allograft function after kidney transplant. The AAC score value could be used as a risk stratification when patients are considered for kidney transplant.