Abdominal Arterial Calcification as an Imaging Biomarker of Mortality in Kidney Transplant Waitlist Patients.

AIM: The supply of donor kidneys (living and deceased) has fallen far behind the need, while the number of patients with end stage kidney disease continues to rise, increasing their risk of cardiovascular mortality. Kidney transplant candidates frequently exhibit large artery calcification, a major contributor to cardiovascular death. This study aimed to evaluate the relationship between abdominal arterial calcification (AAC) and survival in patients awaiting kidney transplant.

METHODS

We modified the coronary calcium scoring method (Modified Agatston Method) and applied it to quantify AAC. This retrospective study included all adult patients (N = 4184) listed for kidney transplant from 2005 to 2023 who had undergone abdominal computed tomography (CT) scans. Patients were categorised into two groups: those who died while on the waiting list (DWL) and those who survived (SWL).

RESULTS

Among 4184 candidates, 446 (10.7%) died while on the waiting list, and 3738 (89.3%) survived to transplant or study end. Patients in the DWL group had significantly higher AAC scores across all vascular sites. The median total AAC score was 3605.8 (IQR 780.1-9017.3) in the DWL group versus 940.1 (IQR 49.2-4915.0) in the SWL group. Each 1000-point increase in total AAC was associated with a 5.1% increase in mortality risk (HR 1.051; p < 0.001). An AAC cutoff of > 1769 correlated with reduced 5-year survival (45.4% vs. 77.4%, p < 0.001).

CONCLUSION

AAC scoring on non-contrast abdominal CT represents a noninvasive biomarker of mortality in kidney transplant waitlist patients and may enhance risk stratification and personalised care.