Hanouneh, Tareq

ABSTRACT 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.

Abstract Background Abdominal arterial calcification is a well-established predictor of cardiovascular events and mortality in kidney failure. Autosomal dominant polycystic kidney disease (ADPKD), a common genetic cause of kidney failure, presents with a distinct vascular profile. However, the burden of abdominal arterial calcification in ADPKD remains inadequately characterized. Clarifying these differences may improve cardiovascular risk stratification and transplant timing. Methods We conducted a retrospective cohort study of 4088 adult patients listed for kidney transplant at three Mayo Clinic sites (2005–2024). Patients were categorized by kidney failure cause: ADPKD vs. non-ADPKD. Abdominal arterial calcification was quantified on non-contrast computed tomography (CT) scans using a modified Agatston scoring method. Propensity score matching (1:1) adjusted for age, sex, race, lipid levels, left ventricular ejection fraction, dialysis exposure, coronary artery disease, neurovascular disease, and smoking history, was performed. Abdominal arterial calcification scores were compared between matched groups, and subgroup analyses evaluated abdominal arterial calcification severity across dialysis durations in ADPKD patients. Results After matching, 309 patients with ADPKD were compared with 309 non-ADPKD chronic kidney disease (CKD) controls. Abdominal arterial calcification scores were significantly lower in the ADPKD group (median: 425.3; IQR: 0.0–2033.5) than in the non-ADPKD group (median: 1256.8; IQR: 96.5–5033.8). Among ADPKD patients, abdominal arterial calcification scores increased with dialysis duration (P &lt; .001). Conclusion ADPKD patients exhibit lower abdominal arterial calcification scores than their non-ADPKD counterparts after adjusting for clinical variables. Abdominal arterial calcification progression with dialysis highlights the importance of early transplant evaluation. This study introduces a novel adaptation of coronary calcium scoring software for quantifying abdominal calcification, offering a standardized approach to vascular risk assessment in kidney transplant candidates.

ABSTRACT Background Abdominal arterial calcification (AAC) is a common comorbidity in patients with end‐stage kidney disease (ESKD) and a predictor of cardiovascular events post‐kidney transplant. However, prior studies lacked a standardized approach to evaluate AAC and its impact on post‐transplant outcomes. This study aimed to correlate AAC score values with post‐kidney transplant outcomes using a modified scoring system traditionally applied to coronary artery calcification. Methods This retrospective study included 14 339 adult patients listed for kidney transplant between 2002 and 2023 at three transplant centers. Among them, 3683 patients met the criteria of undergoing a kidney transplant and an abdominal computed tomography (CT) scan pre‐transplant. We modified the coronary calcium score software by adjusting intake data points to quantify calcification in the abdominal aorta, common iliac, external iliac, and internal iliac arteries. Outcomes focused on post‐transplant mortality. Results In 3683 kidney transplant recipients, higher AAC scores were significantly associated with increased mortality. Each 1000‐unit increase in AAC score elevated hazard ratios (HRs) across arterial regions, including 1.116 for the aorta and 1.389 for the internal iliac (all p < 0.001). Adjusted analyses confirmed AAC as an independent risk factor for mortality. Kaplan–Meier curves demonstrated lower survival with increasing AAC quartiles. Conclusions AAC, measured by a standardized score, is a significant mortality risk factor in kidney transplant recipients. Integrating AAC scores into pre‐transplant evaluations could enhance risk stratification and improve outcomes. Prospective studies are needed to validate these findings and explore interventions to reduce AAC and improve survival.

ABSTRACTUreteral stenosis is a frequent complication after kidney transplantation, causing significant morbidity and potential graft function impairment. Treatment options include conservative management, endourological procedures, surgical interventions and percutaneous nephrostomy (PCN). While PCN effectively relieves obstruction, it comes with its own complications. This study evaluates the risk factors, incidence, complications and outcomes of PCN in this population.We conducted a retrospective case series analysis of 98 kidney transplant recipients who underwent PCN. Data on demographics, clinical characteristics and procedural outcomes were collected and analysed to assess the incidence of complications and identify associated risk factors.Among the 98 recipients, the median age at transplant was 56 years, with 52% being male. The most common comorbidities included hypertension (75.5%) and diabetes mellitus (35.7%). Complications occurred in 38.8% of patients, with infections being the most frequent (74.4%), including urinary tract infections (28.9%) and pyelonephritis (22.4%). The primary organisms identified were gram‐negative bacteria (55.1%). Reconstructive surgery was required in 35.7% of cases and patient survival was 83.7% at follow‐up.In conclusion, PCN in kidney transplant recipients is associated with a high rate of complications, particularly infections. Effective management necessitates the identification and addressing of associated risk factors such as diabetes, elevated BMI and specific induction therapies. While PCN is vital for preserving graft function, further research should focus on refining clinical protocols and developing targeted preventive strategies for high‐risk patients.

Objectives Endovascular aneurysm repair, though minimally invasive and has the benefit of relatively low perioperative complication rates, it is associated with significant long term reintervention rates related to endoleaks. Several variables have been studied to predict the outcomes of endovascular aneurysm repair, 1 of which is the calcium burden of the vasculature. This prompted us to study the association between calcium burden measured by the standardized Agatston scoring system and the outcomes of Endovascular aneurysm repair. Methods This is a retrospective study of patients who underwent Endovascular aneurysm repair from 2008 to 2020 at our institution and who had a non-contrast computerized tomography scan preoperatively, accounting for 87 patients. The calcium burden of the vasculature was measured by the Agatston scoring system allowing for better reproducibility, and the outcome variables included mortality and endoleaks. Results Patients with higher median total calcium scores (≥12966.9) had significantly lesser survival (79.8% vs 52.3% ( P = .002) at five years compared to patients with lower median total calcium score (<12966.9). Also, patients with type 2 endoleaks had higher calcium scores in above the aneurysm level ((1591.2 vs 688.2), P = .05)) compared to patients with no type 2 endoleaks. Conclusion Calcium score assigned using a standardized Agatston scoring system can be used as a predictor of mortality risk assisting in deciding the treatment of choice for patients.

Abstract The scarcity of organ donors relative to the number of patients with End Stage Kidney Disease (ESKD) has led to prolonged waiting times for kidney transplants, contributing to elevated cardiovascular mortality risk. Transplant professionals are tasked with the complex allocation of limited organs to a vulnerable patient group facing heightened morbidity and mortality risk. The need for continuous re-evaluation of waitlisted patients is evident due to the significant number who perish while awaiting transplantation. Among individuals with ESKD, vascular calcification, particularly Abdominal Arterial Calcifications (AAC), holds predictive value for cardiovascular events and mortality. However, a standardized method to quantify AAC's prognostic potential remains lacking, especially for kidney transplant evaluations. This study presents an ensemble machine learning (ML) approach to study the relationship between AAC score and mortality in patients on the waitlist and triage patients needing transplantation. Using the AAC score, the proposed ML model can predict kidney transplant waitlist morality with an accuracy of 78% while its accuracy is 68% without using this score. This study leverages explainable ML to explore the relationship between predictors and mortality in waitlisted patients, aiming to improve patient triage accuracy.