Out of sight, out of mind, but at high risk: incidence, timing and risk factors for hyperkalemia after liver transplant discharge

Background Hyperkalemia occurs in liver transplant (LT) recipients due to calcineurin inhibitor initiation and post-operative renal dysfunction and is associated with significant patient morbidity and resource expenditures. Little is known about the prevalence and timing of hyperkalemia after LT discharge. Methods Adults undergoing LT between 1/2022-12/2024 at a single transplant center were included, excluding simultaneous heart-liver transplant recipients and patients who died before discharge. The primary exposure was time to hyperkalemia (serum potassium > 5.0 mmol/L) within three months of LT discharge. Univariable and multivariable Cox proportional hazards regression was used to identify predictors of hyperkalemia. Results Of 544 patients, 268 (49%) developed hyperkalemia within three months following LT discharge. Compared to patients without hyperkalemia, those who developed hyperkalemia were more likely to have diabetes mellitus (30% vs 20%, p=0.01) and higher laboratory MELD scores (29 vs 24, p=0.02). The median time to the first hyperkalemia episode was 11 days (IQR 5-28) after LT discharge, with the highest incidence occurring during the first week after discharge. 110 patients (20%) had hyperkalemia documented during readmission. On multivariable Cox regression, CKD stages 3a (aHR 1.63, 95% CI 1.11-2.40), 3b (aHR 2.38, 95% CI 1.51-3.74), and 5 (aHR 2.01, 95% CI 1.32–3.06); one week pre-transplant potassium (aHR 1.52, 95% CI 1.24-1.84); and discharge potassium (aHR 1.63, 95% CI 1.24-2.16) were independently associated with hyperkalemia. Conclusion Hyperkalemia is common within the first three months following LT discharge. These findings support the development of risk-stratified surveillance and management guidelines to reduce hyperkalemia-related morbidity and healthcare utilization. Given the cost and access barriers associated with outpatient hyperkalemia treatment, targeted interventions are needed to safeguard patients after discharge.