The impact of severe acute kidney injury requiring renal replacement therapy on survival and renal function of heart transplant recipients - a UK cohort study

Prediction of Kidney Function Improvement After Heart Transplantation

Background/Objectives: Patients with advanced heart failure (HF) often suffer from impaired kidney function. Based on the pathophysiology of types I and II of cardiorenal syndrome, heart transplantation (Htx) may restore renal function. The aim of this study was to identify predictors of improvement in kidney function after HTx. Methods: Htx patients from a tertiary hospital were retrospectively divided into three groups-improvement (n = 24), deterioration (n = 31) and no significant change in eGFR (n = 45)-based on changes in their mean estimated glomerular filtration rate (eGFR) within the first three postoperative months, compared to the last three preoperative months. The threshold for eGFR improvement was defined as a ≥20% increase, while deterioration was defined as a ≥20% decrease. The no significant change group was defined as any change falling between these two values. Results: The median age of analyzed cohort was 54 (45-63) years, and 82% were male. Preoperatively, the improvement group was more frequently treated with inotropes or vasopressors and had significantly higher blood urea and total bilirubin levels before Htx. In the multivariate analysis, total bilirubin before Htx (OR 1.66; 95% CI; 1.24-2.69; p = 0.002) and no need for RRT early after Htx (OR 0.46; 95% CI 0.24-0.88; p = 0.02) were independent predictors of improved kidney function in the first three months after HTx. Conclusions: The improvement in renal function after HTx is uncommon. It could be expected in patients suffering from more severe forms of HF, with impaired kidney and liver function but who did not need RRT after the surgery.

Early Renal Outcomes Following Heart Transplantation Using Organs Procured After Circulatory Death

BACKGROUND

Transplantation using hearts obtained through donation after circulatory death (DCD) is increasing, but data on recipient renal outcomes are limited.

METHODS AND RESULTS

Patients at a single institution who underwent heart transplantation using organs procured through DCD or donation after brain death (DBD) from April 2016 to August 2022 were included in this retrospective cohort study. Hemodynamic measures were collected via right heart catheterization performed 1 week after transplantation. Posttransplantation renal outcomes included estimated glomerular filtration rate at 1 week, 4 weeks, and 16 weeks, and the incidence of acute kidney injury (AKI) and renal replacement therapy within 1 week. The analysis included 225 patients (55 recipients of DCD). Baseline characteristics were comparable between recipients of DCD and DBD. Renal outcomes within 1 week posttransplantation in recipients of DCD were similar to recipients of DBD, including percent change in estimated glomerular filtration rate (-37.9% [-58.6 to -6.2] versus -31.9% [-52.4 to -9.9]; P=0.91), incidence of AKI (47.3% versus 46.5%; P>0.99) and incidence of renal replacement therapy (3.6% versus 4.7%; P>0.99). Recipients of DCD with AKI within 1 week ("early AKI") did not recover to baseline estimated glomerular filtration rate (75.8 [60.2-91.3] mL/min per 1.73 m2) by week 16 (59.3 [46.9-73.6] mL/min per 1.73 m2; P=0.002), whereas recipients without early AKI exhibited comparable estimated glomerular filtration rate to baseline by week 4 (84.5 [70.8-98.5] mL/min per 1.73 m2; P=0.084). Similar trends were observed in recipients of DBD.

CONCLUSIONS

Recipients of DCD demonstrated similar renal outcomes compared with recipients of DBD, supporting the ongoing use of DCD transplantation. Early AKI was associated with persistent renal dysfunction for recipients of both DCD and DBD.

Acute Kidney Injury After Heart Transplantation: Risk Factors and Clinical Outcomes

OBJECTIVE

Acute kidney injury (AKI) requiring renal-replacement therapy (RRT) after heart transplantation (OHT) is common and impairs outcomes. This study aimed to identify independent donor and recipient risk factors associated with RRT after OHT.

DESIGN

A retrospective data analysis.

SETTING

Data were collected from clinical routines in a maximum-care university hospital.

PARTICIPANTS

Patients who underwent OHT.

INTERVENTIONS

The authors retrospectively analyzed data from 264 patients who underwent OHT between 2012 and 2021; 189 patients were eligible and included in the final analysis.

MEASUREMENTS AND MAIN RESULTS

The mean age was 48.0 ± 12.3 years, and 71.4% of patients were male. Ninety (47.6%) patients were on long-term mechanical circulatory support (lt-MCS). Posttransplant AKI with RRT occurred in 123 (65.1%) patients. In a multivariate analysis, preoperative body mass index >25 kg/m² (odds ratio [OR] 4.74, p < 0.001), elevated preoperative creatinine levels (OR for each mg/dL increase 3.44, p = 0.004), administration of red blood cell units during transplantation procedure (OR 2.31, p = 0.041) and ischemia time (OR for each hour increase 1.77, p = 0.004) were associated with a higher incidence of RRT. The use of renin-angiotensin-aldosterone system blockers before transplantation was associated with a reduced risk of RRT (OR 0.36, p = 0.013). The risk of mortality was 6.9-fold higher in patients who required RRT (hazard ratio 6.9, 95% CI: 2.1-22.6 p = 0.001). Previous lt-MCS, as well as donor parameters, were not associated with RRT after OHT.

CONCLUSIONS

The implementation of guideline-directed medical therapy, weight reduction, minimizing ischemia time (ie, organ perfusion systems, workflow optimization), and comprehensive patient blood management potentially influences renal function and outcomes after OHT.

Heart Transplantation-Postoperative Considerations

Heart transplantation (HT) remains the best treatment of patients with severe heart failure who are deemed to be transplant candidates. The authors discuss postoperative management of the HT recipient by system, emphasizing areas where care might differ from other cardiac surgery patients. Working together, critical care physicians, heart transplant surgeons and cardiologists, advanced practice providers, pharmacists, transplant coordinators, nursing staff, physical therapists, occupational therapists, rehabilitation specialists, nutritionists, health psychologists, social workers, and the patient and their loved ones partner to increase the likelihood of a successful outcome.

Neutrophil gelatinase-associated lipocalin as predictor of acute kidney injury requiring renal replacement therapy: A systematic review and meta-analysis

Background

Patients with severe acute kidney injury (AKI) may require renal replacement therapy (RRT), such as hemodialysis and peritoneal dialysis. Neutrophil gelatinase-associated lipocalin (NGAL) is a sensitive indicator for early diagnosis and recognition of AKI; however, its predictive value of AKI-associated need for RRT needs further evaluation.

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, relevant articles were systematically searched and selected from seven databases. The random effects model was applied to evaluate the predictive performance of NGAL for AKI requiring RRT. The Newcastle–Ottawa Scale (NOS) was used to assess the quality of each included study.

Results

A total of 18 studies including 1,787 patients with AKI and having an average NOS score of 7.67 were included in the meta-analysis. For plasma/serum NGAL, the pooled sensitivity and specificity with corresponding 95% confidence interval (CI) were 0.75 (95% CI: 0.68–0.81) and 0.76 (95% CI: 0.70–0.81), respectively. The pooled positive likelihood ratio (PLR) was 2.9 (95% CI: 2.1–4.1), and the pooled negative likelihood ratio (NLR) was 0.34 (95% CI: 0.25–0.46). Subsequently, the pooled diagnostic odds ratio (DOR) was 9 (95% CI: 5–16) using a random effects model, and the area under the curve (AUC) of summary receiver operating characteristic to summarize predictive accuracy was 0.82 (95% CI: 0.79–0.85). For urine NGAL, the pooled sensitivity, specificity, PLR, NLR, DOR, and AUC values were 0.78 (95% CI: 0.61–0.90), 0.77 (95% CI: 0.65–0.85), 3.4 (95% CI: 2.4–4.8), 0.28 (95% CI: 0.15–0.52), 12 (95% CI: 6–24), and 0.84 (95% CI: 0.80–0.87), respectively.

Conclusion

Plasma/serum and urine NGAL levels performed comparably well in predicting AKI requiring RRT. Our findings suggested that NGAL is an effective predictive biomarker for the AKI-associated need for RRT. Nevertheless, more pieces of high-quality evidence and future trials with larger sample sizes are needed for further improvement of patient outcomes.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022346595], identifier [CRD42022346595].

Management of long-term cardiovascular risk factors post organ transplant

PURPOSE OF REVIEW

Cardiovascular disease is one of the leading causes of death in solid organ transplant (SOT) recipients. Early identification of cardiovascular risk factors and their adequate management in this population is key for prevention and improved outcomes.

RECENT FINDINGS

Approximately 80% of SOT present one or more cardiovascular risk factors, with increasing prevalence with time posttransplantation. They are due to the interplay of pretransplant conditions and metabolic consequences of immunosuppressive agents, mainly corticosteroids and calcineurin inhibitors. Among the pharmacological management strategies, statins have shown an important protective effect in SOT.

SUMMARY

Strict surveillance of cardiovascular risk factors is recommended in SOT due to their high prevalence and prognostic implications. Further studies on the best managements strategies in this population are needed.