Blood Pressure and Living Kidney Donors: A Clinical Perspective

Artificial intelligence assisted risk prediction in organ transplantation: a UK Live-Donor Kidney Transplant Outcome Prediction tool

Introduction: Predicting the outcome of a kidney transplant involving a living donor advances donor decision-making donors for clinicians and patients. However, the discriminative or calibration capacity of the currently employed models are limited. We set out to apply artificial intelligence (AI) algorithms to create a highly predictive risk stratification indicator, applicable to the UK's transplant selection process.

Methodology: Pre-transplant characteristics from 12,661 live-donor kidney transplants (performed between 2007 and 2022) from the United Kingdom Transplant Registry database were analyzed. The transplants were randomly divided into training (70%) and validation (30%) sets. Death-censored graft survival was the primary performance indicator. We experimented with four machine learning (ML) models assessed for calibration and discrimination [integrated Brier score (IBS) and Harrell's concordance index]. We assessed the potential clinical utility using decision curve analysis.

Results: XGBoost demonstrated the best discriminative performance for survival (area under the curve = 0.73, 0.74, and 0.75 at 3, 7, and 10 years post-transplant, respectively). The concordance index was 0.72. The calibration process was adequate, as evidenced by the IBS score of 0.09.

Conclusion: By evaluating possible donor-recipient pairs based on graft survival, the AI-based UK Live-Donor Kidney Transplant Outcome Prediction has the potential to enhance choices for the best live-donor selection. This methodology may improve the outcomes of kidney paired exchange schemes. In general terms we show how the new AI and ML tools can have a role in developing effective and equitable healthcare.

Aortic stiffness after living kidney donation: a systematic review and meta-analysis

OBJECTIVES

Increased aortic stiffness measured with carotid-femoral pulse wave velocity (cf-PWV) has been associated with adverse cardiovascular outcomes. Some studies have reported increased cf-PWV in living kidney donors after nephrectomy. This review aimed to determine the effects of living kidney donation on cf-PWV, glomerular filtration rate (GFR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and their differences versus non-nephrectomised healthy individuals.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Electronic databases (MEDLINE, EMBASE, Cochrane Central databases, Cochrane Register of Controlled Trials, Cochrane Methodology Register, Health Technology Database, Technologies in Health, EBM Reviews, ProQuest and 'Grey Matters Light'). Databases were searched from inception to December 2022.

ELIGIBILITY CRITERIA

We searched for studies that measured cf-PWV in living kidney donors before and/or after nephrectomy. Non-nephrectomised healthy individuals included as controls were the comparators. Studies that provided age-adjusted cf-PWV reference values in normotensive healthy individuals were also included.

OUTCOME MEASURES

We evaluated the mean differences in cf-PWV, GFR and BP before-and-after nephrectomy and their mean differences versus non-nephrectomised healthy comparators. We also explored differences in yearly adjusted cf-PWV changes between donors and normotensive healthy individuals.

DATA EXTRACTION/SYNTHESIS

Two independent reviewers extracted data and assessed risk of bias (Risk of Bias tool for non-Randomised studies: ROBINS-I) and quality of evidence (GRADE). Pooled effect estimates were calculated using the inverse variance method and analysed with random effect models.

RESULTS

Nine interventional (652 donors; 602 controls) and 6 reference studies (6278 individuals) were included. cf-PWV increased at 1-year postdonation (p=0.03) and was on average 0.4 m/s (95% CI 0.07; 0.60) higher than in healthy controls (p=0.01). These differences were non-significant 5 years postnephrectomy (p=0.54). GFR decreased after nephrectomy (p<0.001) and remained reduced compared with healthy controls (p<0.001), but SBP and DBP were not significantly different (p≥0.14). Yearly changes in cf-PWV postnephrectomy were similar to age-adjusted reference values in healthy normotensive individuals (p=0.76).

CONCLUSIONS

Aortic stiffness increases independent of BP 1 year after kidney donation, but the long-term effects seem minimal. These findings may impact future consent of prospective living kidney donors.

PROSPERO REGISTRATION NUMBER

CRD42020185551.

Analysis of sexual dysfunction development among male and female living kidney donors

INTRODUCTION

Living kidney donations (LKDs) face a persistent demand for patients with end-stage renal disease, emphasizing the importance of LKDs' growth and success. Although living kidney donors generally exhibit excellent survival rates, little research has explored the development of long-term sexual dysfunction following LKD.

OBJECTIVES

This study aimed to analyze differences in 5-year sexual dysfunction outcomes between male and female living kidney donors, utilizing the TriNetX database, a federated network of electronic medical records from multiple U.S. healthcare organizations.

METHODS

A propensity score-matched cohort study compared 45-year sexual dysfunction outcomes in adult male and female living kidney donors from December 2013 to December 2022. Cohorts were matched on age; sex; race and ethnicity; diabetes, cardiovascular, genitourinary, and psychiatric comorbidities; lifestyle-related factors; and medications that may impact normal sexual functioning. Primary outcomes included hazard ratio (HR) for decreased libido, sexual dysfunction (composite of male erectile dysfunction, ejaculatory disorders, vaginismus/dyspareunia, infertility, orgasmic disorders, arousal/desire disorders), and sexually transmitted diseases. Secondary outcomes assessed sex counseling and interpersonal relationship issues with spouses or partners.

RESULTS

The matched cohorts included 2315 patients each (male, female), and the mean age was 42.3 ± 12.5 years. At 5 years, male donors had a significantly higher HR for sexual dysfunction (HR, 3.768; 95% confidence interval, 1.929-7.358). Erectile dysfunction occurred in 1% of male patients, while vaginismus/dyspareunia affected <1% of female patients. Other sexual disorders, decreased libido, sexually transmitted diseases, and incidences of sexual and interspousal counseling were not significantly different.

CONCLUSION

Male living kidney donors faced a higher risk of developing sexual dysfunction 5 years after donation. While LKD remains a safe and viable alternative, clinicians and donors should be mindful of the potential association with sexual dysfunction postdonation. Further research may enhance support for the well-being of living kidney donors.

Comprehensive Surgical Audit of Live-Related Donor Nephrectomy: Procedural Parameters, Demographics, Health Assessments, Complications, and Postoperative Outcomes

BACKGROUND AND OBJECTIVES

End-stage renal disease (ESRD) rates are on the rise globally, including in India. However, the affordability of dialysis treatment remains a significant challenge for many, with costs varying across different regions. Although cost-effective, kidney transplantation faces challenges like a surgeon shortage, lack of infrastructure, and lack of logistic support. The study examines Indian laparoscopic nephrectomy outcomes and their benefits for donor recovery. It covers kidney donor procedural details, demographics, preoperative health evaluations, complications, and one-month follow-up.

METHODS

Ethical approval was obtained, and the study involved 102 cases at the Indira Gandhi Institute of Medical Science, Patna, Bihar, India, from 2019 to 2023. Detailed preoperative assessments, postoperative complications, and one-month follow-up analyses were conducted. Statistical analysis employed SPSS version 17 (IBM Corp., Armonk, NY).

RESULTS

The results revealed an average surgery time of 152.3 min, blood loss of 205 ± 42 ml, and a hospital stay of 4.6 ± 2.2 days. The study found a female predominance (80.39%), with a mean donor age of 35.9 ± 5.2 years. Preoperative assessments showed robust patient health, with glomerular filtration rate (GFR) exceeding the expected threshold and normal urea levels, creatinine, electrolytes, liver enzymes, bilirubin, albumin, and total protein. Post-nephrectomy complications were reported, with females experiencing more difficulties than males.

CONCLUSION

This study underscores the efficiency and safety of laparoscopic nephrectomy in the Indian context, providing valuable insights into donor demographics, preoperative health assessments, complications, and postoperative outcomes. The findings contribute to understanding laparoscopic nephrectomy outcomes and associated risk factors despite certain limitations.

No difference in follow-up estimated glomerular filtration rate between hypertensive and matched nonhypertensive kidney donors

BACKGROUND

According to current guidelines, kidney donor candidates with controlled hypertension using 1 or 2 antihypertensive drugs may be considered as donor. However, this recommendation is based on the study that antihypertensive drug was initiated in mainly "after donor registration" and this may be white-coat hypertension because of donation-related anxiety. We compared the follow-up eGFR between kidney donors with preexisting hypertension and matched nonhypertensive donors.

METHODS

This single-center retrospective study classified 97 living hypertensive donors previously receiving antihypertensive drugs into two groups: 1 drug group (61 donors) and 2 drugs group (36 donors). We compared the follow-up eGFR between each donor previously receiving antihypertensive drugs and three matched nonhypertensive donors in terms of age, sex, and follow-up duration.

RESULTS

At a mean (range) of 51 months (12-214) in the 1 drug group, and 54 months (12-175) in the 2 drugs group after donation, there was no significant difference in follow-up eGFR between hypertensive donors previously receiving antihypertensive drugs and matched controls in each group and in total donors. There was no difference in the incidence of the patients with follow-up eGFR<45mL/min/m2 in each group and their matched controls. Multiple linear regression analysis showed that baseline eGFR was the only independent predictor for the final follow-up eGFR in the total donors.

CONCLUSION

Our results support the current guidelines that donor candidates with controlled hypertension using 1 or 2 antihypertensive drugs may be considered as donors, and may increase the strength of this recommendation.

Risk for subsequent hypertension and cardiovascular disease after living kidney donation: is it clinically relevant?

The first successful live donor kidney transplant was performed in 1954. Receiving a kidney transplant from a live kidney donor remains the best option for increasing both life expectancy and quality of life in patients with end-stage kidney disease. However, ever since 1954, there have been multiple questions raised on the ethics of live kidney donation in terms of negative impacts on donor life expectancy. Given the close relationship between reduced kidney function in patients with chronic kidney disease (CKD) and hypertension, cardiovascular disease and cardiovascular mortality, information on the impact of kidney donation on these is particularly relevant. In this article, we review the existing evidence, focusing on the more recent studies on the impact of kidney donation on all-cause mortality, cardiovascular mortality, cardiovascular disease and hypertension, as well as markers of cardiovascular damage including arterial stiffness and uraemic cardiomyopathy. We also discuss the similarities and differences between the pathological reduction in renal function that occurs in CKD, and the reduction in renal function that occurs because of a donor nephrectomy. Kidney donors perform an altruistic act that benefits individual patients as well as the wider society. They deserve to have high-quality evidence on which to make informed decisions.

Effects of living kidney donation on arterial stiffness: a systematic review protocol

INTRODUCTION

Kidney donors have been reported to have accelerated progression of aortic stiffness and decreased glomerular filtration compared with healthy non-donors. This is a concern because increased aortic stiffness is an independent predictor of overall cardiovascular disease and all-cause mortality in the general population. To confirm if arterial stiffness increases after donation, we will systematically review all studies that evaluated indices of arterial stiffness in healthy individuals who underwent unilateral nephrectomy for kidney donation compared with age-matched healthy non-nephrectomised controls.

METHODS/ANALYSIS

We will comprehensively search for studies published between 1 January 1960 and 15 March 2021 in MEDLINE, EMBASE, Cochrane Central, OVID and EBM reviews. All prospective (cohort, case-control, case series and before-and-after studies) and retrospective non-randomised studies reporting indices of arterial stiffness in nephrectomised and non-nephrectomised healthy participants will be included. Primary outcome will be the difference in the functional metrics of arterial stiffness between donors and non-donors. Secondary outcomes will be the differences in systolic/diastolic blood pressures, serum creatinine, glomerular filtration, carotid artery intima-media thickness and vascular calcification. Study screening, selection and data extraction will be performed by two independent reviewers. Risk of bias will be independently assessed with the ROBINS-I tool and confidence in evidence by the Grading of Recommendations Assessment, Development and Evaluation recommendations. Qualitative and quantitative data syntheses as well as clinical and statistical heterogeneity (Forest plots, I2 and Cochran's Q statistics) will be evaluated. If clinical and statistical heterogeneity are acceptable, inverse variance-weighted effects will be analysed by random effect models.

ETHICS AND DISSEMINATION

No ethical approval is necessary. Our results will be disseminated through peer-review publication and presentations to guide stakeholders on the evaluation and follow-up care of kidney donors.

PROSPERO REGISTRATION NUMBER

CRD42020185551.

Prevalence, Mechanisms, Treatment, and Complications of Hypertension Postliving Kidney Donation

Living kidney donors represent a unique population of patients. Potential donors are selected based on the belief that their preoperative fitness is likely to mitigate the risks of long- and short-term harm following uninephrectomy. Studies performed on postdonation outcomes have largely focused on mortality and the risk of end-stage renal failure, but have also investigated secondary outcomes such as cardiovascular morbidity and hypertension. It has been postulated that hypertension is a possible outcome of living kidney donation. A variety of studies have been conducted to investigate the prevalence, epidemiology, mechanisms, treatment strategies, and long-term ramifications of hypertension postdonation. These studies are heterogeneous in their population, design, methodology, and outcome measures and have presented contradicting outcomes. Additionally, the absence of a well-matched control group has made it challenging to interpret and generalise the reported findings. As such, it is not possible to definitively conclude that hypertension occurs at a higher rate among donors than the general population. This article will review the evidence of postdonation hypertension prevalence, mechanisms, treatment, and complications.