Assessment of hypertension in kidney transplantation by ambulatory blood pressure monitoring: a systematic review and meta-analysis

Approach to Late Noninfectious Post-Transplant Complications

The management of noninfectious complications in kidney transplant recipients includes a broad spectrum of conditions, including metabolic issues, cardiovascular diseases, and malignancies, each presenting unique challenges for nephrologists managing these patients. Unlike infectious complications, these noninfectious issues require nuanced, multidisciplinary approaches for prevention, diagnosis, and management, emphasizing the need for personalized care plans. Cardiovascular disease is particularly significant, standing as the primary cause of death post-transplantation, with recent data indicating an overtaking of cancer death rates over infections among kidney transplant recipients. The intricacies of managing these patients, influenced by the burden of kidney disease and immunosuppression, highlight the importance of a collaborative care model. Although nephrologists may not directly treat all these conditions, their understanding of the unique aspects of transplant recipients is crucial. They play a pivotal role in coordinating care with specialists such as cardiologists, endocrinologists, hematologists, and oncologists, ensuring comprehensive management that addresses these specific post-transplant complications. This review discusses the epidemiology, underlying mechanisms, clinical manifestations, and management strategies of various noninfectious complications post-kidney transplant, with a focus on cardiovascular, metabolic, oncologic, and hematologic complications.

Visit-to-Visit Systolic Blood Pressure Variability Independently Predicts Cardiovascular Events in a Kidney Transplant Recipients' Cohort

BACKGROUND

The predictive role of blood pressure variability for all-cause mortality and fatal and nonfatal cardiovascular events has been described in the general population and in patients with diabetes, independently of mean BP. Although systolic blood pressure variability has been proposed as an informative measure for predicting clinical outcomes in patients with chronic kidney disease, its role in kidney transplant recipients is still debatable.

METHODS AND RESULTS

We performed a retrospective, observational, monocentric analysis of all kidney transplant recipients in follow-up at the outpatient Nephrology Clinic of San Martino Hospital from January 1, 2016 to December 31, 2016, who underwent kidney transplantation >12 months. The primary outcome was a fatal or nonfatal cardiovascular event (myocardial infarction, unstable angina, stroke, and hospitalization for heart failure). Visit-to-visit systolic blood pressure variability was expressed as the SD of systolic blood pressure values recorded at baseline and 3 months up to 18 months. Among the 272 patients (mean age, 64±13; 63% men) included in the present analyses, for each increase of 2.7 mm Hg in systolic blood pressure SD, the risk for events increased 3-fold (hazard ratio [HR], 3.1 [95% CI, 1.19-7.88]; P=0.02), and patients in the highest tertile of systolic blood pressure SD showed a 4-fold increased risk (HR, 4.1 [95% CI, 1.34-12.43]; P=0.01). This relationship was maintained even after incremental adjustment for time-averaged pulse pressure, age, diabetes, and prior cardiovascular event (HR, 3.2 [95% CI, 1.1-10.0]; P=0.04).

CONCLUSIONS

Long-term blood pressure variability represents a risk factor for cardiovascular events in kidney transplant recipients, even independently by several confounding factors including blood pressure load.

A European Renal Association (ERA) synopsis for nephrology practice of the 2023 European Society of Hypertension (ESH) Guidelines for the Management of Arterial Hypertension

In June 2023, the European Society of Hypertension (ESH) presented and published the new 2023 ESH Guidelines for the Management of Arterial Hypertension, a document that was endorsed by the European Renal Association (ERA). Following the evolution of evidence in recent years, several novel recommendations relevant to the management of hypertension in patients with chronic kidney disease (CKD) appeared in these Guidelines. These include recommendations for target office blood pressure (BP) <130/80 mmHg in most and against target office BP <120/70 mmHg in all patients with CKD; recommendations for use of spironolactone or chlorthalidone for patients with resistant hypertension with estimated glomerular filtration rate (eGFR) higher or lower than 30 mL/min/1.73 m2, respectively; use of a sodium-glucose cotransporter 2 inhibitor for patients with CKD and estimated eGFR ≥20 mL/min/1.73 m2; use of finerenone for patients with CKD, type 2 diabetes mellitus, albuminuria, eGFR ≥25 mL/min/1.73 m2 and serum potassium <5.0 mmol/L; and revascularization in patients with atherosclerotic renovascular disease and secondary hypertension or high-risk phenotypes if stenosis ≥70% is present. The present report is a synopsis of sections of the ESH Guidelines that are relevant to the daily clinical practice of nephrologists, prepared by experts from ESH and ERA. The sections summarized are those referring to the role of CKD in hypertension staging and cardiovascular risk stratification, the evaluation of hypertension-mediated kidney damage and the overall management of hypertension in patients with CKD.

Circadian rhythms in solid organ transplantation

Circadian rhythms are daily cycles in physiology that can affect medical interventions. This review considers how these rhythms may relate to solid organ transplantation. It begins by summarizing the mechanism for circadian rhythm generation known as the molecular clock, and basic research connecting the clock to biological activities germane to organ acceptance. Next follows a review of clinical evidence relating time of day to adverse transplantation outcomes. The concluding section discusses knowledge gaps and practical areas where applying circadian biology might improve transplantation success.

Telemedicine for Kidney Transplant Recipients: Current State, Advantages, and Barriers

Telemedicine is defined as the use of electronic information and communication technologies to provide and support healthcare at a distance. In kidney transplantation, telemedicine is limited but is expected to grow markedly in the coming y. Current experience shows that it is possible to provide transplant care at a distance, with benefits for patients like reduced travel time and costs, better adherence to medication and appointment visits, more self-sufficiency, and more reliable blood pressure values. However, multiple barriers in different areas need to be overcome for successful implementation, such as recipients' preferences, willingness, skills, and digital literacy. Moreover, in many countries, limited digital infrastructure, legislation, local policy, costs, and reimbursement issues could be barriers to the implementation of telemedicine. Finally, telemedicine changes the way transplant professionals provide care, and this transition needs time, training, willingness, and acceptance. This review discusses the current state and benefits of telemedicine in kidney transplantation, with the aforementioned barriers, and provides an overview of future directions on telemedicine in kidney transplantation.

A paradigm shift from office to home-based blood pressure measurement approaches in kidney transplant recipients

PURPOSE OF REVIEW

The unattended blood pressure (BP) readings from home blood pressure (HBP) monitoring should provide more accurate BP readings than attended BP obtained from office blood pressure (OBP). Here, we review evidence supporting the clinical utility of HBP and automatic remote monitoring of blood pressure (ARM-BP) in kidney transplant recipients (KTR).

RECENT FINDINGS

BP from 24-h ambulatory blood pressure monitoring (24-h ABPM) is higher than but better associated with kidney and cardiovascular outcomes compared to OBP and HBP. While there is discordance of BP readings across different BP measurement methods causing BP misclassification, HBP provides BP readings closer to the readings from the 24-h ABPM than those from OBP. Systolic and diastolic BP is better controlled within 30 days after utilizing ARM-BP.

SUMMARY

Compared to OBP, HBP minimizes the attended effect of OBP, and its readings are closer to the gold standard 24-h ABPM. ARM-BP improves BP control in the short term and trials of longer follow-up duration are required to evaluate sustained clinical benefits in KTR. The paradigm of BP monitoring may shift toward HBP, while OBP may be utilized primarily for KTR who cannot perform HBP for hypertension diagnosis and management.

Denervation aggravates renal ischemia reperfusion injury via BMAL1-mediated Nrf2/ARE pathway

AIM

To explore the change of clock gene rhythm under renal denervation (RDN) and its effect on renal function and oxidative stress during renal ischemia-reperfusion (IR) injury.

METHOD

C57/BL6 mice were randomly divided into 4 groups at daytime 7 A M (zeitgeber time [ZT] 0) or at nighttime 7 P M (ZT12) in respectively: Sham (S) group, RDN group, IR group and RDN + IR (DIR) group. Renal pathological and functional changes were assessed by H&E staining, and serum creatinine, urea nitrogen and neutrophil gelatinase-associated lipocalin levels. Renal oxidative stress was detected by SOD and MDA levels, and renal inflammation was measured by IL-6, IL-17 A F and TNF-ɑ levels. BMAL1, CLOCK, Nrf2 and HO-1 mRNA and protein expressions were tested by qPCR and Western Blot.

RESULT

Compared with S groups, the rhythm of BMAL1, CLOCK and Nrf2 genes in the kidney were disordered in RDN groups, while renal pathological and functional indexes did not change significantly. Compared with IR groups, renal pathological and functional indexes were significantly higher in the DIR groups, as well as oxidative stress and inflammation in renal tissues. The nocturnal IR injury in the RDN kidney was the worst while the BMAL1, Nrf2 and HO-1 expressions were the highest. In DIR groups, renal injury was aggravated after the Brusatol treatment, but there was no significant improvement after the t-BHQ treatment at night, which might be consistent with the changes of Nrf2 and HO-1 protein expressions.

CONCLUSION

RDN lead to the disruption of BMAL1-mediated Nrf2 rhythm accumulation in the kidney, which reduced the renal ability to resist oxidative stress and inflammation, due to the impaired effect of activating Nrf2/ARE pathway in renal IR injury at nighttime.

Blood pressure management and long-term outcomes in kidney transplantation: a holistic view over a 35-year period

INTRODUCTION

Hypertension is a burden for most kidney transplant recipients. Whether respect of hypertension guidelines results in better outcomes is unknown.

METHODS

In this multicenter study, office blood pressure at 12 months following transplantation (i.e., after > 20 outpatient visits), and survival were assessed over 35 years among 2004 consecutive kidney transplant recipients who received a first kidney graft from 1985 to 2019 (follow-up: 26,232 patient-years).

RESULTS

Antihypertensive medications were used in 1763/2004 (88.0%) patients. Renin-angiotensin-system blockers were used in 35.6% (47.1% when proteinuria was > 0.5 g/day) and calcium-channel blockers were used in 6.0% of patients. Combined treatment including renin-angiotensin-system-blockers, calcium-channel blockers and diuretics was used in 15.4% of patients receiving ≥ 3 antihypertensive drugs. Blood pressure was controlled in 8.3%, 18.8% and 43.1%, respectively, depending on definition (BP < 120/80, < 130/80, < 140/90 mmHg, respectively) and has not improved since the year 2001. Two-thirds of patients with uncontrolled blood pressure received < 3 antihypertensive classes. Low sodium intake < 2 g/day (vs ≥ 2) was not associated with better blood pressure control. Uncontrolled blood pressure was associated with lower patient survival (in multivariable analyses) and graft survival (in univariate analyses) vs controlled hypertension or normotension. Low sodium intake and major antihypertensive classes had no influence on patient and graft survival.

CONCLUSIONS

Pharmacological recommendations and sodium intake reduction are poorly respected, but even when respected, do not result in better blood pressure control, or patient or graft survival. Uncontrolled blood pressure, not the use of specific antihypertensive classes, is associated with reduced patient, and to a lesser extent, reduced graft survival, even using the 120/80 mmHg cut-off.

Hypertension as Cardiovascular Risk Factor in Chronic Kidney Disease

Hypertension is the leading modifiable cause of premature death and hence one of the global targets of World Health Organization for prevention. Hypertension also affects the great majority of patients with chronic kidney disease (CKD). Both hypertension and CKD are intrinsically related, as hypertension is a strong determinant of worse renal and cardiovascular outcomes and renal function decline aggravates hypertension. This bidirectional relationship is well documented by the high prevalence of hypertension across CKD stages and the dual benefits of effective antihypertensive treatments on renal and cardiovascular risk reduction. Achieving an optimal blood pressure (BP) target is mandatory and requires several pharmacological and lifestyle measures. However, it also requires a correct diagnosis based on reliable BP measurements (eg, 24-hour ambulatory BP monitoring, home BP), especially for populations like patients with CKD where reduced or reverse dipping patterns or masked and resistant hypertension are frequent and associated with a poor cardiovascular and renal prognosis. Even after achieving BP targets, which remain debated in CKD, the residual cardiovascular risk remains high. Current antihypertensive options have been enriched with novel agents that enable to lower the existing renal and cardiovascular risks, such as SGLT2 (sodium-glucose cotransporter-2) inhibitors and novel nonsteroidal mineralocorticoid receptor antagonists. Although their beneficial effects may be driven mostly from actions beyond BP control, recent evidence underline potential improvements on abnormal 24-hour BP phenotypes such as nondipping. Other promising novelties are still to come for the management of hypertension in CKD. In the present review, we shall discuss the existing evidence of hypertension as a cardiovascular risk factor in CKD, the importance of identifying hypertension phenotypes among patients with CKD, and the traditional and novel aspects of the management of hypertensives with CKD.

A parallel evaluation of short- and mid-term changes of ambulatory blood pressure in kidney transplant recipients and kidney donors

Introduction

Kidney transplantation (KTx) is associated with improved blood pressure (BP) levels for kidney transplant recipients (KTRs) without evoking significant changes in donors. However, there is a paucity of studies offering simultaneous detailed evaluation of BP profiles over time in transplant donor-recipient pairs. The aim of the present study was the parallel evaluation of ambulatory BP levels and trajectories in KTRs and their respective living kidney donors in the short and mid-term following KTx.

Methods

The study enrolled 40 prospective adult KTRs and their 40 respective donors. All participants were evaluated with 24-h ambulatory BP monitoring (Mobil-O-Graph NG device) at three time points: baseline (1 month before KTx), 3 months and 12 months after KTx.

Results

In KTRs, 3-month 24-h systolic BP (SBP) was marginally reduced and 12-month 24-h SBP significantly reduced compared with baseline [131.9 ± 13.3 versus 126.4 ± 11.9 mmHg (P = .075) and 123.9 ± 10.3 mmHg (P = .009),  respectively]. At both the 3- and 12-month time points, 24-h diastolic BP (DBP) was significantly reduced [86.7 ± 11.5 versus 82.2 ± 8.1 mmHg (P = .043) and 80.3 ± 8.5 mmHg (P = .009)]. Similar observations were made for day- and night time SBP and DBP. Repeated-measures analysis of variance (ANOVA) showed a significant gradual decrease over time in mean 24-h SBP [F(1.463, 39.505) = 3.616; P = .049, partial η ² = 0.118] and DBP [F(1.374, 37.089) = 11.34; P = .055, partial η ² = 0.116]. In contrast, in kidney donors, 24-h SBP [118.5 ± 11.6 versus 118.2 ± 12.8 mmHg (P = .626) and 119.2 ± 11.4 mmHg (P = .748)] and DBP did not change at 3 or 12 months compared with baseline; repeated measures ANOVA showed no differences in the mean 24-h SBP and DBP levels over time. The number of antihypertensive agents decreas in KTRs and remained stable in donors.

Conclusions

KTx reduces ambulatory BP levels and trajectories in KTRs at 3 months and further so at 12 months post-surgery. Kidney donation does not affect the ambulatory BP levels and trajectories of donors at the same intervals.