Hypertension in kidney transplantation: a consensus statement of the 'hypertension and the kidney' working group of the European Society of Hypertension

A holistic review of sodium intake in kidney transplant patients: More questions than answers

Kidney transplantation (KT) is the best treatment option for end-stage kidney disease (ESKD). Acute rejection rates have decreased drastically in recent years but chronic kidney allograft disease (CKAD) is still an important cause of allograft failure and return to dialysis. Thus, there is unmet need to identify and reverse the cause of CKAD. Additionally, cardiovascular events after KT are still leading causes of morbidity and mortality. One overlooked potential contributor to CKAD and adverse cardiovascular events is increased sodium/salt intake in kidney transplant recipients (KTRs). In general population, the adverse effects of high sodium intake are well known but in KTRs, there is a paucity of evidence despite decades of experience with KT. Limited research showed that sodium intake is high in most KTRs. Moreover, excess sodium intake is associated with elevated blood pressure and albuminuria in some studies involving KTRs. There is also experimental evidence suggesting that increased sodium intake is associated with histologic graft damage. Critical knowledge gaps still remain, including the exact amount of sodium restriction needed in KTRs to optimize outcomes and allograft survival. Additionally, best methods to measure sodium intake and practices to follow-up are not clarified in KTRs. To meet these deficits, prospective long term studies are warranted in KTRs. Moreover, preventive measures must be determined and implemented both at individual and societal levels to achieve sodium restriction in KTRs.

Are There Differences in Skin Autofluorescence-Measured Advanced Glycation End-Product Levels between Chronic Kidney Disease and Kidney Transplant Recipients?

The aim of this cross-sectional study was to evaluate the differences in the levels of advanced glycation end products (AGE) between patients with chronic kidney disease (CKD) and kidney transplant recipients (KTRs) and to investigate the risk factors for the AGE levels in each group of these patients. There were 217 participants total, of which 99 (45.6%) were KTRs and 118 (54.4%) had CKD. Data on the levels of AGE, body mass composition, anthropometric parameters, central and peripheral blood pressure, and clinical and laboratory parameters were gathered for each study participant. The AGE values of the CKD and KTRs groups did not differ from one another. In both groups, a lower estimated glomerular filtration rate, male sex, and older age were positive predictors for increased AGE values. Furthermore, higher levels of AGE were linked to lower central systolic blood pressure (cSBP) in the CKD group, whilst, in the KTRs group, higher levels of AGE were linked to a shorter time since kidney transplantation (KTx), more years of dialysis prior to KTx, lower levels of trunk visceral fat, the presence of arterial hypertension, and the absence of prescriptions for the antihypertensive medications urapidil and angiotensin II receptor blockers. Further studies are needed to better understand the above associations. Consequently, a personalised multidisciplinary approach to assess the cardiovascular as well as dietary and lifestyle risk factors to reduce the AGE levels in both KTRs and CKD patients may be implemented.

"Long-term effects of center volume on transplant outcomes in adult kidney transplant recipients"

BACKGROUND

The influence of center volume on kidney transplant outcomes is a topic of ongoing debate. In this study, we employed competing risk analyses to accurately estimate the marginal probability of graft failure in the presence of competing events, such as mortality from other causes with long-term outcomes. The incorporation of immunosuppression protocols and extended follow-up offers additional insights. Our emphasis on long-term follow-up aligns with biological considerations where competing risks play a significant role.

METHODS

We examined data from 219,878 adult kidney-only transplantations across 256 U.S. transplant centers (January 2001-December 2015) sourced from the Organ Procurement and Transplantation Network registry. Centers were classified into quartiles by annual volume: low (Q1 = 28), medium (Q2 = 75), medium-high (Q3 = 121), and high (Q4 = 195). Our study investigated the relationship between center volume and 5-year outcomes, focusing on graft failure and mortality. Sub-population analyses included deceased donors, living donors, diabetic recipients, those with kidney donor profile index >85%, and re-transplants from deceased donors.

RESULTS

Adjusted cause-specific hazard ratios (aCHR) for Five-Year Graft Failure and Patient Death were examined by center volume, with low-volume centers as the reference standard (aCHR: 1.0). In deceased donors, medium-high and high-volume centers showed significantly lower cause-specific hazard ratios for graft failure (medium-high aCHR = 0.892, p<0.001; high aCHR = 0.953, p = 0.149) and patient death (medium-high aCHR = 0.828, p<0.001; high aCHR = 0.898, p = 0.003). Among living donors, no significant differences were found for graft failure, while a trend towards lower cause-specific hazard ratios for patient death was observed in medium-high (aCHR = 0.895, p = 0.107) and high-volume centers (aCHR = 0.88, p = 0.061).

CONCLUSION

Higher center volume is associated with significantly lower cause-specific hazard ratios for graft failure and patient death in deceased donors, while a trend towards reduced cause-specific hazard ratios for patient death is observed in living donors.

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.

The association between hydrochlorothiazide use and non-melanoma skin cancer in kidney transplant recipients

Background

hydrochlorothiazide (HCTZ) diuretics were correlated with an increased risk of non-melanoma skin cancer (NMSC) and melanoma in the general population. Information is a scarce regarding this effect in kidney transplant recipients who are at increased risk of skin malignancies under immunosuppression.

Methods

Single-center retrospective analysis of adult kidney transplant recipients between 1 January 2010 and 31 December 2015. The primary outcome of the study was the first diagnosis of skin cancer that was removed and pathologically analyzed. Exposure to thiazides was defined as HCTZ use daily for at least one year at a dose of 12.5 mg.

Results

Among 520 kidney transplant recipients, 50 (9.4%) were treated with HCTZ. During a median follow-up of 9.8 years, 67 patients underwent surgical removal and pathological analysis of at least one skin cancer. Exposure to HCTZ during the 3 years following transplantation was associated with an increased risk of skin cancer (P = 0.004). In a multivariate model, there was a significant association between HCTZ exposure and NMSC (HR 2.54, 95%CI 1.26-5.15, P = 0.007). There was a higher rate of basal cell carcinoma with HCTZ exposure, according to both univariate and multivariate analyses (HR 2.61, 95%CI 1.06-6.43, P = 0.037) and (HR 3.03, 95%CI 1.22-7.55, P = 0.017, respectively). However, no significant association was observed between HCTZ exposure and squamous cell carcinoma.

Conclusions

These findings suggest a benefit of increased frequency of dermatologist inspection in kidney transplant recipients receiving HCTZ especially in increased ultraviolet exposure area.

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.

Uncontrolled hypertension is associated with increased risk of graft failure in kidney transplant recipients: a nationwide population-based study

Backgroud

Hypertension is highly prevalent in patients with kidney transplantation caused by transplantation-related immunologic or non-immunologic risk factors. However, whether a strict definition of hypertension (≥130/80 mmHg) and subdivided blood pressure (BP) groups are associated with an increased risk of graft failure after kidney transplantation using a nationwide large cohort study are still unknown.

Methods

Using Korean National Health Insurance Service data, we included 14,249 patients who underwent kidney transplantation from 2002 to 2016. Patients were categorized into five BP groups according to the 2021 Kidney Disease: Improving Global Outcomes practice guidelines for BP management: normal BP (<120/80 mmHg), elevated BP (120-129/ < 80 mmHg), incident hypertension (≥130/80 mmHg), and controlled or uncontrolled hypertension with anti-hypertensive medications.

Results

The primary outcome was graft failure, which occurred in 1934 (13.6%) participants during the 6-year follow-up. After adjusting for covariates, hypertension was associated with a higher risk of graft failure [Adjusted hazard ratio (AHR), 1.70; 95% confidence interval (CI), 1.48-1.96)] than no-hypertension. The AHR for graft failure was the highest in patients with uncontrolled hypertension (AHR, 2.13; 95% CI, 1.80-2.52). The risk of graft failure had a linear relationship with systolic and diastolic BP, and pulse pressure.

Conclusions

In this nationwide population-based study, hypertension ≥130/80 mmHg based on the 2021 KDIGO BP guidelines in kidney transplantion recipients, and elevated systolic and diastolic BP, and pulse pressure were associated with the risk of developing graft failure in kidney transplant recipients.

Arterial hypertension in kidney transplantation: huge importance, but few answers

Abstract Arterial hypertension (AH) after renal transplantation (RTX) is correlated with worse cardiovascular and renal outcomes, with loss of renal function, decreased graft survival and higher mortality. RTX recipients have discrepant blood pressure (BP) values when measured in the office or by systematic methodologies, such as Ambulatory Blood Pressure Monitoring (ABPM), with significant prevalence of no nocturnal dipping or nocturnal hypertension, white coat hypertension and masked hypertension. The aim of the present study was to review the issue of hypertension in RTX, addressing its multifactorial pathophysiology and demonstrating the importance of ABPM as a tool for monitoring BP in these patients. Treatment is based on lifestyle changes and antihypertensive drugs, with calcium channel blockers considered first-line treatment. The best blood pressure target and treatment with more favorable outcomes in RTX are yet to be determined, through well-conducted scientific studies, that is, in terms of AH in RTX, we currently have more questions to answer than answers to give.

Hipertensão arterial no transplante renal: grande importância, mas poucas respostas

Resumo Hipertensão arterial (HA) no póstransplante renal (TXR) se correlaciona com piores desfechos cardiovasculares e renais, com perda de função renal, diminuição da sobrevida do enxerto e maior mortalidade. Receptores de TXR apresentam valores discrepantes de pressão arterial (PA) quando ela é obtida em consultório ou por metodologias sistematizadas, como a Monitorização Ambulatorial da PA (MAPA), com prevalências significantes de ausência de descenso noturno ou hipertensão noturna, hipertensão do avental branco e hipertensão mascarada. O objetivo do presente estudo foi rever a temática da hipertensão no TXR, abordando sua fisiopatologia multifatorial e demonstrando a importância da MAPA como ferramenta de acompanhamento da PA nesses pacientes. O tratamento é baseado em mudanças no estilo de vida e em fármacos anti-hipertensivos, sendo os bloqueadores de canais de cálcio considerados de primeira linha. A melhor meta pressórica e o tratamento com desfechos mais favoráveis no TXR ainda estão por ser determinados, por meio de estudos bem conduzidos cientificamente, ou seja, em termos de HA no TXR temos atualmente mais questões a responder do que respostas a dar.

Hypertension in kidney transplant recipients

Kidney transplantation is considered the treatment of choice for end-stage kidney disease patients. However, the residual cardiovascular risk remains significantly higher in kidney transplant recipients (KTRs) than in the general population. Hypertension is highly prevalent in KTRs and represents a major modifiable risk factor associated with adverse cardiovascular outcomes and reduced patient and graft survival. Proper definition of hypertension and recognition of special phenotypes and abnormal diurnal blood pressure (BP) patterns is crucial for adequate BP control. Misclassification by office BP is commonly encountered in these patients, and a high proportion of masked and uncontrolled hypertension, as well as of white-coat hypertension, has been revealed in these patients with the use of ambulatory BP monitoring. The pathophysiology of hypertension in KTRs is multifactorial, involving traditional risk factors, factors related to chronic kidney disease and factors related to the transplantation procedure. In the absence of evidence from large-scale randomized controlled trials in this population, BP targets for hypertension management in KTR have been extrapolated from chronic kidney disease populations. The most recent Kidney Disease Improving Global Outcomes 2021 guidelines recommend lowering BP to less than 130/80 mmHg using standardized BP office measurements. Dihydropyridine calcium channel blockers and angiotensin-converting enzyme inhibitors/angiotensin-II receptor blockers have been established as the preferred first-line agents, on the basis of emphasis placed on their favorable outcomes on graft survival. The aim of this review is to provide previous and recent evidence on prevalence, accurate diagnosis, pathophysiology and treatment of hypertension in KTRs.

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.

Ambulatory blood pressure trajectories and blood pressure variability in kidney transplant recipients: a comparative study against chronic kidney disease patients

Background

Methods

Results

Conclusion

Sex differences in ambulatory blood pressure levels, control, and phenotypes of hypertension in kidney transplant recipients

OBJECTIVES

Ambulatory blood pressure (BP) control is worse in men compared with women with chronic kidney disease (CKD) and this may partially explain the faster CKD progression in men. This is the first study investigating possible sex differences in prevalence, control and phenotypes of hypertension in kidney transplant recipients (KTRs) with office-BP and 24-h ambulatory BP monitoring (ABPM).

METHODS

This cross-sectional study included 136 male and 69 female stable KTRs who underwent office-BP measurements and 24-h ABPM. Hypertension thresholds for office and ambulatory BP were defined according to the 2017 ACC/AHA and 2021 KDIGO guidelines for KTRs.

RESULTS

Age, time from transplantation, eGFR and history of major comorbidities did not differ between groups. Office SBP/DBP levels were insignificantly higher in men than women (130.3 ± 16.3/77.3 ± 9.4 vs. 126.4 ± 17.8/74.9 ± 11.5 mmHg; P = 0.118/0.104) but daytime SBP/DBP was significantly higher in men (128.5 ± 12.1/83.0 ± 8.2 vs. 124.6 ± 11.9/80.3 ± 9.3 mmHg; P = 0.032/P = 0.044). No significant between-group differences were detected for night-time BP. The prevalence of hypertension was similar by office-BP criteria (93.4 vs. 91.3%; P = 0.589), but higher in men than women with ABPM (100 vs. 95.7%; P = 0.014). The use of ACEIs/ARBs and CCBs was more common in men. Office-BP control was similar (43.3 vs. 44.4%, P = 0.882), but 24-h control was significantly lower in men than women (16.9 vs. 30.3%; P = 0.029). White-coat hypertension was similar (5.1 vs. 7.6%; P = 0.493), whereas masked hypertension was insignificantly more prevalent in men than women (35.3 vs. 24.2%; P = 0.113).

CONCLUSION

BP levels, hypertension prevalence and control are similar by office criteria but significantly different by ABPM criteria between male and female KTRs. Worse ambulatory BP control in male compared with female KTRs may interfere with renal and cardiovascular outcomes.

The assessment of hypertension in kidney transplant patients: time to change our approach?

Kidney transplantation (KT) is an increasingly utilized treatment for end-stage kidney disease. Hypertension either as a cause of kidney disease or as a complication of chronic kidney disease is the most frequently encountered comorbidity of KT patients. Hence, the management of hypertension in KT patients is crucial to prolong patient and graft survival. Ambulatory blood pressure monitoring (ABPM) appeared as a promising technique that has superiority over office and home blood pressure (BP) monitoring to correctly diagnose and manage hypertension. A recent meta-analysis by Pisano et al. including 42 studies with 4115 participants provided strong data for the comparison of ABPM with office BP monitoring in KT patients. In addition to the current literature knowledge, the findings of Pisano et al. filled the long-awaited evidence gap to suggest ABPM as a first-line BP monitoring technique for KT patients. Despite its disadvantages, such as patient discomfort, cost–effectiveness and limited availability, ABPM has crucial advantages in the management of hypertension including the detection of abnormal circadian BP patterns, the assessment of effects of physical activity and short-term variability of BP, and the exclusion of masked and white-coat hypertension.

Ambulatory blood pressure trajectories and blood pressure variability in kidney transplant recipients: a comparative study against hemodialysis patients

Background

Hypertension is the most prevalent cardiovascular risk factor in kidney transplant recipients (KTRs). Preliminary data suggest similar ambulatory blood pressure (BP) levels in KTRs and haemodialysis (HD) patients. This is the first study comparing the full ambulatory BP profile and short-term BP variability (BPV) in KTRs versus HD patients.

Methods

A total of 204 KTRs were matched (2:1 ratio) with 102 HD patients for age and gender. BP levels, BP trajectories and BPV indices over a 24-h ambulatory BP monitoring (ABPM) in KTRs were compared against both the first and second 24-h periods of a standard 48-h ABPM in HD patients. To evaluate the effect of renal replacement treatment and time on ambulatory BP levels, a two-way ANOVA for repeated measurements was performed.

Results

KTRs had significantly lower systolic blood pressure (SBP) and pulse-pressure (PP) levels compared with HD patients during all periods studied (24-h SBP: KTR: 126.5 ± 12.1 mmHg; HD first 24 h: 132.0 ± 18.1 mmHg; P = 0.006; second 24 h: 134.3 ± 17.7 mmHg; P < 0.001); no significant differences were noted for diastolic blood pressure levels with the exception of the second nighttime. Repeated measurements ANOVA showed a significant effect of renal replacement therapy modality and time on ambulatory SBP levels during all periods studied, and a significant interaction between them; the greatest between-group difference in BP (KTRs–HD in mmHg) was observed at the end of the second 24 h [–13.9 mmHg (95% confidence interval –21.5 to –6.2); P < 0.001]. Ambulatory systolic and diastolic BPV indices were significantly lower in KTRs than in HD patients during all periods studied (24-h SBP average real variability: KTRs: 9.6 ± 2.3 mmHg; HD first 24 h: 10.3 ± 3.0 mmHg; P = 0.032; second 24 h: 11.5 ± 3.0 mmHg; P < 0.001). No differences were noted in dipping pattern between the two groups.

Conclusions

SBP and PP levels and trajectories, and BPV were significantly lower in KTRs compared with age- and gender-matched HD patients during all periods studied. These findings suggest a more favourable ambulatory BP profile in KTRs, in contrast to previous observations.

Adherence to antihypertensive drug treatment in kidney transplant recipients

PURPOSE

Hypertension is a common cardiovascular co-morbidity after kidney transplantation and contributes to shortened graft and patient survival outcomes. However, by contrast with adherence to immunosuppressive drugs, adherence to antihypertensive treatment in kidney transplant recipients has been seldom explored. The aim of the current study was to assess adherence to antihypertensive drugs in kidney transplant recipients from the Cliniques Universitaires Saint-Luc and to look for demographic and clinical characteristics associated with drug adherence.

METHODS

Demographic and clinical data were collected from medical files in a standardised case report form. Blood pressure was measured in the sitting position after 5 min rest, using validated oscillometric devices. Drug adherence was assessed by drug dosage in urine using liquid chromatography coupled with tandem mass spectrometry.

RESULTS

Our analysis included 53 kidney transplants recipients (75% of men, mean age: 57.2 ± 12.6 years, time since kidney transplantation: 9.5 ± 7.3 years, blood pressure: 130 ± 16/78 ± 11 mmHg on 2.1 ± 1.1 antihypertensive drugs). The proportion of patients showing full drug adherence, partial drug adherence, and total non-adherence to antihypertensive drugs was 79% (N = 42), 15% (N = 8), and 6% (N = 3), respectively. Adherent patients did not differ from less or non- adherers in any of the analysed characteristics.

CONCLUSION

The proportion of patients adhering to antihypertensive drug treatment among kidney transplant recipients appears similar to that reported for immunosuppressive drugs in renal transplanted patients (∼70%), but much higher than that observed in patients with drug-resistant hypertension (30-40%). Our results need further confirmation in a large, multicenter, prospective cohort.

Unattended automated office blood pressure in living donor kidney transplant recipients

PURPOSE

Hypertension is common in kidney transplant recipients (KTRs). For the evaluation of blood pressure (BP), 24-h ambulatory BP measurements (ABPM) are considered superior to usual office measurements but are also resource demanding and troublesome to many patients. We therefore evaluated the use of unattended automated office BP (AOBP) during the first year following living donor kidney transplantation and compared AOBP with ABPM as obtained 12 months after transplantation.

MATERIALS AND METHODS

Data were retrieved from a cohort of 57 KTRs (mean age 45 ± 14 years, 75% males) who all received kidneys from living donors and had a good graft function (estimated glomerular filtration rate (eGFR) 52 ± 16 ml/min/1.73 m² at 12 months). Unattended AOBP was measured at each visit to the outpatient clinic using the BpTru® device, while ABPM was obtained by Spacelabs® equipment before and 12 months after transplantation.

RESULTS

AOBP remained stable from month 2 (130.2 ± 10.8/82.2 ± 7.8 mmHg) to month 12 (129.0 ± 12.8/83.1 ± 9.6 mmHg) post-transplantation. At 12 months follow-up, ambulatory daytime systolic BP was slightly higher than AOBP (132.7 ± 10.7 vs. 129.4 ± 12.2 mmHg, p = 0.04), while diastolic BP was similar (82.7 ± 7.7 vs. 82.0 ± 10.2 mmHg). Using Bland-Altman plots, 95% limits of agreements were -17.9 to 24.5 mmHg for systolic and -16.5 to 15.1 mmHg for diastolic BP. When considering a target BP of ≤130/<80 mmHg, 62% had sustained hypertension, 9% white coat hypertension and 11% masked hypertension. Using multiple linear regression analysis, only urine albumin-creatinine ratio tended to predict a higher systolic AOBP (p = 0.07).

CONCLUSION

In a cohort of stable living donor KTRs, mean values of unattended AOBP using BpTru® are comparable to daytime ABPM with a misclassification rate of approximately 20%.