Nocturnal Hypertension and Altered Night–Day BP Profile and Atherosclerosis in Renal Transplant Patients

Office or home versus 24-h blood pressure measurement in stable kidney transplant recipients

BACKGROUND

The aim of this study was to quantify hypertension control and evaluate concordance between all commonly available blood pressure (BP) modalities in kidney transplant recipients (KTRs).

METHODS

For this prospective cross-sectional study, 89 stable KTRs were recruited at the Charité Transplant Outpatient Clinic. For each study participant office [manual office BP (MOBP) and automated office BP (AOBP)], 7-day home (HBPM) and 24-hour ambulatory BP (24h-ABPM) measurements were performed.

RESULTS

80 of the 89 patients recruited had sufficient BP recordings. The mean BP for MOBP, AOBP, HBPM and 24h-ABPM was 129/73, 126/71, 131/85 and 130/81 mmHg, respectively. Uncontrolled hypertension, as defined by 24h-ABPM (mean ≥130/80 mmHg), was present in 53 (66%) patients. MOBP, AOBP and HBPM classified 19 (24%), 22 (28%) and 41 (51%) patients, respectively, as 'uncontrolled hypertensive'. The Bland-Altman plot showed good agreement between systolic MOBP, AOBP, HBPM and daytime-ABPM (mean bias: -1 ± 13 mmHg, -4 ± 13 mmHg, 1 ± 10 mmHg, respectively). Uncontrolled night-time hypertension was present in 74 (93%) KTRs, with 71 (89%) patients showing a non-physiological dipping pattern. Moderate positive correlation between daytime-ABPM/HBPM and night-time-ABPM (Pearson correlation coefficients: 0.62-0.73), followed by MOBP/AOBP (Pearson correlation coefficients: 0.49-0.59) was noted. Estimated eGFR and proteinuria displayed weak correlation with 24h-, daytime- and night-time-ABPM (absolute values of Pearson correlation coefficients: 0.04-0.41). No robust association with either 24h-, daytime- or night-time-ABPM was observed for volume status exams.

CONCLUSIONS

Masked hypertension is highly prevalent in KTRs, especially due to high rates of uncontrolled night-time hypertension. HBPM shows the narrowest limits of agreement with daytime-ABPM. Daytime-ABPM and HBPM show the highest, albeit clinically insufficient, correlation with night-time-ABPM. Systematic integration of 24h-ABPM into clinical practice, as proposed by the 2023 ESH guidelines for the management of arterial hypertension, should not be withheld for the KTR population. Clinical trials evaluating the treatment of hypertension in KTRs are urgently needed.

Adverse Drug Events after Kidney Transplantation

Introduction: Kidney transplantation stands out as the optimal treatment for patients with end-stage kidney disease, provided they meet specific criteria for a secure outcome. With the exception of identical twin donor-recipient pairs, lifelong immunosuppression becomes imperative. Unfortunately, immunosuppressant drugs, particularly calcineurin inhibitors like tacrolimus, bring about adverse effects, including nephrotoxicity, diabetes mellitus, hypertension, infections, malignancy, leukopenia, anemia, thrombocytopenia, mouth ulcers, dyslipidemia, and wound complications. Since achieving tolerance is not feasible, patients are compelled to adhere to lifelong immunosuppressive therapies, often involving calcineurin inhibitors, alongside mycophenolic acid or mTOR inhibitors, with or without steroids. Area covered: Notably, these drugs, especially calcineurin inhibitors, possess narrow therapeutic windows, resulting in numerous drug-related side effects. This review focuses on the prevalent immunosuppressive drug-related side effects encountered in kidney transplant recipients, namely nephrotoxicity, post-transplant diabetes mellitus, leukopenia, anemia, dyslipidemia, mouth ulcers, hypertension, and viral reactivations (cytomegalovirus and BK virus). Additionally, other post-kidney-transplantation drugs such as valganciclovir may also contribute to adverse events such as leukopenia. For each side effect, we propose preventive measures and outline appropriate treatment strategies.

Diagnosis of cardiovascular disease in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) are at high risk of cardiovascular disease (CVD) and cardiovascular death. Identifying and monitoring cardiovascular complications and hypertension is important for managing patients with CKD or kidney failure and transplant recipients. Biomarkers of myocardial ischaemia, such as troponins and electrocardiography (ECG), have limited utility for diagnosing cardiac ischaemia in patients with advanced CKD. Dobutamine stress echocardiography, myocardial perfusion scintigraphy and dipyridamole stress testing can be used to detect coronary disease in these patients. Left ventricular hypertrophy and left ventricular dysfunction can be detected and monitored using various techniques with differing complexity and cost, including ECG, echocardiography, nuclear magnetic resonance, CT and myocardial scintigraphy. Atrial fibrillation and other major arrhythmias are common in all stages of CKD, and ambulatory heart rhythm monitoring enables precise time profiling of these disorders. Screening for cerebrovascular disease is only indicated in asymptomatic patients with autosomal dominant polycystic kidney disease. Standardized blood pressure is recommended for hypertension diagnosis and treatment monitoring and can be complemented by ambulatory blood pressure monitoring. Judicious use of these diagnostic techniques may assist clinicians in detecting the whole range of cardiovascular alterations in patients with CKD and enable timely treatment of CVD in this high-risk population.

Amiloride evokes significant natriuresis and weight loss in kidney transplant recipients with and without albuminuria

Albuminuria in kidney transplant recipients (KTRs) is associated with hypertension and aberrant glomerular filtration of serine proteases that may proteolytically activate the epithelial Na+ channel (ENaC). The present nonrandomized, pharmacodynamic intervention study aimed to investigate if inhibition of ENaC increases Na+ excretion and reduces extracellular volume in KTRs dependent on the presence of albuminuria. KTRs with and without albuminuria (albumin-to-creatinine ratio > 300 mg/g, n = 7, and <30 mg/g, n = 7, respectively) were included and ingested a diet with fixed Na+ content (150 mmol/day) for 5 days. On the last day, amiloride at 10 mg was administered twice. Body weight, 24-h urine electrolyte excretion, body water content, and ambulatory blood pressure as well as plasma renin, angiotensin II, and aldosterone concentrations were determined before and after amiloride. Amiloride led to a significant decrease in body weight, increase in 24-h urinary Na+ excretion, and decrease in 24-h urinary K+ excretion in both groups. Urine output increased in the nonalbuminuric group only. There was no change in plasma renin, aldosterone, and angiotensin II concentrations after amiloride, whereas a significant decrease in nocturnal systolic blood pressure and increase in 24-h urine aldosterone excretion was observed in albuminuric KTRs only. There was a significant correlation between 24-h urinary albumin excretion and amiloride-induced 24-h urinary Na+ excretion. In conclusion, ENaC activity contributes to Na+ and water retention in KTRs with and without albuminuria. ENaC is a relevant pharmacological target in KTRs; however, larger and long-term studies are needed to evaluate whether the magnitude of this effect depends on the presence of albuminuria.NEW & NOTEWORTHY Amiloride has a significant natriuretic effect in kidney transplant recipients (KTRs) that relates to urinary albumin excretion. The epithelial Na+ channel may be a relevant direct pharmacological target to counter Na+ retention and hypertension in KTRs. Epithelial Na+ channel blockers should be further investigated as a mean to mitigate Na+ and water retention and to potentially obtain optimal blood pressure control in KTRs.

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.

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

Background

Methods

Results

Conclusion

Number of Teeth and Nutritional Status Parameters Are Related to Intima-Media Thickness in Dalmatian Kidney Transplant Recipients

Although kidney transplantation significantly improves the quality of life of patients with end-stage renal disease (ESRD), the prevalence of cardiovascular disease (CVD) in kidney transplant recipients (KTRs) remains high. Atherosclerosis, post-transplantation metabolic changes, immunosuppressive therapy, and periodontitis contribute to elevated cardiovascular risk in this population. The aim of the study was to evaluate carotid intima-media thickness (IMT) as a surrogate marker of atherosclerosis and to analyze the possible risk factors for IMT in Dalmatian KTRs. Ninety-three KTRs were included in this study. Data on clinical and laboratory parameters, body composition, anthropometry, advanced glycation end-product (AGE) measurements, blood pressure, and arterial stiffness were collected. All participants underwent ultrasound examination of IMT and evaluation of periodontal status. KTRs with carotid IMT ≥ 0.9 were significantly older, had a lower level of total cholesterol, fat mass, end-diastolic velocity (EDV), and had fewer teeth. They also had significantly higher values of pulse wave velocity (PWV) and resistive index (RI). We found positive correlations between carotid IMT and duration of dialysis, age, PWV, AGE, RI, and average total clinical attachment level (CAL). The regression model showed that IMT in KTRs is associated with higher PWV, lower fat mass, and fewer teeth. The results of our study suggest that nutritional and periodontal status are associated with carotid IMT in KTRs.

Ambulatory blood pressure trajectories and blood pressure variability in kidney transplant recipients: a comparative study against haemodialysis 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.

Isolated nocturnal hypertension in pediatric kidney transplant recipients

BACKGROUND

Isolated nocturnal hypertension (INH) is defined as nighttime hypertension in the setting of normal daytime blood pressure (BP), diagnosed by ambulatory BP monitoring (ABPM).

METHODS AND RESULTS

Hypertension affects 60%-80% of pediatric kidney transplant recipients, and INH is the most common type of ambulatory hypertension. INH is associated with an increased prevalence of hypertension-mediated target organ damage such as left ventricular hypertrophy in adults and in pediatric kidney transplant recipients.

CONCLUSION

Ambulatory BP monitoring should be performed annually in all pediatric kidney transplant recipients to diagnose hypertension phenotypes that are not detectable by office BP such as masked hypertension, white-coat hypertension, or INH. Isolated nocturnal hypertension in pediatric transplant patients requires study as a treatment target.

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

Background

Hypertension (HTN) is common following renal transplantation and it is associated with adverse effects on cardiovascular (CV) and graft health. Ambulatory blood pressure monitoring (ABPM) is the preferred method to characterize blood pressure (BP) status, since HTN misclassification by office BP (OBP) is quite common in this population. We performed a systematic review and meta-analysis aimed at determining the clinical utility of 24-h ABPM and its potential implications for the management of HTN in this population.

Methods

Ovid-MEDLINE and PubMed databases were searched for interventional or observational studies enrolling adult kidney transplant recipients (KTRs) undergoing 24-h ABP readings compared with OBP or home BP. The main outcome was the proportion of KTRs diagnosed with HTN by ABPM, home or OBP recordings. Additionally, day-night BP variability and dipper/non-dipper status were assessed.

Results

Forty-two eligible studies (4115 participants) were reviewed. A cumulative analysis including 27 studies (3481 participants) revealed a prevalence of uncontrolled HTN detected by ABPM of 56% [95% confidence interval (CI) 46-65%]. The pooled prevalence of uncontrolled HTN according to OBP was 47% (95% CI 36-58%) in 25 studies (3261 participants). Very few studies reported on home BP recordings. The average concordance rate between OBP and ABPM measurements in classifying patients as controlled or uncontrolled hypertensive was 66% (95% CI 59-73%). ABPM revealed HTN phenotypes among KTRs. Two pooled analyses of 11 and 10 studies, respectively, revealed an average prevalence of 26% (95% CI 19-33%) for masked HTN (MHT) and 10% (95% CI 6-17%) for white-coat HTN (WCH). The proportion of non-dippers was variable across the 28 studies that analysed dipping status, with an average prevalence of 54% (95% CI 45-63%).

Conclusions

In our systematic review, comparison of OBP versus ABP measurements disclosed a high proportion of MHT, uncontrolled HTN and, to a lesser extent, WCH in KTRs. These results suggest that HTN is not adequately diagnosed and controlled by OBP recordings in this population. Furthermore, the high prevalence of non-dippers confirmed that circadian rhythm is commonly disturbed in KTRs.

Role of hypertension in kidney transplant recipients

Cardiovascular events are one of the leading causes of mortality in kidney transplant recipients. Hypertension is the most common comorbidity accompanying chronic kidney disease, with prevalence remaining as high as 90% even after kidney transplantation. It is often poorly controlled. Abnormal blood pressure profiles, such as masked or white-coat hypertension, are also extremely common in these patients. The pathophysiology of blood pressure elevation in kidney transplant recipients is complex and includes transplantation-specific risk factors, which are added to the traditional or chronic kidney disease-related factors. Despite these observations, hypertension management has been an under-researched area in kidney transplantation. Thus, relevant evidence derives either from studies in the general population or from small trials in kidney transplant recipients. Based on the relevant guidelines in the general population, lifestyle modifications should probably be applied as the first step of hypertension management in kidney transplant recipients. The optimal pharmacological management of hypertension in kidney transplant recipients is also not clear. Dihydropyridine calcium channel blockers are commonly used as first line agents because of their lack of adverse effects on the kidney, while other antihypertensive drug classes are under-utilised due to fear of the possible haemodynamic consequences on renal function. This review summarizes the existing data on the pathophysiology, diagnosis, prognostic significance and management of hypertension in kidney transplantation.

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%.

Diagnostic Performance of Office versus Ambulatory Blood Pressure in Kidney Transplant Recipients

INTRODUCTION

Hypertension is the most prominent risk factor in kidney transplant recipients (KTRs). No study so far assessed in parallel the prevalence, control, and phenotypes of blood pressure (BP) or the accuracy of currently recommended office BP diagnostic thresholds in diagnosing elevated ambulatory BP in KTRs.

METHODS

205 stable KTRs underwent office BP measurements and 24-h ambulatory BP monitoring (ABPM). Hypertension was defined as follows: (1) office BP ≥140/90 mm Hg or use of antihypertensive agents following the current European Society of Cardiology/European Society of Hypertension (ESC/ESH) guidelines, (2) office BP ≥130/80 mm Hg or use of antihypertensive agents following the current American College of Cardiology/American Heart Association (ACC/AHA) guidelines, (3) ABPM ≥130/80 mm Hg or use of antihypertensive agents, and (4) ABPM ≥125/75 mm Hg or use of antihypertensive agents.

RESULTS

Hypertension prevalence by office BP was 88.3% with ESC/ESH and 92.7% with ACC/AHA definitions compared to 94.1 and 98.5% at relevant ABPM thresholds. Control rates among hypertensive patients were 69.6 and 43.7% with office BP compared to 38.3 and 21.3% with ABPM, respectively. Both for prevalence (κ-statistics = 0.52, p < 0.001 and 0.32, and p < 0.001) and control rates (κ-statistics = 0.21, p < 0.001 and 0.22, and p < 0.001, respectively), there was moderate or fair agreement of the 2 techniques. White-coat and masked hypertension were diagnosed in 6.7 and 39.5% of patients at the 140/90 threshold and 5.9 and 31.7% of patients at the 130/80 threshold. An office BP ≥140/90 mm Hg had 35.3% sensitivity and 84.9% specificity for the diagnosis of 24-h BP ≥130/80 mm Hg. An office BP ≥130/80 mm Hg had 59.7% sensitivity and 73.9% specificity for the diagnosis of 24-h BP ≥125/75 mm Hg. Receiver operating curve analyses confirmed this poor diagnostic performance.

CONCLUSIONS

At both corresponding thresholds studied, ABPM revealed particularly high hypertension prevalence and poor BP control in KTRs. Misclassification of KTRs by office BP is substantial, due to particularly high rates of masked hypertension. The diagnostic accuracy of office BP for identifying elevated ambulatory BP is poor. These findings call for a wider use of ABPM in KTRs.

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

Hypertension is common in kidney transplantation recipients and may be difficult to treat. Factors present before kidney transplantation, related to the transplantation procedure itself and factors developing after transplantation may contribute to blood pressure (BP) elevation in kidney transplant recipients. The present consensus is based on the results of three recent systematic reviews, the latest guidelines and the current literature. The current transplant guidelines, which recommend only office BP assessments for risk stratification in kidney transplant patients should be reconsidered, given the presence of white-coat hypertension and masked hypertension in this population and the better prediction of adverse outcomes by 24-h ambulatory BP monitoring as indicated in recent systematic reviews. Hypertension is associated with adverse kidney and cardiovascular outcomes and decreased survival in kidney transplant recipients. Current evidence suggests calcium channel blockers could be the preferred first-step antihypertensive agents in kidney transplant patients, as they improve graft function and reduce graft loss, whereas no clear benefit is documented for renin-angiotensin system inhibitor use over conventional treatment in the current literature. Randomized control trials demonstrating the clinical benefits of BP lowering on kidney and major cardiovascular events and recording patient-related outcomes are still needed. These trials should define optimal BP targets for kidney transplant recipients. In the absence of kidney transplant-specific evidence, BP targets in kidney transplant recipients should be similar to those in the wider chronic kidney disease population.

Blood pressure monitoring in kidney transplantation: a systematic review on hypertension and target organ damage

BACKGROUND

Sparse studies show that ambulatory blood pressure monitoring (ABPM) is superior to office BP (oBP) measurements to predict target organ damage and cardiovascular (CV) events in kidney transplant recipients (KTRs). We performed a systematic review aimed at determining the potential associations between BP recordings by different methods and renal and CV outcomes in this population.

METHODS

Major medical databases were searched for studies enrolling adult KTRs undergoing 24h ABPM compared to office or home BP measurements. Main outcomes were: associations between different BP recordings and renal and CV outcomes. Additionally, any association between the circadian BP pattern (dipping/non-dipping status) and outcomes was assessed.

RESULTS

Twenty-two studies (2078 participants) were reviewed. Amongst 12 studies collecting data on renal endpoints, ten studies found that BP assessed by ABPM was a stronger predictor of renal function decline, assessed by serum creatinine (SCr) and/or creatinine clearance (CrCl) or estimated glomerular filtration rate (eGFR), than traditional office measurements. Twelve studies analyzed the relation between different BP recordings and CV target organ damages and reported robust correlations between echocardiographic abnormalities [i.e. left ventricular mass index (LVM/LVMI)] and 24h ABPM, but not with office BPs. Furthermore, 24h ABPM correlated better than oBP with markers of vascular damage, such as carotid intima-media thickness (IMT), diffuse thickening, and endothelial dysfunction. Additionally, abnormal circadian BP pattern (non-dippers and reverse dippers) identified a group of kidney recipients at risk for kidney function loss and CV abnormalities.

CONCLUSIONS

In our systematic review, ABPM reflected target organ damage more closely than oBP in KTRs. Furthermore, altered circadian BP profile associated with renal and CV target organ damages.

Frequency and Patterns of Prescribing Antihypertensive Agents in Outpatient Kidney Transplant Recipients Among Six Cities in China from 2011 to 2018

PURPOSE

Antihypertensive agents are frequently prescribed in kidney transplant recipients (KTRs). However, the frequency and patterns of prescribing antihypertensive agents remain uncharacterized in KTRs in China. Therefore, this investigation was carried out.

METHODS

Retrospective prescription data dated 2011 to 2018 from KTRs in China were accessed using the Hospital Prescription Analysis Program database. Information about sex, birth date, and identification number of the patient; city, date, and department of the medical visit; major diagnoses; and the generic names, specifications, quantities, and usage of prescribed drugs were collected. Antihypertensive agents were grouped into 5 classes: angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers (BBs), calcium channel blockers (CCBs), and diuretics. The frequency and patterns of prescribing these antihypertensive agents were analyzed.

FINDINGS

Prescriptions from 174,749 KTRs (67.2% male; mean age, 42.5 [9.4] years) were obtained, and 58.2% of the patients were prescribed antihypertensive agents. The percentage of patients who received antihypertensive treatment increased from 52.9% in 2011 to 61.6% in 2018 and varied by city. Cyclosporine was associated with higher prescription frequency of antihypertensive agents than was tacrolimus (71.7% vs 63.4%; P < 0.0001). During the 8-year study period, CCBs were most frequently prescribed (39.0%), followed by ARBs (31.9%), BBs (14.3%), ACEIs (11.6%), and diuretics (3.2%). The mean (SD) number of antihypertensive drugs prescribed per KTR was 1.7 (0.8). Almost half of KTRs (51.2%) received just 1 antihypertensive drug. Co-administration of 2 or more antihypertensive drugs presented an obviously upward trend. The most commonly prescribed 2-drug combination was CCB + ARB (44.8%), followed by CCB + BB (20.1%) and CCB + ACEI (13.0%). In the patients who received 3 antihypertensive drugs, the 2 most frequently prescribed combinations were CCB + ARB + BB (37.5%) and CCB + ARB + ACEI (32.7%). Specific data varied by both year and city.

IMPLICATIONS

The prescribing patterns of antihypertensive agents in KTRs varied by city even within same country. Hence, more high-quality research studies on the use of antihypertensive agents in KTRs are needed.

Sleep-Disordered Breathing and 24-Hour Ambulatory Blood Pressure Monitoring in Renal Transplant Patients: Longitudinal Study

Background Sleep-disordered breathing (SDB) is considered a strong risk factor for hypertension in the general population. This disturbance is common in end-stage kidney disease patients on long-term hemodialysis and improves early on after renal transplantation. Whether SDB may be a risk factor for hypertension in renal transplant patients is unclear. Methods and Results We investigated the long-term evolution of simultaneous polysomnographic and 24-hour ambulatory blood pressure (BP) monitoring recordings in a cohort of 221 renal transplant patients. Overall, 404 paired recordings were made over a median follow-up of 35 months. A longitudinal data analysis was performed by the mixed linear model. The apnea-hypopnea index increased from a median baseline value of 1.8 (interquartile range, 0.6-5.0) to a median final value of 3.6 (interquartile range, 1.7-10.4; P=0.009). Repeated categorical measurements of the apnea-hypopnea index were directly associated with simultaneous 24-hour, daytime, and nighttime systolic ambulatory BP monitoring (adjusted analyses; P ranging from 0.002-0.01). In a sensitivity analysis restricted to 139 patients with at least 2 visits, 24-hour, daytime, and nighttime systolic BP significantly increased across visits (P<0.05) in patients with worsening SDB (n=40), whereas the same BP metrics did not change in patients (n=99) with stable apnea-hypopnea index. Conclusions In renal transplant patients, worsening SDB associates with a parallel increase in average 24-hour, daytime, and nighttime systolic BP. These data are compatible with the hypothesis that the link between SDB and hypertension is causal in nature. Clinical trials are, however, needed to definitively test this hypothesis.

Clinical Innovation: A Multidisciplinary Program for the Diagnosis and Treatment of Systemic Hypertension in Children and Adolescents

Pediatric systemic hypertension (HTN) is underdiagnosed and undertreated. The Divisions of Cardiology and Nephrology at our institution developed a comprehensive outpatient HTN program to (1) screen children at risk for HTN, (2) assess cardiovascular health, and (3) optimize medical management. We report our findings during all initial visits (n = 304) from December 2011 to September 2018. Of the cohort, 38% were obese and 36% reported little to no exercise. More than half of patients ≥11 years old did not have recommended lipid screening. When evaluating ambulatory blood pressure monitoring results, clinic blood pressure did not accurately diagnose patients with or without HTN and many patients on antihypertensive medications were inadequately treated. Visit recommendations included addition of or changes to antihypertensive medication in 35% of patients. A multidisciplinary program dedicated to pediatric HTN helps screen patients who are at risk. Ambulatory blood pressure monitoring identifies HTN in patients with normal clinic blood pressure and those on antihypertensive medication.

Plasma microRNA-126-3p and neutrophil-to-lymphocyte ratio in patients with chronic kidney disease: relationships to ambulatory 24-h blood pressure

Pro-inflammatory milieu of chronic kidney disease (CKD) results in endothelial damage and contributes to increased cardiovascular risk. The aim of the study was to evaluate association between neutrophil-to-lymphocyte ratio (NLR) and plasma relative expression of endothelially abundant miR-126-3p with circadian blood pressure (BP) pattern in CKD patients. This single-center observational study involved CKD stage 1-5 patients and healthy age- and sex-matched control subjects. All study participants had 24-h automatic blood pressure measurement (ABPM) performed. Plasma miRNA was quantified by qRT-PCR, in relation to endogenous U6 snRNA. In total, 90 CKD patients (60 ± 14 years, 52% males, 33 renal transplant recipients) and 25 healthy control subjects (55 ± 13 years, 48% males, p > 0.05) were enrolled in the study. We observed a positive correlation between miR-126-3p and average nighttime SBP (rho = 0.27, P = 0.02), average nighttime DBP (rho = 0.32, P = 0.003), night-day SBP ratio (ND-SBP), rho = 0.23, P = 0.03 and night-day DBP ratio (ND-DBP), rho = 0.26, P = 0.02. A positive association was found between NLR and average nighttime SBP (rho = 0.25, P = 0.01), ND-SBP (rho = 0.26, P = 0.006), and ND-DBP (rho = 0.28, P = 0.03). In the multiple regression model, NLR remained an independent predictor of average nighttime SBP (Beta per log change of NLR [95% CI]: 11.2 [1.8-10.6], P = 0.02), whereas miR-126-3p of nighttime DBP (1.88 [0.48; 3.28], p = 0.009), The results of our study point towards a link between both NLR and miR-126-3p and nighttime hypertension in CKD patients.

Ambulatory monitoring unmasks hypertension among kidney transplant patients: single center experience and review of the literature

Background

Disagreements between clinic and ambulatory blood pressure (BP) measurements are well-described in the general population. Though hypertension is frequent in renal transplant recipients, only a few studies address the clinic-ambulatory discordance in this population. We aimed to describe the difference between clinic and ambulatory BP in kidney transplant patients at our institution.

Methods

We compared the clinic and ambulatory BP of 76 adult recipients of a kidney allograft followed at our transplant center and investigated the difference between these methods, considering confounding by demographic and clinical variables.

Results

Clinic systolic BP (SBP) and diastolic BP (DBP) were 128 ± 13/79 ± 9 mmHg. Awake SBP and DBP were 147 ± 18/85 ± 10 mmHg. The clinic-minus-awake SBP and DBP differences were − 18 and − 6 mmHg, respectively. The negative clinic-awake ΔSBP was more pronounced at age > 60 years (p = 0.026) and with tacrolimus use compared to cyclosporine (p = 0.046). Sleep SBP and DBP were 139 ± 21/78 ± 11 mmHg. A non-dipping sleep BP pattern was noted in 73% of patients and was associated with tacrolimus use (p = 0.020).

Conclusions

Our findings suggest pervasive underestimation of BP when measured in the kidney transplant clinic, emphasizes the high frequency of a non-dipping pattern in this population and calls for liberal use of ambulatory BP monitoring to detect and manage hypertension.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1442-7) contains supplementary material, which is available to authorized users.

Hypertension after Kidney Transplantation: Clinical Significance and Therapeutical Aspects

Most of the kidney transplanted patients develop arterial hypertension after renal transplantation. Together with very well-known and usual risk factors, post-transplant hypertension contributes to the whole cardiovascular morbidity and mortality in the kidney transplant population. The reasons of post-transplant hypertension are factors related to donors and recipients, immunosuppressive therapy like Calcineurin Inhibitors (CNI) and surgery procedures (stenosis and kinking of the renal artery and ureteral obstruction). According to Eighth National Committee (JNC 8) recommendations, blood pressure > 140/90 mmHg is considered as hypertension. The usual antihypertensive drugs used for the control of hypertension are Calcium channel blockers (CCB), Angiotensin-converting enzyme (ACE) inhibitors, Angiotensin -II receptor blockers (ARB), B- blockers and diuretics. Follow the KDIGO guidelines the target blood pressure < 140/90 mmHg for patients without proteinuria and < 125/75 mmHg in patients with proteinuria is recommended. Better control of post-transplant hypertension improves the long-term graft and patient's survival.

Cardiovascular Risk Assessment in Pediatric Liver Transplant Patients

OBJECTIVES

Cardiovascular (CV) diseases play a leading role in the mortality of adult liver transplant (LT) recipients. However, data regarding CV risk factors in children after LT remain sparse. The present study assessed the presence of CV risk factors and signs of CV impairment in LT children.

METHODS

A total of 42 LT recipients (21 men, age 9.93 ± 3.57 years) were studied. Body composition [body mass index standard deviation score, percentage of body fat (by bioimpedance analysis)], lipid profiles, glycemic control, blood pressure, and arterial stiffness [assessed by aortic pulse wave velocity (PWV)] were evaluated. The effect of different treatment modalities [tacrolimus (TAC) (n = 30) or cyclosporine (CyA) (n = 11)] was also analyzed.

RESULTS

Almost 18% of children were overweight or obese. Patients on TAC had a significantly higher body fat mass and percentage of body fat compared with the CyA group (P < 0.02). Borderline to high lipid values were present in 40% of patients. Children on CyA had higher serum cholesterol levels compared to TAC (P < 0.004). Nineteen percent of patients had hypertension. Half of the patients had glomerular filtration rate values <90 mL/min/1.73 m, whereas PWV values were above the 95th percentile in 12%.

CONCLUSIONS

Increased body fat, chronic kidney disease, high lipid content, hypertension, and increased arterial stiffness are already present and are in part related to the type of immunosuppression regimen in LT children >5 years following transplantation. Long-term follow-up is needed to evaluate their impact on CV health and survival.

Long-term blood pressure monitoring by office and 24-h ambulatory blood pressure in renal transplant patients: a longitudinal study

Background

Renal transplant patients have a high prevalence of nocturnal hypertension, and hypertension misclassification by office blood pressure (BP) is quite common in these patients. The potential impact of hypertension misclassification by office BP on hypertension management in this population has never been analysed.

Methods

We performed a longitudinal study in a cohort of 260 clinically stable renal transplant patients. In all, 785 paired office and 24-h ambulatory blood pressure monitoring (24-hABPM) measurements over a median follow-up of 3.9 years were available in the whole cohort.

Results

A total of 74% of patients had nocturnal hypertension (&gt;120/70 mmHg). Average office BP and 24-hABPM remained quite stable over follow-up, as did the prevalence of nocturnal hypertension, which was 77% at the last observation. However, the global agreement between office BP and average 24 h, daytime and night-time BP was unsatisfactory (k-statistics 0.10–0.26). In 193 visits (25% of all visits) where office BP indicated the need of antihypertensive therapy institution or modification (BP &gt;140/90 mmHg), 24-hABPM was actually normal (&lt;130/80 mmHg), while in 94 visits (12%), 24-hABPM was in the hypertensive range while office BP was normal. Overall, in 37% of visits, office BP provided misleading therapeutic indications.

Conclusions

Hypertension misclassification by office BP is a common phenomenon in stable renal transplant patients on long-term follow-up. Office BP may lead to inappropriate therapeutic decisions in over one-third of follow-up visits in these patients.

Office, standardized and 24-h ambulatory blood pressure and renal function loss in renal transplant patients

OBJECTIVES

Hypertension is a risk factor for renal function loss in kidney transplant patients but there are still no longitudinal studies focusing on the relationship between ambulatory blood pressure (BP) monitoring (ABPM) and the glomerular filtration rate (GFR) evolution over time in these patients.

METHODS

In a cohort of 260 renal transplant patients, we investigated the longitudinal relationship between repeated office BP measurements and simultaneous GFR measurements (on average 35 paired measurements per patient) and the relationship between baseline ABPM with the same outcome measure (by linear mixed models). Furthermore, we tested the prediction power of baseline ABPM and standardized BP measurements for a combined renal end point (GFR loss >30%, end-stage kidney disease or death) over a 3.7 years follow-up.

RESULTS

Longitudinal office BP measurements were inversely related with simultaneous GFR measurements and the same was true both for baseline daytime and night-time BP. (all P < 0.001). Baseline 24-h ABPM [hazard ratio (5 mmHg):1.11; 95% confidence interval 1.03-1.19] and night-time SBP [hazard ratio (5 mmHg):1.10; 95% confidence interval 1.03-1.17] predicted the combined renal end point and the predictive model based on night-time SBP provided a data-fit superior than that by daytime SBP.

CONCLUSION

In renal transplant patients, daytime and night-time SBP predict the risk of GFR loss overtime, and among the various BP metrics, night-time BP is the strongest indicator of the risk of renal function loss. Optimization of BP control and interventions targeting night-time BP may afford renal benefits in transplant patients, a hypothesis that remains to be tested in a clinical trial.