The chaos of hypertension guidelines for chronic kidney disease patients

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.

Blood pressure targets in CKD 2021: the never-ending guidelines debacle

In 2021, two updated clinical guidelines were published, providing guidance on blood pressure (BP) targets for people with chronic kidney disease (CKD). Kidney Disease: Improving Global Outcomes (KDIGO) updated its 2012 Clinical Practice Guideline for the Management of BP in CKD. Different systolic blood pressure (SBP) and diastolic blood pressure (DBP) targets for CKD (<130/80 and <140/90 mmHg, respectively, for people with a urinary albumin: creatinine ratio >30 mg/g or without pathological albuminuria) were replaced by a single number: an SBP target of <120 mmHg is suggested, when tolerated. This represents a major decrease in the SBP target and the abandonment of DBP targets. The European Society of Cardiology (ESC) also published a 2021 Clinical Guideline on Cardiovascular Disease Prevention in Clinical Practice that updates a prior 2016 guideline on prevention and the 2018 ESC/European Society of Hypertension Clinical Practice Guidelines for the Management of Arterial Hypertension. The 2021 ESC guideline was endorsed by 12 European scientific societies. The recommended office BP targets for people with CKD are <140–130 mmHg SBP (lower SBP is acceptable if tolerated) and <80 mmHg DBP. The question is: What should the practicing physician do now: treat hypertension in people with CKD to an SBP target of <120 mmHg or to a target of <140–130 mmHg? Major guideline bodies are aware of the activities of other major players. There is an urgent need for guideline bodies to establish communication channels, search consensus on major issues that impact the health of hundreds of millions of people worldwide and end individualism in guidelines generation.

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.

Traditional Chinese Medicine Injections Combined With Antihypertensive Drugs for Hypertensive Nephropathy: A Network Meta-Analysis

Background: Hypertension, a risk factor for cardiovascular events, is often associated with chronic kidney disease. This is called hypertensive nephropathy (HN), which negatively affects physical fitness and body mass, leading to economic burden. Traditional Chinese medicine injections (TCMIs) are common traditional Chinese-patent medicine preparations in China. There was a lack of evidence to prove which TCMIs combine with ADs (TCMIs+ADs) may be a therapeutic option for HN. Thus, we systematically reviewed the efficacy and safety of various TCMIs + ADs in patients with HN.

Methods: We conducted a comprehensive search of PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, and VIP information resource integration service platform databases for relevant Chinese- and English-language randomized controlled trials (RCTs) published from database inception until May 2021. Literature screening, data extraction, and quality assessment was performed by two reviewers independently but using the same criteria. We performed the effect modeling to analyze the data for all outcomes and ranked each intervention using the P-score. Furthermore, sensitivity analysis, meta-regression, and funnel plots were used to test the stability, heterogeneity, and publication bias, respectively.

Results: We included 69 RCTs with 6373 patients and including six TCMIs + ADs. Network analysis indicated that the ginkgo leaf extract and dipyridamole combined with ADs (GLED + ADs) was the most efficacious in terms of 24-h urinary protein excretion [mean difference (MD) = −0.70, 95% confidence interval (CI): −0.82 to −0.58; P-score = 1] and systolic blood pressure (MD = −12.95, 95% CI: −21.03 to −4.88; P-score = 0.88), whereas the salvianolate combined with ADs (SA + ADs) showed the highest effectiveness for diastolic blood pressure (MD = −6.88, 95% CI: −10.55 to −3.21; P-score = 0.9). Based on the combined P-score of network meta-analysis results (88% and 85.26%) and sensitivity analysis results (72% and 71.54%), the biplots showed that the GLED + ADs was the most efficacious intervention in all TCMIs + ADs for primary outcomes, followed by the SA + ADs and sodium tanshinone IIA sulfonate combined with ADs (STS + ADs). There was no significant difference in terms of safety between TCMIs + ADs and ADs alone.

Conclusion: Of all the TCMIs + ADs, GLED + ADs, SA + ADs, and STS + ADs may demonstrate a higher efficacy than ADs alone for HN. Weighing with the potential benefits and limitations in methodology, potential heterogeneity and outcomes, we should use various TCMIs with caution in clinical practice. Nevertheless, additional high-quality RCTs are warranted and future research should focus on the clinical value of core outcomes to confirm the effectiveness and safety of TCMIs for HN.

Systematic Review Registration: clinicaltrials.gov, identifier CRD42020205358

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.

Renin-angiotensin system and inflammation update

The most classical view of the renin-angiotensin system (RAS) emphasizes its role as an endocrine regulator of sodium balance and blood pressure. However, it has long become clear that the RAS has pleiotropic actions that contribute to organ damage, including modulation of inflammation. Angiotensin II (Ang II) activates angiotensin type 1 receptors (AT1R) to promote an inflammatory response and organ damage. This represents the pathophysiological basis for the successful use of RAS blockers to prevent and treat kidney and heart disease. However, other RAS components could have a built-in capacity to brake proinflammatory responses. Angiotensin type 2 receptor (AT2R) activation can oppose AT1R actions, such as vasodilatation, but its involvement in modulation of inflammation has not been conclusively proven. Angiotensin-converting enzyme 2 (ACE2) can process Ang II to generate angiotensin-(1-7) (Ang-(1-7)), that activates the Mas receptor to exert predominantly anti-inflammatory responses depending on the context. We now review recent advances in the understanding of the interaction of the RAS with inflammation. Specific topics in which novel information became available recently include intracellular angiotensin receptors; AT1R posttranslational modifications by tissue transglutaminase (TG2) and anti-AT1R autoimmunity; RAS modulation of lymphoid vessels and T lymphocyte responses, especially of Th17 and Treg responses; interactions with toll-like receptors (TLRs), programmed necrosis, and regulation of epigenetic modulators (e.g. microRNAs and bromodomain and extraterminal domain (BET) proteins). We additionally discuss an often overlooked effect of the RAS on inflammation which is the downregulation of anti-inflammatory factors such as klotho, peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α), transient receptor potential ankyrin 1 (TRPA1), SNF-related serine/threonine-protein kinase (SNRK), serine/threonine-protein phosphatase 6 catalytic subunit (Ppp6C) and n-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP). Both transcription factors, such as nuclear factor κB (NF-κB), and epigenetic regulators, such as miRNAs are involved in downmodulation of anti-inflammatory responses. A detailed analysis of pathways and targets for downmodulation of anti-inflammatory responses constitutes a novel frontier in RAS research.

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.

Pelacarsen for lowering lipoprotein(a): implications for patients with chronic kidney disease

Chronic kidney disease (CKD) patients are at an increased risk of cardiovascular disease (CVD) and statins may not be protective in advanced CKD. The reasons for the limited efficacy of statins in advanced CKD are unclear, but statins may increase plasma levels of the highly atherogenic molecule lipoprotein(a), also termed Lp(a), as well as PCSK9 (protein convertase subtilisin/kexin type 9) levels. Lp(a) has also been linked to calcific aortic stenosis, which is common in CKD. Moreover, circulating Lp(a) levels increase in nephrotic syndrome with declining renal function and are highest in patients on peritoneal dialysis. Thus, the recent publication of the Phase 2 randomized controlled trial of pelacarsen [also termed AKCEA-APO(a)-LRx and TQJ230], a hepatocyte-directed antisense oligonucleotide targeting the LPA gene messenger RNA, in persons with CVD should be good news for nephrologists. Pelacarsen safely and dose-dependently decreased Lp(a) levels by 35-80% and a Phase 3 trial [Lp(a)HORIZON, NCT04023552] is planned to run from 2020 to 2024. Unfortunately, patients with estimated glomerular filtration rate <60 mL/min or urinary albumin:creatinine ratio >100 mg/g were excluded from Phase 2 trials and those with 'significant kidney disease' will be excluded from the Phase 3 trial. Optimized exclusion criteria for Lp(a)HORIZON would provide insights into the role of Lp(a) in CVD in CKD patients.

Blood pressure targets in chronic kidney disease: an update on the evidence

PURPOSE OF REVIEW

Hypertension is the leading modifiable cause of cardiovascular events and of mortality and is generally considered as a direct cause of chronic kidney disease. Defining optimal blood pressure targets in patients with chronic kidney disease is therefore of critical importance.

RECENT FINDINGS

Over the recent years, results and post-hoc analyses of several important trials comparing blood pressure targets which included patients with chronic kidney disease have been published. Although these results provide important means to understand the consequences of high blood pressure and to improve the management of hypertension in chronic kidney disease, they led to remarkably different interpretations and recommendations in the current guidelines.

SUMMARY

The present review summarizes the current evidence and areas of controversy for the definition of blood pressure targets in patients with chronic kidney disease.

Blood pressure targets in patients with chronic kidney disease: MDRD and AASK now confirming SPRINT

Recent American and European hypertension guidelines are not in agreement regarding blood pressure (BP) targets for persons with chronic kidney disease (CKD). Previous analyses from the African American Study on Kidney Disease (AASK) and Modification of Diet in Renal Disease (MDRD) trials suggested that strict BP control confers nephroprotection for patients with proteinuria, but a mortality benefit was not apparent. In contrast, an analysis of the Systolic Blood Pressure Intervention Trial (SPRINT) subpopulation of CKD patients showed a mortality benefit with the systolic blood pressure (SBP) <120 mmHg versus the SBP <140 target. A recent analysis of the combined MDRD and AASK cohorts supports previous evidence on nephroprotection but also findings from the SPRINT trial on all-cause mortality benefits of intensive versus usual BP control in individuals with CKD.