When conventional heart failure therapy is not enough: angiotensin receptor blocker, direct renin inhibitor, or aldosterone antagonist?

Renin-angiotensin-aldosterone pathway modulators in chronic kidney disease: A comparative review

Chronic kidney disease presents a health challenge that has a complex underlying pathophysiology, both acquired and inherited. The pharmacotherapeutic treatment options available today lower the progression of the disease and improve the quality of life but cannot completely cure it. This poses a challenge to the healthcare provider to choose, from the available options, the best way to manage the disease as per the presentation of the patient. As of now, the recommended first line of treatment to control the blood pressure in chronic kidney disease is the administration of renin-angiotensin-aldosterone system modulators. These are represented mainly by the direct renin inhibitor, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers. These modulators are varied in their structure and mechanisms of action, hence showing varying treatment outcomes. The choice of administration of these modulators is determined by the presentation and the co-morbidities of the patient, the availability and affordability of the treatment option, and the expertise of the healthcare provider. A direct head-to-head comparison between these significant renin-angiotensin-aldosterone system modulators is lacking, which can benefit healthcare providers and researchers. In this review, a comparison has been drawn between the direct renin inhibitor (aliskiren), angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers. This can be of significance for healthcare providers and researchers to find the particular loci of interest, either in structure or mechanism, and to intervene as per the case presentation to obtain the best possible treatment option.

Inhibition of Interleukin-6/glycoprotein 130 signalling by Bazedoxifene ameliorates cardiac remodelling in pressure overload mice

The role of IL-6 signalling in hypertensive heart disease and its sequelae is controversial. Our group demonstrated that Bazedoxifene suppressed IL-6/gp130 signalling in cancer cells but its effect on myocardial pathology induced by pressure overload is still unknown. We explored whether Bazedoxifene could confer benefits in wild-type C57BL/6J mice suffering from transverse aortic constriction (TAC) and the potential mechanisms in H9c2 myoblasts. Mice were randomized into three groups (Sham, TAC, TAC+Bazedoxifene, n = 10). Morphological and histological observations suggested TAC aggravated myocardial remodelling while long-term intake of Bazedoxifene (5 mg/kg, intragastric) attenuated pressure overload-induced pathology. Echocardiographic results indicated Bazedoxifene rescued cardiac function in part. We found Bazedoxifene decreased the mRNA expression of IL-6, MMP2, Col1A1, Col3A1 and periostin in murine hearts after 8-week surgery. By Western blot detection, we found Bazedoxifene exhibited an inhibition of STAT3 activation in mice three hours and 8 weeks after TAC. Acute TAC stress (3 hours) led to down-regulated ratio of LC3-Ⅱ/LC3-Ⅰ, while in mice after long-term (8 weeks) TAC this ratio becomes higher than that in Sham mice. Bazedoxifene inverted the autophagic alteration induced by TAC at both two time-points. In H9c2 myoblasts, Bazedoxifene suppressed the IL-6-induced STAT3 activation. Moreover, IL-6 reduced the ratio of LC3-Ⅱ/LC3-Ⅰ, promoted P62 expression but Bazedoxifene reversed both changes in H9c2 cells. Our data suggested Bazedoxifene inhibited IL-6/gp130 signalling and protected against cardiac remodelling together with function deterioration in TAC mice.

Clinical efficacy, safety and tolerability of aliskiren monotherapy: a protocol for an umbrella review

INTRODUCTION

Aliskiren is a newly developed medicine. As one of the effective renin-angiotensin-aldosterone system inhibitors, its role in lowering blood pressure has been recognised. However, its safety and tolerability still remain controversial. The aim of the paper is to systematically summarise the published studies about the clinical efficacy and side effects of aliskiren monotherapy.

METHODS AND ANALYSIS

A comprehensive review of PubMed, Embase and Cochrane Library databases published from inception until June 2019 will be conducted. The selected articles are meta-analyses that integrated the randomised controlled studies, which evaluated efficacy, safety and tolerability of aliskiren monotherapy. Two people will select eligible articles and extract data independently. Any disputes will be resolved by discussion or the arbitration of a third person. The quality of reporting evidence will be assessed using the AMSTAR 2 tool. Study selection process will be presented using a flowchart. We will re-analyse each outcome with the random effect methods if necessary. If possible, we will also calculate 95% prediction intervals for each random effect estimate, by using Egger's test to evaluate if the reporting bias existed.

ETHICS AND DISSEMINATION

Ethical approval is not required for the study, as we only collected data from available published materials. This umbrella review will be also submitted to a peer-reviewed journal for publication after completion.

PROSPERO REGISTRATION NUMBER

CRD42019142141.

Effect of Genetic and Nongenetic Factors on the Clinical Response to Mineralocorticoid Receptor Antagonist Therapy in Egyptians with Heart Failure

This prospective cohort study evaluated the association between the renin angiotensin aldosterone system genotypes and response to spironolactone in 155 Egyptian patients with heart failure with reduced ejection fraction (HFrEF). Genotype frequencies for AGT rs699 were: CC = 16%, CT = 48%, and TT = 36%. Frequencies for CYP11B2 rs1799998 were: TT = 33%, TC = 50%, and CC = 17%. After 6 months of spironolactone treatment, change in the left ventricular ejection fraction (LVEF) differed by AGT rs699 (CC, 14.6%; TC, 7.9%; TT, 2.7%; P = 2.1E‐26), and CYP11B2 rs1799998 (TT, 9.1%; TC, 8.7%; CC, 1.4%; P = 0.0006) genotypes. Multivariate linear regression showed that the AGT rs699 and CYP11B2 rs1799998 polymorphisms plus baseline serum potassium explained 71% of variability in LVEF improvement (P = 0.001), 63% of variability in serum potassium increase (P = 2.25E‐08), and 39% of the variability in improvement in quality of life (P = 2.3E‐04) with spironolactone therapy. These data suggest that AGT and CYP11B2 genotypes as well as baseline serum K are predictors of spironolactone response in HFrEF.

Development of hypotension in patients newly diagnosed with heart failure in UK general practice: retrospective cohort and nested case-control analyses

OBJECTIVES

Hypotension is of particular relevance for patients with heart failure (HF), since almost all HF drugs cause lowering of blood pressure (BP) and it is associated with a poor prognosis. We aimed to investigate hypotension incidence and risk factors in patients with incident HF in the UK.

DESIGN

Retrospective cohort study including nested case-control analyses.

SETTING

The Health Improvement Network UK primary care database.

PARTICIPANTS

18 677 adult patients with incident HF during 2000-2005 were followed and cases of hypotension (systolic BP ≤90 mm Hg) were identified. Controls were age-matched, sex-matched and date-matched to cases (1:2).

PRIMARY AND SECONDARY OUTCOME MEASURES

We estimated hypotension incidence in the full study population and relevant subgroups (eg, sex and age). Potential risk factors for hypotension overall and for multiple versus single hypotensive episodes were evaluated using conditional logistic regression and unconditional regression models, respectively.

RESULTS

During a mean follow-up of 3.31 years, 2565 patients (13.7%) developed hypotension. The incidence of hypotension was 3.17 cases per 100 patient years (95% confidence interval (CI): 3.05-3.30), and was markedly increased in women aged 18-39 years (n=32; 17.72 cases per 100 patient-years; 95% CI: 9.69-29.73). Hypotension risk factors included high healthcare utilisation (proxy measure for HF severity and general comorbidity; eg, ≥10 primary care physician visits versus none, odds ratio (OR): 2.29; 95% CI: 1.34-3.90), previous hypotensive episodes (OR: 2.32; 95% CI: 1.84-2.92), renal failure and use of aldosterone antagonists, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. Risk factors identified for hypotension generally overlapped with those for multiple versus single hypotensive episodes.

CONCLUSIONS

Hypotension occurs frequently in patients with incident HF. Our findings may help identify patients most likely to benefit from close BP monitoring. The increased incidence of hypotension in young women with HF requires investigation.

Hyperkalemia in the Hypertensive Patient

PURPOSE OF REVIEW

Hyperkalemia develops in a patient with systemic arterial hypertension (HTN) if one or more risk factors are present, namely chronic kidney disease (CKD) (especially severe stage 4-5 CKD), diabetes mellitus (DM), heart failure (HF), or pharmacological therapies that interfere with potassium homeostasis, mainly through renin-angiotensin-aldosterone inhibition (RAASi). Hyperkalemia is a considerable reason of morbidity (emergency department (ED) visits and hospitalizations) and portends a higher mortality risk in patients at risk; for instance, hyperkalemia increases the risk of mortality within 1 day of a hyperkalemic event. This review aims to identify the risk factors for high-serum potassium, highlight the risk versus benefit of RAASi in certain patient populations, and outline preventive as well as therapeutic strategies for hyperkalemia.

RECENT FINDINGS

A growing body of evidence supports the safety and efficacy of cation-exchange resins, patiromer, or sodium zirconium cyclosilicate, in patients with a compelling indication for RAASi, yet in whom such therapy was complicated by hyperkalemia, allowing these patients to benefit from continued RAASi therapy. In summary, novel cation exchange polymers present the clinician with a new and safe strategy to address hyperkalemia in patients with a compelling indication for ongoing RAASi therapy instead of withdrawal of such therapy.

Is there a role for combination anti-remodelling therapy for heart failure secondary to chronic rheumatic mitral regurgitation?

Introduction:

The value of combination anti-remodelling therapy for heart failure (HF) secondary to mitral regurgitation (MR) is unknown. We studied the effect of anti-remodelling therapy on clinical and echocardiographic parameters in patients with severe chronic rheumatic mitral regurgitation (CRMR) presenting in HF.

Methods:

Thirty-one patients (29 females) at Chris Hani Baragwanath Academic Hospital, treated with combination therapy for HF due to CRMR and New York Heart Association functional class II–III symptoms, underwent prospective six-month follow up.

Results:

Mean age was 50.7 ± 8.5 years. No patients died or were hospitalised for HF during the study period. No worsening of clinical symptoms or functional status, or left and right ventricular echocardiographic parameters (p > 0.05) was noted. Peak left atrial systolic strain improved at six months (18.7 ± 7.7 vs 23.6 ± 8.5%, p = 0.02).

Conclusion:

This preliminary analysis suggests that combination anti-remodelling therapy may be beneficial for HF secondary to CRMR. We had no HF-related admissions or deaths, and no deterioration in echocardiographic parameters of ventricular size and function.

Impact of Aldosterone Antagonists on Sudden Cardiac Death Prevention in Heart Failure and Post-Myocardial Infarction Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background and Objectives

Sudden cardiac death (SCD) is a severe burden of modern medicine. Aldosterone antagonist is publicized as effective in reducing mortality in patients with heart failure (HF) or post myocardial infarction (MI). Our study aimed to assess the efficacy of AAs on mortality including SCD, hospitalization admission and several common adverse effects.

Methods

We searched Embase, PubMed, Web of Science, Cochrane library and clinicaltrial.gov for randomized controlled trials (RCTs) assigning AAs in patients with HF or post MI through May 2015. The comparator included standard medication or placebo, or both. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Event rates were compared using a random effects model. Prospective RCTs of AAs with durations of at least 8 weeks were selected if they included at least one of the following outcomes: SCD, all-cause/cardiovascular mortality, all-cause/cardiovascular hospitalization and common side effects (hyperkalemia, renal function degradation and gynecomastia).

Results

Data from 19,333 patients enrolled in 25 trials were included. In patients with HF, this treatment significantly reduced the risk of SCD by 19% (RR 0.81; 95% CI, 0.67–0.98; p = 0.03); all-cause mortality by 19% (RR 0.81; 95% CI, 0.74–0.88, p<0.00001) and cardiovascular death by 21% (RR 0.79; 95% CI, 0.70–0.89, p<0.00001). In patients with post-MI, the matching reduced risks were 20% (RR 0.80; 95% CI, 0.66–0.98; p = 0.03), 15% (RR 0.85; 95% CI, 0.76–0.95, p = 0.003) and 17% (RR 0.83; 95% CI, 0.74–0.94, p = 0.003), respectively. Concerning both subgroups, the relative risks respectively decreased by 19% (RR 0.81; 95% CI, 0.71–0.92; p = 0.002) for SCD, 18% (RR 0.82; 95% CI, 0.77–0.88, p < 0.0001) for all-cause mortality and 20% (RR 0.80; 95% CI, 0.74–0.87, p < 0.0001) for cardiovascular mortality in patients treated with AAs. As well, hospitalizations were significantly reduced, while common adverse effects were significantly increased.

Conclusion

Aldosterone antagonists appear to be effective in reducing SCD and other mortality events, compared with placebo or standard medication in patients with HF and/or after a MI.

Effect of Mineralocorticoid Receptor Antagonists on Cardiac Structure and Function in Patients With Diastolic Dysfunction and Heart Failure With Preserved Ejection Fraction: A Meta-Analysis and Systematic Review

BACKGROUND

There has been an increasing interest in use of mineralocorticoid receptor antagonists (MRAs) in patients with heart failure with preserved ejection fraction (HFPEF). However, a comprehensive evaluation of MRA effects on left ventricular (LV) structure and function in these patients is lacking. In this meta-analysis, we evaluated the effects of MRAs on LV structure and function among patients with diastolic dysfunction or HFPEF.

METHODS & RESULTS

Randomized, controlled clinical trials evaluating the efficacy of MRAs in patients with diastolic dysfunction or HFPEF were included. The primary outcome was change in E/e', a specific measure of diastolic function. Secondary outcomes included changes in other measures of diastolic function, LV structure, surrogate markers for myocardial fibrosis (carboxy-terminal peptide of procollagen type I [PICP] and amino-terminal peptide of pro-collagen type-II [PIIINP]), blood pressure, and exercise tolerance. In the pooled analysis, MRA use was associated with significant reduction in E/e' (weighted mean difference [WMD] [95% confidence interval {CI}]: -1.68 [-2.03 to -1.33]; P<0.0001) and deceleration time (WMD [95% CI]: -12.0 ms [-23.3 to -0.7]; P=0.04) as compared with control, suggesting and improvement in diastolic function. Furthermore, blood pressure and levels of PIIINP and PICP were also significantly reduced with MRA therapy with no significant change in LV mass or dimensions.

CONCLUSION

MRA therapy in patients with asymptomatic diastolic dysfunction or HFPEF is associated with significant improvement in diastolic function and markers of cardiac fibrosis without a significant change in LV mass or dimensions.

Misconceptions and facts about treating hypertension

Hypertension is a powerful risk factor strongly linked to adverse cardiovascular outcomes. Because of its high prevalence, health care providers at many levels are involved in treating hypertension. Distinct progress has been made in improving the rates of hypertension awareness and treatment over years, but the overall control of hypertension remains inadequate. Several recent guidelines from different sources have been put forward in an attempt to bridge the gap between existing evidence and clinical practice. Despite this effort, several misconceptions about treating hypertensive cardiovascular disease continue to persist among clinicians. This review highlights some of the misconceptions regarding antihypertensive therapy.

Short-term effects of catheter-based renal denervation on cardiac sympathetic drive and cardiac baroreflex function in heart failure

OBJECTIVES

Sympathetic drive, especially to the heart, is elevated in heart failure and is strongly associated with poor outcome. The mechanisms causing the increased sympathetic drive to the heart remain poorly understood. Catheter-based renal denervation (RDN), which reduces blood pressure (BP) and sympathetic drive in hypertensive patients, is a potential treatment in heart failure. The aim of this study was to investigate the short-term effects of catheter-based RDN on BP, heart rate (HR) and cardiac sympathetic nerve activity (CSNA) and on baroreflex function in a conscious, large animal model of heart failure.

METHODS

Adult Merino ewes were paced into heart failure (ejection fraction<40%) and then instrumented to directly record CSNA. The resting levels and baroreflex control of CSNA and HR were measured before and 24h after bilateral renal (n=6) or sham (n=6) denervation. RDN was performed using the Symplicity Flex Catheter System® (Medtronic) using the same algorithm as in patients.

RESULTS

Catheter-based RDN significantly reduced resting diastolic BP (P<0.01) and mean arterial blood pressure (P<0.05), but did not change resting HR or CSNA compared with sham denervation. Renal denervation reduced the BP at which CSNA was at 50% of maximum (BP50; P<0.005) compared with sham denervation.

CONCLUSIONS

In an ovine model of heart failure, catheter-based RDN did not reduce resting CSNA in the short-term. There was, however, a lack of a reflex increase in CSNA in response to the fall in arterial pressure due to a leftward shift in the baroreflex control of CSNA, which may be due to denervation of renal efferent and/or afferent nerves.