Change in renal function associated with drug treatment in heart failure: national guidance

Inhibitors of the renin–angiotensin–aldosterone (RAAS) system are cornerstones of the management of patients with heart failure with reduced left ventricular ejection fraction (HFrEF). However, RAAS inhibitors may cause decline in renal function and/or hyperkalaemia, particularly during initiation and titration, intercurrent illness and during worsening of heart failure. There is very little evidence from clinical trials to guide the management of renal dysfunction. The Renal Association and British Society for Heart Failure have collaborated to describe the interactions between heart failure, RAAS inhibitors and renal dysfunction and give clear guidance on the use of RAAS inhibitors in patients with HFrEF. During initiation and titration of RAAS inhibitors, testing renal function is mandatory; a decline in renal function of 30% or more can be acceptable. During intercurrent illness, there is no evidence that stopping RAAS inhibitor is beneficial, but if potassium rises above 6.0 mmol/L, or creatinine rises more than 30%, RAAS inhibitors should be temporarily withheld. In patients with fluid retention, high doses of diuretic are needed and a decline in renal function is not an indication to reduce diuretic dose: if the patient remains congested, more diuretics are required. If a patient is hypovolaemic, diuretics should be stopped or withheld temporarily. Towards end of life, consider stopping RAAS inhibitors. RAAS inhibition has no known prognostic benefit in heart failure with preserved ejection fraction. Efforts should be made to initiate, titrate and maintain patients with HFrEF on RAAS inhibitor treatment, whether during intercurrent illness or worsening heart failure.

Heart failure and acute renal dysfunction in the cardiorenal syndrome

Just under 1 million people in the UK have symptomatic heart failure. Decompensated heart failure is associated with a particularly poor prognosis with in-hospital mortality at around 10%. Over the last 30 years renin-angiotensin-aldosterone system antagonists have been shown to have incremental benefit on improved quality of life, reduced hospitalisation and mortality rates in those with heart failure with reduced ejection fraction. Concomitant chronic kidney disease and 'acute kidney injury' are common and associated with adverse outcomes.In patients with decompensated heart failure, congestion is a key driver of deterioration in renal function. Decongestion is fundamental to successful management. Yet it is not uncommon to see prognostically important medication (such as angiotensin converting enzyme inhibitors and mineralocorticoid antagonists) inappropriately stopped, along with under-diuresis of the patient. This leaves the patient still in a state of congestion without the prognostic medication at discharge, with resultant adverse outcome. The British Society for Heart Failure and the Renal Association have produced consensus guidance to help guide management in a more consistent fashion based on heart failure classification, whether the patient is congested and the degree of renal impairment. Early heart failure specialist review is associated with improved patient outcomes.

Chronic Kidney Disease Has a Graded Association with Death and Cardiovascular Outcomes in Stable Coronary Artery Disease: An Analysis of 21,911 Patients from the CLARIFY Registry

: Chronic kidney disease (CKD) is associated with an increased cardiovascular risk in a broad spectrum of populations. However, the risk associated with a reduced estimated glomerular filtration rate (eGFR) in patients with stable coronary artery disease receiving standard care in the modern era, independently of baseline cardiovascular disease, risk factors, and comorbidities, remains unclear. We analyzed data from 21,911 patients with stable coronary artery disease, enrolled in 45 countries between November 2009 and July 2010 in the CLARIFY registry. Patients with abnormal renal function were older, with more comorbidities, and received slightly lower-although overall high-rates of evidence-based secondary prevention therapies than patients with normal renal function. The event rate of patients with CKD stage 3b or more (eGFR <45 mL/min/1.73 m2) was much higher than that associated with any comorbid condition. In a multivariable adjusted Cox proportional hazards model, lower eGFR was independently associated with a graded increased risk of cardiovascular mortality, with adjusted HRs (95% CI) of 0.98 (0.81-1.18), 1.31 (1.05-1.63), 1.77 (1.38-2.27), and 3.12 (2.25-4.33) for eGFR 60-89, 45-59, 30-44, and <30 mL/min/1.73 m2, compared with eGFR ≥90 mL/min/1.73 m2. A strong graded independent relationship exists between the degree of CKD and cardiovascular mortality in this large cohort of patients with chronic coronary artery disease, despite high rates of secondary prevention therapies. Among clinical risk factors and comorbid conditions, CKD stage 3b or more is associated with the highest cardiovascular mortality.

Does specialist review for patients with suspected heart failure predict better outcomes? An observational study on the utility of compliance with NICE guidelines

OBJECTIVES

Compare outcomes in patients with suspected heart failure (HF) and raised natriuretic peptides who are reviewed in a specialist HF clinic in line with National Institute for Health and Care Excellence (NICE) guidelines (compliant group) versus patients who are not reviewed in the clinic (non-compliant group).

DESIGN

Retrospective observational study.

SETTING

Single large UK district general hospital.

PARTICIPANTS

567 consecutive patients in primary care with raised N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels (>400 pg/mL) from February to September 2014.

INTERVENTIONS

161 (28%) patients were referred to the specialist HF clinic and 406 (72%) were not. Outcomes were compared between the two groups.

OUTCOME MEASURES

All-cause and cardiovascular (CV) hospitalisations and all-cause mortality.

RESULTS

The compliant group were slightly younger than the non-compliant group (78±9 vs 80±9; p=0.019) but had much higher NT-pro-BNP (3108±4526 vs 2271±3637 pg/mL; p<0.0001). Despite this, over a mean follow-up period of 9±2 months, rates of all-cause hospitalisation (24% vs 44%; p<0.0001) and CV hospitalisation (3% vs 15%, p<0.0001) were significantly lower in the compliant group versus the non-compliant group, respectively. There was no significant difference in mortality rates (6% compliant group vs 8% non-compliant group; p=0.487).

CONCLUSIONS

Hospitalisation rates in patients with suspected HF and raised NT-pro-BNP were extremely high over a relatively short follow-up period. Patients reviewed in a specialist HF clinic had much higher NT-pro-BNP levels, suggesting they were at higher risk of adverse outcomes, yet also had significantly lower rates of all-cause and CV hospitalisation. Our findings support implementation of the relevant NICE guidelines for patients with suspected HF.

Exploring the Waveform Characteristics of Tidal Breathing Carbon Dioxide, Measured Using the N-Tidal C Device in Different Breathing Conditions (The General Breathing Record Study): Protocol for an Observational, Longitudinal Study

BACKGROUND

In an increasingly comorbid population, there are significant challenges to diagnosing the cause of breathlessness, and once diagnosed, considerable difficulty in detecting deterioration early enough to provide effective intervention. The burden of the breathless patient on the health care economy is substantial, with asthma, chronic heart failure, and pneumonia affecting over 6 million people in the United Kingdom alone. Furthermore, these patients often have more than one contributory factor to their breathlessness symptoms, with conditions such as dysfunctional breathing pattern disorders-an under-recognized component. Current methods of diagnosing and monitoring breathless conditions can be extensive and difficult to perform. As a consequence, home monitoring is poorly complied with. In contrast, capnography (the measurement of tidal breath carbon dioxide) is performed during normal breathing. There is a need for a simple, easy-to-use, personal device that can aid in the diagnosis and monitoring of respiratory and cardiac causes of breathlessness.

OBJECTIVE

The aim of this study was to explore the use of a new, handheld capnometer (called the N-Tidal C) in different conditions that cause breathlessness. We will study whether the tidal breath carbon dioxide (TBCO₂) waveform, as measured by the N-Tidal C, has different characteristics in a range of respiratory and cardiac conditions.

METHODS

We will perform a longitudinal, observational study of the TBCO₂ waveform (capnogram) as measured by the N-Tidal C capnometer. Participants with a confirmed diagnosis of asthma, breathing pattern disorders, chronic heart failure, motor neurone disease, pneumonia, as well as volunteers with no history of lung disease will be asked to provide twice daily, 75-second TBCO₂ collection via the N-Tidal C device for 6 months duration. The collated capnograms will be correlated with the underlying diagnosis and disease state (stable or exacerbation) to determine if there are different TBCO₂ characteristics that can distinguish different respiratory and cardiac causes of breathlessness.

RESULTS

This study's recruitment is ongoing. It is anticipated that the results will be available in late 2018.

CONCLUSIONS

The General Breathing Record Study will provide an evaluation of the use of capnography as a diagnostic and home-monitoring tool for various diseases.

REGISTERED REPORT IDENTIFIER

RR1-10.2196/9767.

Drug therapies in chronic heart failure: a focus on reduced ejection fraction

There are multiple evidence-based drug treatments for chronic heart failure (HF), both disease-modifying agents and those for symptom control. The majority of the evidence base supports drugs used in HF with reduced left ventricular ejection fraction. The mainstay of disease modification involves manipulation of neurohormonal activation that occurs in HF. In addition to established angiotensin-converting enzyme inhibitors, beta blockers and mineralocorticoid receptor antagonists (MRAs), newer agents are now available such as the angiotensin receptor neprilysin inhibitors. Achieving the optimal drug regimen is complex and best performed by a specialist heart failure team. We aim to provide a comprehensive overview of contemporary drug therapies in chronic heart failure, as well as practical guidance for their use. There is a focus on treating patients with challenging comorbidities such as hypotension and chronic kidney disease (CKD), where a thorough understanding of drug therapy is essential. Multiple trials assessing the benefits of new therapies in HF, such as intravenous iron, are also ongoing.

Monitoring of arrhythmia and sudden death in a hemodialysis population: The CRASH-ILR Study

INTRODUCTION

It has been suggested that sudden cardiac death (SCD) contributes around 50% of cardiovascular and 27% of all-cause mortality in hemodialysis patients. The true burden of arrhythmias and arrhythmic deaths in this population, however, remains poorly characterised. Cardio Renal Arrhythmia Study in Hemodialysis (CRASH-ILR) is a prospective, implantable loop recorder single centre study of 30 established hemodialysis patients and one of the first to provide long-term ambulatory ECG monitoring.

METHODS

30 patients (60% male) aged 68±12 years receiving hemodialysis for 45±40 months with varied etiology (diabetes 37%, hypertension 23%) and left ventricular ejection fraction (LVEF) 55±8% received a Reveal XT implantable loop recorder (Medtronic, USA) between August 2011 and October 2014. ECG data from loop recorders were transmitted at each hemodialysis session using a remote monitoring system. Primary outcome was SCD or implantation of a (tachy or bradyarrhythmia controlling) device and secondary outcome, the development of arrhythmia necessitating medical intervention.

RESULTS

During 379,512 hours of continuous ECG monitoring (mean 12,648±9,024 hours/patient), there were 8 deaths-2 SCD and 6 due to generalised deterioration/sepsis. 5 (20%) patients had a primary outcome event (2 SCD, 3 pacemaker implantations for bradyarrhythmia). 10 (33%) patients reached an arrhythmic primary or secondary end point. Median event free survival for any arrhythmia was 2.6 years (95% confidence intervals 1.6-3.6 years).

CONCLUSIONS

The findings confirm the high mortality rate seen in hemodialysis populations and contrary to initial expectations, bradyarrhythmias emerged as a common and potentially significant arrhythmic event.

Iron deficiency in heart failure: Efficacy and safety of intravenous iron therapy

AIM

To discuss the pathophysiology of iron metabolism in chronic heart failure (CHF) and the current knowledge of the efficacy of intravenous (IV) iron therapy in patients with CHF and identify points of controversy as well as highlight areas for future research.

DISCUSSION

Iron deficiency is a recognized complication of many chronic conditions. Numerous studies have reported that iron deficiency is highly prevalent in patients with CHF and is associated with exercise intolerance, reduced quality of life, and increased risk of hospitalization and mortality. Several small studies have demonstrated IV iron to be associated with improvements in symptoms, exercise capacity, quality of life, renal function, New York Heart Association (NYHA) functional class and left ventricular ejection fraction (LVEF), and reduction in NT-pro-brain natriuretic peptide (NT-proBNP) in patients with CHF and iron deficiency. Two larger-scale trials confirming these results (FAIR-HF and CONFIRM-HF) have led to guideline recommendations that IV iron therapy should be considered in patients with CHF with reduced ejection fraction and iron deficiency (serum ferritin <100 μg/L, or ferritin between 100 and 299 μg/L with transferrin saturation <20%) to provide symptomatic relief and improve exercise capacity and quality of life.

CONCLUSION

Intravenous iron therapy improves symptoms, exercise capacity, and quality of life, at least in the short-to-intermediate time. However, there are still currently no standardized criteria used to define iron deficiency and the underlying mechanism of iron deficiency in CHF remains incompletely understood. Further work is required to improve the ability to identify iron deficiency in patients with CHF and evaluate the effect of iron repletion on hard endpoints including hospitalization and mortality.

Hemoglobin and Change in Hemoglobin Status Predict Mortality, Cardiovascular Events, and Bleeding in Stable Coronary Artery Disease

BACKGROUND

Anemia is a predictor of adverse outcomes in acute myocardial infarction. We studied the relationship of hemoglobin, or its change over time, and outcomes in patients with stable coronary artery disease.

METHODS

The ProspeCtive observational LongitudinAl RegIstry oF patients with stable coronary arterY disease is a prospective, cohort study of outpatients with stable coronary artery disease (32,901 in 45 countries 2009-2010): 21,829 with baseline hemoglobin levels. They were divided into hemoglobin quintiles and anemia status (anemic or normal at baseline/follow-up: normal/normal; anemic/normal; normal/anemic; anemic/anemic. All-cause mortality, cardiovascular events, and major bleeding at 4-year follow-up were assessed.

RESULTS

Low baseline hemoglobin was an independent predictor of all-cause, cardiovascular, and noncardiovascular mortality, the composite of cardiovascular death/myocardial infarction or stroke and major bleeds (all P <.001; unadjusted models). Anemia at follow-up was independently associated with all-cause mortality (hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.55-2.33 for anemic/anemic; 1.87; 1.54-2.28 for normal/anemic; both P <.001), noncardiovascular mortality (P <.001), and cardiovascular mortality (P = .001). Patients whose baseline anemia normalized (anemic/normal) were not at increased risk of death (HR, 1.02; 95% CI, 0.77-1.35), although the risk of major bleeding was greater (HR, 2.06; 95% CI, 1.23-3.44; P = .013) than in those with normal hemoglobin throughout. Sensitivity analyses excluding patients with heart failure and chronic kidney disease at baseline yielded qualitatively similar results.

CONCLUSIONS

In this large population with stable coronary artery disease, low hemoglobin was an independent predictor of mortality, cardiovascular events, and major bleeds. Persisting or new-onset anemia is a powerful predictor of cardiovascular and noncardiovascular mortality.

Impact of chronic kidney disease on use of evidence-based therapy in stable coronary artery disease: a prospective analysis of 22,272 patients

Purpose

To assess the frequency of chronic kidney disease (CKD), define the associated demographics, and evaluate its association with use of evidence-based drug therapy in a contemporary global study of patients with stable coronary artery disease.

Methods

22,272 patients from the ProspeCtive observational LongitudinAl RegIstry oF patients with stable coronary arterY disease (CLARIFY) were included. Baseline estimated glomerular filtration rate (eGFR) was calculated (CKD-Epidemiology Collaboration formula) and patients categorised according to CKD stage: >89, 60–89, 45–59 and <45 mL/min/1.73 m².

Results

Mean (SD) age was 63.9±10.4 years, 77.3% were male, 61.8% had a history of myocardial infarction, 71.9% hypertension, 30.4% diabetes and 75.4% dyslipidaemia. Chronic kidney disease (eGFR<60 mL/min/1.73 m²) was seen in 22.1% of the cohort (6.9% with eGFR<45 mL/min/1.73 m²); lower eGFR was associated with increasing age, female sex, cardiovascular risk factors, overt vascular disease, other comorbidities and higher systolic but lower diastolic blood pressure. High use of secondary prevention was seen across all CKD stages (overall 93.4% lipid-lowering drugs, 95.3% antiplatelets, 75.9% beta-blockers). The proportion of patients taking statins was lower in patients with CKD. Antiplatelet use was significantly lower in patients with CKD whereas oral anticoagulant use was higher. Angiotensin-converting enzyme inhibitor use was lower (52.0% overall) and inversely related to declining eGFR, whereas angiotensin-receptor blockers were more frequently prescribed in patients with reduced eGFR.

Conclusions

Chronic kidney disease is common in patients with stable coronary artery disease and is associated with comorbidities. Whilst use of individual evidence-based medications for secondary prevention was high across all CKD categories, there remains an opportunity to improve the proportion who take all three classes of preventive therapies. Angiotensin-converting enzyme inhibitors were used less frequently in lower eGRF categories. Surprisingly the reverse was seen for angiotensin-receptor blockers. Further evaluation is required to fully understand these associations. The CLARIFY (ProspeCtive observational LongitudinAl RegIstry oF patients with stable coronary arterY disease) Registry is registered in the ISRCTN registry of clinical trials with the number ISRCTN43070564. http://www.controlled-trials.com/ISRCTN43070564.

The impact of age and chronic kidney disease on secondary prevention post-primary percutaneous coronary intervention

OBJECTIVE

Historical data suggest elderly patients and those with chronic kidney disease (CKD) receive suboptimal secondary prevention following myocardial infarction (MI). We evaluated the impact of age and CKD on secondary prevention following primary percutaneous coronary intervention (PPCI) in a contemporary unselected cohort.

DESIGN

We studied 1169 consecutive patients from five UK centres receiving PPCI for ST elevation MI, with use of evidence-based secondary prevention at discharge assessed by age (<60, 60-75 and >75 years) and estimated glomerular filtration rate (eGFR). Follow-up prescribing practice was assessed in 567 patients.

RESULTS

One-fifth of patients receiving PPCI were >75 years. This group received fewer secondary prevention drugs at discharge compared to younger patients (P < 0.01 for β-blockers, angiotensin-converting enzyme (ACE) inhibitors/angiotensin receptor blockers (ARB) and statins). By 6 weeks post-PPCI, there was a small drop-off in evidence-based therapy; β-blocker and statin use in those >75 years fell from 90% to 86% and 96% to 93%, respectively. CKD (eGFR<60 ml/min/1.73 m(2)) was seen in 17.6%. Declining renal function was associated with age, female sex and lower use of ACE inhibitor/ARB. At discharge 83.5% of patients with eGFR<60 ml/min/1.73 m(2) were receiving ACE inhibitors/ARB, dropping to 77.5% at 6 weeks (compared with 95% and 92%, respectively, in patients with eGFR >60 ml/min/1.73 m(2)).

CONCLUSION

The uptake of secondary prevention medication is high following PPCI in the UK, even in the elderly and in those with renal dysfunction. A focus on strategies to improve up-titration and continuation of drugs following discharge is required.

Clinical utility of biomarkers in chronic kidney disease and chronic heart failure

Biomarkers have an increasingly important clinical role in managing patients with heart failure as well as those with kidney disease, both common conditions with generally poor prognostic outcomes and huge impacts on healthcare economics. For patients with chronic heart failure, biomarkers have become centre place in streamlining diagnostic pathways as well as identifying those with worse prognosis. There is much interest in the role for biomarkers in identifying patients at risk of acute kidney injury, although a number of these currently remain as research tools or are in the early stages of evaluation in clinical practice. Patients with cardiorenal syndrome represent a particular challenge to the clinician, and recent studies have suggested a valuable clinical role for certain biomarkers in this setting, either on their own or in combination. This paper will focus on biomarkers with a current clinical role in patients with cardiorenal disease (natriuretic peptides and neutrophil gelatinase-associated lipocalin), although brief reference will be made to other biomarkers with potential future application.

Resting heart rate and outcomes in patients with cardiovascular disease: where do we currently stand?

BACKGROUND

Data from large epidemiological studies suggest that elevated heart rate is independently associated with cardiovascular and all-cause mortality in patients with hypertension and in those with established cardiovascular disease. Clinical trial findings also suggest that the favorable effects of beta-blockers and other heart rate-lowering agents in patients with acute myocardial infarction and congestive heart failure may be, at least in part, due to their heart rate-lowering effects. Contemporary clinical outcome prediction models such as the Global Registry of Acute Coronary Events (GRACE) score include admission heart rate as an independent risk factor.

AIMS

This article critically reviews the key epidemiology concerning heart rate and cardiovascular risk, potential mechanisms through which an elevated resting heart rate may be disadvantageous and evaluates clinical trial outcomes associated with pharmacological reduction in resting heart rate.

CONCLUSIONS

Prospective randomised data from patients with significant coronary heart disease or heart failure suggest that intervention to reduce heart rate in those with a resting heart rate >70 bpm may reduce cardiovascular risk. Given the established observational data and randomised trial evidence, it now appears appropriate to include reduction of elevated resting heart rate by lifestyle +/- pharmacological therapy as part of a secondary prevention strategy in patients with cardiovascular disease.

UK guidelines for referral and assessment of adults for heart transplantation

Patients with advanced heart failure have a dismal prognosis and poor quality of life. Heart transplantation provides an effective treatment for a subset of these patients. This article provides cardiologists with up-to-date information about referral for transplantation, the role of left ventricular assist devices prior to transplant, patient selection, waiting-list management and donor heart availability. Timing is of central importance; patients should be referred before complications (eg, cardiorenal syndrome or secondary pulmonary hypertension) have developed that will increase the risk of, or potentially contraindicate, transplantation. Issues related to heart failure aetiology, comorbidity and adherence to medical treatment are reviewed. Finally, the positive role that cardiologists can play in promoting and facilitating organ donation is discussed.

Role of cardiovascular magnetic resonance as a gatekeeper to invasive coronary angiography in patients presenting with heart failure of unknown etiology

BACKGROUND

In patients presenting with new-onset heart failure of uncertain etiology, the role of coronary angiography (CA) is unclear. Although conventionally performed to differentiate underlying coronary artery disease from dilated cardiomyopathy, CA is associated with a risk of complications and may not detect an ischemic cause resulting from arterial recanalization or an embolic episode. In this study, we assessed the diagnostic accuracy of a cardiovascular magnetic resonance (CMR) protocol incorporating late gadolinium enhancement (LGE) and magnetic resonance CA as a noninvasive gatekeeper to CA in determining the etiology of heart failure in this subset of patients.

METHODS AND RESULTS

One hundred twenty consecutive patients underwent CMR and CA. The etiology was ascribed by a consensus panel that used the results of the CMR scans. Similarly, a separate consensus group ascribed an underlying cause by using the results of CA. The diagnostic accuracy of both strategies was compared against a gold-standard panel that made a definitive judgment by reviewing all clinical data. The study was powered to show noninferiority between the 2 techniques. The sensitivity of 100%, specificity of 96%, and diagnostic accuracy of 97% for LGE-CMR were equivalent to CA (sensitivity, 93%; specificity, 96%; and diagnostic accuracy, 95%). As a gatekeeper to CA, LGE-CMR was also found to be a cheaper diagnostic strategy in a decision tree model when United Kingdom-based costs were assumed. The economic merits of this model would change, depending on the relative costs of LGE-CMR and CA in any specific healthcare system.

CONCLUSION

This study showed that LGE-CMR is a safe, clinically effective, and potentially economical gatekeeper to CA in patients presenting with heart failure of uncertain etiology.