Treatment-induced increase in total body potassium in patients at high risk of ventricular arrhythmias; a randomized POTCAST substudy

OBJECTIVE

Hypokalemia is associated with increased risk of arrhythmias and it is recommended to monitor plasma potassium (p-K) regularly in at-risk patients with cardiovascular diseases. It is poorly understood if administration of potassium supplements and mineralocorticoid receptor antagonists (MRA) aimed at increasing p-K also increases intracellular potassium.

METHODS

Adults aged≥18 years with an implantable cardioverter defibrillator (ICD) were randomized (1:1) to a control group or to an intervention that included guidance on potassium rich diets, potassium supplements, and MRA to increase p-K to target levels of 4.5-5.0 mmol/l for six months. Total-body-potassium (TBK) was measured by a Whole-Body-Counter along with p-K at baseline, after six weeks, and after six months.

RESULTS

Fourteen patients (mean age: 59 years (standard deviation 14), 79% men) were included. Mean p-K was 3.8 mmol/l (0.2), and mean TBK was 1.50 g/kg (0.20) at baseline. After six-weeks, p-K had increased by 0.47 mmol/l (95%CI:0.14;0.81), p = 0.008 in the intervention group compared to controls, whereas no significant difference was found in TBK (44 mg/kg (-20;108), p = 0.17). After six-months, no significant difference was found in p-K as compared to baseline (0.16 mmol/l (-0.18;0.51), p = 0.36), but a significant increase in TBK of 82 mg/kg (16;148), p = 0.017 was found in the intervention group compared to controls.

CONCLUSIONS

Increased potassium intake and MRAs increased TBK gradually and a significant increase was seen after six months. The differentially regulated p-K and TBK challenges current knowledge on potassium homeostasis and the time required before the full potential of p-K increasing treatment can be anticipated.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT03833089).

Targeted potassium levels to decrease arrhythmia burden in high risk patients with cardiovascular diseases (POTCAST): Study protocol for a randomized controlled trial

BACKGROUND

Low plasma potassium (p-K) is associated with increased risk of malignant arrhythmia and observational studies indicate protective effects of p-K in the upper reference level. However, randomized clinical studies are needed to document whether actively increasing p-K to high-normal levels is possible and safe and improves cardiovascular outcomes.

OBJECTIVE

To investigate if increased p-K reduces the risk of malignant arrhythmia and all-cause death in high-risk patients with a cardiovascular disease treated with an implantable cardioverter defibrillator (ICD) for primary or secondary preventive causes. Secondly, to investigate whether high-normal p-K levels can be safely reached and maintained using already available medications and potassium-rich dietary guidance.

METHODS

This is a prospective, randomized, and open-labelled study enrolling patient at high-risk of malignant arrhythmias. According to sample size calculations, 1,000 patients will be randomized 1:1 to either an investigational regiment that aims to increase and maintain p-K at high-normal levels (4.5-5.0 mmol/L) or to usual standard of care and followed for an expected four years. The trial will run until a total of 291 events have occurred providing an α = 0.05 and 1-β = 0.80. The composite primary endpoint includes ventricular tachycardia >125 bpm lasting >30 seconds, any appropriate ICD-therapy, and all-cause mortality. At present, 739 patients have been randomized.

CONCLUSIONS

We present the rationale for the design of the POTCAST trial. The inclusion was initiated 2019 and is expected to be finished 2022. The study will show if easily available treatments to increase p-K may be a new treatment modality to protect against malignant arrythmias.

Influence of renal impairment on aldosterone status, calcium metabolism, and vasopressin activity in outpatients with systolic heart failure

Aims

Renal dysfunction (RD) is associated with increased morbidity and mortality in heart failure (HF). At present, no specific treatment for patients with RD, to prevent progression of HF, has been developed. How different hormone axes—and thereby potential treatment options—are affected by RD in HF warrants further investigations.

Methods and results

Patients with left ventricular ejection fraction (LVEF) <0.45% were enrolled prospectively from an outpatient HF clinic. Glomerular filtration rate was estimated by the Chronic Kidney Disease Epidemiology Collaboration equation (eGFR), and patients were grouped by eGFR: eGFR group I, ≥90 mL/min/1.73 m²; eGFR group II, 60–89 mL/min/1.73 m²; and eGFR group III, ≤59 mL/min/1.73 m². Multivariate linear regression models were developed to evaluate the associations between eGFR groups and hormones. A total of 149 patients participated in the study. Median age was 69 [interquartile range (IQR): 64–73] and 26% were female; LVEF was 33% (IQR: 27–39), 78% were in functional class II–III, median eGFR was 74 (54–89) mL/min/1.73 m², and median N‐terminal pro‐brain natriuretic peptide was 1303 pg/mL (IQR: 441–2740). RD was associated with increased aldosterone, parathyroid hormone (PTH), and copeptin concentrations (P < 0.05 for all) after adjustment for traditional confounders and medical treatment.

Conclusions

RD is associated with increased concentrations of aldosterone, PTH, and copeptin in systolic HF outpatients. Our results underscore the importance of treatment with mineralocorticoid receptor antagonist in systolic HF in particular in patients with RD and suggest that vasopressin and parathyroid receptor antagonism are potential treatment options in HF patients with known RD.

Galectin 3: association to neurohumoral activity, echocardiographic parameters and renal function in outpatients with heart failure

Background

Galectin 3 (Gal-3) reflects cardiac fibrosis in heart failure HF, but has also been associated to renal fibrosis and impaired renal function. Previous research has suggested that Gal-3 could be a cardio-renal biomarker, but it has never been tested simultaneous in a single study whether Gal-3 reflects echocardiographic measures, neurohumoral activity and renal function.

The aim of this study was to evaluate the relationship between plasma concentrations of Gal-3 and neurohumoral activity, myocardial and renal function in patients with HF, including advanced echocardiographic measures and 24-h urinary albumin excretion (albuminuria).

Methods

We prospectively enrolled 132 patients with reduced left ventricular ejection fraction (LVEF) referred to an outpatient HF clinic. The patients had a median age of 70 years (interquartile rage: 64–75), 26.5 % were female, median LVEF was 33 % (27–39 %) and 30 % were in NYHA class III-IV.

Results

Patients with plasma concentrations of Gal-3 above the median had significantly lower estimated glomerular filtration rate (eGFR) and this association remained significant in multivariate regression analysis (β: −0.010; 95 % CI −0.012–-0.008; P < 0.001), adjusted for age, gender, medical treatment. Plasma concentrations of Gal-3 were not associated with albuminuria (Beta: 0.008; 95 % CI:-0.028–0.045; P = 0.652). There were no association between plasma concentrations of Gal-3 and myocardial function or structure estimated by LVEF, LVmassIndex, LVIDd, E/é or LV global longitudinal strain (P > 0.05 for all). In multivariate analyses plasma concentrations of Gal-3 were significantly associated with the cardiac biomarkers: NT-proBNP (β: 0.047; 95 % CI: 0.008–0.086; P = 0.020), proANP (β: 0.137; 95 % CI: 0.067–0.207; P < 0.001), chromogranin A (β: 0.123; 95 % CI: 0.052–0.194; P < 0.001) and Copeptin (β: 0.080; 95 % CI: 0.000–0.160; P = 0.049). Multivariate analysis was adjusted for eGFR, age, gender and medical treatment.

Conclusions

Increased plasma concentrations of Gal-3 are associated with reduced eGFR and increased plasma concentrations of NT-proBNP, proANP, chromogranin A and Copeptin, but not with echocardiographic parameters reflecting myocardial function. These results suggest that Gal-3 reflects both increased neurohumoral activity and reduced eGFR, but not myocardial function in patients with systolic HF.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0290-7) contains supplementary material, which is available to authorized users.

Association between left ventricular global longitudinal strain and natriuretic peptides in outpatients with chronic systolic heart failure

Background

Both impaired left ventricular (LV) global longitudinal strain (GLS) and increased plasma concentrations of natriuretic peptides(NP) are associated with a poor outcome in heart failure (HF). Increased levels of NP reflect increased wall stress of the LV. However, little is known about the relationship between LV GLS and NP. This aim of this study was to evaluate the relationship between the echocardiographic measure LV GLS and plasma levels of NP.

Methods

We prospectively included 149 patients with verified systolic HF at the baseline visit in an outpatient HF clinic. LV GLS was assessed by two dimension speckle tracking and plasma concentrations of N-terminal-pro-brain-natriuretic-peptide (NT-proBNP) and pro-atrial-natriuretic-peptide (proANP) were analysed.

Results

The patients had a median age of 70 years, 28.2 % were females, 26.5 % were in functional class III-IV, median left ventricular ejection fraction (LVEF) was 33 % and median LV GLS was −11 %. LV GLS was associated with increased plasma concentrations of NT-proBNP and proANP in multivariate logistic regression (NT-proBNP: Odds Ratio_GLS: 7.25, 95 %-CI: 2.48-21.1, P < 0.001 and proANP: Odds Ratio_GLS: 3.26, 95-%-CI: 1.28-8.30, P = 0.013) and linear regression (NT-proBNP: β_GLS: 1.19, 95 %-CI: 0.62-1.76, P < 0.001 and proANP: β_GLS: 0.42, 95-%-CI: 0.11-0.72, P = 0.007) models after adjustment for traditional confounders (age, gender, body-mass-index, atrial fibrillation, renal function) and left atrial volume index.

Conclusion

Impaired LV GLS is associated with increased plasma concentrations of NP and our data suggest that left ventricular myocardial mechanics estimated by LV GLS reflects myocardial wall stress in chronic systolic HF.

Iron deficiency: Prevalence and relation to cardiovascular biomarkers in heart failure outpatients

BACKGROUND

Both iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked.

OBJECTIVES

To identify the prevalence of ID in a HF clinic and evaluate whether ID is associated with increased plasma concentrations of different cardiovascular biomarkers that carry a poor prognosis.

METHODS

We prospectively included 149 patients with systolic HF referred to an outpatients HF clinic. ID was defined as ferritin<100 μg/L or ferritin 100-300 μg/L and Tranferin-saturation<0.20. Five different cardiovascular biomarkers were analyzed on frozen plasma.

RESULTS

The patients had a median age of 70 (Interquartile range: 64-75) years, 25% were females, 29% were in functional class III-IV and LVEF was 32 (27-39) %. The prevalence of ID was 45% (95%-confidence interval (CI): 37-53%). In multivariate analyses, ID was not associated with plasma concentrations of troponin I, NT-proBNP, MR-proANP, chromogranin A or copeptin (P>0.05 for all) but with plasma concentrations of hs-CRP (odds ratio: 2.03, 95%-CI: 1.02-4.02, P=0.043).

CONCLUSION

ID is frequent in an outpatient HF clinic. ID is not associated with cardiovascular biomarkers after adjustment for traditional confounders. Inflammation, but not neurohormonal activation is associated with ID in systolic HF. Further studies are needed to understand iron metabolism in elderly HF patients.

Influence of renal impairment on myocardial function in outpatients with systolic heart failure: an echocardiographic and cardiac biomarker study

BACKGROUND

Renal dysfunction (RD) is associated with poor outcome in systolic heart failure (HF). Left ventricular ejection fraction (LVEF) is not depressed to a greater extent in patients with RD compared to patients with normal renal function, but it is relatively unknown whether other measures of myocardial function are impaired by RD. The objective of the present study is to evaluate whether RD in systolic HF is associated with excessive impairment of myocardial function, evaluated by strain analysis and cardiac biomarkers.

METHODS

Patients with LVEF <0.45% were enrolled from an outpatient HF clinic. The patients underwent advanced echocardiography. Glomerular filtration rate was estimated by the CKD-EPI equation (eGFR) and patients grouped by eGFR: eGFR group-I, ≥ 90 ml/min/1.73 m(2); eGFR group-II, 60-89 ml/min/1.73 m(2); and eGFR group-III, ≤ 59 ml/min/1.73 m(2). Multivariate regression models were developed to evaluate the associations between eGFR groups, echocardiographic measures and cardiac biomarkers.

RESULTS

A total of 149 patients participated in the study. Median age was 69 years, 26% were female; LVEF was 33%. Patients with a low eGFR were older (P < 0.001), but there were no differences in frequency of atrial fibrillation, hypertension, diabetes and ischemic heart disease between eGFR groups (P > 0.05 for all). RD was associated with impaired global longitudinal strain (P = 0.018), increased E/e' (P = 0.032), larger left atria (P = 0.038) and increased levels of proANP (P < 0.001), NT-proBNP (P < 0.001) and troponin I (P = 0.019) after adjustment for traditional confounders.

CONCLUSIONS

Echocardiographic measures and biomarkers reflecting different aspects of myocardial function are impaired in systolic HF patients with RD and the increased mortality risk in these patients may partly be explained by a depressed cardiac function.

Incidence and Predictors of End-Stage Renal Disease in Outpatients With Systolic Heart Failure

Background—

Renal dysfunction is an important prognostic factor in heart failure (HF), but whether this dysfunction progresses to end-stage renal disease (ESRD) is unknown. Therefore, we examined incidence and predictors of ESRD in outpatients with HF.

Methods and Results—

Patients with systolic HF were identified in The Danish Heart Failure database and new-onset ESRD from the Danish Registry on Dialysis. Renal function was estimated by The Chronic Kidney Disease Epidemiology Collaboration equation and patients grouped by estimated glomerular filtration rate (eGFR)—group I: ≥60 mL/min per 1.73 m 2 , group II: 30 to 59 mL/min per 1.73 m 2 , group III: 15 to 29 mL/min per 1.73 m 2 , group IV: <15 mL/min per 1.73 m 2 . Cox hazard models for time to ESRD, to death, and the composite end point of ESRD or death were constructed and predictors of ESRD identified. A total of 8204 patients were included in the analyses. Median age was 70 years (Q, 61–77), 28% were women, median left ventricular ejection fraction was 30% (Q, 24–40), and median eGFR was 68 (Q, 51–85) mL/min per 1.73 m 2 . Forty-one patients developed ESRD (1.3/1000 patient-years). Baseline eGFR group II ( P <0.001), eGFR group III ( P <0.001), eGFR group IV ( P <0.001), uncontrolled hypertension ( P =0.049), need of diuretics, and age <60 years ( P =0.016) were associated with time to ESRD.

Conclusions—

ESRD is rare in outpatients with systolic HF and is mainly observed in patients with an eGFR <30 mL/min per 1.73 m 2 . A low eGFR, age <60 years, need of diuretics, and uncontrolled hypertension identify patients with an increased risk for ESRD.

Prognostic significance of cardiovascular biomarkers and renal dysfunction in outpatients with systolic heart failure: a long term follow-up study

OBJECTIVE

To assess whether the prognostic significance of cardiovascular (CV) biomarkers, is affected by renal dysfunction (RD) in systolic heart failure (HF).

BACKGROUND

It is unknown, whether the prognostic significance of CV biomarkers, such as N-terminal-pro-brain-natriuretic-peptide (NT-proBNP), high-sensitive troponin T (hsTNT), pro-atrial natriuretic peptide (proANP), copeptin and pro-adrenomedullin (proADM), is affected by renal function in HF.

METHODS

Clinical data and laboratory tests from 424 patients with systolic HF were collected prospectively. The patients were followed for 4.5 years (interquartile range: 2-7.7 years). CV biomarkers were analyzed on frozen plasma, and renal function was estimated by the Modification of Diet in Renal Disease (MDRD) formula. Cox proportional hazard models for mortality risk were constructed and tests for interaction between each CV biomarker and RD were performed.

RESULTS

Median age was 73 years (51-83), 29% were female, LVEF was 30% (13-45), 74% were NYHA classes I-II and estimated glomerular filtration rate (eGFR) was 68 ml/min/1.73 m(2) (18-157). A total of 252 patients died. All five biomarkers--log(NT-proBNP) (HR: 2.13, 95% CI: 1.57-2.87:, P<0.001), hsTNT (HR: 3.07, 95% CI: 1.90-4.96 P<0.001), proANP (HR: 1.02, 95% CI: 1.01-1.03, P<0.001), copeptin (HR: 1.02, 95% CI: 1.01-1.03, P=0.008) and proADM (HR: 2.37, 95% CI: 1.66-3.38, P<0.001)--were associated with mortality risk, but not affected by RD (P>0.05 for all interactions).

CONCLUSION

Established and new CV biomarkers are closely associated with renal function in HF. However, their prognostic significance is not affected by RD, and all CV biomarkers can be used for risk stratification independently of renal function.