Interplay between natriuretic peptides and left atrial mechanics and the relation to recurrence of atrial fibrillation following catheter ablation.

The relationship between natriuretic peptides and atrial distension is not fully understood. We sought to examine their interrelationship and how they relate to atrial fibrillation (AF) recurrence following catheter ablation. We analyzed patients enrolled in the AMIO-CAT trial (amiodarone vs. placebo for reducing AF recurrence). Echocardiography and natriuretic peptides were assessed at baseline. Natriuretic peptides included mid-regional proANP (MR-proANP) and N-terminal proBNP (NT-proBNP). Atrial distension was assessed by left atrial strain measured by echocardiography. The endpoint was AF recurrence within 6 months after a 3-month blanking period. Logistic regression was used to assess the association between log-transformed natriuretic peptides and AF. Multivariable adjustments were made for age, gender, randomization, and left ventricular ejection fraction. Of 99 patients, 44 developed AF recurrence. No differences in natriuretic peptides nor echocardiography were observed between the outcome groups. In unadjusted analyses, neither MR-proANP nor NT-proBNP were significantly associated with AF recurrence [MR-proANP: OR = 1.06 (0.99-1.14), per 10% increase; NT-proBNP: OR = 1.01 (0.98-1.05), per 10% increase]. These findings were consistent after multivariable adjustments. However, atrial strain significantly modified the association between MR-proANP and AF (p for interaction = 0.009) such that MR-proANP was associated with AF in patients with high atrial strain [OR = 1.24 (1.06-1.46), p = 0.008, per 10% increase] but not in patients with low atrial strain. In patients with high atrial strain, an MR-proANP > 116 pmol/L posed a fivefold higher risk of AF recurrence [HR = 5.38 (2.19-13.22)]. Atrial natriuretic peptide predicts AF recurrence in patients with preserved atrial distension. Assessing atrial strain may assist the interpretation of natriuretic peptides.

Hypoxia briefly increases diuresis but reduces plasma volume by fluid redistribution in women.

We have recently reported that hypobaric hypoxia (HH) reduces plasma volume (PV) in men by decreasing total circulating plasma protein (TCPP). Here, we investigated whether this applies to women and whether an inflammatory response and/or endothelial glycocalyx shedding could facilitate the TCCP reduction. We further investigated whether acute HH induces a short-lived diuretic response that was overlooked in our recent study, where only 24-h urine volumes were evaluated. In a strictly controlled crossover protocol, 12 women underwent two 4-day sojourns in a hypobaric chamber: one in normoxia (NX) and one in HH equivalent to 3,500-m altitude. PV, urine output, TCPP, and markers for inflammation and glycocalyx shedding were repeatedly measured. Total body water (TBW) was determined pre- and postsojourns by deuterium dilution. PV was reduced after 12 h of HH and thereafter remained 230-330 mL lower than in NX (P < 0.0001). Urine flow was 45% higher in HH than in NX throughout the first 6 h (P = 0.01) but lower during the second half of the first day (P < 0.001). Twenty-four-hour urine volumes (P ≥ 0.37) and TBW (P ≥ 0.14) were not different between the sojourns. TCPP was lower in HH than in NX at the same time points as PV (P < 0.001), but inflammatory or glycocalyx shedding markers were not consistently increased. As in men, and despite initially increased diuresis, HH-induced PV contraction in women is driven by a loss of TCPP and ensuing fluid redistribution, rather than by fluid loss. The mechanism underlying the TCPP reduction remains unclear but does not seem to involve inflammation or glycocalyx shedding.NEW & NOTEWORTHY This study is the first to investigate the mechanisms underlying plasma volume (PV) contraction in response to hypoxia in women while strictly controlling for confounders. PV contraction in women has a similar time course and magnitude as in men and is driven by the same mechanism, namely, oncotically driven redistribution rather than loss of fluid. We further report that hypoxia facilitates an increase in diuresis, that is, however, short-lived and of little relevance for PV regulation.

Investigating the roles of hyperglycaemia, hyperinsulinaemia and elevated free fatty acids in cardiac function in patients with type 2 diabetes via treatment with insulin compared with empagliflozin: protocol for the HyperCarD2 randomised, crossover trial.

INTRODUCTION: Type 2 diabetes (T2D) is characterised by elevated plasma glucose, free fatty acid (FFA) and insulin concentrations, and this metabolic profile is linked to diabetic cardiomyopathy, a diastolic dysfunction at first and increased cardiovascular disease (CVD) risk. Shifting cardiac metabolism towards glucose utilisation has been suggested to improve cardiovascular function and CVD risk, but insulin treatment increases overall glucose oxidation and lowers lipid oxidation, without reducing CVD risk, whereas SGLT2 inhibitors (SGLT2i) increase FFA, ketone body concentrations and lipid oxidation, while decreasing insulin concentrations and CVD risk. The aim of the present study is to elucidate the importance of different metabolic profiles obtained during treatment with a SGLT2i versus insulin for myocardial function in patients with T2D. METHODS AND ANALYSES: Randomised, crossover study, where 20 patients with T2D and body mass index>28 kg/m2 receive 25 mg empagliflozin daily or NPH insulin two times per day first for 5 weeks followed by a 3-week washout before crossing over to the remaining treatment. Insulin treatment is titrated to achieve similar glycaemic control as with empagliflozin. In those randomised to insulin first, glycaemia during an initial empagliflozin run-in period prior to randomisation serves as target glucose. Metabolic and cardiac evaluation is performed before and at the end of each treatment period.The primary endpoint is change (treatment-washout) in left ventricular peak filling rate, as assessed by cardiac MRI with and without acute lowering of plasma FFAs with acipimox. Secondary and explorative endpoints are changes in left atrial passive emptying fraction, left ventricular ejection fraction, central blood volume and metabolic parameters. ETHICS AND DISSEMINATION: This study is approved by the Danish Medicines Agency (ref. nr.: 2017061587), the Danish Data Protection Agency (ref. nr.: AHH-2017-093) and the Capital Region Ethics Committee (ref. nr.: H-17018846). The trial will be conducted in accordance with ICH-GCP guidelines and the Declaration of Helsinki and all participants will provide oral and written informed consent. Our results, regardless of outcome, will be published in relevant scientific journals and we also will seek to disseminate results through presentations at scientific meetings. TRIAL REGISTRATION NUMBER: EudraCT: 2017-002101.

Diagnostic and prognostic value of the electrocardiogram in stable outpatients with type 2 diabetes.

Aims. The European Society of Cardiology guidelines on diabetes and cardiovascular disease (CVD) recommend an electrocardiogram (ECG) in patients with diabetes and hypertension or with suspected CVD. We investigated whether ECG abnormalities can be used as a diagnostic and prognostic marker of heart failure (HF) in patients with type-2 diabetes (T2D) in secondary care diabetes-clinics. Methods. We included 722 patients with T2D in sinus rhythm. HF with preserved ejection fraction (HFpEF) was defined according to the European Society of Cardiology guidelines. Heart failure with mid-range ejection fraction (HFmrEF) was patients with dyspnoea and an LVEF 41-49%. Heart failure with reduced ejection fraction (HFrEF) or asymptomatic left ventricular systolic dysfunction (ALVSD) was defined as a LVEF ≤40%. Results. Overall, 24% patients had ECG abnormalities. A total of 15% had HF whereof 48% had ECG abnormalities. A normal ECG had a 99.3% negative predictive value (NPV) of ruling out HFrEF/ALVSD. In a sub-group with 0-1 simple clinical risk markers, the ECG ruled out both HFrEF/ALVSD, HFmrEF, and HFpEF with an NPV of 96.6%. The hazard-ratio (HR) of incident CVD or death in patients with HF and a normal ECG compared with patients without HF was 1.85 [95%CI 1.01-3.39], p = .05, while an abnormal ECG increased the HR to 3.84 [2.33-6.33], p < .001. Conclusion. HFrEF/ALVSD and HFmrEF were rare and HFpEF was frequent in this T2D population. A normal ECG ruled out HFrEF/ALVSD and in a sub-population with 0-1 simple clinical risk markers also both HFrEF/ALVSD, HFmrEF, and HFpEF.Key messagesWhat is already known about this subject?In early studies of unselected patients from primary care with suspected chronic heart failure, the presence of a normal ECG was found be useful to rule out heart failure with reduced ejection fraction.What does this study add?This study confirms that a standard electrocardiogram when normal in 722 stable outpatients with type 2 diabetes can be used to rule out HFrEF/ALVSD. Further, it adds knowledge about the risk of incident cardiovascular disease or death as a pathologic electrocardiogram increases the hazard ratio.How might this implicate clinical practice?With this study clinicians in secondary diabetes care clinics can use an electrocardiogram to select patients to undergo echocardiography when suspecting heart failure with reduced ejection fraction, as a normal electrocardiogram will rule out this diagnosis with a negative predictive value of >99%.

Diet-induced hypertension in rats is associated with increased renal vasoconstrictor response to angiotensin II after imitated endothelial dysfunction.

The mechanisms behind development of diet-induced hypertension remain unclear. The kidneys play a paramount role in blood volume and blood pressure regulation. Increases in renal vascular resistance lead to increased mean arterial blood pressure (MAP) due to reduced glomerular filtration rate and Na+ excretion. Renal vascular resistance may be increased by several factors, e.g. sympathetic output, increased activity in the renin-angiotensin system or endothelial dysfunction. We examined if a 14-week diet rich in fat, fructose or both led to increased renal vascular resistance and blood pressure. Sixty male Sprague-Dawley rats received normal chow (Control), high-fat chow (High Fat), high-fructose in drinking water (High Fructose), or a combination of high-fat and high-fructose diet (High Fat + Fruc) for 14 weeks from age 4-weeks. Measurements included body weight (BW), telemetry blood pressures, renal blood flow in anesthetized rats, plasma concentrations of atrial natriuretic peptide and glucose, as well as vessel myography in renal segmental arteries. Body weight increased in both groups receiving high fat, whereas MAP increased only in the High Fat + Fruc group. Renal blood flow did not differ between groups showing that renal vascular resistance was not increased by the diets. After inhibiting nitric oxide and prostacyclin production, renal blood flow reductions to Angiotensin II infusions were exaggerated in the groups receiving high fructose. MAP correlated positively with heart rate in all rats tested. Our data suggest that diet-induced hypertension is not caused by an increase in renal vascular resistance. The pathophysiological mechanisms may include altered signaling in the renin-angiotensin system and increases in central sympathetic output in combination with reduced baroreceptor sensitivity leading to increased renal vasoconstrictor responses.

Dipeptidyl peptidase-3 is associated with severity of liver disease and circulatory complications in patients with cirrhosis.

BACKGROUND: Patients with cirrhosis suffer from a complex multiorgan disturbance and their prognosis is influenced by the development of portal hypertension and systemic circulatory dysfunction. Although non-invasive techniques such as transient elastography aid in early detection, there is an unmet need for reliable markers of these clinically significant complications. METHODS: We conducted an exploratory single-center study investigating dipeptidyl peptidase-3 (DPP3) concentrations in various vascular beds in a cohort of 48 patients with cirrhosis and 16 healthy controls. Liver vein catheterisation with sampling from femoral artery and femoral, renal and hepatic veins as well as measurement of hepatic pressure and liver function via indocyanine green and galactose elimination tests were performed. RESULTS: DPP3 concentrations were higher in cirrhotic patients compared to controls (12.6 vs. 7.4 ng/mL, p = 0.006) and increased according to the severity of cirrhosis. DPP3 associated with MELD-Na score, Child class, indocyanine green clearance, increased DPP3 with the increased hepatic venous pressure gradient (p = 0.015) as well as increased heart rate and reduced systemic vascular resistance. DPP3 concentrations predicted the presence of clinically significant portal hypertension in cirrhotic patients (AUROC 0.78, 95% CI 0.65-0.9). CONCLUSION: DPP3 is a promising marker for portal hypertension and systemic hemodynamic changes in cirrhosis.

Sex-specific mortality prediction by pro-C-type natriuretic peptide measurement in a prospective cohort of patients with ST-elevation myocardial infarction.

OBJECTIVE: To determine the predictive value of pro-C-type natriuretic peptide (pro-CNP) measurement in plasma sampled on admission from patients presenting with ST-elevation myocardial infarction (STEMI). DESIGN: Prospective cohort study. SETTING: Two University Hospitals in Denmark. PARTICIPANTS: 1760 consecutive patients (470 females and 1290 males) with confirmed STEMI. MAIN OUTCOMES AND MEASURES: The main outcome was all-cause mortality at 1 year after presentation and the primary measure was pro-CNP concentration in plasma at admission in all patients and longitudinal measurements in a consecutive subgroup of 287 patients. A reference population (n=688) defined cut-off values of increased pro-CNP concentrations. RESULTS: In all patients, an increased pro-CNP concentration was associated with a higher all-cause mortality after 1 year (HR 1.6, 95% CI 1.1 to 2.4, Plogrank=0.009) including an interaction of sex (p=0.03). In separate sex-stratified analyses, female patients showed increased all-cause mortality (HR1 year 2.6, 95% CI 1.5 to 4.6), Plogrank <0.001), whereas no differences were found in male patients (HR1 year 1.1, 95% CI 0.7 to 1.9, Plogrank=0.66). After adjusting for potential risk factors, we found increased pro-CNP concentrations≥the median value to be independently associated with increased risk of mortality in female patients within 1 year (HR per 1 pmol/L increase: 1.04, 95% CI 1.01 to 1.06, p=0.007). Moreover, we found indications of sex differences in pro-CNP concentrations over time (higher pro-CNP in males (4.4, 95% CI -0.28 to 9.1 pmol/L, p=0.07) and interaction of sex and time (p=0.13)), and that hypertension was independently associated with higher pro-CNP (4.5, 95% CI 0.6 to 8.4 pmol/L, p=0.03). CONCLUSIONS: In female but not male patients presenting with STEMI, high concentrations of pro-CNP (≥median) at admission independently indicate a higher risk of all-cause mortality. The findings are remarkably specific for female patients, suggesting a different vascular phenotype beyond traditional measures of coronary artery flow compared with male patients.

Admission biomarkers among patients with acute myocardial-infarction related cardiogenic shock with or without out-of-hospital cardiac arrest an exploratory study.

BACKGROUND: Acute myocardial infarction complicated by cardiogenic shock (AMICS) with or without out-of-hospital cardiac arrest (OHCA) have some pathophysiological differences and could potentially be considered as two individual clinical entities. Thus, there may also be differences in terms of blood borne biomarkers. PURPOSE: To explore potential differences in concentrations of the biomarkers lactate, mid-regional proadrenomedullin (MRproADM), Copeptin, pro-atrial natriuretic peptide (proANP), Syndecan-1, soluble thrombomodulin (sTM), soluble suppression of tumorigenicity 2 (sST2) and neutrophil gelatinase-associated lipocalin (NGAL), in patients with AMICS with or without OHCA. METHOD: Patients admitted for acute coronary angiography due to suspected ST-elevation myocardial infarction were enrolled during a 1-year period. In the present study 86 patients with confirmed AMICS at admission were included. RESULTS: In the adjusted analysis OHCA patients had higher levels of lactate (p = 0.008), NGAL (p = 0.03) and sTM (p = 0.011) while the level of sST2 was lower (p = 0.029). There was little difference in 30-day mortality between the OHCA and non-OHCA groups (OHCA 37% vs. non-OHCA 38%). CONCLUSION: AMICS patients with or without OHCA had similar 30-day mortality but differed in terms of Lactate, NGAL, sTM and sST2 levels. These findings support that non-OHCA and OHCA patients with CS could be considered as two individual clinical entities.

Plasma marker for systemic inflammation is increased in Mexican Tarahumara following ultra-distance running.

OBJECTIVES: Previous studies have suggested that acute exercise-induced cardiac and kidney damage following ultra-distance running is low in Mexican Tarahumara even though C-reactive protein (CRP) remained elevated 24 hours post-race. We aimed to study if the plasma biomarker, soluble urokinase-type plasminogen activator receptor (suPAR), could replace or complement CRP as a systemic inflammation biomarker in Tarahumara men and women following ultra-distance running. METHODS: Plasma samples were collected pre-race and at three to six different time points post-race in Mexican Tarahumara competing in three independent ultramarathons; men running 78 km (GroupI, n = 9), women running 52 km (GroupII, n = 3), and men running 63 km (GroupIII, n = 10). Baseline anthropometry, blood pressure, glycated hemoglobin, and hemoglobin were measured, aerobic fitness was estimated by submaximal step test, absolute and relative running intensity assessed using combined heart rate and accelerometry. Plasma was collected pre- and post-race to analyze concentrations of suPAR, and-for women only-a panel of inflammatory, cardiac and kidney plasma biomarkers. Mixed-effect models were used to evaluate the effect of ultramarathon running on plasma suPAR concentrations. RESULTS: Compared to pre-race values, suPAR was significantly elevated in plasma <5 minutes after the three ultramarathon races (70%-109% increase of the mean for the three groups). Furthermore, plasma suPAR remained significantly elevated up to 6 hours post-race for all three groups of runners independent of running intensity. CONCLUSIONS: The results suggest that suPAR can complement, but not replace CRP following ultra-distance running in Tarahumara men and women.

Mortality in cardiogenic shock is stronger associated to clinical factors than contemporary biomarkers reflecting neurohormonal stress and inflammatory activation.

PURPOSE: To validate the IABP-SHOCK II risk score in a Danish cohort and assess the association between the IABP-SHOCK II risk score and admission concentration of biomarkers reflecting neurohormonal - (Copeptin, Pro-atrial natriuretic peptide (proANP), Mid-regional pro-adrenomedullin (MRproADM)) and inflammatory (ST2) activation in patients with CS complicating ST segment elevation myocardial infarction (STEMI). METHODS: A total of 137 consecutive patients admitted with STEMI and CS at two tertiary heart centres were stratified according to the IABP-SHOCK II risk score (0-2; 3/4; 5-9), and had blood sampled upon admission. RESULTS: Plasma concentrations of Copeptin (median (pmol/L) score 0-2: 313; score 3/4: 682; score 5-9: 632 p < 0.0001), proANP (pmol/L) (1459; 2225; 2876 p = 0.0009) and MRproADM (nmol/L) (0.86; 1.2; 1.4 p = 0.04) were significantly associated with the risk score, whereas ST2 (ng/mL) was not (44; 60; 45 p = 0.23). The IABP-SHOCK II risk score predicted 30-day mortality (score 0-2: 22%; score 4/3: 51%; score 5-9: 72%, area under the curve (AUC): 0.73, plogrank < 0.0001), while the tested biomarkers did not (AUC: 0.51

Unexpected, isolated activated partial thromboplastin time prolongation: A practical mini-review.

A common inquiry in coagulation laboratories is how to interpret an unexpected, isolated prolonged activated partial thromboplastin time (APTT). In this context, isolated means together with a normal prothrombin time (PT) and/or normal international normalized ratio (INR). This finding may lead to contact with laboratory doctors for further advice on a diagnostic strategy. Occasionally, the need for a diagnostic algorithm can be subacute, where surgery has to be postponed until an explanation for the isolated, prolonged APTT has been established. Activated partial thromboplastin time as a coagulation test was developed to monitor patients with hemophilia. Different APTT reagents display considerable differences in their sensitivity to deficiencies of coagulation factors. An isolated, prolonged APTT is seen in (a) individuals/patients with lupus anticoagulants, (b) patients in treatment with anticoagulants, mainly heparin, and (c) patients with deficiencies of specific coagulation factors. In this tutorial review, we summarize what may cause an isolated prolonged APTT and we present a simple diagnostic algorithm to differentiate between lupus anticoagulants (common) and factor deficiencies (rare). The identification of an isolated prolonged APTT as well as the underlying cause can be of the utmost importance in ensuring the correct therapeutic follow-up.

Adjunctive dabigatran therapy improves outcome of experimental left-sided Staphylococcus aureus endocarditis.

BACKGROUND: Staphylococcus aureus is the most frequent and fatal cause of left-sided infective endocarditis (IE). New treatment strategies are needed to improve the outcome. S. aureus coagulase promotes clot and fibrin formation. We hypothesized that dabigatran, could reduce valve vegetations and inflammation in S. aureus IE. METHODS: We used a rat model of severe aortic valve S. aureus IE. All infected animals were randomized to receive adjunctive dabigatran (10 mg/kg b.i.d., n = 12) or saline (controls, n = 11) in combination with gentamicin. Valve vegetation size, bacterial load, cytokine, cell integrins expression and peripheral platelets and neutrophils were assessed 3 days post-infection. RESULTS: Adjunctive dabigatran treatment significantly reduced valve vegetation size compared to controls (p< 0.0001). A significant reduction of the bacterial load in aortic valves was seen in dabigatran group compared to controls (p = 0.02), as well as expression of key pro-inflammatory markers keratinocyte-derived chemokine, IL-6, ICAM-1, TIMP-1, L-selectin (p< 0.04). Moreover, the dabigatran group had a 2.5-fold increase of circulating platelets compared to controls and a higher expression of functional and activated platelets (CD62p+) unbound to neutrophils. CONCLUSION: Adjunctive dabigatran reduced the vegetation size, bacterial load, and inflammation in experimental S. aureus IE.

Lactate is a Prognostic Factor in Patients Admitted With Suspected ST-Elevation Myocardial Infarction.

AIMS: The diagnosis of cardiogenic shock depends on clinical signs of poor perfusion and low blood pressure. Lactate concentration will increase with poor tissue perfusion, and it has prognostic value in cardiogenic shock patients. We sought to assess the prognostic value of lactate concentration in subjects admitted with suspected ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS: In 2,094 (93%) out of 2,247 consecutive suspected STEMI-subjects, lactate concentration was measured on admission. The prognostic value of lactate concentration on 30-day mortality was assessed in addition to clinical signs of peripheral hypoperfusion, systolic blood pressure (sBP), and left ventricular ejection fraction (LVEF) in multivariable models.Lactate concentration added prognostic information beyond signs of peripheral hypoperfusion, sBP, and LVEF, and was independently associated with 30-day mortality (hazard ratio [95% confidence interval] 1.11 [1.07-1.14], P < 0.0001). Lactate also provided predictive information on 30-day mortality to the combination of signs of peripheral hypoperfusion, sBP, and LVEF (area under the receiver-operating characteristics curve = 0.88 vs. 0.83, P < 0.0001). CONCLUSIONS: In conclusion, admission lactate concentration in suspected STEMI-subjects contains prognostic information on 30-day mortality when added to variables used in cardiogenic shock-definition. We recommend lactate measurement in STEMI-subjects, especially when signs of compromised hemodynamics are present.

Copeptin levels and invasive hemodynamics in patients with advanced heart failure.

AIM: Arginine vasopressin is a potent vasoconstrictory hormone and arginine vasopressin release is upregulated in heart failure (HF). The aim of this study was to evaluate if copeptin (the C-terminal part of provasopressin) is related to invasive hemodynamics in HF. METHODS & RESULTS: Right heart catheterization was performed in patients with advanced HF referred for evaluation for heart transplantation. Sixty-five patients (mean age 54 ± 12 years, left ventricular ejection fraction 19 ± 8% and median copeptin levels of 16.7 pmol/l (interquartile range: 11-30 pmol/l) were included. In multivariate analysis, increased levels of log (copeptin) were associated with a reduced CI (r = 0.65 and p = 0.04). CONCLUSION: Increased copeptin levels in plasma are associated with hemodynamic parameters obtained at right heart catheterization in patients with HF, in particular-reduced cardiac index. Copeptin could be a useful biomarker for abnormal resting hemodynamics in HF.

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.

Natriuretic Propeptides as Markers of Atrial Fibrillation Burden and Recurrence (from the AMIO-CAT Trial).

Natriuretic peptides are established plasma markers of systolic heart failure, but their usefulness for the evaluation of atrial fibrillation (AF) is unknown. We examined mid-regional pro-atrial natriuretic peptide (MR-proANP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients undergoing ablation for AF. A subpopulation of 102 patients (median age 60 [52;65], 82% male) from the AMIO-CAT trial (Recurrence of arrhythmia following short-term oral AMIOdarone after CATheter ablation for atrial fibrillation: a double-blind, randomized, placebo-controlled study) undergoing ablation for paroxysmal (n = 55) or persistent (n = 47) AF was studied. MR-proANP and NT-proBNP were measured before ablation and at 1, 3, and 6 months' follow-up. Three-day Holter monitoring was performed before ablation, and 6 to 8 weeks and 6 months after ablation. Plasma MR-proANP and NT-proBNP concentrations were higher during AF than during sinus rhythm before ablation (188 pmol/L [131;260] vs 94 pmol/L [64;125], p <0.001; 78 pmol/L [43;121] vs 10.3 pmol/L [5.9;121], p <0.001) and at 1, 3, and 6 months' follow-up. Categories of AF burden on 3-day Holter monitoring (0%, 0% to 99%, and 99% to 100%) were associated with plasma concentrations of both MR-proANP (94 pmol/L [55;127] vs 117 pmol/L [88;185] vs 192 pmol/L [127;261], p <0.001) and NT-proBNP (10 pmol/L [5.9;22] vs 22 pmol/L [8.9;53] vs 81 pmol/L [45;116], p <0.001). In a multivariate regression analysis, however, there was no significant association between baseline propeptide concentrations and recurrence of AF at 6 months' follow-up. In conclusion, AF was associated with higher plasma concentrations of MR-proANP and NT-proBNP than sinus rhythm. Moreover, AF burden was associated with subsequent concentrations of both MR-proANP and NT-proBNP. The results suggest that natriuretic propeptide measurement reflects functional cardiac dysfunction during AF, and that AF burden should be included in biochemical assessment of left ventricular dysfunction.

Plasma pro-atrial natriuretic peptide to estimate fluid balance during open and robot-assisted esophagectomy: a prospective observational study.

BACKGROUND: It remains debated how much fluid should be administered during surgery. The atrial natriuretic peptide precursor proANP is released by atrial distension and deviations in plasma proANP are reported associated with perioperative fluid balance. We hypothesized that plasma proANP would decrease when the central blood volume is compromised during the abdominal part of robot-assisted hybrid (RE) esophagectomy and that a positive fluid balance would be required to maintain plasma proANP. METHODS: Patients undergoing RE (n = 25) or open (OE; n = 25) esophagectomy for gastroesophageal cancer were included consecutively in this prospective observational study. Plasma proANP was determined repetitively during esophagectomy to allow for distinction between the abdominal and thoracic part of the procedure. The RE group was 15° head up tilted during the abdominal procedure. RESULTS: The blood loss was 250 (150-375) (RE) and 600 ml (390-855) (OE) (p = 0.01), but the two groups of patients were provided with a similar positive fluid balance: 1705 (1390-1983) vs. 1528 ml (1316-1834) (p = 0.4). However, plasma proANP decreased by 21% (p < 0.01) during the abdominal part of RE carried out during moderate head-up tilt, but only by 11% (p = 0.01) during OE where the patients were supine. Plasma proANP and fluid balance were correlated in the RE-group (r = 0.5 (0.073-0.840), p = 0.02) and tended to correlate in the OE group (r = 0.4 (-0.045-0.833), p = 0.08). CONCLUSION: The results support that plasma proANP decreases when the central blood volume is compromised and suggest that an about 2200 ml surplus administration of crystalloid is required to maintain plasma proANP during esophagectomy. TRIAL REGISTRATION: Clinicaltrials.gov ( NCT02077673 ). Registered retrospectively February 12th 2014.

Specificity of B-Type Natriuretic Peptide Assays: Cross-Reactivity with Different BNP, NT-proBNP, and proBNP Peptides.

BACKGROUND: B-type natriuretic peptides (BNPs) are used clinically to diagnose and monitor heart failure and are present in the circulation as multiple proBNP-derived fragments. We investigated the specificity of BNP immunoassays with glycosylated and nonglycosylated BNP, N-terminal proBNP (NT-proBNP), and proBNP peptides to probe the cross-reactivity of each assay. METHODS: Nine B-type natriuretic peptides were studied,including synthetic and recombinant BNP (Shionogi, Scios, Mayo), human and synthetic glycosylated and nonglycosylated NT-proBNP (HyTest, Roche Diagnostics), and human glycosylated and nonglycosylated proBNP (HyTest, Scios). Five BNP [Abbott, Abbott POC, Alere, Beckman Coulter, Siemens (Centaur)], 9 NT-proBNP [Ortho-Clinical Diagnostics, Roche, Response, bioMerieux, Siemens (Dimension, Immulite, Stratus CS), Mitsubishi] and 3 research-use-only proBNP immunoassays [Biosite (Alere), Bio-Rad, Goetze] were evaluated. Specificity was assessed by calculating the recovery between baseline and peptide-spiked human plasma pools at target concentrations of 100 ng/L BNP, 300 ng/L proBNP, or 450 ng/L NT-proBNP. All assays were performed in duplicate. RESULTS: BNP and NT-proBNP assays demonstrated substantial cross-reactivity with proBNP peptides. NT-proBNP assays do not detect glycosylated forms of either NT-proBNP or proBNP. proBNP assays preferentially detect the BNP 1-32 peptide and have minimal cross-reactivity with BNP peptides and glycosylated proBNP. CONCLUSIONS: BNP or NT-proBNP results are not transferable among the current existing immunoassays owing to their differences in cross-reactivity and ability to detect various glycosylated forms of proBNP-derived fragments. Opportunities remain to standardize and harmonize BNP and NT-proBNP assays, as well as to develop specific proBNP assays, to widen their clinical scope of use.

Neurohormonal activation and exercise tolerance in patients supported with a continuous-flow left ventricular assist device.

BACKGROUND: Neurohormones play a key role in regulating hemodynamics in heart failure (HF) both at rest and during exercise. In contrast, little is known about the importance of neurohormonal regulation for exercise capacity in continuous-flow left ventricular assist device (CF-LVAD) patients. The aim of this study was to assess the relation between neurohormonal activation patterns in CF-LVAD patients and exercise capacity. METHODS: Plasma concentrations of the C-terminal portion of pro-arginine vasopressin precursor (copeptin), pro-adrenomedullin (proADM), pro-B-type (proBNP) and pro-atrial (proANP) natriuretic peptides were measured in 25 CF-LVAD patients (HeartMate II) in the morning prior to maximal cardiopulmonary exercise testing determining peak oxygen uptake (peak VO2). Quality of life (QOL) was determined by questionnaires. RESULTS: Peak VO2 was severely reduced averaging 13.0±5.3ml/kg/min and exhibited strong negative correlations with copeptin, r=-0.61 (p=0.001) and proADM, r=-0.56 (p=0.005). Additionally comparing patients with peak VO2<14 vs≥14ml/kg/min demonstrated significant differences in copeptin and proADM concentrations, 2.8±0.8 vs 2.1±0.7pmol/l (p=0.03) and 1.0±0.5 vs 0.7±0.2nmol/l (p=0.01), respectively. In contrast natriuretic peptides were not associated with maximal exercise capacity. Lower QOL correlated with increasing proBNP. CONCLUSION: Resting plasma levels of proADM and copeptin are significantly correlated with peak VO2 in CF-LVAD patients. Future studies should address if interventions to lower the levels of these markers are associated with restoration of exercise tolerance.