Wall stress modulates brain natriuretic peptide production in pressure overload cardiomyopathy

Human epididymis protein 4 is a useful predictor of post-operative prognosis in patients with severe aortic stenosis

AIMS

The human epididymis protein 4 (HE4), a novel fibrosis marker, is expressed only in activated fibroblasts and is thought to reflect ongoing left ventricular (LV) fibrosis. LV fibrosis is a feature of severe aortic stenosis (AS) and is related to the post-operative outcome of patients with AS. We investigated the relationship between serum levels of HE4 and the post-operative prognosis of patients with severe AS.

METHODS AND RESULTS

We measured the serum HE4 levels of 55 participants (80.8 ± 8.0 years old, male n = 26, 46%) with severe AS prior to surgical aortic valve replacement (n = 31, 56%) or transcatheter aortic valve implantation (n = 24, 44%) at Kumamoto University Hospital in 2018. We followed them for cardiovascular (CV) death or hospitalization for heart failure (HF) for 3 years. Serum HE4 levels were positively correlated with computed tomography-extracellular volume (CT-ECV) values (r = 0.53, P = 0.004). Kaplan-Meier curves demonstrated a significantly higher probability of hospitalization for HF or CV-related death in the patients with high HE4 (greater than the median HE4 value) compared with the patients with low HE4 (lower than the median HE4 value) (log-rank P = 0.003). Multivariate analysis showed HE4 (log(HE4)) to be an independent prognostic factor [hazard ratio (HR): 7.50; 95% confidence interval (CI): 1.81-31.1; P = 0.005]. Receiver operating characteristic (ROC) curve analysis suggested that HE4 is a marker of increased risk of CV-related death or hospitalization for HF at 3 years after surgery, with an area under the curve (AUC) of 0.76 (95% CI: 0.62-0.90; P = 0.003).

CONCLUSIONS

We found that HE4 is a potentially useful biomarker for predicting future CV events in patients scheduled for AS surgery. Measuring serum HE4 values could help consider AS surgery.

Quantifying Hemodynamic Cardiac Stress and Cardiomyocyte Injury in Normotensive and Hypertensive Acute Heart Failure

BACKGROUND

The characterization of the different pathophysiological mechanisms involved in normotensive versus hypertensive acute heart failure (AHF) might help to develop individualized treatments.

METHODS

The extent of hemodynamic cardiac stress and cardiomyocyte injury was quantified by measuring the B-type natriuretic peptide (BNP), N-terminal proBNP (NT-proBNP), and high-sensitivity cardiac troponin T (hs-cTnT) concentrations in 1152 patients presenting with centrally adjudicated AHF to the emergency department (ED) (derivation cohort). AHF was classified as normotensive with a systolic blood pressure (SBP) of 90-140 mmHg and hypertensive with SBP > 140 mmHg at presentation to the ED. Findings were externally validated in an independent AHF cohort (n = 324).

RESULTS

In the derivation cohort, with a median age of 79 years, 43% being women, 667 (58%) patients had normotensive and 485 (42%) patients hypertensive AHF. Hemodynamic cardiac stress, as quantified by the BNP and NT-proBNP, was significantly higher in normotensive as compared to hypertensive AHF [1105 (611-1956) versus 827 (448-1419) pg/mL, and 5890 (2959-12,162) versus 4068 (1986-8118) pg/mL, both p < 0.001, respectively]. Similarly, the extent of cardiomyocyte injury, as quantified by hs-cTnT, was significantly higher in normotensive AHF as compared to hypertensive AHF [41 (24-71) versus 33 (19-59) ng/L, p < 0.001]. A total of 313 (28%) patients died during 360 days of follow-up. All-cause mortality was higher in patients with normotensive AHF vs. patients with hypertensive AHF (hazard ratio 1.66, 95%CI 1.31-2.10; p < 0.001). Normotensive patients with a high BNP, NT-proBNP, or hs-cTnT had the highest mortality. The findings were confirmed in the validation cohort.

CONCLUSION

Biomarker profiling revealed a higher extent of hemodynamic stress and cardiomyocyte injury in patients with normotensive versus hypertensive AHF.

Detection of soluble suppression of tumorigenicity 2 and N-terminal B-type natriuretic peptide in a rat model of aortic regurgitation: differential responses to omecamtiv mecarbil

OBJECTIVES

Both N-terminal fragment of B-type natriuretic peptide (NT-proBNP) and soluble isoform of ST2 (sST2) have been identified as biomarkers of heart failure. We evaluated the plasma levels of NT-proBNP and sST2 in a rat model of severe aortic valve regurgitation (AR) and correlated these findings with echocardiographic measurements. We also examined the impact of omecamtiv mecarbil (OM) on these parameters.

METHODS

The plasma levels of NT-proBNP and sST2 were measured in 18 rats both before and 2 months after surgical induction of AR, and at these same time points, in six rats assigned to a sham-procedure control group. Plasma biomarkers were then measured again after infusion of OM or placebo in rats with AR (n=8 and 10, respectively) and OM alone in the sham control rats (n=6). Echocardiographic measurements were collected before and 2 months after induction of AR.

RESULTS

Our results revealed increased levels of plasma NT-proBNP (219 ± 34 pg/mL vs. 429 ± 374 pg/mL; p<0.001) in rats with AR at day 7 after infusion of placebo, whereas plasma levels of sST2 were higher in this cohort after infusion of either OM or placebo. We identified a significant positive correlation between plasma sST2 with posterior wall thickness in diastole (r=0.34, p<0.05) and total body weight (r=0.45, p<0.01) in rats with surgically induced AR.

CONCLUSIONS

Because sST2 increased markedly, whereas NT-proBNP remained unchanged, when OM was administered, we hypothesize that sST2 has a distinct capability to detect deleterious effects of passive muscle tension, not reliably assessed by NT-proBNP, in the setting of AR.

Global Longitudinal Strain and Biomarkers of Cardiac Damage and Stress as Predictors of Outcomes After Transcatheter Aortic Valve Implantation

Background Global longitudinal strain (GLS) is a sensitive measure of left ventricular function and a risk marker in severe aortic stenosis. We sought to determine whether biomarkers of cardiac damage (cardiac troponin) and stress (NT-proBNP [N-terminal pro-B-type natriuretic peptide]) could complement GLS to identify patients with severe aortic stenosis at highest risk. Methods and Results From a multicenter prospective cohort of patients with symptomatic severe aortic stenosis who underwent transcatheter aortic valve implantation, we measured absolute GLS (aGLS), cardiac troponin, and NT-proBNP at baseline in 499 patients. Left ventricular ejection fraction <50% was observed in 19% and impaired GLS (aGLS <15%) in 38%. Elevations in cardiac troponin and NT-proBNP were present in 79% and 89% of those with impaired GLS, respectively, as compared with 63% and 60% of those with normal GLS, respectively (P<0.001 for each). aGLS <15% was associated with increased mortality in univariable analysis (P=0.009), but, in a model with both biomarkers, aGLS, and clinical covariates included, aGLS was not associated with mortality; elevation in each biomarker was associated with an increased hazard of mortality (adjusted hazard ratio, >2; P≤0.002 for each) when the other biomarker was elevated, but not when the other biomarker was normal (interaction P=0.015). Conclusions Among patients with symptomatic severe aortic stenosis undergoing transcatheter aortic valve implantation, elevations in circulating cardiac troponin and NT-proBNP are more common as GLS worsens. Biomarkers of cardiac damage and stress are independently associated with mortality after transcatheter aortic valve implantation, whereas GLS is not. These findings may have implications for risk stratification of asymptomatic patients to determine optimal timing of valve replacement.

Association of aortic distensibility and left ventricular function in patients with stenotic bicuspid aortic valve and preserved ejection fraction: a CMR study

To determine the relationship between aortic distensibility and left ventricular (LV) remodeling, myocardial strain and blood biomarkers in patients with stenotic bicuspid aortic valve (BAV) and preserved ejection fraction (EF) by cardiovascular magnetic resonance (CMR). 43 stenotic BAV patients were prospectively selected for 3.0 T CMR. Patients were divided into LV remodeling group (LV mass/volume ≥ 1.15, n = 21) and non-remodeling group (LV mass/volume < 1.15, n = 22). Clinical characteristics, biochemical data including cardiac troponin T(cTNT), N-terminal pro-B type natriuretic peptide (NT-proBNP) and creatine kinase isoenzyme (CK-MB) were noted. Distensibility of middle ascending aorta (mid-AA) and proximal descending aorta, LV structural and functional parameters, global and regional myocardial strain were measured. Compared to non-remodeling group, LV remodeling group had significantly decreased LV global strain (radial: 26.04 ± 8.70% vs. 32.92 ± 7.81%, P = 0.009; circumferential: - 17.20 ± 3.38% vs. - 19.65 ± 2.34%, P = 0.008; longitudinal: - 9.13 ± 2.34% vs. - 11.63 ± 1.99%, P < 0.001) and decreased mid-AA distensibility (1.22 ± 0.24 10-3 mm/Hg vs 1.60 ± 0.41 10-3 mm/Hg, P = 0.001). In addition, mid-AA distensibility was independently associated with LV remodeling (β =  - 0.282, P = 0.003), and it was also significantly correlated with LV global strain (radial: r = 0.392, P = 0.009; circumferential: r =  - 0.348, P = 0.022; longitudinal: r =  - 0.333, P = 0.029), cTNT (r =  - 0.333, P = 0.029) and NT-proBNP (r =  - 0.440, P = 0.003). In this cohort with stenotic BAV and preserved EF, mid-AA distensibility is found significantly associated with LV remolding, which encouraging to better understand mechanism of ventricular vascular coupling.

Regulation and impact of cardiac lymphangiogenesis in pressure-overload-induced heart failure

AIMS

Lymphatics are essential for cardiac health, and insufficient lymphatic expansion (lymphangiogenesis) contributes to development of heart failure (HF) after myocardial infarction. However, the regulation and impact of lymphangiogenesis in non-ischemic cardiomyopathy following pressure-overload remains to be determined. Here, we investigated cardiac lymphangiogenesis following transversal aortic constriction (TAC) in C57Bl/6 and Balb/c mice, and in end-stage HF patients.

METHODS & RESULTS

Cardiac function was evaluated by echocardiography, and cardiac hypertrophy, lymphatics, inflammation, edema, and fibrosis by immunohistochemistry, flow cytometry, microgravimetry, and gene expression analysis. Treatment with neutralizing anti-VEGFR3 antibodies was applied to inhibit cardiac lymphangiogenesis in mice.We found that VEGFR3-signaling was essential to prevent cardiac lymphatic rarefaction after TAC in C57Bl/6 mice. While anti-VEGFR3-induced lymphatic rarefaction did not significantly aggravate myocardial edema post-TAC, cardiac immune cell levels were increased, notably myeloid cells at 3 weeks and T lymphocytes at 8 weeks. Moreover, whereas inhibition of lymphangiogenesis did not aggravate interstitial fibrosis, it increased perivascular fibrosis and accelerated development of left ventricular (LV) dilation and dysfunction. In clinical HF samples, cardiac lymphatic density tended to increased, although lymphatic sizes decreased, notably in patients with dilated cardiomyopathy. Similarly, comparing C57Bl/6 and Balb/c mice, lymphatic remodeling post-TAC was linked to LV dilation rather than to hypertrophy. The striking lymphangiogenesis in Balb/c was associated with reduced cardiac levels of macrophages, B cells, and perivascular fibrosis at 8 weeks post-TAC, as compared with C57Bl/6 mice that displayed weak lymphangiogenesis. Surprisingly, however, it did not suffice to resolve myocardial edema, nor prevent HF development.

Prognostic relevance of B-type natriuretic peptide in patients with moderate mixed aortic valve disease

Aims

Data on B‐type natriuretic peptide (BNP) levels and adverse outcomes in patients with moderate mixed aortic valve disease (MAVD), defined as moderate aortic stenosis (AS) and regurgitation (AR), are scarce. Therefore, this study investigated the impact of BNP on the clinical outcomes in such patients.

Methods and results

Clinical data from 81 patients (mean age, 74.1 ± 6.8 years; 50.6%, men) treated for moderate MAVD and left ventricular ejection fraction (LVEF) ≥ 50% during 2010–2018 were retrospectively analysed. Specific echocardiographic data of the study patients were LVEF of 57.8 ± 5.0%, aortic valve index of 0.64 ± 0.04 cm²/m², peak aortic valve velocity of 3.38 ± 0.29 m/s, and AR vena contracta width of 4.2 ± 0.7 mm. The median BNP level was 61.4 pg/mL (interquartile range, 29.7–109.9). The primary endpoint was a composite of all‐cause death, heart failure hospitalization, and aortic valve replacement, and its cumulative incidence at 5 years was 57.7%. Multivariable analysis revealed that age (hazard ratio, 1.079; 95% confidence interval, 1.028–1.133; P = 0.002) and BNP levels (hazard ratio, 1.028; 95% confidence interval, 1.003–1.053; P = 0.027) were significantly related to the endpoint; specifically, BNP > 61.4 pg/mL had significantly higher incidence rates of the endpoint than those with a BNP ≤ 61.4 pg/mL (70.3% vs. 45.5% at 5 years; P = 0.018). Compared with patients with BNP ≤ 61.4 pg/mL, those with BNP > 61.4 pg/mL had significantly worse left ventricular global longitudinal strain (−17.1 ± 3.6% vs. −18.7 ± 2.6%; P = 0.029), along with higher left ventricular mass index (116.9 ± 27.8 g/m² vs. 103.5 ± 19.7 g/m²; P = 0.014), relative wall thickness (0.45 ± 0.07 vs. 0.42 ± 0.05; P = 0.022), left atrial volume index (46.0 ± 28.4 mL/m² vs. 31.4 ± 10.3 mL/m²; P = 0.003), pulmonary artery systolic pressure (32.6 ± 9.7 mmHg vs. 28.2 ± 4.7 mmHg; P = 0.011), and prevalence of moderate or greater tricuspid regurgitation (15.0% vs. 0.0%; P = 0.012).

Conclusions

Patients with moderate MAVD are at higher risk of unfavourable clinical outcomes, and age and BNP are independently related to the occurrence of adverse events. High BNP levels may reflect extravalvular cardiac damage in patients with moderate MAVD.

Elevated Brain Natriuretic Peptide and High Brachial Pulse Pressure in Patients With Diabetes

BACKGROUND

Heart failure (HF) is frequent in patients with diabetes mellitus (DM), and early detection improves prognosis. We investigated whether analysis of brachial blood pressure (BP) in daily practice can identify patients with DM and high risk for subsequent HF, as defined by brain natriuretic peptide (BNP) >50 pg/ml.

METHODS

3,367 outpatients with DM without a history of cardiovascular disease were enrolled in a prospective study.

RESULTS

Age (mean ± SD) was 56 ± 14 years, 57% were male, 78% had type 2 DM, and HbA1C was 7.4 ± 1.4%. A history of hypertension was recorded in 43% of patients and uncontrolled BP was observed in 13%. BNP concentration (mean ± SD) was 21 ± 21 ng/l and 9% of patients had high risk of incident HF. Brachial pulse pressure (PP) was the best BP parameter associated with high risk of incident HF compared with diastolic, systolic, or mean BP (area under the receiver operating characteristic curve: 0.70, 0.65, 0.57, and 0.57, respectively). A multivariate analysis demonstrated that elevated PP was independently associated with high risk of incident HF (odds ratio [95% confidence interval, CI]: 2.1 [1.5-2.8] for PP ≥65 mm Hg). Study of central aortic BP and pulse wave velocity on 117 patients demonstrated that high risk of incident HF was associated with increased arterial stiffness and subendocardial ischemia. After a mean follow-up of 811 days, elevated PP was associated with increased all-cause mortality (hazard ratio [95% CI]: 1.7 [1.1-2.8]).

CONCLUSIONS

Brachial PP is powerful and independent "easy to record" BP parameter associated with high risk of incident HF in diabetic patients.

Association of Annual N-Terminal Pro-Brain Natriuretic Peptide Measurements With Clinical Events in Patients With Asymptomatic Nonsevere Aortic Stenosis: A Post Hoc Substudy of the SEAS Trial

IMPORTANCE

Recent studies have questioned the presumed low-risk status of patients with asymptomatic nonsevere aortic stenosis (AS). Whether annual N-terminal pro-brain natriuretic peptide (NT-proBNP) measurements are useful for risk assessment is unknown.

OBJECTIVE

To assess the association of annual NT-proBNP measurements with clinical outcomes in patients with nonsevere AS.

DESIGN, SETTING, AND PARTICIPANTS

Analysis of annual NT-proBNP concentrations in the multicenter, double-blind Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) randomized clinical trial was performed. SEAS was conducted from January 6, 2003, to April 1, 2008. Blood samples were analyzed in 2016, and data analysis was performed from February 10 to October 10, 2021. SEAS included 1873 patients with asymptomatic AS not requiring statin therapy with transaortic maximal flow velocity from 2.5 to 4.0 m/s and preserved ejection fraction. This substudy included 1644 patients (87.8%) with available blood samples at baseline and year 1.

EXPOSURES

Increased age- and sex-adjusted NT-proBNP concentrations at year 1 and a 1.5-fold or greater relative NT-proBNP concentration change from baseline to year 1. Moderate AS was defined as baseline maximal flow velocity greater than or equal to 3.0 m/s.

MAIN OUTCOMES AND MEASURES

Aortic valve events (AVEs), which are a composite of aortic valve replacement, cardiovascular death, or incident heart failure due to AS progression, were noted. Landmark analyses from year 1 examined the association of NT-proBNP concentrations with outcomes.

RESULTS

Among 1644 patients, 996 were men (60.6%); mean (SD) age was 67.5 (9.7) years. Adjusted NT-proBNP concentrations were within the reference range (normal) in 1228 of 1594 patients (77.0%) with NT-proBNP values available at baseline and in 1164 of 1644 patients (70.8%) at year 1. During the next 2 years of follow-up, the AVE rates per 100 patient-years for normal vs increased adjusted NT-proBNP levels at year 1 were 1.39 (95% CI, 0.86-2.23) vs 7.05 (95% CI, 4.60-10.81) for patients with mild AS (P < .01), and 10.38 (95% CI, 8.56-12.59) vs 26.20 (95% CI, 22.03-31.15) for those with moderate AS (P < .01). Corresponding all-cause mortality rates were 1.05 (95% CI, 0.61-1.81) vs 4.17 (95% CI, 2.42-7.19) for patients with mild AS (P < .01), and 1.60 (95% CI, 0.99-2.57) vs 4.78 (95% CI, 3.32-6.87) for those with moderate AS (P < .01). In multivariable Cox proportional hazards regression models, the combination of a 1-year increased adjusted NT-proBNP level and 1.5-fold or greater NT-proBNP level change from baseline was associated with the highest AVE rates in both patients with mild AS (hazard ratio, 8.12; 95% CI, 3.53-18.66; P < .001) and those with moderate AS (hazard ratio, 4.05; 95% CI, 2.84-5.77; P < .001).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that normal NT-proBNP concentrations at 1-year follow-up are associated with low AVE and all-cause mortality rates in patients with asymptomatic nonsevere AS. Conversely, an increased 1-year NT-proBNP level combined with a 50% or greater increase from baseline may be associated with high AVE rates.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00092677.

Clinical Assessment of Ventricular Wall Stress in Understanding Compensatory Hypertrophic Response and Maladaptive Ventricular Remodeling

Ventricular wall stress (WS) is an important hemodynamic parameter to represent myocardial oxygen demand and ventricular workload. The normalization of WS is regarded as a physiological feedback signal that regulates the rate and extent of ventricular hypertrophy to maintain myocardial homeostasis. Although hypertrophy is an adaptive response to increased biomechanical stress, persistent hypertrophic stimulation forces the stressed myocardium into a progressive maladaptive process called ventricular remodeling, consisting of ventricular dilatation and dysfunction in conjunction with the development of myocyte hypertrophy, apoptosis, and fibrosis. The critical determinant of this pathological transition is not fully understood, but an energetic mismatch due to uncontrolled WS is thought to be a central mechanism. Despite extensive basic investigations conducted to understand the complex signaling pathways involved in this maladaptive process, clinical diagnostic studies that translate these molecular and cellular changes are relatively limited. Echocardiographic assessment with or without direct measurement of left ventricular pressure used to be a mainstay in estimating ventricular WS in clinical medicine, but in recent years more and more noninvasive applications with magnetic resonance imaging have been studied. In this review article, basic clinical applications of WS assessment are discussed to help understand the progression of ventricular remodeling.

The determinants of plasma brain natriuretic peptide level in severe aortic valve stenosis patients undergoing transcatheter aortic valve implantation

BACKGROUND

Brain or B-type natriuretic peptide (BNP) is an objective marker to diagnose the presence of heart failure (HF) and assess its severity. However, the determinants of serum BNP level in elderly patients with severe aortic valve stenosis (AS) referred for transcatheter aortic valve implantation (TAVI) have not been well investigated.

METHODS

We prospectively studied 106 AS patients who underwent TAVI. Cardiac catheterization, transesophageal echocardiography, and blood collection for plasma BNP level measurements were performed simultaneously just before the TAVI procedures.

RESULTS

Ninety-nine patients (83.9±5.0 years, 33% male) were studied. The natural logarithm of BNP (lnBNP) level was 5.4±0.9 pg/mL. Significant correlations with lnBNP level were observed in: 1) the history of syncope, prior HF medication, and New York Heart Association class III or IV (R=0.255, p=0.011) (R=0.210, p=0.037) (R=0.402, p<0.001), 2) albumin and hemoglobin level (R=-0.289, p=0.004) (R=0.263, p=0.009), 3) Left ventricular (LV) ejection fraction and global longitudinal strain (LVGLS) (R=-0.338, p<0.001) (R=0.447, p<0.001), 4) LV end-diastolic volume index (EDVI), LV mass index, and left atrial volume index (R=0.280, p=0.005) (R=0.366, p<0.001) (R=0.337, p<0.001), 5) the catheter-measured pressure gradient across the aortic valve (AVPG) (R=0.365, p<0.001). Note that LV wall stress was not significantly correlated with lnBNP level. LVGLS, AVPG, hemoglobin level, and LVEDVI were independently correlated with ln BNP level (R=0.652, LVGLS; β=0.395, p<0.006, AVPG; β=0.291, p=0.001, hemoglobin level; β=-0.216, p=0.011, and LVEDVI; β=0.203, p=0.016, respectively).

CONCLUSIONS

In severe AS patients candidate for TAVI, multiple factors, including the severities of AS and HF conditions and subclinical LV dysfunction determined by LVGLS affects plasma BNP level.

B-type natriuretic peptide as a surrogate marker for survival in patients undergoing cardiac surgery

Background

B-type natriuretic peptide (BNP) is a biomarker predicting morbidity and mortality in patients with congestive heart failure. However, the usefulness of pre- or postoperative BNP levels in patients undergoing cardiac surgery remains uncertain. We sought to determine the association of pre- or postoperative BNP levels on mortality in patients undergoing cardiac surgery under cardiopulmonary bypass (CPB).

Methods

This study retrospectively evaluated 1,642 patients undergoing cardiac surgery under CPB over 2 years. The primary outcomes were 30-day and overall mortality after cardiac surgery.

Results

The 30-day mortality rate was 3.0% (n=49), and the overall mortality occurred in 118 patients during the mean follow-up period of 24.9±8.9 months. In multivariable analyses, preoperative BNP level was not significantly associated with 30-day [odds ratio (OR), 1.03; 95% confidence interval (CI), 0.99–1.06; P=0.06] or overall [hazard ratio (HR), 1.01; 95% CI, 0.98–1.03; P=0.50] mortalities. However, the postoperative BNP level was significantly associated with 30-day (OR, 1.05; 95% CI, 1.02–1.09; P=0.001) and overall (HR, 1.03; 95% CI, 1.01–1.04; P=0.01) mortalities. As a sensitivity analysis, postoperative BNP levels were divided into quartiles. The top quartile (≥484 pg/mL) was identified as a strong predictor of overall mortality (HR, 2.18; 95% CI, 1.14–4.19; P=0.02).

Conclusions

Preoperative BNP level was not associated with mortality after cardiac surgery. However, postoperative BNP level was associated with mortality after cardiac surgery, especially in patients with high levels (≥484 pg/mL). Further studies in larger cohorts are necessary to validate these results.

NT-pro-BNP as marker for cardiac strain that may be caused by high-output arteriovenous shunting in a haemodialysis patient. A case report

BACKGROUND

An arteriovenous fistula (AVF) is the first choice when considering access for haemodialysis (HD). When a forearm AVF fails an upper arm AVF is a frequent subsequent dialysis access option. The latter may cause cardiac strain. NT-pro-B-type natriuretic peptide (NT-NT-proBNP) is a marker used to estimate volume overload and cardiac strain. This case report shows the benefit of using longitudinal individual follow-up of pre-dialysis NT-proBNP in clinical practice to detect changes in cardiac condition that may be due to high-output AVF.

CASE PRESENTATION

An 18 years old patient performed HD via an upper arm AVF before he was admitted to our unit. NT-proBNP was above the upper detection level of 70,000 ng/L. Echocardiography revealed a left-ventricular cardiac insufficiency. Interdialytic weight gain (IDWG) was above 5%. He was instructed to lower fluid intake and IDWG towards 2%. Four months later NT-proBNP surpassed 70,000 ng/L again. Flow in the brachial artery was at 3034 ml/min. Reconstructive surgery of the AVF did not reduce flow and NT-proBNP in the long run. Clinically, he worsened to NYHA class III-IV. It was decided to close the upper arm AVF and to replace it with a lower arm AVF leading to a reduced artery flow of 1344 mL/min. The clinical condition successively recovered and NT-proBNP decreased to 7000 ng/L.

CONCLUSIONS

Pre-dialysis NT-proBNP should be considered as a suitable routine marker for cardiac strain such as caused by high-output AVF besides variables such as IDWG. Brachial artery flow besides AVF flow measurement is helpful.

Baseline NT-proBNP Accurately Predicts Symptom Response to Transcatheter Aortic Valve Implantation

Background

Up to 30% of patients undergoing transcatheter aortic valve implantation (TAVI) experience minimal symptomatic benefit or die within 1 year, indicating an urgent need for enhanced patient selection. Previous analyses of baseline NT‐proBNP (N‐terminal pro‐brain natriuretic peptide) and TAVI outcomes have assumed a linear relationship, yielding conflicting results. We reexamined the relationship between baseline NT‐proBNP and symptomatic improvement after TAVI.

Methods and Results

Symptom status, clinical and echocardiographic data, and baseline NT‐proBNP were reviewed from 144 consecutive patients undergoing TAVI for severe symptomatic aortic stenosis. The primary end point was change in New York Heart Association functional class at 1 year. There was a nonlinear, inverted‐U relationship between log‐baseline NT‐proBNP and post‐TAVI change in NYHA class (R²=0.4559). NT‐proBNP thresholds of <800 and >10 000 ng/L accurately predicted no symptomatic improvement at 1 year (sensitivity 88%, specificity 83%, positive predictive value 72%, negative predictive value 93%). In adjusted analyses, baseline NT‐proBNP outside this “sweet‐spot” range was the only factor independently associated with poor functional outcome (high: NT‐proBNP >10 000 ng/L, odds ratio [OR], 65; 95% CI, 6–664; low: NT‐proBNP <800 ng/L, OR, 73; 95% CI, 7–738).

Conclusions

Baseline NT‐proBNP is a useful prognostic marker to predict poor symptom relief after TAVI and may indicate when intervention is likely to be futile. Both low (<800 ng/L) and very high (>10 000 ng/L) levels are strongly associated with poor functional outcome, suggesting an alternative cause for symptoms in the former scenario and an irrevocably diseased left ventricle in the latter. Further evaluation of this relationship is warranted.

Therapeutic hypothermia after cardiac arrest increases the plasma level of B-type natriuretic peptide

Natriuretic peptides (NPs) regulate blood pressure and fluid homeostasis and exert various effects on the cardiovascular system. Recently, the relationship between NPs and the energy metabolism has been reported, and using a cell culture experiment system, we previously showed that NP activated brown cells in a low temperature environment while also suppressing a decrease in the cell temperature. However, few reports have described the secretion of NPs in cold environments, and there have been almost no studies of B-type natriuretic peptide (BNP) in humans. We investigated how NPs respond to cold environments in 21 patients who underwent therapeutic hypothermia (TH) after cardiac arrest. The plasma BNP levels were significantly increased (more than fivefold) during TH (logarithmically from 1.98 ± 0.79 to 2.63 ± 0.59, P < 0.01). During TH, diastolic pulmonary artery pressure (PAP) significantly decreased, and there were no significant changes in the stroke volume index (SVI). This increase of BNP was not associated with any hemodynamic changes. In contrast to our findings for BNP, the change in A-type NP (ANP) was quite small. We detected a significant increase in the plasma BNP levels during TH, unrelated to hemodynamics. This elevation of BNP levels seems to be potential influenced by hypothermia.

Sleeping Difficulty and Subjective Short Sleep Duration are Associated with Serum N-terminal Pro-brain Natriuretic Peptide Levels in the Elderly Population

Objective It is well known that poor sleep increases the risk of heart failure (HF). However, the underlying mechanisms remain unclear. In this study, we investigated the association of poor sleep with hemodynamic stress on the left ventricle, which was a key factor for the development of HF in elderly individuals. Methods A total of 2,301 participants (≥65 years old) without cardiac disease were enrolled in this cross-sectional analysis. We evaluated the subjective sleep quality, sleeping difficulty, subjective sleep duration, use of sleeping pills, and daytime dysfunction using the Pittsburgh Sleep Quality Index, a 19-item self-reported questionnaire. We assessed serum N-terminal pro-brain natriuretic peptide (NT-proBNP) as a marker of hemodynamic stress on the left ventricle, and we defined high NT-proBNP as a serum NT-proBNP level ≥ 125 pg/mL. Results Sleeping difficulty was significantly associated with high NT-proBNP levels [odds ratio (OR), 1.46; 95% confidence interval (CI), 1.16-1.85; p<0.005]. A subjective short sleep duration was also significantly associated with high NT-proBNP levels (OR, 1.69; 95% CI, 1.03-2.75; p<0.05). A subjective poor sleep quality, the use of sleeping pills, and daytime dysfunction were not associated with serum NT-proBNP levels. All data were adjusted for the age, sex, body mass index, serum hemoglobin concentration, serum creatinine level, systolic blood pressure, diastolic blood pressure, and use of antihypertensive medications. Conclusion Poor sleep was associated with high hemodynamic stress to the left ventricle in elderly population.

Prognostic Value of N-Terminal Pro-form B-Type Natriuretic Peptide in Patients With Moderate Aortic Stenosis

Plasma B-type natriuretic peptide (BNP) and its N-terminal pro-form, NT-proBNP, can predict outcomes in patients with severe aortic stenosis (AS). However, their prognostic value in moderate AS is currently unknown. The present study included 261 patients diagnosed with moderate AS (1.0 <aortic valve area ≤1.5 cm²) in 2012 with serum NT-pro BNP level collected within ±3 months of the echocardiographic assessment. Patients were divided into 2 groups according to the median NT-proBNP value (888 pg/dl) and all-cause mortality compared. Median age was 78 years and 64% of patients were male. There were 131 (50%) patients with lower-median NT-pro BNP levels (≤888 pg/dl) and 130 (50%) with higher-median NT-pro BNP levels (>888 pg/dl). During a median follow up of 2.7 years, there were 136 (52%) deaths. Mortality rate was much higher in patients with higher-median NT-pro BNP compared to those with lower-median NT-pro BNP levels (p <0.001). Higher-median NT-pro BNP level was significantly associated with higher mortality rate (hazard ratio 3.11; 95% confidence interval 1.78 to 5.46, p <0.001) even after adjusting for confounders. Aortic valve replacement (AVR) was performed in 82 (31%) patients and median time to AVR was 2.1 years. Patients with higher-median NT-pro BNP had higher mortality rate compared to patients with lower-median NT-pro BNP even after AVR (p <0.01). In conclusion, higher NT-proBNP level is associated with higher mortality rates in patients with moderate AS even among those undergoing AVR.

Blood biomarkers in patients with bicuspid aortic valve disease

BACKGROUND

Patients with a bicuspid aortic valve (BAV) are at risk of developing valve deterioration and aortic dilatation. We aimed to investigate whether blood biomarkers are associated with disease stage in patients with BAV.

METHODS

Serum levels of high sensitivity C-reactive protein (hsCRP), high sensitivity troponin T (hsTnT), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and total transforming growth factor-beta 1 (TGF-ß1) were measured in adult BAV patients with valve dysfunction or aortic pathology. Age-matched general population controls were included for TGFß-1 measurements. Correlation analyses and multivariable linear regression were used to determine the association between (2log-transformed) biomarker levels and aortic valve regurgitation, aortic valve stenosis, aortic dilatation, or left ventricular function.

RESULTS

hsCRP and hsTnT were measured in the total group of 183 patients (median age 34 years, 25th-75th percentile 23-46), NT-proBNP in 162 patients, and TGF-ß1 beta in 108 patients. Elevated levels of NT-proBNP were found in 20% of the BAV patients, elevated hsTnT in 6%, and elevated hsCRP in 7%. Higher hsTnT levels were independently associated with aortic regurgitation [odds ratio per doubling (OR_2log) 1.34, 95% CI 1.01;1.76] and higher NT-proBNP levels with aortic valve maximal velocity (ß_2log 0.17, 95%CI 0.07;0.28) and aortic regurgitation (OR_2log 1.41, 95%CI 1.11;1.79). Both BAV patients with (9.9 ± 2.7 ng/mL) and without aortic dilatation (10.4 ± 2.9 ng/mL) showed lower TGF-ß1 levels compared to general population controls (n = 85, 11.8 ± 3.2 ng/mL).

CONCLUSIONS

Higher NT-proBNP and hsTNT levels were associated with aortic valve disease in BAV patients. TGF-ß1 levels were lower in BAV patients than in the general population, and not related to aortic dilatation. Longitudinal data are needed to further investigate the prognostic value of biomarkers in these patients.

Association of Common Carotid Artery Measurements with N-terminal Pro B-type Natriuretic Peptide in Elderly Participants

Objective Numerous studies have reported an association between common carotid artery (CCA) parameters and atherosclerotic cardiovascular disease (CVD). However, the association between CCA parameters and hemodynamic stress on the left ventricle in elderly patients remains unclear. Methods We assessed CCA parameters, including the height-adjusted CCA interadventitial diameter (diameter/height), mean intima-media thickness (IMT), number of plaques, plaque score, resistance index (RI), and pulsatility index (PI) with ultrasonography, using serum N-terminal pro-brain natriuretic peptide (NT-proBNP) levels as a marker for hemodynamic stress on the left ventricle in 1,315 participants ≥70 years old without CVD. Of these participants, 706 had hypertension, defined as taking antihypertensive medications, having a systolic blood pressure ≥140 mmHg, and/or having a diastolic blood pressure ≥90 mmHg. Results After adjusting for the confounding factors, the CCA interadventitial diameter/height was significantly associated with the log NT-proBNP in both the normotensive group (β=0.125, p=0.002) and hypertensive group (β=0.080, p=0.029). The RI was significantly associated with the log NT-proBNP in the hypertensive group (β=0.176, p<0.001) but not in the normotensive group. In addition, the PI was significantly associated with the log NT-proBNP in the hypertensive group (β=0.156, p<0.001) but not in the normotensive group. However, no significant association was observed between the mean IMT, number of plaques, and plaque score and log NT-proBNP. Conclusion CCA measurements may be useful markers for hemodynamic stress on the left ventricle in elderly patients.

Relationship between B-type natriuretic peptide and invasive haemodynamics in patients with severe aortic valve stenosis

AIMS

In patients with aortic stenosis (AS), B-type natriuretic peptide (BNP) is a prognostic marker. However, there is little information on the association between BNP and invasive haemodynamics in AS. The aim of the present study was to assess the hitherto not well-defined relationship between BNP and invasive haemodynamics in patients with severe AS undergoing aortic valve replacement (AVR) with a view to understand the link between high BNP and poor prognosis in these patients. In particular, we were interested in the association between BNP and combined pre-capillary and post-capillary pulmonary hypertension (CpcPH).

METHODS AND RESULTS

BNP was measured in 252 patients (age 74 ± 10 years, 58% male patients) with severe AS [indexed aortic valve area 0.4 ± 0.1 cm² /m² and left ventricular ejection fraction (LVEF) 57 ± 12%] the day before cardiac catheterization. Patients were followed for a median (interquartile range) period of 3.1 (2.3-4.3) years after surgical (n = 157) or transcatheter (n = 95) AVR. The prevalence of CpcPH (mean pulmonary artery pressure ≥ 25 mmHg, mean pulmonary artery wedge pressure > 15 mmHg, and pulmonary vascular resistance > 3 Wood units) was 13%. The median BNP plasma concentration was 188 (78-452) ng/L. The indexed aortic valve area was similar across BNP quartiles (P = 0.21). Independent predictors of higher BNP (ln transformed) included lower haemoglobin (beta = -0.18; P < 0.001), lower LVEF (beta = -0.20; P < 0.001), more severe mitral regurgitation (beta = 0.20; P < 0.001), higher mean pulmonary artery wedge pressure (beta = -0.37; P < 0.001), and higher pulmonary vascular resistance (beta = 0.21; P < 0.001). In a multivariate model with CpcPH rather than its haemodynamic components, CpcPH was independently associated with higher BNP (0.21; P < 0.001). Higher ln BNP was associated with higher mortality [hazard ratio 1.90 (95% confidence interval 1.33-2.71); P < 0.001] in the univariate analysis. Patients in the third and fourth BNP quartiles had a more than six-fold risk of death compared with patients in the first and second quartiles [hazard ratio 6.29 (95% confidence interval 1.86-21.27); P = 0.003]. In the multivariate analysis, lower LVEF [hazard ratio 0.96 (95% confidence interval 0.94-0.99) per 1% increase; P = 0.01] and CpcPH [hazard ratio 4.58 (95% confidence interval 1.89-11.09); P = 0.001] but not BNP were independently associated with mortality. The areas under the receiver operator characteristics curve for BNP for the prediction of CpcPH and mortality were 0.88 and 0.74, respectively.

CONCLUSIONS

In patients with severe AS, higher BNP is a marker of the presence of CpcPH and its contributors. The association between BNP and such an adverse haemodynamic profile at least in part explains the ability of BNP to predict long-term post-AVR mortality.

Cardiac Intervention Improves Heart Disease and Clinical Outcomes in Patients With Muscular Dystrophy in a Multidisciplinary Care Setting

Background

Patients with muscular dystrophy (MD) represent a vulnerable patient population with no clearly defined care model in modern‐day clinical practice to manage a high burden of heart disease and comorbidities. We demonstrate the effectiveness of cardiac interventions, namely the initiation and optimization of medical and device therapies, as part of a multidisciplinary care approach to improve clinical outcomes in patients with MD.

Methods and Results

We conducted a prospective cohort study at the Neuromuscular Multidisciplinary clinic following patients with dystrophinopathies, limb‐girdle MD, type 1 myotonic dystrophy, and facioscapulohumeral MD. A negative control group classified as non‐MD myopathies without heart disease, was also tracked. Our cohort of 185 patients (median age: 42 years; 79 [42.7%] women), included 145 patients with MD. Cardiomyopathy was present in 65.6% of the patients with dystrophinopathies (21 of 32) and 27.3% of the patients with limb‐girdle MD (9 of 33). Conduction abnormalities were common in type 1 myotonic dystrophy (33.3% [20/60] patients). Cardiac intervention reversed systolic dysfunction, with left ventricular ejection fraction improving from 43% to 50.0% over a 3‐year period. A sustained reduction in healthcare utilization was also observed. The number of outpatient clinic visits decreased from 3.0 to 1.5 visits per year, the duration of hospitalizations was reduced from 14.2 to 0.9 days per year, and the number of cardiac‐related hospitalizations decreased from 0.4 to 0.1 hospitalizations per year associated with low mortality.

Conclusions

Our study demonstrates that cardiac intervention as part of a comprehensive multidisciplinary care approach to treating patients with MD leads to a sustained improvement in clinical outcomes.

Low and elevated B-type natriuretic peptide levels are associated with increased mortality in patients with preserved ejection fraction undergoing transcatheter aortic valve replacement: an analysis of the PARTNER II trial and registry

Aims

B-type natriuretic peptide (BNP) is a cardiac neurohormone that is secreted in response to ventricular volume expansion and pressure overload. There are conflicting data regarding the association between BNP levels and outcomes after transcatheter aortic valve replacement (TAVR). We therefore sought to assess the association between baseline BNP and adverse outcomes in patients with symptomatic, severe aortic stenosis (AS), and left ventricular ejection fraction (LVEF) ≥50%, undergoing TAVR in the PARTNER 2 Trial and Registry.

Methods and results

A total of 1782 patients were included in the analysis, and BNP was evaluated both as a continuous log-transformed value and by a priori categories: low (&lt;50 pg/mL), normal (≥50 and &lt;100 pg/mL), moderately elevated (≥100 and &lt;400 pg/mL), or markedly elevated (≥400 pg/mL). Clinical outcomes from discharge to 2 years were compared between patients according to their baseline BNP level, using Kaplan–Meier event rates and multivariable Cox proportional hazards regression models. After adjustment, spline curves revealed a non-linear association between log-transformed BNP and all-cause and cardiovascular mortality in which both the lowest and highest values were associated with increased mortality. Two-year all-cause mortality rates for those with low (n = 86), normal (n = 202), moderately elevated (n = 885), and markedly elevated (n = 609) baseline BNP were 20.0%, 9.8%, 17.7%, and 26.1%, respectively. In adjusted models, compared to a normal baseline BNP, low [adjusted hazard ratio (HR) 2.6, 95% confidence interval (CI) 1.3–5.0, P-value 0.005], moderately elevated (adjusted HR 1.6, 95% CI 1.0–2.6, P-value 0.06), and markedly elevated (adjusted HR 2.1, 95% CI 1.3–3.5, P-value 0.003) BNP were associated with increased all-cause mortality, driven by cardiovascular mortality.

Conclusions

In a large cohort of patients with severe symptomatic AS and preserved LVEF undergoing TAVR, all-cause and cardiovascular mortality rates at 2 years were higher in patients with low and markedly elevated BNP levels.

Clinical Trial Registration

https://clinicaltrials.gov/ unique identifier #NCT01314313, #NCT02184442, #NCT03222128, and #NCT03222141.

The relationship between serum NT-proBNP levels and severity of coronary artery disease assessed by SYNTAX score in patients with acute myocardial infarction

Background/aim

In the present study, we aimed to investigate the relationship between NT-proBNP and SYNTAX score, which is a measure of the complexity of coronary artery disease.

Materials and methods

We enrolled 405 consecutive patients with myocardial infarction who underwent coronary angiographic examination. Patients were divided into 3 groups according to their SYNTAX scores. Those with SYNTAX score ≤22 were included in the low SYNTAX score group (LSTX), those with a score of 23–32 were included in the intermediate SYNTAX score group (ISTX), and those with a score of ≥33 were included in the high SYNTAX score group (HSTX).

Results

NT-proBNP levels were found to be significantly higher in the HSTX group compared to the other groups (P < 0.001) and in the ISTX group compared to the LSTX group (P < 0.001). The NT-proBNP levels demonstrated an increase from low SYNTAX score to high SYNTAX score tertiles.

Conclusions

NT-ProBNP levels in patients with myocardial infarction on admission were independently associated with extent, severity, and complexity of coronary atherosclerosis as assessed by SYNTAX score.

The prevalence of cardio-metabolic risk factors is differentially elevated in obesity-prone Osborne-Mendel and obesity-resistant S5B/Pl rats

AIMS

Individual susceptibility to develop obesity may impact the development of cardio-metabolic risk factors that lead to obesity-related comorbid conditions. Obesity-prone Osborne-Mendel (OM) rats expressed higher levels of visceral adipose inflammation than obesity-resistant, S5B/Pl (S5B) rats. However, the consumption of a high fat diet (HFD) differentially affected OM and S5B rats and induced an increase in visceral adipose inflammation in S5B rats. The current study examined the effects of HFD consumption on cardio-metabolic risk factors in OM and S5B rats.

MATERIALS & METHODS

Glucose regulation and circulating levels of lipids, adiponectin and C-reactive protein were assessed following 8 weeks of HFD or low fat diet (LFD) consumption. Left ventricle hypertrophy and mRNA expression of cardiovascular disease biomarkers were also quantified in OM and S5B rats.

KEY FINDINGS

Circulating levels of triglycerides were higher, while HDL cholesterol, adiponectin and glycemic control were lower in OM rats, compared to S5B rats. In the left ventricle, BNP and CTGF mRNA expression were higher in OM rats and IL-6, IL-1β, VEGF, and iNOS mRNA expression were higher in S5B rats.

SIGNIFICANCE

These findings support the hypothesis that cardio-metabolic risk factors are increased in obesity-prone individuals, which may increase the risk for the development of obesity-related comorbidities. In the current models, obesity-resistant S5B rats also exhibited cardiovascular risk factors supporting the importance of monitoring cardiovascular health in individuals characterized as obesity-resistant.

B-type natriuretic peptide is associated with remodeling and exercise capacity after transcatheter aortic valve replacement for aortic stenosis

Background

We aimed to assess longitudinal changes of B‐type natriuretic peptide (BNP) in aortic stenosis (AS) patients treated by transcatheter aortic valve replacement (TAVR).

Methods

From our TAVR database, we identified 193 consecutive patients with severe symptomatic AS who underwent TAVR and were prospectively followed using serial BNP levels and echocardiography. Patients were divided into subgroups according to type of left ventricular (LV) remodeling as having normal LV mass and relative wall thickness, or showing concentric remodeling (CR), concentric hypertrophy (CH), and eccentric hypertrophy (EH).

Results

At baseline, 30 patients (16%) had EH, 115 (60%) had CH, 37 (19%) had CR, and 11 (6%) had normal LV geometry. After TAVR, BNP decreased in the first 30 days, with further improvement during follow‐up. Patients with EH had higher BNP at baseline (P < 0.01) and a greater subsequent decrease (P < 0.001). During the median follow‐up of 1331 days (interquartile range: 632‐1678), 119 (62%) patients died. BNP showed a time‐dependent association with all‐cause mortality both in a univariable (hazards ratio [HR] 1.24, 95% confidence interval [CI]: 1.04‐1.47, P = 0.017), and in a multivariable model with Society of Thoracic Surgeons score and baseline BNP forced into the analysis (HR 1.32, 95% CI: 1.001‐1.73, P = 0.049). Elevated BNP was associated with a larger LV end‐diastolic volume index (P < 0.001) and shorter 6‐minute walk test distance (P = 0.013) throughout follow‐up.

Conclusion

In patients with AS, BNP was associated with LV remodeling phenotypes and functional status before and after TAVR. Elevated BNP levels were associated with poor prognosis.

Natriuretic Peptides in Cardiac Anesthesia and Intensive Care

Natriuretic peptides, predominantly B-type, are widely used in cardiology as prognostic and diagnostic biomarkers or, much less often, as a substantive treatment tool. They are hormones that are produced mainly in the myocardium in response to overload and ischemia, and their level quite accurately reflects the degree of myocardial dysfunction. Although their use in cardiac anesthesia and intensive care setting seems to be very beneficial for assessing the risk of acute disturbance of myocardial function or its laboratory monitoring, the actual significance of natriuretic peptides in this area is not yet recognized. This is due to the lack of clear diagnostic and prognostic values for these biomarkers supported by high-quality researches. On the basis of the available data, main advantages, existing difficulties, and most effective ways of using natriuretic peptides for determining the risk of heart surgery and assessing the severity of sepsis, pneumonia, and other critical conditions have been discussed in this review. In addition, the expediency of using natriuretic peptides as target parameters for goal-oriented therapy and as a substantive tool for treatment is considered.

Association of N-Terminal Pro B-Type Natriuretic Peptide With Blood Pressure and Pulse Pressure in Elderly People - A Cross-Sectional Population Study

BACKGROUND

N-Terminal pro B-type natriuretic peptide (NT-proBNP) is widely used as a marker of ventricular dysfunction. However, data regarding the association of NT-proBNP with blood pressure (BP) and pulse pressure (PP) in the elderly population are limited.Methods and Results:The present cross-sectional study involved 6,529 participants, aged ≥70 years, without cardiovascular disease (CVD), who underwent general health examinations. Serum NT-proBNP concentrations were determined, with high NT-proBNP concentrations defined as those ≥125 pg/mL. Subjects were divided into five groups based on PP (<50, ≥50 to <60, ≥60 to <70, ≥70 to <80, and ≥80 mmHg). NT-proBNP was positively associated with systolic BP, whereas a U-shaped association was found between diastolic BP and NT-proBNP. The odds ratios for high NT-proBNP concentrations in the PP ≥80 and ≥70 to <80 mmHg groups (OR 1.83 [P<0.001] and 1.40 [P<0.005], respectively) were significantly higher than in the PP <50 mmHg group. All data were adjusted for age, sex, body mass index, hemoglobin concentration, serum creatinine, pulse rate, smoking, alcohol intake, and antihypertensive medication intake, and the presence of diabetes and dyslipidemia.

CONCLUSIONS

The results suggest that NT-proBNP concentrations may be a marker of not only ventricular dysfunction, but also arterial stiffness in the elderly population without CVD.

Nppa and Nppb act redundantly during zebrafish cardiac development to confine AVC marker expression and reduce cardiac jelly volume

Atrial natriuretic peptide (nppa/anf) and brain natriuretic peptide (nppb/bnp) form a gene cluster with expression in the chambers of the developing heart. Despite restricted expression, a function in cardiac development has not been demonstrated by mutant analysis. This is attributed to functional redundancy; however, their genomic location in cis has impeded formal analysis. Using genome editing, we have generated mutants for nppa and nppb, and found that single mutants were indistinguishable from wild type, whereas nppa/nppb double mutants displayed heart morphogenesis defects and pericardial oedema. Analysis of atrioventricular canal (AVC) markers show expansion of bmp4, tbx2b, has2 and versican expression into the atrium of double mutants. This expanded expression correlates with increased extracellular matrix in the atrium. Using a biosensor for hyaluronic acid to measure the cardiac jelly (cardiac extracellular matrix), we confirmed cardiac jelly expansion in nppa/nppb double mutants. Finally, bmp4 knockdown rescued the expansion of has2 expression and cardiac jelly in double mutants. This definitively shows that nppa and nppb function redundantly during cardiac development to restrict gene expression to the AVC, preventing excessive cardiac jelly synthesis in the atrial chamber.

Changes in Biomarker Profile and Left Ventricular Hypertrophy Regression: Results from the Frequent Hemodialysis Network Trials

BACKGROUND

Regression of left ventricular hypertrophy (LVH) is feasible with more frequent hemodialysis (HD). We aimed to ascertain pathways associated with regression of left ventricular mass (LVM) in patients enrolled in the Frequent HD Network (FHN) trials.

METHODS

This was a post hoc observational cohort study. We hypothesized LVH regression with frequent HD was associated with a different cardiovascular biomarker profile. Regressors were defined as patients who achieved a reduction of more than 10% in LVM at 12 months. Progressors were defined as patients who had a minimum of 10% increase in LVM at 12 months.

RESULTS

Among 332 randomized patients, 243 had biomarker data available. Of these, 121 patients did not progress or regress, 77 were regressors, and 45 were progressors. Mean LVM change differed between regressors and progressors by -65.6 (-74.0 to -57.2) g, p < 0.001. Regressors had a median (interquartile range) increase in dialysis frequency (from 3.0 [3.0-3.0] to 4.9 [3-5.7] per week, p = 0.001) and reductions in pre-dialysis systolic (from 149.0 [136.0-162.0] to 136.0 [123.0-152.0] mm Hg, p < 0.001) and diastolic (from 83.0 [71.0-91.0] to 76.0 [68.0-84.0] mm Hg, p < 0.001) blood pressures. Klotho levels increased in regressors versus progressors (76.9 [10.5-143.3] pg/mL, p = 0.024). Tissue inhibitors of metalloproteinase (TIMP)-2 levels fell in regressors compared to progressors (-7,853 [-14,653 to -1,052] pg/mL, p = 0.024). TIMP-1 and log (brain natriuretic -peptide [BNP]) levels also tended to fall in regressors. Changes in LVM correlated inversely with changes in klotho (r = -0.24, p = 0.014). -Conclusions: Markers of collagen turnover and changes in klotho levels are potential novel pathways associated with regression of LVH in the dialysis population, which will require further prospective validation.

The Relationships Between BNP and Neurocardiac Injury Severity, Noninvasive Cardiac Output, and Outcomes After Aneurysmal Subarachnoid Hemorrhage

INTRODUCTION

Neurocardiac injury, a type of myocardial dysfunction associated with neurological insult to the brain, occurs in 31-48% of aneurysmal subarachnoid hemorrhage (aSAH) patients. Cardiac troponin I (cTnI) is commonly used to diagnose neurocardiac injury. Brain natriuretic peptide (BNP), another cardiac marker, is more often used to evaluate degree of heart failure. The purpose of this study was to examine the relationships between BNP and (a) neurocardiac injury severity according to cTnI, (b) noninvasive continuous cardiac output (NCCO), and (c) outcomes in aSAH patients.

METHOD

This descriptive longitudinal study enrolled 30 adult aSAH patients. Data collected included BNP and cTnI levels and NCCO parameters for 14 days and outcomes (modified Rankin Scale [mRS] and mortality) at discharge and 3 months. Generalized estimating equations were used to evaluate associations between BNP and cTnI, NCCO, and outcomes.

RESULTS

BNP was significantly associated with cTnI. For every 1 unit increase in log BNP, cTnI increased by 0.05 ng/ml ( p = .001). Among NCCO parameters, BNP was significantly associated with thoracic fluid content ( p = .0003). On multivariable analyses, significant associations were found between BNP and poor mRS. For every 1 unit increase in log BNP, patients were 3.16 times more likely to have a poor mRS at discharge ( p = .021) and 5.40 times more likely at 3 months ( p < .0001).

CONCLUSION

There were significant relationships between BNP and cTnI and poor outcomes after aSAH. BNP may have utility as a marker of neurocardiac injury and outcomes after aSAH.

Serum Soluble ST2 and Diastolic Dysfunction in Hypertensive Patients

Background

Echocardiographic evaluation of left ventricular (LV) structural and functional alterations in hypertension has some limitations, potentially overcome by using biomarkers. ST2, a prognostic biomarker for heart failure and myocardial infarction patients, was less studied in hypertension.

Aim

To analyze the relationship between serum ST2 levels and diastolic dysfunction (DD) in hypertension.

Method

We enrolled 88 hypertensive outpatients (average age 65 years, 69.3% females) in a prospective study, stratified for presence of LV hypertrophy (LVH). For each patient clinical examination, lab workup (routine and serum ST2 levels) and echocardiography were performed.

Results

Hypertensive patients with LVH had higher age, pulse pressure, mean arterial pressure, and serum ST2, while having lower serum albumin than those without LVH. Serum ST2 levels correlate with parameters of LV remodeling and DD. We found that 5.3% of ST2 level variability was caused by a 1-unit variation of cardiovascular risk. We identified cut-off values for discriminating hypertension with LVH versus that without LVH and grade 2 DD versus normal diastolic performance.

Conclusion

ST2 could be used as diagnostic biomarker for cardiac remodeling and altered diastolic performance in hypertension, providing additional data to echocardiography. It could represent a milestone in early detection of cardiac performance alteration.

Changing concept in treatment of asymptomatic severe aortic stenosis and normal ejection fraction: time for biomarkers reappraisal

The uncertainty of whether/how to treat asymptomatic patients with isolated severe aortic stenosis and normal left ventricular ejection fraction is one of the most topical in cardiovascular medicine. Recently, the AVATAR trial: first ever randomized trial in the setting of aortic stenosis has been started in an attempt to adequately address this 'burning issue'. In light of this fact it is important to identify biomarkers which might help in risk stratification of these patients, not only in the referring physician's office during a routine exam, but also for preoperative patients scheduled for surgical replacement/transcatheter aortic valve implantation. This report is focusing on novel laboratory parameters which might be helpful in this risk stratification.

Biologic variability of N-terminal pro-brain natriuretic peptide in adult healthy cats

Objectives The biologic variability of N-terminal pro-brain natriuretic peptide (NT-proBNP) and its impact on diagnostic utility is unknown in healthy cats and those with cardiac disease. The purpose of this study was to determine the biologic variation of NT-proBNP within-day and week-to-week in healthy adult cats. Methods Adult cats were prospectively evaluated by complete blood count (CBC), biochemistry, total thyroxine, echocardiography, electrocardiography and blood pressure, to exclude underlying systemic or cardiac disease. Adult healthy cats were enrolled and blood samples were obtained at 11 time points over a 6 week period (0, 2 h, 4 h, 6 h, 8 h, 10 h and at weeks 2, 3, 4, 5 and 6). The intra-individual (coefficient of variation [CVI]) biologic variation along with index of individuality and reference change values (RCVs) were calculated. Univariate models were analyzed and included comparison of the six different time points for both daily and weekly samples. This was followed by a Tukey's post-hoc adjustment, with a P value of <0.05 being significant. Results The median daily and weekly CVI for the population were 13.1% (range 0-28.7%) and 21.2% (range 3.9-68.1%), respectively. The index of individuality was 0.99 and 1 for daily and weekly samples, respectively. The median daily and weekly RCVs for the population were 39.8% (range 17.0-80.5%) and 60.5% (range 20.1-187.8%), respectively. Conclusions and relevance This study demonstrates high individual variability for NT-proBNP concentrations in a population of adult healthy cats. Further research is warranted to evaluate NT-proBNP variability, particularly how serial measurements of NT-proBNP may be used in the diagnosis and management of cats with cardiac disease.

Reduced immunoreactivities of B-type natriuretic peptide in pulmonary arterial hypertension rats after ranolazine treatment

Pulmonary arterial hypertension (PAH) is a severe pulmonary vascular disease characterized by sustained increase in the pulmonary arterial pressure and excessive thickening and remodeling of the distal small pulmonary arteries. During disease progression, structural remodeling of the right ventricular (RV) impairs pump function, creates pro-arrhythmic substrates and triggers for arrhythmias. Notably, RV failure and lethal arrhythmias are major contributors to cardiac death in PAH that are not directly addressed by currently available therapies. Ranolazine (RAN) is an anti-anginal, anti-ischemic drug that has cardioprotective effects of heart dysfunction. RAN also has anti-arrhythmic effects due to inhibition of the late sodium current in cardiomyocytes. Therefore, we hypothesized that RAN could reduce the mal-adaptive structural remodeling of the RV, and prevent triggered ventricular arrhythmias in the monocrotaline-induced rat model of PAH. RAN reduced ventricular hypertrophy, reduced levels of B-type natriuretic peptide, and decreased the expression of fibrosis. In addition, RAN prevented cardiovascular death in rat model of PAH. These results support the notion that RAN can improve the functional properties of the RV, highlighting its potential benefits in the setting of heart impairment.

Clinical Applications of Natriuretic Peptides in Assessment of Valvular Heart Disease

Biomarkers such as natriuretic peptides (NPs) have evolving clinical utility beyond the scope of heart failure. The role of NPs in the management of valvular heart disease is a growing area of investigation. NPs have much potential in the assessment of asymptomatic patients with hemodynamically significant valvular lesions who have traditionally been excluded from consideration of surgical intervention. NPs also have a role in the risk stratification of these patients as well as in routine surveillance and monitoring. Together with echocardiographic data and functional status, NPs are being incorporated into the management of valvular heart disease. In this review we examine the evidence for the role of natriuretic peptides in assessment of VHD.

A simplified protocol for the isolation and culture of cardiomyocytes and progenitor cells from neonatal mouse ventricles

The neonatal heart is a very useful tool for the study of biochemical pathways and properties of cardiomyocytes and as it has the potential to regenerate for a brief period of time from birth; it is also useful to study cardiac regeneration. However, as the heart matures, this proficiency for regeneration is reduced. This regenerative potential may be influenced by the microenvironment of the heart in the early stages of postnatal development and therefore, cell cultures derived at this stage may contain functional cardiomyocytes and progenitor cells. The aim of this study was to identify key steps in the isolation and culture of such early stage-neonatal mouse hearts to allow maximum migration of cardiomyocytes from the explant and their maintenance as functional, long term cultures. Explant cultures of mouse ventricles preserved 3-dimensional structure and generated migrating layers of cardiomyocytes that expressed alpha sarcomeric actin which could be further sub-cultured by enzymatic dissociation. Western blotting demonstrated expression of c-KIT, GATA4, alpha sarcomeric actin and connexin43 proteins after 20 days of explant culture. ACTA1, GATA4, and CX43 continued to express in five weeks old explant cultures while the c-KIT protein was expressed up to two passages during sub-culture. Real time PCR and SQRT PCR also demonstrated gene expression of cardiomyocyte markers in long term cultures. Migrating cells from the explants assembled into contracting spheroids after subculture and expressed the c-KIT protein. Progenitor markers CD44, CD90, and extracellular proteins, periostin and vimentin demonstrated the preservation of cellular heterogeneity in such cultures. Supplementation with Hydrocortisone maintained a cardioprotective environment and reduced the non-myocyte population. This is an optimized and efficient method for the generation of neonatal heart cultures that is not labor intensive and does not require supplementation with cytokines.

N-terminal pro-B-type natriuretic peptide measurement is useful in predicting left ventricular hypertrophy regression after aortic valve replacement in patients with severe aortic stenosis

BACKGROUND

The predictive factors for early left ventricular hypertrophy (LVH) regression after aortic valve replacement (AVR) have not been fully elucidated. This study was conducted to investigate which preoperative parameters predict early LVH regression after AVR.

METHODS AND RESULTS

87 consecutive patients who underwent AVR due to isolated severe aortic stenosis (AS) were analysed. Patients with ejection fraction <50% or concomitant coronary artery disease were excluded from the analysis. Preoperative evaluation including echocardiography and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurement was performed and midterm follow-up echocardiography was done at a median of 9 months after AVR. The presence of complete regression of LVH at the midterm follow-up was determined. In multivariate analysis, including preoperative echocardiographic parameters, only E/e' ratio was associated with midterm LVH regression (OR 1.11, 95% CI 1.01 to 1.22; p=0.035). When preoperative NT-proBNP was added to the analysis, logNT-proBNP was found to be the single significant predictor of midterm LVH regression (OR 2.00, 95% CI 1.08 to 3.71; p=0.028). By receiver operating characteristic curve analysis, a cut-off value of 440 pg/mL for NT-proBNP yielded a sensitivity of 72% and a specificity of 77% for the prediction of LVH regression after AVR.

CONCLUSIONS

Preoperative NT-proBNP was an independent predictor for early LVH regression after AVR in patients with isolated severe AS.

Early trends in N-terminal pro-brain natriuretic peptide values after left ventricular assist device implantation for chronic heart failure

Left ventricular assist devices (LVADs) acutely decrease left ventricular wall stress. Thus, early postoperative levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) should decrease. This study investigated postoperative changes in NT-proBNP levels, the parameters related to changes, and the possible association with complications by performing a retrospective analysis of changes in daily NT-proBNP (pg/ml) levels from admission to discharge both before and after LVAD implantation in a tertiary referral center. For 72 patients implanted with HeartMate II LVADs, baseline NT-proBNP levels were elevated at 3,943 ng/ml (interquartile range 1,956 to 12,964). Preoperative stabilization led to marked decreases in NT-proBNP. Levels peaked 3 days after surgery and subsequently decreased. Patients with complicated postoperative courses had higher early postoperative elevations. By discharge, NT-proBNP decreased markedly but was still 2.83 (1.60 to 5.76) times the age-based upper limit of normal. The 26% reduction in NT-proBNP between admission and discharge was due mostly to the preoperative reductions and not those induced by the LVAD itself. The decrease was not associated with decreases in LV volume. In conclusion, preoperative treatment reduces NT-proBNP values. The magnitude of early postoperative changes is related to the clinical course. Levels at discharge remain markedly elevated and similar to values after preoperative stabilization despite presumptive acute LV unloading.

Prognostic values of highly sensitive cardiac troponin T and B-type natriuretic peptide for clinical features in hypertrophic obstructive cardiomyopathy: a cross-sectional study

OBJECTIVES

Although B-type natriuretic peptide (BNP) and highly sensitive cardiac troponin T (cTnT) are useful for the evaluation of clinical features in various cardiovascular diseases, there are comparatively few data regarding the utility of these parameters in patients with hypertrophic obstructive cardiomyopathy (HOCM). The goal of this study was to assess the association between BNP, cTnT and clinical parameters in patients with HOCM.

DESIGN

Cross-sectional survey

SETTINGS

The relationship between BNP, cTnT and clinical end points and echocardiographic data was investigated.

PARTICIPANTS

This study included 102 consecutive outpatients with HOCM who were clinically stable.

RESULTS

BNP was significantly associated with both maximum left ventricular (LV) wall thickness (r=0.28; p=0.003), and septal peak early transmitral filling velocity/peak early diastolic mitral annulus velocity (r=0.51; p=0.0001). No statistically significant associations were seen between cTnT and any echocardiographic parameters, but the presence of atrial fibrillation (AF) was associated with a high level of cTnT (p=0.01).

CONCLUSIONS

BNP is useful for monitoring clinical parameters and as a reflection of both LV systolic/diastolic function and increased LV pressure in patients with HOCM. A high level of serum cTnT is associated with the presence of AF.

Usefulness of serial B-type natriuretic peptide assessment in asymptomatic aortic stenosis

B-type natriuretic peptide (BNP) level may be a useful prognostic marker for the management of asymptomatic patients with aortic stenosis (AS). The aim of this study was to identify the echocardiographic determinants of BNP changes during follow-up in AS. We studied 61 asymptomatic patients with greater than moderate AS and preserved left ventricular (LV) ejection fraction who underwent rest and exercise Doppler echocardiography with concomitant BNP level measurement at baseline. BNP measurement was repeated after inclusion every 6 months. Patients were divided into 2 groups according to the median of BNP changes during follow-up. According to parameters at rest, patients in the high BNP changes group had significantly higher E/e' ratio. Statistically significant correlations were found between BNP changes and E/e' ratio and indexed left atrial area. According to exercise parameters, patients in the high BNP changes group had significantly lower exercise-induced increase in LV ejection fraction. Statistically significant correlations were found between BNP changes and exercise-induced changes in LV ejection fraction. After adjustment for age, mean aortic pressure gradient, and BNP level at baseline, multivariate analysis identified indexed left atrial area, E/e' at rest, and exercise-induced increase in ejection fraction as independent determinants of BNP changes during follow-up. In conclusion, this study shows that, in asymptomatic patients with preserved LV function and moderate AS, serial BNP measurements may widely vary. Subclinical LV diastolic and systolic dysfunctions are frequently present in patients with higher serial BNP changes.