Expression of atrial and brain natriuretic peptides and their genes in hearts of patients with cardiac amyloidosis

Natriuretic peptide testing strategies in heart failure: A 2023 update

Natriuretic peptides (NPs), including B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP), have been recommended as standard biomarkers for diagnosing heart failure (HF), and one of the strongest risk predictors for mortality and HF hospitalization regardless of ejection fraction (EF) and etiology of HF. BNP is an active neurohormone opposing renin-angiotensin-aldosterone and sympathetic nervous system overactivated in HF, whereas NT-proBNP is an inactive prohormone released from cardiomyocytes in response to wall stress. Despite substantial advances in the development of guideline-directed medical therapy (GDMT) for HF with reduced EF, studies demonstrating direct benefits of NP-guided chronic HF therapy on mortality, HF hospitalization, and GDMT optimization have yielded conflicting results. However, accumulating evidence shows that achieving prespecified BNP or NT-proBNP target over time is significantly associated with favorable outcomes, suggesting that benefits of serially measured NPs may be limited to particular groups of HF patients, such as those with extreme levels of baseline BNP or NT-proBNP, which could represent severe phenotypes of HF associated with natriuretic peptide resistance or cardiorenal syndrome. Over the past decade, clinical utilization of BNP and NT-proBNP has been expanded, especially using serial NP measurements for guiding HF therapy, optimizing GDMT and identifying at-risk patients with HF phenotypes who may be minimally symptomatic or asymptomatic.

Cardiac amyloidosis and aortic stenosis: a state-of-the-art review

Cardiac amyloidosis is caused by the extracellular deposition of amyloid fibrils in the heart, involving not only the myocardium but also any cardiovascular structure. Indeed, this progressive infiltrative disease also involves the cardiac valves and, specifically, shows a high prevalence with aortic stenosis. Misfolded protein infiltration in the aortic valve leads to tissue damage resulting in the onset or worsening of valve stenosis. Transthyretin cardiac amyloidosis and aortic stenosis coexist in patients > 65 years in about 4-16% of cases, especially in those undergoing transcatheter aortic valve replacement. Diagnostic workup for cardiac amyloidosis in patients with aortic stenosis is based on a multi-parametric approach considering clinical assessment, electrocardiogram, haematologic tests, basic and advanced echocardiography, cardiac magnetic resonance, and technetium labelled cardiac scintigraphy like technetium-99 m (99mTc)-pyrophosphate, 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid, and 99mTc-hydroxymethylene diphosphonate. However, a biopsy is the traditional gold standard for diagnosis. The prognosis of patients with coexisting cardiac amyloidosis and aortic stenosis is still under evaluation. The combination of these two pathologies worsens the prognosis. Regarding treatment, mortality is reduced in patients with cardiac amyloidosis and severe aortic stenosis after undergoing transcatheter aortic valve replacement. Further studies are needed to confirm these findings and to understand whether the diagnosis of cardiac amyloidosis could affect therapeutic strategies. The aim of this review is to critically expose the current state-of-art regarding the association of cardiac amyloidosis with aortic stenosis, from pathophysiology to treatment.

Prognosis of light chain amyloidosis: a multivariable analysis for survival prediction in patients with cardiac involvement proven by endomyocardial biopsy

BACKGROUND

Cardiac involvement is a main determinant of mortality in light chain (AL) amyloidosis but data on survival of patients with cardiac AL amyloidosis proven by endomyocardial biopsy (EMB) are sparse.

METHODS

This study analysed clinical, laboratory, electrocardiography and echocardiographic parameters for their prognostic value in the assessment of patients with AL amyloidosis and cardiac involvement. Patients with AL amyloidosis who had their first visit to the amyloidosis centre at the University Hospital Heidelberg between 2006 and 2017 (n=1628) were filtered for cardiac involvement proven by EMB. In the final cohort, mortality-associated markers were analysed by univariate and multivariable Cox regression. Cut-off values for each parameter were calculated using the survival time.

RESULTS

One-hundred and seventy-four patients could be identified. Median overall survival time was 1.5 years and median follow-up time was 5.2 years. At the end of the investigation period, 115 patients had died. In multivariable analysis, New York Heart Association-functional class >II (HR 1.65; 95% CI 1.09 to 2.50; p=0.019), left ventricular global longitudinal strain (HR 1.12; 95% CI 1.03 to 1.22; p=0.007), left ventricular end-systolic volume (HR 1.02; 95% CI 1.01 to 1.03; p=0.001), systolic pulmonary artery pressure (HR 0.98; 95% CI 0.96 to 0.99; p=0.027), N-terminal pro-B-type natriuretic peptide (HR 1.57; 95% CI 1.17 to 2.11; p=0.003) and difference in free light chains (HR 1.30; 95% CI 1.05 to 1.62; p=0.017) were independently predictive.

CONCLUSION

Among all patients with AL amyloidosis those with cardiac involvement represent a high-risk population with limited therapy options. Therefore, accurate risk stratification is necessary to identify cardiac amyloidosis patients with favourable prognosis. Incorporation of modern imaging techniques into existing or newly developed scoring systems is a promising option that might enable the implementation of risk-adapted therapeutic strategies.

Secondary cardiac amyloidosis in a patient with mixed connective tissue disease: A case report

We report the case of a 62-year-old man who presented with shortness of breath, cough, bilateral lower limbs' swelling, and blackish discoloration of multiple fingertips over the past 2 months. Anti-Ribonucleoprotein antibodies were found to be present, and gadolinium-based cardiac MRI showed non-vascular subendocardial enhancement with diffuse symmetrical thickening of the left ventricular wall. A diagnosis of Mixed connective tissue disease with secondary cardiac amyloidosis was thus made, and the patient was successfully managed with intravenous cyclophosphamide, corticosteroids, and other supportive measures. Although extremely rare, this case shows that secondary cardiac amyloidosis should be considered while managing patients with MCTD.

Endothelial Function Is Preserved in Patients with Wild-Type Transthyretin Amyloid Cardiomyopathy

Heart failure (HF) is associated with endothelial dysfunction. Vascular function per se plays an important role in cardiac function, whether it is a cause or consequence. However, there is no information on vascular function in patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM). The purpose of this study was to evaluate vascular function in patients with ATTRwt-CM. We measured flow-mediated vasodilation (FMD) as an index of endothelial function and nitroglycerine-induced vasodilation (NID) as an index of vascular smooth muscle function and brachial artery intima-media thickness (bIMT) and brachial-ankle pulse wave velocity (baPWV) as indices of arterial stiffness in 22 patients with ATTRwt-CM and in 22 one-by-one matched control patients using vascular function confounding factors. FMD was significantly greater in patients with ATTRwt-CM than in the controls (5.4 ± 3.4% versus 3.5 ± 2.4%, p = 0.038) and the N-terminal pro-brain natriuretic peptide (NT-proBNP) level was significantly greater in patients with ATTRwt-CM than in the controls (2202 ± 1478 versus 470 ± 677 pg/mL, p < 0.001). There were no significant differences in NID, bIMT or baPWV between the two groups. There was a significant relationship between NT-proBNP and FMD in patients with ATTRwt-CM (r = 0.485, p = 0.022). NT-proBNP showed no significant relationships with NID, bIMT or baPWV. Conclusions: Endothelial function was preserved in patients with ATTRwt-CM. Patients with ATTRwt-CM may have compensatory effects with respect to endothelial function through elevation of BNP.

Red flags for the diagnosis of cardiac amyloidosis: simple suggestions to raise suspicion and achieve earlier diagnosis

Cardiac amyloidosis is an infiltrative disease characterized by extracellular deposition of insoluble amyloid fibrils in the heart leading to organ dysfunction. Despite recent diagnostic advances, the diagnosis of cardiac amyloidosis is often delayed or even missed. Furthermore, a long diagnostic delay is associated with adverse outcomes, with the early diagnosed patients showing the longest survival. In this narrative review we aimed to summarize the 'red flags' that may facilitate the correct diagnosis. The red flags may be classified as clinical, biohumoral, electrocardiographic, echocardiographic, and cardiac magnetic resonance features and should promptly raise the suspicion of cardiac amyloidosis in order to start a correct diagnostic pathway and targeted treatment strategies that may improve patients' outcomes.

Biochemistry of the Endocrine Heart

Simple Summary

Besides being a muscle and an electrochemically active organ, the heart is a true endocrine organ. As endocrine cells, cardiac myocytes possess all the needed chemical necessities for translation, post-translational modifications, and complex peptide proteolysis. In addition, intracellular granules in the cells contain not only peptides destined for secretion but also important granin molecules involved in maintaining a regulated secretory pathway. In this review, we highlight the biochemical phenotype of the endocrine heart, recapitulating that the cardiac myocytes are truly and fully capable endocrine cells.

Abstract

Production and release of natriuretic peptides and other vasoactive peptides are tightly regulated in mammalian physiology and involved in cardiovascular homeostasis. As endocrine cells, the cardiac myocytes seem to possess almost all known chemical necessities for translation, post-translational modifications, and complex peptide proteolysis. In several ways, intracellular granules in the cells contain not only peptides destined for secretion but also important granin molecules involved in maintaining a regulated secretory pathway. In this review, we will highlight the biochemical phenotype of the endocrine heart recapitulating that the cardiac myocytes are capable endocrine cells. Understanding the basal biochemistry of the endocrine heart in producing and secreting peptides to circulation could lead to new discoveries concerning known peptide products as well as hitherto unidentified cardiac peptide products. In perspective, studies on natriuretic peptides in the heart have shown that the post-translational phase of gene expression is not only relevant for human physiology but may prove implicated also in the development and, perhaps one day, cure of human cardiovascular disease.

Morpho-functional changes of cardiac telocytes in isolated atrial amyloidosis in patients with atrial fibrillation

Telocytes are interstitial cells with long, thin processes by which they contact each other and form a network in the interstitium. Myocardial remodeling of adult patients with different forms of atrial fibrillation (AF) occurs with an increase in fibrosis, age-related isolated atrial amyloidosis (IAA), cardiomyocyte hypertrophy and myolysis. This study aimed to determine the ultrastructural and immunohistochemical features of cardiac telocytes in patients with AF and AF + IAA. IAA associated with accumulation of atrial natriuretic factor was detected in 4.3-25% biopsies of left (LAA) and 21.7-41.7% of right (RAA) atrial appendage myocardium. Telocytes were identified at ultrastructural level more often in AF + IAA, than in AF group and correlated with AF duration and mitral valve regurgitation. Telocytes had ultrastructural signs of synthetic, proliferative, and phagocytic activity. Telocytes corresponded to CD117+, vimentin+, CD34+, CD44+, CD68+, CD16+, S100-, CD105- immunophenotype. No significant differences in telocytes morphology and immunophenotype were found in patients with various forms of AF. CD68-positive cells were detected more often in AF + IAA than AF group. We assume that in aged AF + IAA patients remodeling of atrial myocardium provoked transformation of telocytes into "transitional forms" combining the morphological and immunohistochemical features with signs of fibroblast-, histiocyte- and endotheliocyte-like cells.

Systemic ATTR-amyloidosis, a Rare Form of Internal Organ Damage

The article presents the case report of a rare hereditary form of systemic ATTR-amyloidosis in Russian patient with a discussion of approaches to the diagnosis and treatment of this form, also based on the own experience in the management of such patients. Modern ideas about the pathogenesis of the disease as well as detailed information about the clinical manifestations of amyloid cardiopathy and of other organs are presented. The nature of structural and hemodynamic changes in the heart is discussed on the basis of experience, including own, ultrasound examination of the heart in patients with amyloidosis, especially the article focuses the reader's attention on the true infiltrative nature of transtiretin amyloid cardiopathy in contrast to AL-amyloidosis, in which there is a significant inflammatory component that determines a more unfavorable natural course of AL-amyloidosis of the heart. The article discusses the differential diagnosis of different types of amyloidosis, the diagnostic difficulties associated with weak congophilia of transtiretin amyloidosis and at the same time substantiates the need for morphological verification of the diagnosis. Modern methods of treatment of ATTR-amyloidosis are discussed.

Value of natriuretic peptides and tissue Doppler imaging in the estimation of left ventricular filling pressure in patients with cardiac amyloidosis

Background

Estimation of left ventricular filling pressures (LVFP) is a determining factor in the follow-up of patients with cardiac amyloidosis (CA). Natriuretic peptides (NPs) and tissue Doppler imaging may be used to monitor LVFP in patients with CA. The aim of this study was to evaluate the value of NPs and Doppler parameters in estimating LVFP in patients with CA.

Methods

Fifty patients with biopsy-verified light chain (n=31), A protein amyloidosis (AA) (n=1), apoliporotein A2 (n=1) or bone scintigraphy-proven transthyretin (n=17) CA were retrospectively included. All patients underwent right heart catheterisation (RHC). Among them, 48 (96%) and 43 (86%) had assays of NPs (20 brain natriuretic peptide (BNP), 27 N-terminal pro-hormone brain natriuretic peptide (NT-proBNP) and 1 both) and transthoracic echocardiography performed within 24 hours of RHC, respectively.

Results

The median BNP and NT-proBNP levels were 1000 (243–1477) ng/L and 10 106 (2935–13 348) ng/L, respectively. Echocardiography demonstrated left atrial enlargement with a mean volume of 47±16 mL and low tissue Doppler lateral Ea of 5±2 cm/s. The mean early diastolic mitral inflow velocity on early lateral mitral annular diastolic velocity ratio (E/Ea) ratio was 18±7, and the mean pulmonary capillary wedge pressure (PCWP) by RHC was 18±8 mm Hg. There was no correlation between BNP (r=0.260, p=0.774) or NT-proBNP (r=−0.103, p=0.984) levels and PCWP. There was a slight correlation between E/Ea ratio and PCWP (r=0.337, p=0.029). E/Ea ratio >14 performed poorly in differentiating elevated and low LVFP.

Conclusion

In patients with CA, NPs do not accurately estimate PCWP. Tissue Doppler-derived mitral E/Ea ratio is correlated with PCWP, but the slight correlation requires to estimate LVFP in a broad clinical and imaging context to avoid diagnostic errors.

Immunolocalization of natriuretic peptides and their receptors in goat (Capra hircus) heart

Natriuretic peptides are structurally similar, but genetically distinct, hormones that participate in cardiovascular homeostasis by regulating blood and extracellular fluid volume and blood pressure. We investigated the distribution of natriuretic peptides and their receptors in goat (Capra hircus) heart tissue using the peroxidase-anti-peroxidase (PAP) immunohistochemical method. Strong staining of atrial natriuretic peptide (ANP) was observed in atrial cardiomyocytes, while strong staining for brain natriuretic peptide (BNP) was observed in ventricular cardiomyocytes. Slightly stronger cytoplasmic C-type natriuretic peptide (CNP) immunostaining was detected in the ventricles compared to the atria. Natriuretic peptide receptor-A (NPR-A) immunoreactivity was more prominent in the atria, while natriuretic peptide receptor-B (NPR-B) immunoreactivity was stronger in the ventricles. Cytoplasmic natriuretic peptide receptor-C (NPR-C) immunoreactivity was observed in both the atria and ventricles, although staining was more prominent in the ventricles. ANP immunoreactivity ranged from weak to strong in endothelial and vascular smooth muscle cells. Endothelial cells exhibited moderate to strong BNP immunoreactivity, while vascular smooth cells displayed weak to strong staining. Endothelial cells exhibited weak to strong cytoplasmic CNP immunoreactivity. Vascular smooth muscle cells were labeled moderately to strongly for CNP. Weak to strong cytoplasmic NPR-A immunoreactivity was found in the endothelial cells and vascular smooth muscle cells stained weakly to moderately for NPR-A. Endothelial and vascular smooth cells exhibited weak to strong cytoplasmic NPR-B immunoreactivity. Moderate to strong NPR-C immunoreactivity was observed in the endothelial and smooth muscle cells. Small gender differences in the immunohistochemical distribution of natriuretic peptides and receptors were observed. Our findings suggest that endothelial cells, vascular smooth cells and cardiomyocytes express both natriuretic peptides and their receptors.

Cardiac telocytes. From basic science to cardiac diseases. I. Atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is nowadays considered to be one of the most important causes of heart failure, stroke, cognitive decline, vascular dementia, sudden death and overall cardiovascular morbidity. Recently were published a few articles suggesting a possible involvement of telocytes in the development of atrial fibrillation. The purpose of this article is to analyze the results obtained in the field systematically, and to see if there is enough data to support a possible involvement of telocytes in arrhythmogenesis.

MATERIALS AND METHODS

To this end, we performed a systematic review of the relevant scientific literature, indexed in PubMed, Web of Science, and Scopus.

RESULTS AND DISCUSSIONS

Our systematic review of the published data identified five articles containing original data, based on which the association between telocytes and atrial fibrillation was inferred in later studies. We analyzed the usefulness of the information contained in the original articles to support this association, showing a lack of definite proofs correlating telocytes with atrial fibrillation.

CONCLUSIONS

Even if a few articles implied a potential association between AF and telocytes, the current data is not enough to support it. Moreover, even an association between the morphology, characteristics, or density of the telocytes in the atrium/pulmonary veins and AF is potentially speculative, and more studies should be performed before implying it with a reasonable degree of certainty.

NT pro B type natriuretic peptide levels in constrictive pericarditis and restrictive cardiomyopathy

BACKGROUND

The differentiation of constrictive pericarditis (CP) from restrictive cardiomyopathy (RCM) may be clinically difficult and may require multiple investigations. Even though brain natriuretic peptide (BNP) is shown to be higher in patients with RCM as compared to CP, the clinical utility is not fully established especially in Indian patients known to have advanced CP and myocardial involvement.

METHODS AND RESULTS

We measured NT-pro-BNP levels in 49 patients suspected of having either CP or RCM, diagnosed on the basis of echocardiography, computed tomography, magnetic resonance imaging, endomyocardial biopsy and cardiac catheterization data as needed. Twenty nine patients (Mean age - 26 yrs, 24 males) had CP and 20 patients (Mean age - 39 yrs, 14 males) had RCM. The median plasma NT-pro-BNP levels were significantly higher in RCM as compared to CP [1775 (208-7500) pg/ml vs 124 (68-718) pg/ml, respectively; p = 0.001]. A cut off value of 459 pg/ml had sensitivity, specificity and overall accuracy of 90%, 86% and 88% respectively, for differentiating CP from RCM.

CONCLUSIONS

The NT-pro-BNP levels are significantly elevated in RCM as compared to CP.

Weight loss, saline loading, and the natriuretic peptide system

Background

In epidemiologic studies, obesity has been associated with reduced natriuretic peptide (NP) concentrations. Reduced NP production could impair the ability of obese individuals to respond to salt loads, increasing the risk of hypertension and other disorders. We hypothesized that weight loss enhances NP production before and after salt loading.

Methods and Results

We enrolled 15 obese individuals (mean BMI 45±5.4 kg/m²) undergoing gastric bypass surgery. Before and 6 months after surgery, subjects were admitted to the clinical research center and administered a large‐volume intravenous saline challenge. Echocardiography and serial blood sampling were performed. From the pre‐operative visit to 6 months after surgery, subjects had a mean BMI decrease of 27%. At the 6‐month visit, N‐terminal pro‐atrial NP (Nt‐proANP) levels were 40% higher before, during, and after the saline infusion, compared with levels measured at the same time points during the pre‐operative visit (P<0.001). The rise in Nt‐pro‐ANP induced by the saline infusion (≈50%) was similar both before and after surgery (saline, P<0.001; interaction, P=0.2). Similar results were obtained for BNP and Nt‐proBNP; resting concentrations increased by 50% and 31%, respectively, after gastric bypass surgery. The increase in NP concentrations after surgery was accompanied by significant decreases in mean arterial pressure (P=0.004) and heart rate (P<0.001), and an increase in mitral annular diastolic velocity (P=0.02).

Conclusion

In obese individuals, weight loss is associated with a substantial increase in the “setpoint” of circulating NP concentrations. Higher NP concentrations could contribute to an enhanced ability to handle salt loads after weight loss.

Role of natriuretic peptide to predict cardiac abnormalities in patients with hereditary transthyretin amyloidosis

BACKGROUND

Familial amyloid polyneuropathy (FAP) mainly targets the peripheral nervous system and heart. Early noninvasive detection of cardiac impairment is critical for therapeutic management.

AIM

To assess if amino-terminal pro-brain natriuretic peptide (NT-proBNP) or troponin T (cTnT) can predict echocardiographic left-ventricle (LV) impairment in FAP.

METHODS

Thirty-six asymptomatic carriers and patients with FAP had echocardiographic measurement of left-ventricular (LV) systolic function, hypertrophy (LVH) and estimation of filling pressure (FP).

RESULTS

Overall, median age, NT-proBNP, and LV ejection fraction were, respectively, 59 years (41-74), 323 pg/ml (58-1960), and 60% (51-66). Twelve patients had increased cTnT. Prevalence of ATTR gene mutations was 53% for Val30Met. Four individuals were asymptomatic, 6 patients had isolated neurological clinical signs, and 26 had echo-LV abnormalities. The ROC curve identified NT-proBNP patients with echo-LV abnormalities (area: 0.92; (0.83-0.99), p = 0.001) at a threshold >82 pg/ml with a sensitivity of 92%, and a specificity of 90%. Increased in NT-proBNP occurred in patients with SD and/or LVH with or without increase in FP. Elevated cTnT (>0.01 ng/ml) was only observed in patients with LVH and systolic dysfunction, with or without FP.

CONCLUSION

In FAP, NT-proBNP was associated with cardiac impairment suggesting that NT-proBNP could be used in carriers or in FAP patients with only neurologic symptoms for identifying the appropriate time to start cardiac echocardiographic assessment and follow-up. cTnT identified patients with severe cardiac disease.

An N-terminal pro-atrial natriuretic peptide (NT-proANP) 'aggregation-prone' segment involved in isolated atrial amyloidosis

Isolated atrial amyloidosis (IAA) is a common localized form of amyloid deposition within the atria of the aging heart. The main constituents of amyloid fibrils are atrial natriuretic peptide (ANP) and the N-terminal part of its precursor form (NT-proANP). An 'aggregation-prone' heptapeptide ((114)KLRALLT(120)) was located within the NT-proANP sequence. This peptide self-assembles into amyloid-like fibrils in vitro, as electron microscopy, X-ray fiber diffraction, ATR FT-IR spectroscopy and Congo red staining studies reveal. Consequently, remedies/drugs designed to inhibit the aggregation tendency of this 'aggregation-prone' segment of NT-proANP may assist in prevention/treatment of IAA, congestive heart failure (CHF) or atrial fibrillation (AF).

[Senile systemic amyloidosis: definition, diagnosis, why thinking about?]

Senile systemic amyloidosis (SSA) is characterized by infiltration of amyloid transthyretin fibrils in the myocardium. SSA occurs mainly (but not always) in elderly men. SSA leads to hypertrophic and/or restrictive cardiomyopathy complicated by conduction disturbances, atrial arrhythmia and systemic embolization (stroke…). That is why SSA needs a special care and to be diagnosed. Cardiac SSA diagnosis needs to exclude two other forms of cardiac amyloidosis: AL amyloidosis (light chain) and hereditary transthyretin amyloidosis (genetic testing). Scintigraphic 99mTc-DPD heart retention is observed in cardiac amyloidosis. DPD heart retention is more frequent in cardiac transthyretin amyloidosis than in cardiac AL amyloidosis. Specific treatments of cardiac TTR amyloidosis are in development.

Clinical and echocardiographic correlates of elevated troponin in amyloid light-chain cardiac amyloidosis

Increased troponin is associated with poor survival in patients with amyloid light-chain (AL) amyloidosis with cardiac involvement (CAL). The purpose of this investigation was to define the relation between increased troponin and clinical, morphologic, and functional features. The comparative utility of clinical, echocardiographic, and biochemical measurements in predicting survival in CAL was also investigated. One hundred seventeen patients with CAL were divided into 2 groups: normal troponin I (<0.06 ng/ml, n = 42) or increased troponin I (≥0.06 ng/ml, n = 75). Patients in the high troponin I group were older (63 vs 58 years, p = 0.04), with higher B-type natriuretic peptide levels (1,417 vs 936 pg/ml, p = 0.0004). The high troponin I group also had higher echocardiography-determined early/late mitral inflow velocity ratio (2.2 vs 1.4, p = 0.005) and myocardial performance index (0.59 vs 0.45, p = 0.04) and lower stroke index (28 vs 38 ml/beat/m(2), p <0.0001) and left atrial systolic force (5.9 vs 8.4 k-dynes, p = 0.037) than the normal troponin group. Median survival was significantly shorter in the high troponin group (11 vs 45 months, p <0.001). At time of CAL diagnosis, univariate predictors of all-cause mortality included increased troponin, older age, male gender, New York Heart Association class III to IV, >2 organs involved, higher B-type natriuretic peptide, lower creatinine clearance, greater ventricular septal thickness, and higher myocardial performance index. However, by multivariate Cox survival analysis, only increased troponin was a significant predictor for all-cause mortality (hazard ratio 3.1, p = 0.002). In conclusion, increased troponin is associated with worse left ventricular and left atrial functions by echocardiography in patients with CAL. Among baseline variables, it is the strongest predictor of all-cause mortality in multivariate analysis. Troponin is a powerful tool in clinical and prognostic assessments of patients with CAL.

Longitudinal left ventricular function for prediction of survival in systemic light-chain amyloidosis: incremental value compared with clinical and biochemical markers

OBJECTIVES

The aim of the study was to determine whether longitudinal left ventricular (LV) function provides prognostic information in a large cohort of patients with systemic light-chain (AL) amyloidosis.

BACKGROUND

AL amyloidosis is associated with a high incidence of cardiovascular events. Reduced myocardial longitudinal function is one of the hallmarks of myocardial involvement in this rare disease.

METHODS

Two hundred six consecutive patients with biopsy-proven AL amyloidosis were investigated in this prospective observational study. Echocardiographic imaging parameters, mean tissue Doppler-derived longitudinal strain (LS), and two-dimensional global longitudinal strain (2D-GLS) of the LV, cardiac serological biomarkers, and comprehensive clinical disease characteristics were assessed. The primary endpoint was all-cause mortality or heart transplantation.

RESULTS

After a median follow-up of 1207 days, LS and 2D-GLS were significant predictors of survival in AL amyloidosis. The cutoff values discriminating survivors from nonsurvivors were -10.65% for LS and -11.78% for 2D-GLS. In a multivariable echocardiographic Cox model, only diastolic dysfunction and 2D-GLS remained as independent predictors of survival. In comprehensive clinical models, 2D-GLS (p < 0.0001), diastolic dysfunction (p < 0.01), the pathologic free light chains (p < 0.05), cardiac troponin-T (cTnT) (p < 0.01), and the Karnofsky index (p < 0.001) remained as independent predictors. 2D-GLS delineated a superior prognostic value compared with that derived from pathologic free light chains or cTnT in patients evaluated before firstline chemotherapy (n = 113; p < 0.0001), and remained the only independent predictor besides the Karnofsky index in subjects with preserved LV ejection fraction (≥50%; n = 127; p < 0.01). LS and 2D-GLS both offered significant incremental information (p < 0.001) for the assessment of outcome compared with clinical variables (age, Karnofsky index, and New York Heart Association functional class) and serological biomarkers.

CONCLUSIONS

In the largest serial investigation reported so far, reduced LV longitudinal function served as an independent predictor of survival in AL amyloidosis and offered incremental information beyond standard clinical and serological parameters.

B-type natriuretic peptide: from posttranslational processing to clinical measurement

BACKGROUND

Plasma cardiac natriuretic peptides and peptide fragments from their molecular precursors are markers of heart disease. Clinical studies have defined the current diagnostic utility of these markers, whereas biochemical elucidation of peptide structure and posttranslational processing has revealed new plasma peptide forms of potential clinical use.

CONTENT

Natriuretic propeptide structures undergo variable degrees of endo- and exoproteolytic cleavages as well as amino acid modifications, which leave the plasma phase of the peptides highly heterogeneous and dependent on cardiac pathophysiology and capacity. An ongoing characterization of the molecular heterogeneity may not only help us to appreciate the biosynthetic capacity of the endocrine heart but may also lead to the discovery of new and more disease-specific targets for future molecular diagnosis.

SUMMARY

Peptides derived from pro-atrial natriuretic peptide and pro-B-type natriuretic peptide are useful plasma markers in heart failure. New data have defined cardiac myocytes as competent endocrine cells in posttranslational processing and cellular secretion.

Cardiac amyloidosis: a practical approach to diagnosis and management

Cardiac amyloidosis, the primary determinant of prognosis in systemic amyloidoses, is characterized by infiltration of myocardium by amyloid protein resulting in cardiomyopathy and conduction disturbances. Cardiac involvement is primarily encountered in immunoglobulin (AL) and transthyretin-associated (hereditary/familial and senile) amyloidoses. Although the latter variants could be indolent, untreated AL amyloidosis with clinical cardiac involvement is a rapidly fatal disease. The management decisions of cardiac amyloidosis are based on the underlying cause. Although treatment of senile systemic amyloidosis is largely supportive, the therapeutic approaches for AL amyloidosis include chemotherapy, autologous stem cell transplantation, and, rarely, cardiac transplantation. The familial variant is potentially curable with a liver ± cardiac transplantation. This narrative review outlines a practical approach to these challenging diagnoses in the face of rapidly evolving management strategies.

Different factors affecting human ANP amyloid aggregation and their implications in congestive heart failure

Aims

Atrial Natriuretic Peptide (ANP)-containing amyloid is frequently found in the elderly heart. No data exist regarding ANP aggregation process and its link to pathologies. Our aims were: i) to experimentally prove the presumptive association of Congestive Heart Failure (CHF) and Isolated Atrial Amyloidosis (IAA); ii) to characterize ANP aggregation, thereby elucidating IAA implication in the CHF pathogenesis.

Methods and Results

A significant prevalence (85%) of IAA was immunohistochemically proven ex vivo in biopsies from CHF patients. We investigated in vitro (using Congo Red, Thioflavin T, SDS-PAGE, transmission electron microscopy, infrared spectroscopy) ANP fibrillogenesis, starting from α-ANP as well as the ability of dimeric β-ANP to promote amyloid formation. Different conditions were adopted, including those reproducing β-ANP prevalence in CHF. Our results defined the uncommon rapidity of α-ANP self-assembly at acidic pH supporting the hypothesis that such aggregates constitute the onset of a fibrillization process subsequently proceeding at physiological pH. Interestingly, CHF-like conditions induced the production of the most stable and time-resistant ANP fibrils suggesting that CHF affected people may be prone to develop IAA.

Conclusions

We established a link between IAA and CHF by ex vivo examination and assessed that β-ANP is, in vitro, the seed of ANP fibrils. Our results indicate that β-ANP plays a crucial role in ANP amyloid deposition under physiopathological CHF conditions. Overall, our findings indicate that early IAA-related ANP deposition may occur in CHF and suggest that these latter patients should be monitored for the development of cardiac amyloidosis.

Cardiac amyloidosis responding to bortezomib: case report and review of literature

We report a case of a 53-year old patient with symptoms of congestive heart failure in whom a restrictive cardiomyopathy and a kappa-chain monoclonal gammopahty were diagnosed. Treatment with eight cycles of Bortezomib, a proteasome inhibitor, resulted in a significant regression of myocardial amyloid deposition and a notable clinical and hemodynamic improvement. Over the last few years, the management of cardiac amyloidosis has taken advantage of many of the advances of the chemotherapeutic regimens, as well as the wider availability of stem cell transplantation. The management of cardiac amyloidosis is also expected to evolve and improve with the better understanding of the specific mechanisms of amyloidogenesis and myocardial deposition. This will probably make certain molecules targeting specific sites in this process, as potentially effective and minimally toxic compared therapy with the currently used ones. In this article, we describe one of the first reported cases of cardiac amyloidosis, successfully treated with Bortezomib. We describe and discuss the mechanisms of action of Bortezomib and provide a detailed review of cardiac amyloidosis, from pathophysiology to diagnosis and treatment.

Relevance of urocortins to cardiovascular disease

Acquired cardiovascular diseases such as coronary heart disease, peripheral artery disease and related vascular problems contribute to more than one-third of worldwide morbidity and mortality. In many instances, particularly in the under developed world, cardiovascular diseases are diagnosed at a late stage limiting the scope for improving outcomes. A range of therapies already exist for established cardiovascular disease, although there is significant interest in further understanding disease pathogenesis in order to improve diagnosis and achieve primary and secondary therapeutic goals. The urocortins are a group of recently defined peptide members of the corticotrophin-releasing factor family. Previous pre-clinical work and human association studies suggest that urocortins have potential to exert some beneficial and other detrimental effects on the heart and major blood vessels. More current evidence however favours beneficial effects of urocortins, for example these peptides have been shown to inhibit production of reactive oxygen species and vascular cell apoptosis, and thus may have potential to antagonise the progression of cardiovascular disease. This review summarises published data on the potential role of urocortins in cardiovascular disease.

Elevated NT-proBNP levels should be interpreted in elderly patients presenting with dyspnea

BACKGROUND

B-type natriuretic peptide (BNP) assay is a useful tool in order to diagnose dyspnea due to congestive heart failure (CHF). On the other hand many other diseases could affect BNP levels. The aim of this study was to investigate a group of elderly patients admitted to an Internal Medicine unit because of dyspnea.

PATIENTS AND METHODS

NT-proBNP was assessed in 132 consecutive patients aged 80±6 years because of dyspnea. History data, anthropometric, clinical and biochemical parameters were collected. Renal function was assessed by the CKD-EPI formula. Diagnosis of pulmonary disease such as infections and chronic obstructive disease was considered and was analyzed as a single parameter. Statistical analysis was carried out dividing patients with high NT-proBNP from those with normal NT-proBNP according to the Januzzi cut-off.

RESULTS

NT-proBNP was higher than the normal reference values in 68.7% of patients and its levels increased in the 5 different stages of chronic kidney disease. Subjects with high NT-proBNP had lower haemoglobin levels (11.6±2.1 vs 12.8±1.9 g/dl, p=0.003), higher prevalence of atrial fibrillation (54.3 vs 25%, p=0.001), and lower prevalence of pulmonary diseases (29.7 vs 57.5%, p=0.005). Logistic regression analysis showed that NT-proBNP levels were independently associated with haemoglobin (OR 1.307 95% CI 1.072-1.593, p=0.008) and pulmonary diseases (OR 3.069 95% CI 1.385-6.801, p=0.006).

CONCLUSIONS

A disease different from CHF appears to affect NT-proBNP plasma levels. Therefore, determination of its levels does not seem to help clinicians in the definition of dyspnea in elderly people with different comorbidities.

Catastrophic cardiac amyloidosis

We report a case of a 61-year-old patient presenting with cardiogenic shock. His echocardiogram suggested typical features of cardiac amyloidosis. This case demonstrates that cardiac amyloidosis can present acutely and may be catastrophic.

Exercise-induced changes of B-type natriuretic peptide uncover the unknown coronary artery disease in patients with chest pain and normal left ventricular systolic function

AIM

The diagnostic and prognostic utility of B-type natriuretic peptide (BNP) has been shown in patients either with heart failure or with known coronary artery disease (CAD). We aimed to investigate the utility of the exercise-induced changes of BNP in patients with chest pain, unknown CAD, and normal left ventricular systolic function.

METHODS

We evaluated 100 consecutive patients (mean age 58.7 ± 9 years) (80% male) with left ventricular ejection fraction of more than 50%. Blood samples were collected and BNP was measured before exercise stress testing, at peak, and 20 min after it. All patients underwent coronary artery angiography. We used univariate and multivariate logistic regression analysis.

RESULTS

An increment in BNP values of 1.3 fold (from before to peak exercise BNP values) have 11 times greater odds of having CAD [odds ratio (OR): 11.45 with 95% confidence interval (CI): 3.48–37.66, P < 0.001]. Receiver operating curve analysis revealed a sensitivity of 81.8% and a specificity of 71.8%. Multivariate analysis revealed that BNP increment from before to peak exercise remained statistically significant regardless of the presence of other risk factors for atherosclerosis (OR: 18.59 with 95% CI: 4.14–83.45, P < 0.001). Interestingly, patients showing 1.79 times increment of before to peak exercise BNP values have 19 times greater odds of having multivessel disease (OR: 19.28 with 95% CI: 4.95–75.17, P < 0.001) with a sensitivity of 81% and specificity of 81.8%.

CONCLUSION

The exercise-induced changes of BNP in patients with chest pain, normal left ventricular systolic function, and unknown CAD may uncover patients with CAD and discriminate those with angiographically severe one.

Biosynthesis of cardiac natriuretic peptides

Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac peptides has only been elucidated during the last decade. The cellular synthesis including amino acid modifications and proteolytic cleavages has proven considerably more complex than initially perceived. Consequently, the elimination phase of the peptide products in circulation is not yet well characterized. An ongoing characterization of the molecular heterogeneity will help appreciate the biosynthetic capacity of the endocrine heart and could introduce new diagnostic possibilities. Notably, different biosynthetic products may not be equal markers of the same pathophysiological processes. An inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly competent endocrine cells. The structurally related atrial natriuretic peptide will be mentioned where appropriate, whereas C-type natriuretic peptide will not be considered as a cardiac peptide of relevance in mammalian physiology.

Cardiac amyloidosis: approaches to diagnosis and management

Amyloidosis is a clinical disorder caused by the extracellular deposition of misfolded, insoluble aggregated protein with a characteristic ss pleated sheet configuration that produces apple-green birefringence under polarized light when stained with Congo red dye. The spectrum of organ involvement can include the kidneys, heart, blood vessels, central and peripheral nervous systems, liver, intestines, lungs, eyes, skin, and bones. Cardiovascular amyloidosis can be primary, a part of systemic amyloidosis, or the result of chronic systemic disease elsewhere in the body. The most common presentations are congestive heart failure because of restrictive cardiomyopathy and conduction abnormalities. Recent developments in imaging techniques and extracardiac tissue sampling have minimized the need for invasive endomyocardial biopsy for amyloidosis. Cardiac amyloidosis management will vary depending on the subtype but consists of supportive treatment of cardiac related symptoms and reducing the amyloid fibrils formation attacking the underlying disease. Despite advances in treatment, the prognosis for patients with amyloidosis is still poor and depends on the underlying disease type. Early diagnosis of cardiac amyloidosis may improve outcomes but requires heightened suspicion and a systematic clinical approach to evaluation. Delays in diagnosis, uncertainties about the relative merits of available therapies, and difficulties in mounting large-scale clinical trials in rare disorders combine to keep cardiac amyloidosis a challenging problem. This review outlines current approaches to diagnosis, assessment of disease severity, and treatment of cardiac amyloidosis.

Anhedonia and altered cardiac atrial natriuretic peptide following chronic stressor and endotoxin treatment in mice

Chronic stressors and inflammatory immune activation may contribute to pathophysiological alterations associated with both major depression and cardiovascular disease. The present study, conducted in mice, assessed whether a chronic stressor of moderate severity that induced an anhedonic effect, when coupled with a bacterial endotoxin, lipopolysaccharide (LPS), additively or interactively provoked circulating and heart atrial natriuretic peptide (ANP), a potentially useful diagnostic and prognostic tool in cardiac diseases. As well, given the potential role of inflammatory processes in both depression and cardiovascular disease, we assessed pro-inflammatory mRNA expression in heart in response to the stressor and the LPS treatments. Male CD-1 mice that had been exposed to a chronic, variable stressor over 4 weeks displayed reduced sucrose consumption, possibly reflecting the anhedonic effects of the stressor. Treatment with LPS (10mug) provoked increased circulating corticosterone levels in both chronically stressed and non-stressed mice. Moreover, ANP concentrations in plasma and in the left ventricle were increased by both the stressor and the LPS treatments, as were left atrial and ventricular cytokine (interleukin-1beta; tumor necrosis factor-alpha) mRNA expression. Further, these treatments synergistically influenced the rise of plasma ANP. A link may exist between stressor-provoked depressive features (anhedonia) and immune activation, with elevated levels of ANP, a potential marker of cardiovascular disturbance. These findings are consistent with the view that chronic stressors and inflammatory immune activation may represent a common denominator subserving the frequent comorbidity between these illnesses.

Serum levels of NT-proBNP as surrogate for cardiac amyloid burden: new evidence from gadolinium-enhanced cardiac magnetic resonance imaging in patients with amyloidosis

BACKGROUND

The prognostic value of NT-proBNP has been recognized in patients with amyloidosis complicated by cardiac involvement. We aimed to use contrast enhanced cardiac magnetic resonance imaging (CMR) to identify functional and structural alterations related to levels of NT-proBNP better to understand the mechanisms of its release in cardiac amyloidosis.

METHODS AND RESULTS

CMR was performed on a 1.5-T scanner in 34 patients with biopsy proven amyloid light chain (AL; n = 27) or hereditary transthyretin related (TTR; n = 7) amyloidosis. NT-proBNP was higher in patients with (n = 25) compared to patients without cardiac involvement (n = 9) (2931 (IQR: 972-8629; min-max: 25-27,277) pg/ml vs. 177 (IQR: 71-1431; min-max: 22-7935) pg/ml, p = 0.008). ROC analysis identified a NT-proBNP of <2426.5 pg/ml as optimal discriminator for event free survival (682 +/- 65 days). NT-proBNP did not correlate with LV- ejection fraction, end-diastolic and end-systolic volumes or stroke volume. There was a moderate correlation between NT-proBNP and LV-mass (R = 0.52, p = 0.003) and extent of late gadolinium enhancement (LGE; R = 0.41, p = 0.04).

CONCLUSIONS

This study confirms the prognostic value of NT-proBNP in patients with AL and TTR amyloidosis and provides the novel finding that NT-proBNP correlates with surrogates of myocardial amyloid burden such as LV-mass and LGE, supporting the concept of NT-proBNP as a biomarker reflecting the severity of cardiac amyloid infiltration.

B-type natriuretic peptide receptors in hypertrophied adult rat cardiomyocytes

Brain natriuretic peptide (BNP) binds to three types of natriuretic peptide receptors, NPR-A, -B and -C (NPRs). The expression shape of BNP and NPRs seems to be an important modulator factor in the pathogenesis of cardiac hypertrophy. The aim of this study was to evaluate the expression of NPRs in an animal model of pressure overload hypertrophy. Left ventricular hypertrophy was induced by chronic abdominal aortic banding in adult male Wistar rats. After six weeks, NPRs gene expression was evaluated with RT-PCR, BNP plasma concentration and BNP positive myocytes were measured with ELISA and immunohistochemistry techniques respectively. NPR-A and NPR-C mRNA expression was significantly increased in left ventricular hypertrophied cardiomyocytes by 1.6-fold and 2.1-fold respectively (P<0.01). Abdominal aortic banding increased significantly BNP plasma concentration (630+/-8pg/ml vs 106+/-4pg/ml; P<0.01). The percentage of BNP positive cells in normal myocardial tissue were 40% while in the hypertrophied one it raised to 80%. The data suggest that in our left ventricular hypertrophy model, the NPR-A and NPR-C receptors were increased in association to the increased BNP level. This relationship may amplify beneficial paracrine/autocrine effects of BNP on cardiac remodelling in response to hemodynamic overload.

Gene expression of natriuretic peptides and their receptors type-A and-C after myocardial infarction in rats

The purpose of this study was to investigate myocardial mRNA expression of brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) in different regions of the heart at three different time points after induction of myocardial infarction (MI) in rats. Furthermore, we examined putative changes in mRNA expression of natriuretic peptide receptors (NPRs), NPR-A and NPR-C, in myocardium and peripheral organs. Substantial increase in the mRNA levels of both BNP and ANP in the infarcted as well as non-infarcted regions were observed after induction of MI. These findings were paralleled by elevated circulating concentrations of ANP, BNP and N-terminal proANP (Nt-proANP). In addition, the mRNA levels of the clearance receptor, NPR-C, were augmented in the infarcted and non-infarcted regions of the left ventricular wall (LV), while it was decreased in the kidneys and lungs 28 days post-MI. Based on these data, we propose that, in addition to increased myocardial secretion of BNP and ANP, reduced peripheral clearance by NPR-C may contribute to the observed increase in circulating plasma concentrations of the natriuretic peptides after induction of MI in rats.

ProBNP‐derived peptides in cardiac disease

The natriuretic peptides constitute a family of structurally related peptides that regulate fluid homeostasis, vascular tonus and growth. After the discovery of an endocrine component of the heart almost 25 years ago, the cardiac natriuretic peptides have now been fully accepted as useful markers in diverse aspects of cardiology including as diagnostic, therapeutic and prognostic markers of cardiac disease. In humans, atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are mainly synthesized and secreted by the failing heart, whereas the related C-type natriuretic peptide (CNP) appears to be a local regulatory peptide secreted by the vascular endothelium. Accordingly, CNP is not a cardiac peptide. With the recent implementation of sensitive and specific immunoassays, increased plasma concentrations of proBNP-derived peptides have now been associated with several cardiac conditions, where the major application today seems related to ventricular dysfunction. Recently, focus has also turned to ischemic heart disease, since myocardial hypoxia increases the local BNP gene expression. This review recapitulates the established clinical applications of measuring proBNP-derived peptides in plasma. Furthermore, the evidence of increased cardiac BNP expression in ischemic heart disease will be emphasized. In turn, plasma measurement of proBNP-derived peptides may still hold new possibilities in screening for coronary artery disease.

Matrix metalloproteinases and their tissue inhibitors in cardiac amyloidosis: relationship to structural, functional myocardial changes and to light chain amyloid deposition

BACKGROUND

Cardiac amyloidosis is characterized by amyloid infiltration resulting in extracellular matrix disruption. Amyloid cardiomyopathy due to immunoglobulin light chain protein (AL-CMP) deposition has an accelerated clinical course and a worse prognosis compared with non-light chain cardiac amyloidoses (ie, forms associated with wild-type or mutated transthyretin [TTR]). We therefore tested the hypothesis that determinants of proteolytic activity of the extracellular matrix, the matrix metalloproteinases (MMPs), and their tissue inhibitors (TIMPs) would have distinct patterns and contribute to the pathogenesis of AL-CMP versus TTR-related amyloidosis.

METHODS AND RESULTS

We studied 40 patients with systemic amyloidosis: 10 AL-CMP patients, 20 patients with TTR-associated forms of cardiac amyloidosis, ie, senile systemic amyloidosis (involving wild-type TTR) or mutant TTR, and 10 patients with AL amyloidosis without cardiac involvement. Serum MMP-2 and -9, TIMP-1, -2, and -4, brain natriuretic peptide values, and echocardiography were determined. AL-CMP and TTR-related amyloidosis groups had similar degrees of increased left ventricular wall thickness. However, brain natriuretic peptide, MMP-9, and TIMP-1 levels were distinctly elevated accompanied by marked diastolic dysfunction in the AL-CMP group versus no or minimal increases in the TTR-related amyloidosis group. Brain natriuretic peptide, MMPs, and TIMPs were not correlated with the degree of left ventricular wall thickness but were correlated to each other and to measures of diastolic dysfunction. Immunostaining of human endomyocardial biopsies showed diffuse expression of MMP-9 and TIMP-1 in AL-CMP and limited expression in TTR-related amyloidosis hearts.

CONCLUSIONS

Despite comparable left ventricular wall thickness with TTR-related cardiac amyloidosis, AL-CMP patients have higher brain natriuretic peptide, MMPs, and TIMPs, which correlated with diastolic dysfunction. These findings suggest a relationship between light chains and extracellular matrix proteolytic activation that may play an important role in the functional and clinical manifestations of AL-CMP, distinct from the other non-light chain cardiac amyloidoses.

Diagnostic and prognostic impact of brain natriuretic peptide in cardiac and noncardiac diseases

OBJECTIVE

Cardiac secretion of brain natriuretic peptide (BNP) increases with the progression of congestive heart failure (CHF). The plasma measurement of BNP emerged recently as a useful, cost-effective biomarker for the diagnosis and prognosis of CHF.

METHODS

BNP assay is useful for evaluating patients with acute dyspnea, because a low level can help rule out CHF in primary care settings and reduce the demand for echocardiography. Equally, BNP level can be particularly useful in recognizing heart failure in a patient with acute dyspnea and a history of chronic obstructive pulmonary disease.

RESULTS

However, although the clinical use of BNP as a biomarker in CHF is increasing, the specificity of BNP in CHF is not strong, suggesting that other mechanisms beyond simple ventricular stretch stimulate BNP release. Multiple disorders in the intensive care unit, apart from CHF, cause elevated BNP levels, including cardiovascular disease states such as ischemia, arrhythmias, cardiac hypertrophy, and coronary endothelial dysfunction, as well as disorders of no cardiac origin, such as sepsis, septic shock, and acute respiratory distress syndrome. Moreover, the impact of increased BNP in patients with sepsis is not clear. The relationship between BNP and both left ventricular ejection fraction and left-sided filling pressures is weak, and data on the prognostic impact of high BNP levels in patients with sepsis are conflicting.

CONCLUSION

Nevertheless, this review highlights the potential benefits of BNP in the recognition and management of heart failure, and defines the gray zones of BNP levels; it also identifies conditions influencing BNP levels in relation to a certain heart failure and describes conditions of no cardiac origin with increased BNP.

Evaluation of myocardial changes in familial amyloid polyneuropathy after liver transplantation

OBJECTIVE

The progression of cardiac amyloidosis is a prognostic factor after liver transplantation (LT) in familial amyloid polyneuropathy (FAP). The aim of this study was to assess myocardial changes in FAP amyloidgenic transthyretin (ATTR) Val30Met after LT.

PATIENTS AND METHODS

Twelve Japanese FAP ATTR Val30Met patients who underwent LT and were followed for more than 2 years, were examined with serial echocardiography after LT. Serum BNP levels were measured in 9 patients.

RESULTS

A significant increase in mean left atrial diameter and interventricular septal thickness was observed after LT. The increase in left atrial diameter was correlated with the presence of granular sparkling echo (GSE) at preoperative examination. Serum brain natriuretic peptide (BNP) levels in patients with left atrial diameter dilation (152.0+/-157.6 pg/mL) were higher than in those without left atrial diameter dilation (32.0+/-30.0 pg/mL).

CONCLUSION

LAD and IVS were significantly increased after LT compared with preoperative examinations in Japanese FAP ATTR Val30Met patients. BNP is an important biochemical indicator of myocardiac dysfunction in FAP patients. GSE is a useful echocardiographic marker to predict cardiac amyloidosis after LT.

Evaluation and management of the cardiac amyloidosis

Cardiac amyloidosis describes clinically significant involvement of the heart by amyloid deposition, which may or may not be associated with involvement of other organs. The purpose of this review is to summarize the current state of evidence for the effective evaluation and management of cardiac amyloidosis. Acquired systemic amyloidosis occurs in more than 10 per million person-years in the U.S. population. Although no single noninvasive test or abnormality is pathognomonic of cardiac amyloid, case-control studies indicate that echocardiographic evidence of left ventricular wall thickening, biatrial enlargement, and increased echogenicity in conjunction with reduced electrocardiographic voltages is strongly suggestive of cardiac amyloidosis. Furthermore, newer echocardiographic techniques such as strain and strain rate imaging can demonstrate impairment in longitudinal function before ejection fraction becomes abnormal. Recent observational studies also suggest that cardiovascular magnetic resonance imaging yields characteristic findings in amyloidosis, offering promise for the early detection of cardiac involvement, and the presence of detectable cardiac troponin and elevated B-type natriuretic peptide in serum of affected patients portends an adverse prognosis. Management strategies for cardiac amyloid are largely based on nonrandomized single-center studies. One of the few published randomized studies shows the superiority of oral prednisolone and melphalan compared with colchicine in systemic AL amyloidosis. Intermediate-dose infusional chemotherapy regimes (such as vincristine, adriamycin, and dexamethasone) and high-dose chemotherapy with peripheral stem cell rescue have been used widely, but treatment-related mortality remains substantial with chemotherapy. Recent studies also indicate promising strategies to stabilize the native structures of amyloidogenic proteins; inhibit fibril formation; and disrupt established deposits using antibodies, synthetic peptides, and small-molecule drugs.

Percutaneous Coronary Revascularization Reduces Plasma N-Terminal Pro-B-Type Natriuretic Peptide Concentration in Stable Coronary Artery Disease

OBJECTIVES

The purpose of this work was to assess the effect of percutaneous coronary revascularization (PCR) on plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration.

BACKGROUND

Left ventricular (LV) dysfunction is associated with increased plasma natriuretic peptide concentrations. The effect of ischemia resolution on plasma natriuretic peptide is not known.

METHODS

Twenty-six patients with stable angina, normal LV systolic function, and isolated stenoses of the left anterior descending (LAD) coronary artery were studied. All patients had angiographically and physiologically significant lesions defined by cine-angiography and intracoronary pressure wire.

RESULTS

After revascularization, 24 patients demonstrated significant decrease in mean plasma NT-proBNP 8 weeks after PCR (from 177.2 +/- 190.8 pg/ml to 105.0 +/- 92.4 pg/ml, p = 0.03). The mean decrease in log NT-proBNP was 0.533, corresponding to geometric mean decrease of NT-proBNP by a factor of 59% (95% confidence interval 48.2% to 71.4%, p < 0.00005). Reduction in NT-proBNP was independent of change in LV systolic function.

CONCLUSIONS

This study demonstrates that removal of fixed LAD stenosis reduces plasma NT-proBNP concentration. This has implications for interpretation of natriuretic peptide levels in clinical settings and as screening tool for LV systolic dysfunction.

Increased Brain Natriuretic Peptide Secretion is a Marker of Disease Progression in Nonobstructive Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is associated with increased plasma brain natriuretic peptide (BNP), but sequential plasma and myocardial BNP assessment in stable and dilated HCM has never been performed.

METHODS AND RESULTS

Forty consecutive HCM patients (42 +/- 8 years, 25 males) underwent cardiac catheterization, angiography, and left ventricular (LV) endomyocardial biopsy. During follow-up (70.5 +/- 6.7 months), 30 patients (Group 1) remained stable whereas 10 patients (Group 2) progressed to dilated phase. Group 2 patients underwent a second invasive study with LV biopsy. BNP plasma levels were measured at baseline and at follow-up in all patients. All biopsies were processed for histology and immunohistochemistry with anti-BNP antibodies. BNP plasma levels remained unchanged in Group 1, whereas it significantly increased in all Group 2 patients who exhibited an elevation of LV and right ventricular end-diastolic pressure. Immunohistochemistry showed an increase of BNP-positive myocytes in follow-up biopsies when compared with baseline (75.0 +/- 15.0 % versus 29.8 +/- 10.0 %; P = .005) with a significant correlation with LV end-diastolic pressure (r = 0.78, P < .001) and plasma BNP (r = 0.83, P < .001).

CONCLUSIONS

Progression to end-stage of HCM is characterized by further increase of myocardial and plasma BNP. Serial assessment of plasma BNP may provide noninvasive recognition of hemodynamic deterioration, allowing prompt institution of heart failure therapy.