N-terminal pro-BNP in sclerodermic patients on bosentan therapy for PAH

Systemic sclerosis-associated pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is the leading cause of death in systemic sclerosis (SSc) and affects up to 12% of all patients with SSc, with a 50% mortality rate within 3 years of PAH diagnosis. Compared with the idiopathic form of PAH (IPAH), patients with SSc-associated PAH (SSc-PAH) have a threefold increased risk of death and may receive a diagnosis late in the course of disease because of insidious onset and the high prevalence of cardiac, musculoskeletal, and pulmonary parenchymal comorbidities. Treatment with conventional forms of PAH therapy often yield poor results compared with IPAH cohorts; unfortunately, the exact reasons behind this remain poorly understood but likely include variations in the pathologic mechanisms, differences in cardiovascular response to increasing afterload, and inadequate strategies to detect and treat SSc-PAH early in its course. Current methods for screening and longitudinal evaluation of SSc-PAH, such as the 6-min walk test, transthoracic echocardiography, and MRI, each have notable advantages and disadvantages. We provide an up-to-date, focused review of SSc-PAH and how it differs from IPAH, including pathogenesis, appropriate screening for disease onset, and new approaches to treatment and longitudinal assessment of this disease.

N-TproBNP as biomarker in systemic sclerosis

Systemic sclerosis (SSc) is a connective tissue disorder characterized by tissue fibrosis affecting the skin and internal organs, fibroproliferative vasculopathy, and autoimmune activation. SSc still heralds a poor prognosis with significant morbidity and mortality. Early detection of organ involvement is critical as currently available treatments are most effective when started early. Many candidate biomarkers have been investigated in the past two decades. However, despite the enormous efforts, no accurate tool to predict the pattern of organ involvement and to assess disease activity has been yet identified. The N-terminal fragment of probrain natriuretic peptide (N-TproBNP) is a neurohormone released by ventricular myocytes in response to pressure overload. N-TproBNP is highly relevant for diagnosis, prognosis, and prediction of pulmonary arterial hypertension in SSc. Moreover, several studies support its potential benefit for cardiac assessment of scleroderma patients. Conversely, the role of N-TproBNP as surrogate marker of pulmonary fibrosis and skin involvement is much less clear. We provide an extensive review of the studies that have previously investigated the role of N-TproBNP as candidate biomarker in scleroderma manifestations, presenting also the findings of a recent study we conducted in a cohort of 87 SSc patients.

B-type natriuretic peptide in rheumatic diseases: a cardiac biomarker or a sophisticated acute phase reactant?

Natriuretic peptides (NP) are secreted by cardiomyocytes and are reliable markers of cardiac dysfunction and cardiovascular risk by reflecting myocardial stress due to various etiologies. Clinical and occult heart involvement is frequently observed in patients with rheumatic diseases and is associated with increased morbidity and mortality. Cardiac disease in autoimmune disorders encompasses different pathophysiological mechanisms including inflammation and involving either the myocardium or the coronary/pulmonary vessels. Although the major trigger for the synthesis and release of NP is myocardial strain, there is also some support for the concept that inflammation stimulates the neurohormonal system of the heart leading to increased production of NP. Recent studies have focused on the association of NP and inflammation in the context of rheumatic diseases, suggesting that up-regulation of neurohormonal axis in these conditions is linked with inflammation. Additionally the NP have a well-documented role in the diagnostic work-up of patients with connective tissue disease who are at increased risk of developing pulmonary hypertension, as the right ventricular overload results in increased NP synthesis and release. However the precise role of NP in the assessment and the management of cardiovascular risk in patients with rheumatic diseases is yet to be established. In the current article we discuss the pathophysiologic mechanisms involved in enhanced NP expression in patients with rheumatic disorders and their potential clinical implication in daily practice.

Left atrial volume and N-terminal pro-B type natriuretic peptide are associated with elevated pulmonary artery pressure in patients with systemic sclerosis

Early detection of pulmonary hypertension (PH) in patients with systemic sclerosis (SSc) is essential as it leads to substantial morbidity and mortality irrespective of its etiology. The aim of our study was to determine whether noninvasive biochemical and/or echocardiographic indices can predict the presence of PH in these patients. We prospectively studied 66 patients (mean age of 57.7 +/- 12.1 years, 63 women) with SSc without clinical manifestations of heart failure. All patients underwent standard and tissue Doppler echocardiography. Plasma N-terminal pro-B type natriuretic peptide (NT-proBNP) and asymmetric dimethylarginine (ADMA) levels were also measured. In 24 (36%) patients, the diagnosis of PH was established by echocardiography (systolic pulmonary artery pressure value > or =40 mmHg). Left atrial (LA) volume, NT-proBNP, ADMA, ratio of early transmitral filling velocity to early diastolic velocity of the mitral annulus (mitral E/E (m)), and right ventricular myocardial performance index (MPI) were univariate predictors of PH. In multivariate analysis, NT-proBNP, LA volume, and right ventricular MPI were independent predictors of PH in SSc patients. LA volume and NT-proBNP may be useful noninvasive markers for the prediction of elevated pulmonary artery pressure in patients with SSc. These parameters should be considered when assessing this population for risk stratification and for identification of patients demanding further investigation and institution of specific therapy for the disease at the time when it is most likely to be effective.

Biomarkers in systemic sclerosis

Systemic sclerosis is an autoimmune inflammatory disorder of unknown etiologycharacterized b y pronounced fibroproliferative alterations in the microvasculature, and frequent cellular and humoral immunity abnormalities, culminating in a severe and often progressive fibrotic process. Numerous biomarkers reflecting the three main pathogenetic mechanisms in systemic sclerosis have been described; however, aside from several disease-specific autoantibodies, other biomarkers have not been thoroughly validated and require further study. Thus, there is an unmet need for validated biomarkers for diagnosis, disease classification, and evaluation of organ involvement and therapeutic response in systemic sclerosis.