Left heart disease: a frequent cause of early pulmonary hypertension in systemic sclerosis, unrelated to elevated NT-proBNP levels or overt cardiac fibrosis but associated with increased levels of MR-proANP and MR-proADM: retrospective analysis of a French Canadian cohort

Serum Biomarkers in Connective Tissue Disease-Associated Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening complication of connective tissue diseases (CTDs) characterised by increased pulmonary arterial pressure and pulmonary vascular resistance. CTD-PAH is the result of a complex interplay among endothelial dysfunction and vascular remodelling, autoimmunity and inflammatory changes, ultimately leading to right heart dysfunction and failure. Due to the non-specific nature of the early symptoms and the lack of consensus on screening strategies-except for systemic sclerosis, with a yearly transthoracic echocardiography as recommended-CTD-PAH is often diagnosed at an advanced stage, when the pulmonary vessels are irreversibly damaged. According to the current guidelines, right heart catheterisation is the gold standard for the diagnosis of PAH; however, this technique is invasive, and may not be available in non-referral centres. Hence, there is a need for non-invasive tools to improve the early diagnosis and disease monitoring of CTD-PAH. Novel serum biomarkers may be an effective solution to this issue, as their detection is non-invasive, has a low cost and is reproducible. Our review aims to describe some of the most promising circulating biomarkers of CTD-PAH, classified according to their role in the pathophysiology of the disease.

Prognostic value of right atrial dilation in patients with pulmonary embolism

Aims

Right atrial (RA) dilation and stretch provide prognostic information in patients with cardiovascular diseases. We investigated the prevalence, confounding factors and prognostic relevance of RA dilation in patients with pulmonary embolism (PE).

Methods

Overall, 609 PE patients were consecutively included in a prospective single-centre registry between September 2008 and August 2017. Volumetric measurements of heart chambers were performed on routine non-electrocardiographic-gated computed tomography and plasma concentrations of mid-regional pro-atrial natriuretic peptide (MR-proANP) measured on admission. An in-hospital adverse outcome was defined as PE-related death, cardiopulmonary resuscitation, mechanical ventilation or catecholamine administration.

Results

Patients with an adverse outcome (11.2%) had larger RA volumes (median 120 (interquartile range 84-152) versus 102 (78-134) mL; p=0.013), RA/left atrial (LA) volume ratios (1.7 (1.2-2.4) versus 1.3 (1.1-1.7); p<0.001) and MR-proANP levels (282 (157-481) versus 129 (64-238) pmol·L^-1; p<0.001) compared to patients with a favourable outcome. Overall, 499 patients (81.9%) had a RA/LA volume ratio ≥1.0 and a calculated cut-off value of 1.8 (area under the curve 0.64, 95% CI 0.56-0.71) predicted an adverse outcome, both in unselected (OR 3.1, 95% CI 1.9-5.2) and normotensive patients (OR 2.7, 95% CI 1.3-5.6). MR-proANP ≥120 pmol·L^-1 was identified as an independent predictor of an adverse outcome, both in unselected (OR 4.6, 95% CI 2.3-9.3) and normotensive patients (OR 5.1, 95% CI 1.5-17.6).

Conclusions

RA dilation is a frequent finding in patients with PE. However, the prognostic performance of RA dilation appears inferior compared to established risk stratification markers. MR-proANP predicted an in-hospital adverse outcome, both in unselected and normotensive PE patients, integrating different prognostic relevant information from comorbidities.

Current Understanding of Circulating Biomarkers in Pulmonary Hypertension Due to Left Heart Disease

Pulmonary hypertension due to left heart disease (PH-LHD; Group 2), especially in the setting of heart failure with preserved ejection fraction (HFpEF), is the most frequent cause of PH. Despite its prevalence, no effective therapies for PH-LHD are available at present. This is largely due to the lack of a concise definition for hemodynamic phenotyping, existence of significant gaps in the understanding of the underlying pathology and the impact of associated comorbidities, as well as the absence of specific biomarkers that can aid in the early diagnosis and management of this challenging syndrome. Currently, B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are guideline-recommended biomarkers for the diagnosis and prognosis of heart failure (HF) and PH. Endothelin-1 (ET-1), vascular endothelial growth factor-D (VEGF-D), and microRNA-206 have also been recently identified as new potential circulating biomarkers for patients with PH-LHD. In this review, we aim to present the current state of knowledge of circulating biomarkers that can be used to guide future research toward diagnosis, refine specific patient phenotype, and develop therapeutic approaches for PH-LHD, with a particular focus on PH-HFpEF. Potential circulating biomarkers identified in pre-clinical models of PH-LHD are also summarized here.

Biomarkers for Pulmonary Vascular Remodeling in Systemic Sclerosis: A Pathophysiological Approach

Pulmonary arterial hypertension (PAH) is a severe complication of systemic sclerosis (SSc) associated with high morbidity and mortality. There are several biomarkers of SSc-PAH, reflecting endothelial physiology, inflammation, immune activation, extracellular matrix, metabolic changes, or cardiac involvement. Biomarkers associated with diagnosis, disease severity and progression have been identified, however, very few have been tested in a prospective setting. Some antinuclear antibodies such as nucleosome antibodies (NUC), anti-centromere antibodies (CENP-A/B) and anti-U3-ribonucleoprotein (anti-U3-RNP) are associated with PAH while anti-U1-ribonucleoprotein (anti-U1-RNP) is associated with a reduced PAH risk. Anti-endothelin receptor and angiotensin-1 receptor antibodies might be good markers of SSc-PAH and progression of pulmonary vasculopathy. Regarding the markers reflecting immune activation and inflammation, there are many inconsistent results. CXCL-4 was associated with SSc progression including PAH and lung fibrosis. Growth differentiation factor (GDF)-15 was associated with PAH and mortality but is not specific for SSc. Among the metabolites, kynurenine was identified as diagnostic marker for PAH, however, its pathologic role in the disease is unclear. Endostatin, an angiostatic factor, was associated with heart failure and poor prognosis. Established heart related markers, such as N-terminal fragment of A-type natriuretic peptide/brain natriuretic peptide (NT-proANP, NT-proBNP) or troponin I/T are elevated in SSc-PAH but are not specific for the right ventricle and may be increased to the same extent in left heart disease. Taken together, there is no universal specific biomarker for SSc-PAH, however, there is a pattern of markers that is strongly associated with a risk of vascular complications in SSc patients. Further comprehensive, multicenter and prospective studies are warranted to develop reliable algorithms for detection and prognosis of SSc-PAH.

Left ventricular diastolic dysfunction and increased left ventricular mass index related to pulmonary hypertension in patients with systemic autoimmune disease without pericardial effusion

PURPOSE

We investigated the relationship of left ventricular (LV) diastolic dysfunction and LV mass index (LVMI) against pulmonary hypertension (PH) in systemic autoimmune disease (SAD).

METHODS

A total of 84 SAD patients (68 females; 53±17years; systemic lupus erythematosus, 27%; scleroderma, 17%; vasculitis, 16%; mixed connective tissue disease, 13% and polymyositis/dermatomyositis complex, 10%) without significant pericardial effusion (PE) on TTE (Vivid E9, GE) were analyzed. On TTE, PH was defined as peak tricuspid regurgitation velocity (TRV) of ≥2.9m/s based upon 2015 ESC guideline. Left atrial volume index (LAVI) and E/E' were measured as indicators of LV diastolic dysfunction. LVMI was also measured.

RESULTS

Seven patients (8%) had PH. PH patients had greater LAVI (p<0.001), E/E' (p=0.004), LVMI (p=0.009) than non-PH patients. LAVI (R=0.458), E/E' (R=0.337), and LVMI (R=0.313) significantly and positively correlated with TRV (all p<0.05). Multiple regression analysis was performed to explore determinants of TRV. Age, female sex, and brain natriuretic peptide (BNP) were included in all the models. Three multiple regression models were generated using 1) LAVI, 2) E/E', and 3) LVMI and included LAVI, E/E', LVMI, and BNP as significant variables influencing TRV. Multi logistic regression analysis for predicting TRV of ≥2.9m/s showed that LAVI, and E/E' were significant predictors (Odds ratio, 1.296, and 1.370, respectively).

CONCLUSION

In SAD patients without PE, LV diastolic dysfunction and increment of LVMI was closely associated with PH based upon TRV. LAVI and E/E' were independent predictors for PH. Measuring LAVI and E/E' may be a key to determine the mechanism of PH in these patients.

Risk factors for severity and manifestations in systemic sclerosis and prediction of disease course

Systemic sclerosis (SSc, or scleroderma) is a rheumatic disease with distinct features that encompass autoimmunity, vascular lesions (vasculopathy) and tissue fibrosis. The disease has a high morbidity and mortality compared with other rheumatic diseases. This review discusses risk factors and markers that predict the disease course and the occurrence of disease manifestations, with an emphasis on major organ involvement. In addition, risk factors will be described that are associated with mortality in SSc patients. The review addresses the impact of recent developments on screening, diagnosis and risk stratification as well as the need for further research where data are lacking.

Ultrasound signs of pulmonary fibrosis in systemic sclerosis as timely indicators for chest computed tomography

OBJECTIVES

Systemic sclerosis (SSc) patients in the early stages of pulmonary fibrosis (PF) often have few or no symptoms, normal to borderline pulmonary function tests, and negative chest X-ray (CXR); high-resolution computed tomography (HRCT) is the only reliable means of detecting the early signs of PF. However, thoracic ultrasound (TUS) enables detection of pleural thickening, pleural/subpleural nodules, and other subpleural lung abnormalities across 70% of the subpleural surface. We reassessed concordance between TUS abnormalities and HRCT findings in SSc patients, to see whether TUS pleural line thickness (normally <3.0 mm) could be used to earmark those with asymptomatic PF for timely HRCT assessment.

METHOD

In total, 175 SSc patients (nine males, 166 females), aged 46.46±15.33 years, were given CXR, TUS, HRCT, echocardiography, and pulmonary function tests.

RESULTS

In the 26 patients without HRCT signs of PF, pleural line thickness was ≤3.0 mm. In diffuse SSc, 97/137 patients showed pleural line thickening (between 3.0 and 5 mm) and subpleural nodules in 32/97; and 35/137 showed major pleural line thickening (≥5.0 mm) with nodules, with good concordance with HRCT patterns indicating lung fibrosis severity. HRCT was normal in 5/137, with pleural line thickness≤3.0 mm.

CONCLUSIONS

TUS imaging of pleural/subpleural structures can detect ultrasonographic signs of initial PF prior to the onset of respiratory symptoms and function test abnormalities and, together with current criteria, could thereby enable exclusion of PF in SSc patients. Indicating some patients for selective referral to HRCT can thereby delay unwarranted procedures, provided that pulmonary function and TUS images are stable.

Management of connective tissue disease-associated interstitial lung disease

A thorough, often multidisciplinary assessment to determine extrathoracic versus intrathoracic disease activity and degrees of impairment is needed to optimize the management of connective tissue disease (CTD)-associated interstitial lung disease (ILD). Pharmacologic intervention with immunosuppression is the mainstay of therapy for all forms of CTD-ILD, but should be reserved for those that show clinically significant and/or progressive disease. The management of CTD-ILD is not yet evidence based and there is a need for controlled trials across the spectrum of CTD-ILD. Nonpharmacologic management strategies and addressing comorbidities or aggravating factors should be included in the comprehensive treatment plan for CTD-ILD.