Stress Doppler echocardiography in systemic sclerosis: evidence for a role in the prediction of pulmonary hypertension

Use of exercise tests in screening for pulmonary arterial hypertension in systemic sclerosis: A systematic literature review

Background and objective

Patients with systemic sclerosis (SSc) and pulmonary arterial hypertension (PAH) have a poor prognosis, accounting for 30% of all SSc-related deaths. Guidelines recommend annual screening for PAH regardless of symptoms, as early treatment improves outcomes. Current protocols include combinations of clinical features, biomarkers, pulmonary function tests, and echocardiography. None include exercise testing, although early-stage PAH may only be evident during exercise. This systematic review assessed the performance of exercise tests in predicting the presence of PAH in patients with SSc, where PAH was confirmed through right heart catheterisation (RHC).

Methods

Comprehensive literature searches were performed using MEDLINE, EMBASE, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trails, CINAHL, Scopus and Web of Science from inception to May 2023. Articles were screened for eligibility by two independent reviewers. Eligibility criteria included the use of a non-invasive exercise test to screen adult patients to detect PAH in a population without a previous diagnosis of PAH, with diagnosis confirmed by RHC.

Results

Eight studies met the inclusion criteria, describing at least one of three different non-invasive exercise tests: cardiopulmonary exercise test, six-minute walk test and stress Doppler echocardiography. All studies found that exercise tests had some ability to predict the presence of PAH, with sensitivity between 50% and 100% and specificity from 73% to 91%.

Conclusion

Exercise tests are infrequently used for screening for PAH in SSc but can predict the presence of PAH. More data are required to establish which tests are most effective.

Right Ventricle and Autoimmune Diseases

Autoimmune diseases can express pathologies in specific organs (e.g. thyroid, pancreas, skin) or generate systemic pathologies (generalized lupus erythematosus, rheumatoid arthritis, systemic sclerosis), the latter usually present systemic inflammatory phenomena. Some studies have reported alterations in right ventricular contractility in patients with rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, and juvenile idiopathic arthritis, which may contribute to the known outcome of increased cardiovascular risk. However, there is not much information available on the causes that generate these alterations, the most likely being small vessel damage and fibrosis due to subclinical inflammation.1-5 In this sense, the disease in which the alterations of the right ventricle have been more studied is systemic sclerosis, specifically at the changes induced due to pulmonary arterial hypertension, this being one of the main causes of death in this group of patients after the significant decrease in mortality associated with the sclerodermic renal crisis with the treatment of angiotensin-converting enzyme inhibitors. In this review, we will focus on explaining the structural and functional changes that occur in the right ventricle of patients with systemic sclerosis, from early alterations to late complications. In this context, it is necessary to distinguish between right heart alterations that occur in patients with systemic sclerosis and pulmonary arterial hypertension and those that occur without pulmonary arterial hypertension and that can be attributed to other causes such as microvascular damage or myocardial fibrosis.

Understanding and managing cardiac involvement in systemic sclerosis

INTRODUCTION

Cardiac involvement is common in systemic sclerosis occurring in up to 80% of patients. Primary myocardial dysfunction results from impairment of coronary microvascular circulation, myocardial inflammation and fibrosis with the prevalence of atherosclerosis remaining contradictory.

AREAS COVERED

This review presents the various aspects of cardiac involvement in SSc from a pathophysiological, clinical, diagnostic and therapeutic standpoint. Imaging modalities with emerging role in the understanding of mechanisms and prompt diagnosis of myocardial fibrosis namely cardiac magnetic resonance are also discussed.

EXPERT OPINION

Cardiac involvement in SSc - and particularly primary myocardial disease - remains a challenge as clinical symptoms manifest in advanced stages of heart failure and convey poor prognosis. Over the last years the introduction of sophisticated imaging methods of myocardial function has resulted in a better understanding of the underlying pathophysiological processes of myocardial damage such as microvasculopathy, inflammation, diffuse or focal fibrosis. Such developments could contribute to the identification of patients at higher risk for subclinical heart involvement for whom diligent surveillance and prompt initiation of therapy with cardioprotective and/or immunosuppressive drugs coupled with invasive interventions namely radiofrequency ablation, implantable cardioverter-defibrillator when indicated, may improve long-term outcomes.

Exercise-Induced Pulmonary Hypertension: A Valid Entity or Another Factor of Confusion?

Exercise-induced pulmonary hypertension EIPH has been defined as an increase in mean pulmonary arterial pressure (mPAP) during exercise in otherwise normal values at rest. EIPH reflects heart and/or lung dysfunction and may precede the development of manifest pulmonary hypertension (PH) in a proportion of patients. It is also associated with decreased life expectancy in patients with heart failure with reduced ejection fraction (HFrEF) or left ventricle (LV) valvular diseases. Diastolic dysfunction exacerbated during exercise relates to increased LV filling pressure and left atrial pressure (LAP). In this context backward, transmitted pressure alone or accompanied with backward blood flow promotes EIPH. The gold standard of EIPH assessment remains the right heart catheterization during exercise, which is an accurate but invasive method. Alternatively, non-invasive diagnostic modalities include exercise stress echocardiography (ESE) and cardiopulmonary exercise testing (CPET). Both diagnostic tests are performed under gradually increasing physical stress using treadmill and ergo-cycling protocols. Escalating workload during the exercise is analogous to the physiological response to real exercise. The results of the latter techniques show good correlation with invasive measurements, but they suffer from lack of validation and cut-off value determination. Although it is not officially recommended, there are accumulated data supporting the importance of EIPH diagnosis in the assessment of other mild/subclinical or probably fatal diseases in patients with latent PH or heart failure or LV valvular disease, respectively. Nevertheless, larger, prospective studies are required to ensure its role in clinical practice.

Deep Learning for Detection of Exercise-Induced Pulmonary Hypertension Using Chest X-Ray Images

Background

Stress echocardiography is an emerging tool used to detect exercise-induced pulmonary hypertension (EIPH). However, facilities that can perform stress echocardiography are limited by issues such as cost and equipment.

Objective

We evaluated the usefulness of a deep learning (DL) approach based on a chest X-ray (CXR) to predict EIPH in 6-min walk stress echocardiography.

Methods

The study enrolled 142 patients with scleroderma or mixed connective tissue disease with scleroderma features who performed a 6-min walk stress echocardiographic test. EIPH was defined by abnormal cardiac output (CO) responses that involved an increase in mean pulmonary artery pressure (mPAP). We used the previously developed AI model to predict PH and calculated PH probability in this cohort.

Results

EIPH defined as ΔmPAP/ΔCO >3.3 and exercise mPAP >25 mmHg was observed in 52 patients, while non-EIPH was observed in 90 patients. The patients with EIPH had a higher mPAP at rest than those without EIPH. The probability of PH based on the DL model was significantly higher in patients with EIPH than in those without EIPH. Multivariate analysis showed that gender, mean PAP at rest, and the probability of PH based on the DL model were independent predictors of EIPH. A model based on baseline parameters (age, gender, and mPAP at rest) was improved by adding the probability of PH predicted by the DL model (AUC: from 0.65 to 0.74; p = 0.046).

Conclusion

Applying the DL model based on a CXR may have a potential for detection of EIPH in the clinical setting.

Exercise Pulmonary Resistances Predict Long-Term Survival in Systemic Sclerosis

BACKGROUND

Pulmonary hemodynamics during exercise may reveal early pulmonary vascular disease and may be of clinical and prognostic relevance in systemic sclerosis (SSc). We aimed to assess the prognostic relevance of exercise pulmonary resistances in patients with SSc with no or mildly increased mean pulmonary arterial pressure (mPAP).

RESEARCH QUESTION

Are pulmonary resistances at peak exercise independent predictors of mortality in systemic sclerosis?

STUDY DESIGN AND METHODS

All SSc patients with resting mPAP < 25 mm Hg and at least one year of follow-up data who underwent symptom-limited exercise right heart catheterization between April 2005 and December 2018 were analyzed retrospectively. Age-adjusted Cox regression analysis was used to evaluate the association between pulmonary resistances and all-cause mortality.

RESULTS

The cohort consisted of 80 patients: 73 women and 7 men with a mean age of 57 years (interquartile range [IQR], 47-67 years) and a mean follow-up time of 10.4 years (IQR, 8.5-11.8 years). At baseline, resting mPAP of ≤ 20 mm Hg and 21 to 24 mm Hg was found in 68 and 12 patients, respectively. Pulmonary vascular resistance (PVR) and total pulmonary resistance (TPR) at peak exercise were associated significantly with mortality (P = .006 [hazard ratio (HR), 2.20; 95% CI, 1.26-3.87] and P = .026 [HR, 1.56; 95% CI, 1.06-2.29]), whereas resting PVR and TPR were not (P = .087 [HR, 2.27; 95% CI, 0.89-5.83] and P = .079 [HR, 1.88; 95% CI, 0.93-3.80]). The mPAP per cardiac output (CO) and transpulmonary gradient (TPG) per CO slopes were associated significantly with mortality (P = .047 [HR, 1.14; 95% CI, 1.002-1.286] and P = .034 [HR, 1.34; 95% CI, 1.02-1.76]) as well. The area under the receiver operating characteristic curve for exercise PVR to predict 10-year mortality was 0.917 (95% CI, 0.797-1.000).

INTERPRETATION

PVR and TPR at peak exercise, mPAP/CO slope, and TPG/CO slope are predictors of age-adjusted long-term mortality in SSc patients with no or mildly increased pulmonary arterial pressure.

Reduced pulmonary vascular reserve during stress echocardiography in confirmed pulmonary hypertension and patients at risk of overt pulmonary hypertension

Noninvasive estimation of systolic pulmonary artery pressure (SPAP) during exercise stress echocardiography (ESE) is recommended for pulmonary hemodynamics evaluation but remains flow-dependent. Our aim was to assess the feasibility of pulmonary vascular reserve index (PVRI) estimation during ESE combining SPAP with cardiac output (CO) or exercise-time and compare its value in three group of patients: with invasively confirmed pulmonary hypertension (PH), at risk of PH development (PH risk) mainly with systemic sclerosis and in controls (C) without clinical risk factors for PH, age-matched with PH risk patients. We performed semisupine ESE in 171 subjects: 31 PH, 61 PH at risk and 50 controls as well as in 29 young, healthy normals. Rest and stress assessment included: tricuspid regurgitant flow velocity (TRV), pulmonary acceleration time (ACT), CO (Doppler-estimated). SPAP was calculated from TRV or ACT when TRV was not available. We estimated PVRI based on CO (peak CO/SPAP*0.1) or exercise-time (ESE time/SPAP*0.1). During stress, TRV was measurable in 44% patients ACT in 77%, either one in 95%. PVRI was feasible in 65% subjects with CO and 95% with exercise-time (p < 0.0001). PVRI was lower in PH compared to controls both for CO-based PVRI (group 1 = 1.0 ± 0.95 vs group 3 = 4.28 ± 2.3, p < 0.0001) or time-based PVRI estimation (0.66 ± 0.39 vs 3.95 ± 2.26, p < 0.0001). The proposed criteria for PH detection were for CO-based PVRI ≤ 1.29 and ESE-time based PVRI ≤ 1.0 and for PH risk ≤ 1.9 and ≤ 1.7 respectively. Noninvasive estimation of PVRI can be obtained in near all patients during ESE, without contrast administration, integrating TRV with ACT for SPAP assessment and using exercise time as a proxy of CO. These indices allow for comparison of pulmonary vascular dynamics in patients with varied exercise tolerance and clinical status.

Exercise Pulmonary Hypertension Predicts Clinical Outcomes in Patients With Dyspnea on Effort

BACKGROUND

Abnormal pulmonary arterial pressure (PAP) responses to exercise have been described in select individuals; however, clinical and prognostic implications of exercise pulmonary hypertension (exPH) among broader samples remains unclear.

OBJECTIVES

This study sought to investigate the association of exPH with clinical determinants and outcomes.

METHODS

The authors studied individuals with chronic exertional dyspnea and preserved ejection fraction who underwent cardiopulmonary exercise testing with invasive hemodynamic monitoring. Exercise pulmonary hypertension was ascertained using minute-by-minute PAP and cardiac output (CO) measurements to calculate a PAP/CO slope, and exPH defined as a PAP/CO slope >3 mm Hg/l/min. The primary outcome was cardiovascular (CV) hospitalization or all-cause mortality.

RESULTS

Among 714 individuals (age 57 years, 59% women), 296 (41%) had abnormal PAP/CO slopes. Over a mean follow-up of 3.7 ± 2.9 years, there were 208 CV or death events. Individuals with abnormal PAP/CO slope had a 2-fold increased hazard of future CV or death event (multivariable-adjusted hazard ratio: 2.03; 95% confidence interval: 1.48 to 2.78; p < 0.001). The association of abnormal PAP/CO slope with outcomes remained significant after excluding rest PH (n = 146, hazard ratio: 1.75; 95% confidence interval: 1.21 to 2.54; p = 0.003). Both pre- and post-capillary contributions to exPH independently predicted adverse events (p < 0.001 for both).

CONCLUSIONS

Exercise pulmonary hypertension is independently associated with CV event-free survival among individuals undergoing evaluation of chronic dyspnea. These findings suggest incremental value of exercise hemodynamic assessment to resting measurements alone in characterizing the burden of PH in individuals with dyspnea. Whether PH and PH subtypes unmasked by exercise can be used to guide targeted therapeutic interventions requires further investigation.

Exercise Echocardiography Predicts Future Development of Pulmonary Hypertension in a High-risk Cohort of Patients with Systemic Sclerosis

Objective.

To evaluate whether a positive exercise echocardiogram (EE) predicts future development of pulmonary arterial hypertension (PAH) in a high-risk cohort of patients with systemic sclerosis (SSc).

Methods.

Patients with SSc with features associated with an increased risk for PAH were recruited into a prospective, observational cohort. All patients underwent clinical assessment and EE. A positive EE was defined as an increase of ≥ 20 mmHg in the right ventricular systolic pressure with exercise. All patients with positive EE underwent right heart catheterization (RHC).

Results.

The study included 85 patients. In the positive EE cohort, 10 of 43 patients (23%) developed resting pulmonary hypertension (PH) on RHC over a mean 4-year followup period [4 with PAH, 5 with pulmonary venous hypertension (PVH), and 1 with PH associated with interstitial lung disease]. In the persistently negative EE cohort, only 3 of 42 patients (7%) developed resting PH (1 PAH, 2 PVH; p = 0.04). Of the remaining 33 patients in the positive EE group who did not develop resting PH, 22 (67%) had a persistently positive EE over an average 5-year followup period.

Conclusion.

In this high-risk cohort of patients with SSc, a positive EE may predict the future development of resting PH. In addition, a majority of patients may have a persistently positive EE for years without progression to resting PH. Finally, a consistently negative EE may identify patients at low risk for future PH.

A review of exercise pulmonary hypertension in systemic sclerosis

In general, pulmonary vascular disease has important negative prognostic implications, regardless of the associated condition or underlying mechanism. In this regard, systemic sclerosis is of particular interest as it is the most common connective tissue disease associated with pulmonary hypertension, and a well-recognized at-risk population. In the setting of systemic sclerosis and unexplained dyspnea, the concept of using exercise to probe for underlying pulmonary vascular disease has acquired significant interest. In theory, a diagnosis of systemic sclerosis-associated exercise pulmonary hypertension may allow for earlier therapeutic intervention and a favorable alteration in the natural history of the pulmonary vascular disease. In the context of underlying systemic sclerosis, the purpose of this article is to provide a comprehensive review of the evolving definition of exercise pulmonary hypertension, the current role and methodologies for non-invasive and invasive exercise testing, and the importance of the right ventricle.

Screening for pulmonary arterial hypertension in systemic sclerosis

Pulmonary arterial hypertension (PAH) is a dreaded complication of systemic sclerosis (SSc) that occurs in ∼10% of patients. Most individuals present with severe symptoms, significant functional impairment and severe haemodynamics at diagnosis, and survival after PAH diagnosis is poor. Therefore, early diagnosis through systematic screening of asymptomatic patients has the potential to identify PAH at an early stage. Current evidence suggests that early diagnosis and treatment of PAH in patients with SSc may lead to better clinical outcomes. Annual screening may include echocardiography, but this can miss some patients due to suboptimal visualisation or insufficient tricuspid regurgitation. Other options for screening include the DETECT algorithm or the use of a combination of pulmonary function testing (forced vital capacity/diffusing capacity of the lung for carbon monoxide ratio) and N-terminal-pro-brain natriuretic peptide levels. Symptomatic patients, those with an elevated tricuspid regurgitation velocity on echocardiogram with or without secondary echocardiographic features of PAH, and those who screen positive on the DETECT or other pulmonary function test algorithms should undergo right heart catheterisation. Exercise echocardiography or cardiopulmonary exercise testing, nailfold capillaroscopy and molecular biomarkers are promising but, as yet, unproven potential options. Future screening studies should employ systematic catheterisation to define the true predictive values for PAH.

Screening can detect PAH at an early stage of the disease, which permits earlier medical interventions and may improve outcomes in systemic sclerosis patients.bit.ly/2Q5akGu

Potential role of exercise echocardiography and right heart catheterization in the detection of early pulmonary vascular disease in patients with systemic sclerosis

Pulmonary vascular disease represents one of the most frequent complications in systemic sclerosis leading to increased mortality. The recognition and appropriate clinical management of early pulmonary vascular disease could significantly improve the prognosis of affected patients. Early pulmonary vascular disease is characterized by the histological signs of pulmonary vascular remodeling, mildly increased mean pulmonary arterial pressure (21–24 mmHg) at rest, abnormal pulmonary hemodynamics during exercise, decreased exercise capacity, and a high risk for development of pulmonary arterial hypertension. Pulmonary hemodynamics can be investigated during exercise by echocardiography or by right heart catheterization both representing important clinical tools for the screening and confirmation of early pulmonary vascular disease. Further studies are needed to better understand the clinical course of systemic sclerosis patients with early pulmonary vascular disease and to define the characteristics of patients that will or will not profit from pulmonary arterial hypertension treatment.

Abnormal pulmonary artery systolic pressure response after exercise in systemic sclerosis patients: A PRISMA-compliant meta-analysis

BACKGROUND

Pulmonary artery systolic pressure (PASP) is an important parameter for detecting pulmonary arterial hypertension (PAH). The difference between rest PASP and post-exercise PASP (ΔPASP) may play a role in predicting and screening resting PAH. The aim of this study is to analyze ΔPASP in systemic sclerosis (SSc) patients with PAH or non-PAH and suggest a cutoff value of ΔPASP for detection of PAH.

METHODS

PubMed, Embase, and Web of Science were searched for relevant publications up to July 7, 2018. Characteristics of control, no PAH, exercise-induced PAH (EIPH) and PAH subgroups in SSc patients were extracted. R 3.5.0 with the "meta" package was used to conduct this meta-analysis.

RESULTS

Twelve articles involving 1279 patients were included in this study. The subgroups meta-analysis showed pooled mean ΔPASP in different subgroups: control group (8.6 mmHg, 95% CI: 6.9-10.5), no PAH group (12.2 mmHg, 95% CI: 11.2-13.2), EIPH group (26.0 mmHg, 95% CI: 24.2-27.7) and PAH group (36.2 mmHg, 95% CI: 29.7-42.7).

CONCLUSION

Combining the results of our study with the previous studies, an abnormal increase in PASP after exercise could indicate the development of PAH in SSc patients. In addition, if ΔPASP>29 mmHg, a high suspicion of PAH should be raised.

The Right Heart International Network (RIGHT-NET): Rationale, Objectives, Methodology, and Clinical Implications

The Right Heart International Network is a multicenter international study aiming to prospectively collect exercise Doppler echocardiography tests of the right heart pulmonary circulation unit (RHPCU) in large cohorts of healthy subjects, elite athletes, and individuals at risk of or with overt pulmonary hypertension. It is going to provide standardization of exercise stress echocardiography of RHPCU and explore the full physiopathologic response.

Update of screening and diagnostic modalities for connective tissue disease-associated pulmonary arterial hypertension

OBJECTIVE

Pulmonary arterial hypertension (PAH) has high morbidity and mortality in connective tissue diseases (CTDs), especially systemic sclerosis (SSc). In this systematic review, we provide an update on screening measures for early detection of PAH in CTD.

METHODS

Manuscripts published between July 2012 and October 2017, which incorporated screening measures to identify patients with PAH by right heart catheterization, were identified. Risk of bias was assessed using the QUADAS-2 tool.

RESULTS

The systematic review resulted in 1514 unique citations and 22 manuscripts were included for final review; the majority of manuscripts had a lower risk of bias based on the QUADAS-2 tool. There were 16 SSc cohort studies and 6 case-control studies (SSc 4, SLE 2). Four SSc cohort studies evaluated transthoracic echocardiography (TTE) only. Eight SSc cohort studies evaluated composite measures including ASIG, DETECT, and a combination of tricuspid regurgitation velocity (TRV) and PFT variables. DETECT and ASIG had greater sensitivity and negative predictive value (NPV) compared to the 2009 ESC/ERS guidelines in different cohorts. The addition of PFT variables, such as DLCO or FVC/ DLCO ratio, to TRV, resulted in greater sensitivity and NPV compared to TRV alone.

CONCLUSION

Current screening for PAH in CTDs is centered on SSc. Data continues to support the use of TTE and provides additional evidence for use of composite measures.

Stressing the Cardiopulmonary Vascular System: The Role of Echocardiography

The cardiopulmonary vascular system represents a key determinant of prognosis in several cardiorespiratory diseases. Although right heart catheterization is considered the gold standard for assessing pulmonary hemodynamics, a comprehensive noninvasive evaluation including left and right ventricular reserve and function and cardiopulmonary interactions remains highly attractive. Stress echocardiography is crucial in the evaluation of many cardiac conditions, typically coronary artery disease but also heart failure and valvular heart disease. In stress echocardiographic applications beyond coronary artery disease, the assessment of the cardiopulmonary vascular system is a cornerstone. The possibility of coupling the left and right ventricles with the pulmonary circuit during stress can provide significant insight into cardiopulmonary physiology in healthy and diseased subjects, can support the diagnosis of the etiology of pulmonary hypertension and other conditions, and can offer valuable prognostic information. In this state-of-the-art document, the topic of stress echocardiography applied to the cardiopulmonary vascular system is thoroughly addressed, from pathophysiology to different stress modalities and echocardiographic parameters, from clinical applications to limitations and future directions.

An official European Respiratory Society statement: pulmonary haemodynamics during exercise

There is growing recognition of the clinical importance of pulmonary haemodynamics during exercise, but several questions remain to be elucidated. The goal of this statement is to assess the scientific evidence in this field in order to provide a basis for future recommendations.

Right heart catheterisation is the gold standard method to assess pulmonary haemodynamics at rest and during exercise. Exercise echocardiography and cardiopulmonary exercise testing represent non-invasive tools with evolving clinical applications. The term “exercise pulmonary hypertension” may be the most adequate to describe an abnormal pulmonary haemodynamic response characterised by an excessive pulmonary arterial pressure (PAP) increase in relation to flow during exercise. Exercise pulmonary hypertension may be defined as the presence of resting mean PAP <25 mmHg and mean PAP >30 mmHg during exercise with total pulmonary resistance >3 Wood units. Exercise pulmonary hypertension represents the haemodynamic appearance of early pulmonary vascular disease, left heart disease, lung disease or a combination of these conditions. Exercise pulmonary hypertension is associated with the presence of a modest elevation of resting mean PAP and requires clinical follow-up, particularly if risk factors for pulmonary hypertension are present. There is a lack of robust clinical evidence on targeted medical therapy for exercise pulmonary hypertension.

Changes in pulmonary exercise haemodynamics in scleroderma: a 4-year prospective study

Pulmonary arterial hypertension (PAH) is a feared complication of systemic sclerosis. In this prospective cohort study, we monitored the changes in resting and exercise pulmonary haemodynamics of scleroderma patients without initial PAH over a mean follow-up period of ∼4 years.

All patients underwent exercise echocardiography and cardiopulmonary exercise testing at baseline and follow-up. A subgroup underwent exercise right heart catheter (RHC) investigations. The primary end-point was the echocardiographic systolic pulmonary arterial pressure at 50 W exercise (sPAP50).

We included 99 patients, of whom 58 had a complete dataset. Three out of 99 patients developed RHC-confirmed PAH (0.75 cases per 100 patient-years). sPAP50 increased (p<0.001) and peak oxygen uptake (secondary end-point) decreased significantly (p=0.001) during follow-up, but there was no significant change in resting sPAP (p=0.38). In the RHC subgroup (n=28), mean (m)PAP and pulmonary vascular resistance at 50 W increased significantly (p=0.02 and p=0.002, respectively), but resting mPAP was unchanged.

Scleroderma patients without PAH develop a mild but significant deterioration of pulmonary exercise haemodynamics and exercise capacity over a 4-year follow-up period, indicating a progression of pulmonary vascular disease. The manifestation rate of RHC-confirmed PAH was 0.75 cases per 100 patient-years.

Stress echo 2020: the international stress echo study in ischemic and non-ischemic heart disease

BACKGROUND

Stress echocardiography (SE) has an established role in evidence-based guidelines, but recently its breadth and variety of applications have extended well beyond coronary artery disease (CAD). We lack a prospective research study of SE applications, in and beyond CAD, also considering a variety of signs in addition to regional wall motion abnormalities.

METHODS

In a prospective, multicenter, international, observational study design, > 100 certified high-volume SE labs (initially from Italy, Brazil, Hungary, and Serbia) will be networked with an organized system of clinical, laboratory and imaging data collection at the time of physical or pharmacological SE, with structured follow-up information. The study is endorsed by the Italian Society of Cardiovascular Echography and organized in 10 subprojects focusing on: contractile reserve for prediction of cardiac resynchronization or medical therapy response; stress B-lines in heart failure; hypertrophic cardiomyopathy; heart failure with preserved ejection fraction; mitral regurgitation after either transcatheter or surgical aortic valve replacement; outdoor SE in extreme physiology; right ventricular contractile reserve in repaired Tetralogy of Fallot; suspected or initial pulmonary arterial hypertension; coronary flow velocity, left ventricular elastance reserve and B-lines in known or suspected CAD; identification of subclinical familial disease in genotype-positive, phenotype- negative healthy relatives of inherited disease (such as hypertrophic cardiomyopathy).

RESULTS

We expect to recruit about 10,000 patients over a 5-year period (2016-2020), with sample sizes ranging from 5,000 for coronary flow velocity/ left ventricular elastance/ B-lines in CAD to around 250 for hypertrophic cardiomyopathy or repaired Tetralogy of Fallot. This data-base will allow to investigate technical questions such as feasibility and reproducibility of various SE parameters and to assess their prognostic value in different clinical scenarios.

CONCLUSIONS

The study will create the cultural, informatic and scientific infrastructure connecting high-volume, accredited SE labs, sharing common criteria of indication, execution, reporting and image storage of SE to obtain original safety, feasibility, and outcome data in evidence-poor diagnostic fields, also outside the established core application of SE in CAD based on regional wall motion abnormalities. The study will standardize procedures, validate emerging signs, and integrate the new information with established knowledge, helping to build a next-generation SE lab without inner walls.

Exercise echocardiography for the assessment of pulmonary hypertension in systemic sclerosis: a systematic review

BACKGROUND

Pulmonary arterial hypertension (PAH) complicates the course of systemic sclerosis (SSc) and is associated with poor prognosis. The elevation of systolic pulmonary arterial pressure (sPAP) during exercise in patients with SSc with normal resting haemodynamics may anticipate the development of PAH. Exercise echocardiography (ExEcho) has been proposed as a useful technique to identify exercise-induced increases in sPAP, but it is unclear how to clinically interpret these findings. In this systematic review, we summarize the available evidence on the role of exercise echocardiography to estimate exercise-induced elevations in pulmonary and left heart filling pressures in patients with systemic sclerosis.

METHODS

We conducted a systematic review of the literature using MEDLINE, Cochrane Library and Web of Knowledge, using the vocabulary terms: ('systemic sclerosis' OR 'scleroderma') AND ('exercise echocardiography') AND ('pulmonary hypertension'). Studies including patients with SSc without a prior diagnosis of PAH, and subjected to exercise echocardiography were included. All searches were limited to English and were augmented by review of bibliographic references from the included studies. The quality of evidence was assessed by the Effective Public Health Practice Project system.

RESULTS

We identified 15 studies enrolling 1242 patients, who were mostly middle-aged and female. Several exercise methods were used (cycloergometer, treadmill and Master's two step), with different protocols and positions (supine, semi-supine, upright); definition of a positive test also varied widely. Resting estimated sPAP levels varied from 18 to 35 mm Hg, all in the normal range. The weighted means for estimated sPAP were 22.2 ± 2.9 mmHg at rest and 43.0 ± 4.3 mmHg on exercise; more than half of the studies reported mean exercise sPAP ≥40 mmHg. The assessment of left ventricular diastolic function on peak exercise was reported in a minority of studies; however, when assessed, surrogate variables of left ventricular (LV) diastolic dysfunction were associated with higher sPAP on exercise.

CONCLUSIONS

We found very high heterogeneity in the methods, the protocols and the estimated sPAP response to exercise. LV diastolic dysfunction was common and was associated with greater elevation of sPAP on exercise.

SAPHIRE: Stress and Pulmonary Hypertension in Rheumatoid Evaluation-A Prevalence Study

Pulmonary artery hypertension (PAH) is a disorder of elevated resistance in the pulmonary arterial vessels, reflected by elevation of measured pulmonary artery pressure (PAP), and presenting with breathlessness and, if untreated, progressing to right heart failure and death. The heightened prevalence of PAH in populations with underlying systemic autoimmune conditions, particularly scleroderma and its variants, is well recognised, consistent with the proposed autoimmune contribution to PAH pathogenesis, along with disordered thrombotic, inflammatory, and mitogenic factors. Rheumatoid arthritis (RA) is one of a group of systemic autoimmune conditions featuring inflammatory symmetrical erosive polyarthropathy as its hallmark. This study explored the prevalence of PAH in a population of unselected individuals with RA, using exercise echocardiography (EchoCG). The high prevalence of EchoCG-derived elevation of PAP (EDEPP) in this population (14%) suggests that, like other autoimmune conditions, RA may be a risk factor for PAH. Patients with RA may therefore represent another population for whom PAH screening with noninvasive tools such as EchoCG may be justified.

Prediction of new onset of resting pulmonary arterial hypertension in systemic sclerosis

BACKGROUND

Early detection of pulmonary arterial hypertension (PH) is crucial in systemic scleroderma. However, predictors of new onset of resting PH during follow-up (FUPH) have been poorly explored.

AIM

To determine whether nailfold videocapillaroscopy (NVC) grade and exercise echocardiographic variables are predictors of FUPH.

METHODS

We prospectively enrolled 40 patients with systemic sclerosis (age 54±13 years; 68% women). All patients underwent graded semisupine exercise echocardiography and NVC. Baseline resting PH and FUPH were defined as systolic pulmonary arterial pressure (sPAP)>35 mmHg, and exercise-induced PH (EIPH) as exercise sPAP>50 mmHg.

RESULTS

Seventeen patients developed EIPH (43%). During follow-up (FU) (25±15 months), 11 patients without baseline PH developed FUPH (28%), all from the EIPH group. Patients with FUPH were significantly older (60±14 vs 50±12 years; P=0.04), had higher resting and exercise sPAP (30±4 vs 22±5 and 60±12 vs 40±11 mmHg, respectively; P<0.0001) and a higher exercise E/e' ratio (9.4±0.7 vs 5.8±0.4; P=0.0003) and presented more frequently NVC grade>2 (90% vs 35%; P=0.0009). After adjustment for age, resting sPAP, exercise sPAP and NVC grade>2 were associated with maximal resting sPAP during follow-up and FUPH (P<0.05). Patients with both EIPH and NVC grade>2 had a very high incidence of FUPH (82%), and both variables remained strongly associated with FUPH after adjustment for age (hazard ratio 11.6, 95% confidence interval 2.4-55.3; P=0.002).

CONCLUSION

Exercise echocardiography and NVC can identify a subgroup of patients with systemic sclerosis who are at risk of developing FUPH.

Rest and exercise echocardiography for early detection of pulmonary hypertension

Early detection of pulmonary hypertension (PH) is essential to ensure that patients receive timely and appropriate treatment for this progressive disease. Rest and exercise echocardiography has been used to screen patients in an attempt to identify early stage PH. However, current PH guidelines recommend against exercise tests because of the lack of evidence. We reviewed previous studies to discuss the current standpoint concerning rest and exercise echocardiography in PH. Around 20 exercise echocardiography studies were included to assess the cutoff value for exercise-induced pulmonary hypertension (EIPH). Approximately 40 exercise echocardiography studies were also included to evaluate the pulmonary artery pressure-flow relationship as assessed by the slope of the mean pulmonary artery pressure and cardiac output (ΔmPAP/ΔQ). There were several EIPH and ΔmPAP/ΔQ reference values in individuals with pulmonary vascular disease. We believed that assessing the ΔmPAP/ΔQ makes sense from a physiological standpoint, and the clinical value should be confirmed in future studies. Exercise echocardiography is an appealing alternative in PH. Further studies are needed to assess the prognostic value of the pulmonary artery pressure-flow relationship in high-risk subjects.

Right ventricular thickness as predictor of global myocardial performance in systemic sclerosis: A Doppler tissue imaging study

BACKGROUND

Cardiopulmonary involvement in systemic sclerosis (SSc) is a poor prognostic factor, due to pulmonary hypertension and right ventricular dysfunction. We assessed the echocardiographic parameters of right ventricular (RV) function in SSc and correlated echocardiographic findings to clinical features of the disease.

METHODS

Thirty patients with SSc (cases) and 30 healthy, age-matched subjects (controls) were studied. Echocardiography, including tissue Doppler imaging, was used to evaluate cardiac function.

RESULTS

Pulmonary hypertension could be documented in only 5 cases by Doppler echo, using Bernoulli principle. RV diastolic function was significantly deranged in cases. RV systolic function and left ventricle (LV) diastolic function were also significantly deranged in the cases. RV thickness was increased in patients with SSc. There were no significant differences in the echocardiographic variables between diffuse and limited subtypes of SSc. Myocardial performance index (MPI) of both ventricles were increased in cases. We could demonstrate RV thickness as the single most important predictor of MPI of both ventricles with sensitivity of 82% and specificity of 72% for RV-MPI and 63% for LV-MPI. Diastolic function was not found to be affected by disease duration or Rodnan skin score.

CONCLUSION

Patients with SSc exhibit abnormal RV and LV diastolic functions as well as abnormal RV systolic function. RV wall thickness was found to be simple and the single best predictor of global myocardial performance. RV dysfunction may be a response to intermittent pulmonary arterial hypertension, lung parenchymal involvement, or secondary to LV diastolic dysfunction in SSc.

Stress Doppler echocardiography for early detection of systemic sclerosis-associated pulmonary arterial hypertension

INTRODUCTION

In patients with systemic sclerosis (SSc), associated pulmonary arterial hypertension (SSc-APAH) is the leading cause of death. The objective of this prospective screening study was to analyse sensitivity and specificity of stress Doppler echocardiography (SDE) in detecting pulmonary hypertension (PH).

METHODS

Pulmonary artery pressures and further parameters of PH were assessed by echocardiography and right heart catheterisation (RHC) at rest and during exercise in patients with SSc. Investigators of RHC were blinded to the results of non-invasive measurements.

RESULTS

Of 76 patients with SSc (64 were female and mean age was 58±14 years), 22 (29 %) had manifest PH confirmed by RHC: four had concomitant left heart diseases, three had lung diseases, and 15 had SSc-APAH. Echocardiography at rest missed PH diagnosis in five of 22 patients with PH when a cutoff value for systolic pulmonary arterial pressure (PASP) was more than 40 mm Hg at rest. The sensitivity of echocardiography at rest was 72.7 % (95 % confidence interval (CI) 0.52-0.88), and specificity was 88.2 % (95 % CI 0.78-0.95). When a cutoff value for PASP was more than 45 mm Hg during low-dose exercise, SDE missed PH diagnosis in one of the 22 patients with PH and improved sensitivity to 95.2 % (95 % CI 0.81-1.0) but reduced specificity to 84.9 % (95 % CI 0.74-0.93). Reduction of specificity was partly due to concomitant left heart disease.

CONCLUSIONS

The results of this prospective cross-sectional study using RHC as gold standard in all patients showed that SDE markedly improved sensitivity in detecting manifest PH to 95.2 % compared with 72.7 % using echocardiography at rest only. Thus, for PH screening in patients with SSc, echocardiography should be performed at rest and during exercise.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01387035. Registered 29 June 2011.

Recent advances in scleroderma-associated pulmonary hypertension

PURPOSE OF REVIEW

This review summarizes recent advances in pulmonary hypertension, a leading cause of morbidity and mortality in scleroderma (SSc).

RECENT FINDINGS

Although WHO Group I pulmonary arterial hypertension (PAH) is the most common cause of pulmonary hypertension, all WHO Groups can occur. PAH is now a criterion for the diagnosis of SSc. Results of recent research have resulted in greater insight into the epidemiology of SSc-pulmonary hypertension with regard to prevalence, incidence and clinical risk factors. There is also greater understanding of the role of inflammation in the pathogenesis of SSc-PAH. Advances have also been made in the evaluation and screening of patients with SSc-PAH, and early detection has been shown to improve survival in a disease that typically has worse outcomes than other forms of PAH. Finally, recommendations have been made with regard to goal-directed therapy.

SUMMARY

Although there have been many recent advances in SSc-pulmonary hypertension, further research is needed in order to prevent/cure this deadly complication.

Systemic sclerosis: Recent insights

Systemic sclerosis is an orphan connective tissue disease characterized by alterations of the microvasculature, disturbances of the immune system and massive deposition of collagen and other matrix substances in the skin and internal organs. A major achievement of the recent years has been the validation of new classification criteria, allowing earlier diagnosis and earlier treatment of systemic sclerosis, before irreversible fibrosis and organ damage appeared ("window of opportunity"). Raynaud's phenomenon is usually the first sign of the disease and is considered as the main sentinel sign for the identification of very early systemic sclerosis. Systemic sclerosis is clinically heterogeneous and disease course remains unpredictable. Its prognosis depends on cardiopulmonary involvement and recent studies aim to identify serum or genetic biomarkers predictive of severe organ involvement. Moreover, the prospective follow-up of large cohorts has provided and will offer critical material to identify strong prognostic factors. Whereas the outcomes of vascular manifestations of the disease has been recently improved due to targeted therapy, recent data have highlighted that mortality has not changed over the past 40 years. This reflects the absence of efficacy of current available drugs to counteract the fibrotic process. Nevertheless, several targeted immunity therapies, commonly with proven efficacy in other immune diseases, are about to be investigated in systemic sclerosis. Indeed, promising results in small and open studies have been reported. This article deals with recent insights into classification criteria, pathogenesis, organ involvements, outcome and current and possible future therapeutic options in systemic sclerosis.

Low Cost Magnetic Resonance Imaging-Compatible Stepper Exercise Device for Use in Cardiac Stress Tests

Cardiovascular disease is the leading cause of death worldwide. Many cardiovascular diseases are better diagnosed during a cardiac stress test. Current approaches include either exercise or pharmacological stress echocardiography and pharmacological stress magnetic resonance imaging (MRI). MRI is the most accurate noninvasive method of assessing cardiac function. Currently there are very few exercise devices that allow collection of cardiovascular MRI data during exercise. We developed a low-cost exercise device that utilizes adjustable weight resistance and is compatible with magnetic resonance (MR) imaging. It is equipped with electronics that measure power output. Our device allows subjects to exercise with a leg-stepping motion while their torso is in the MR imager. The device is easy to mount on the MRI table and can be adjusted for different body sizes. Pilot tests were conducted with 5 healthy subjects (3 male and 2 female, 29.2 ± 3.9 yr old) showing significant exercise-induced changes in heart rate (+42%), cardiac output (+40%) and mean pulmonary artery (PA) flow (+%49) post exercise. These data demonstrate that our MR compatible stepper exercise device successfully generated a hemodynamically stressed state while allowing for high quality imaging. The adjustable weight resistance allows exercise stress testing of subjects with variable exercise capacities. This low-cost device has the potential to be used in a variety of pathologies that require a cardiac stress test for diagnosis and assessment of disease progression.

Determinants of exercise-induced pulmonary arterial hypertension in systemic sclerosis

BACKGROUND

Exercise-induced pulmonary arterial hypertension (EIPH) in systemic sclerosis (SSc) has already been observed but its determinants remain unclear. The aim of this study was to determine the incidence and the determinants of EIPH in SSc.

METHODS AND RESULTS

We prospectively enrolled 63 patients with SSc (age 54±3years, 76% female) followed in CHU Sart-Tilman in Liège. All patients underwent graded semi-supine exercise echocardiography. Systolic pulmonary arterial pressure (sPAP) was derived from the peak velocity of the tricuspid regurgitation jet and adding the estimation of right atrial pressure, both at rest and during exercise. Resting pulmonary arterial hypertension (PH) was defined as sPAP > 35 mmHg and EIPH as sPAP > 50 mmHg during exercise. The following formulas were used: mean PAP (mPAP) = 0.61 × sPAP + 2, left atrial pressure (LAP)=1.9+1.24 × left ventricular (LV) E/e' and pulmonary vascular resistance (PVR)=(mPAP-LAP)/LV cardiac output (CO) and slope of mPAP-LVCO relationship=changes in mPAP/changes in LVCO. Resting PH was present in 3 patients (7%) and 21 patients developed EIPH (47%). Patients with EIPH had higher resting LAP (10.3 ± 2.2 versus 8.8 ± 2.3 mmHg; p = 0.03), resting PVR (2.6 ± 0.8 vs. 1.4 ± 1.1 Woods units; p=0.004), exercise LAP (13.3 ± 2.3 vs. 9 ± 1.7 mmHg; p < 0.0001), exercise PVR (3.6 ± 0.7 vs. 2.1 ± 0.9 Woods units; p = 0.02) and slope of mPAP-LVCO (5.8 ± 2.4 vs. 2.9 ± 2.1 mmHg/L/min; p < 0.0001). After adjustment for age and gender, exercise LAP (β=3.1 ± 0.8; p=0.001) and exercise PVR (β=7.9 ± 1.7; p=0.0001) were independent determinants of exercise sPAP.

CONCLUSION

EIPH is frequent in SSc patients and is mainly related to both increased exercise LV filling pressure and exercise PVR.