Influence of Pulmonary Vascular Reserve on Exercise-Induced Pulmonary Hypertension in Patients with Systemic Sclerosis

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.

Impact of Exercise-Induced Pulmonary Hypertension on Right Ventricular Function and on Worsening of Cardiovascular Risk in HIV Patients

Background and Aim: Exercise-induced pulmonary hypertension (ExPH) predicts clinical outcomes, such as all-cause mortality and cardiovascular (CV) hospitalizations, in patients with dyspnea on effort. We investigated its prognostic significance in human immunodeficiency virus (HIV)-affected patients. Methods: In 52 consecutive HIV patients with either low (n = 47) or intermediate probability (n = 5) of PH at rest, we evaluated—at time 0 and after 2 years—the prognostic determinants of CV risk, according to the 2015 European Society of Cardiology (ESC)/European Respiratory Society (ERS) Guidelines. Patients were classified with or without ExPH at stress echocardiography (ESE) and cardiopulmonary exercise test (CPET). We then related ExPH at time 0 with clinical worsening (CV risk score increase >20% after 2 years). Results: Right ventricle (RV) systolic function was significantly reduced in patients with ExPH compared to those without ExPH at CPET. This also occurred in patients with intermediate/high probability compared to those with low probability of ExPH at ESE. The former exhibited worse values of TAPSE and FAC (p < 0.001 and p = 0.01, respectively). A significantly higher proportion of patients with ExPH (CPET) or with intermediate/high probability of ExPH (ESE) had higher sPAP (p < 0.001), mPAP (p = 0.004) and higher TRV (p = 0.006), as well as higher right atrial area (p < 0.001) and indexed right atrial volume (p = 0.004). Total pulmonary vascular resistance (expressed by the ratio between TRV and the velocity-time integral at the level of the right ventricular outflow tract) was higher both in patients with ExPH and in those with intermediate/high probability of ExPH (p < 0.001). Patients with intermediate/high probability of ExPH at ESE showed a trend (p = 0.137) towards clinical worsening compared to those with low probability of ExPH. No patients with low probability of ExPH had a >20% increased CV risk score after 2 years. We found an association between higher NT-proBNP and the presence or intermediate/high probability of ExPH after 2 years (p = 0.048 at CPET, p = 0.033 at ESE). Conclusions: The assessment of ExPH may predict a trend of increasing CV risk score over time. If confirmed at a longer follow-up, ExPH could contribute to better risk stratification in HIV patients.

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.

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.

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.

Aerobic and resistance exercise in systemic sclerosis: State of the art

INTRODUCTION

Patients with systemic sclerosis (SSc) experience reduced exercise capacity and muscle strength compared with healthy subjects. There are also indications of reduced levels of physical activity.

OBJECTIVE

To present the current knowledge of physical exercise in SSc.

RESULTS

Most studies presently available [three case studies, one single subject experimental design, one study comparing patients with healthy controls, one quasi experimental design (pre-post), two clinical trials and two random controlled trials] have included small samples of patients, mostly composed of patients with and without pulmonary involvement. It seems that patients with SSc without pulmonary involvement are able to perform and benefit from aerobic exercises of at least moderate intensity. Exercise tolerance, aerobic capacity, walking distance, muscle strength and muscle function as well as health-related quality of life (HRQL) have been found to be improved after participation in programmes including aerobic exercise and aerobic exercise combined with resistance exercises. Improvements seem to be only partially retained at follow up. Patients with pulmonary involvement may also experience improved muscle strength, physical and aerobic capacity, as well as HRQL following exercise.

CONCLUSIONS

Patients with SSc without pulmonary involvement can be recommended to be as physically active as the general population. Patients with mild pulmonary involvement can be recommended to be physically active by engaging in exercises of moderate intensity and to participate in moderate-load resistance exercises. Health professionals should inform patients with SSc about the importance of physical activity and avoidance of a sedentary lifestyle.

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.

Exercise echocardiography for structural heart disease

Since the introduction of transcatheter structural heart intervention, the term "structural heart disease" has been widely used in the field of cardiology. Structural heart disease refers to congenital heart disease, valvular heart disease, and cardiomyopathy. In structural heart disease, valvular heart disease is frequently identified in the elderly. Of note, the number of patients who suffer from aortic stenosis (AS) and mitral regurgitation (MR) is increasing in developed countries because of the aging of the populations. Transcatheter aortic valve replacement and percutaneous mitral valve repair has been widely used for AS and MR, individually. Echocardiography is the gold standard modality for initial diagnosis and subsequent evaluation of AS and MR, although the difficulties in assessing patients with these diseases still remain. Here, we review the clinical usefulness and prognostic impact of exercise echocardiography on structural heart disease, particularly on AS and MR.

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.

Exercise testing can unmask right ventricular dysfunction in systemic sclerosis patients with normal resting pulmonary artery pressure

BACKGROUND

Pulmonary arterial hypertension (PAH) is a frequent complication of systemic sclerosis (SSc). Diagnosis usually occurs late and often after the development of irreversible right heart dysfunction. Exercise testing is increasingly used for assessing right ventricular (RV) function when resting hemodynamics do not account for symptoms. We hypothesized that SSc patients without resting pulmonary hypertension could have impaired exercise capacity and RV contractile reserve with exercise thus unmasking early RV dysfunction and pulmonary vascular disease.

METHODS

Treadmill exercise stress echocardiography with concurrent expired gas analysis was performed in 25 SSc patients with normal resting pulmonary arterial pressure (PAP) and healthy controls (n = 50). Additionally, controls and SSc patients were compared to those with established PAH (n = 23). Parameters of RV systolic function (RV fractional area change (FAC), Doppler tissue (DTI) s' velocity, systolic strain and strain rate (S-Sr)) were evaluated at baseline and post-exercise with the difference (Δ) being contractile reserve.

RESULTS

RV contractile reserve was reduced in the SSc group with normal resting PAP, compared with healthy controls (Δs': 6.1 ± 2.3 vs 8.0 ± 2.2 cm s(-1), p < 0.001; and ΔS-Sr: 2.3 ± 0.5 vs 2.6 ± 0.2s(-1), p = 0.02) in association with a significantly higher mean PAP with exercise (25.5 ± 6.6 vs 19.9 ± 7.2 mmHg, p < 0.001). PAH patients demonstrated the lowest levels of contractile reserve (Δs', Δ strain, ΔS-Sr and ΔFAC, all p < 0.05).

CONCLUSION

Exercise stress testing unmasks reduced RV contractile reserve in SSc patients with normal resting PAP. Subclinical RV dysfunction during exercise may be a surrogate for early pulmonary vascular disease in SSc patients.