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

Systolic Dysfunction in Systemic Sclerosis: Prevalence and Prognostic Implications

Objective

Primary cardiac involvement is presumed to account for a substantial part of disease-related mortality in systemic sclerosis (SSc). Still, there are knowledge gaps on the evolution and total burden of systolic dysfunction in SSc. Here we evaluated prospective left ventricular (LV) and right ventricular (RV) systolic function in an unselected SSc cohort and assessed the burden of systolic dysfunction on mortality.

Methods

From the Oslo University Hospital cohort, 277 SSc patients were included from 2003-2016 and compared with healthy controls. Serial echocardiographies were reevaluated in order to detect change in systolic function. Right heart catheterization was performed on patients suspected of pulmonary hypertension. Descriptive and regression analyses were conducted.

Results

At baseline, LV systolic dysfunction by ejection fraction less than 50%, or a global longitudinal strain greater than -17.0%, was found in 12% and 24%, respectively. RV systolic dysfunction measured by tricuspid annular plane systolic excursion (TAPSE) less than 17 mm was evident in 10%. Follow-up echocardiography was performed after a median of 3.3 years (interquartile range [IQR] 1.5-5.6). At follow-up, LV systolic function remained stable, whereas RV function evaluated by TAPSE deteriorated (mean 23.1 to 21.7 mm, P = 0.005) equaling a 15% prevalence of RV systolic dysfunction. RV systolic function predicted mortality in multivariable models (hazard ratio 0.41, 95% confidence interval [CI] 0.19-0.90, P value 0.027), whereas LV systolic function lost predictive significance when adjusted for TAPSE.

Conclusion

In this unselected and prospective study, systolic dysfunction of the LV and RV was a frequent complication of SSc. LV systolic function remained stable across the observation period, whereas RV function deteriorated and predicted mortality.

Electrocardiographic Findings in Systemic Sclerosis

Systemic sclerosis (SSc) is an autoimmune connective tissue disease which affects various tissues and organs, including skin, lungs, kidneys, gastrointestinal tract and cardiovascular system. Cardiac involvement is the most commonly recognized problem and a significant cause of morbidity. Abnormal ECG is present in 25-75% of patients with SSc and is considered to be an independent predictor of mortality. It is known that the supraventricular arrhythmias are considered as more common in SSc patients, occurring in about two-thirds of the cases, and more often than ventricular tachyarrhythmias. It has been established that right bundle branch block is associated with an increased risk of mortality and that it is an independent predictor of mortality, and should be considered as a marker of the severity of the disease in SSc. Th e prolonged QTc interval is an independent risk factor for a sudden cardiac death reflecting the instability of repolarization and predisposing the onset of cardiac arrhythmias.The prognosis of the disease depends on the SSc subtype and the involvement of internal organs. SSc is a lifelong disease and cannot be cured, but knowing that cardiac dysfunction significantly worsens the prognosis, early detection of cardiac complications and appropriate therapy can influence its progress and improve the patients’ quality of life.

Relation of Right Atrial Mechanics to Functional Capacity in Patients With Systemic Sclerosis

Cardiac involvement in systemic sclerosis (SSc) implies a worse prognosis. Little is known about the right atrial (RA) mechanics in this disease, but recent data suggest that it correlates well with the functional capacity of the patients in conditions with known right heart involvement. Thus we aimed to investigate the abnormalities of the RA function as compared with healthy subjects and to assess the potential correlations between RA mechanics and the functional capacity in SSc patients using 2D speckle tracking technique. A total of 70 SSc patients (age: 57 ± 12 years) were investigated. Functional capacity was measured with 6-minute walk test (6MWT). Echocardiographic parameters of the right ventricular (RV) systolic function (TAPSE, RVFAC), parameters of the tricuspid inflow (E, A), and tricuspid annular systolic (S), early- (e') and late- (a') diastolic myocardial velocities were measured. RV wall thickness was obtained. RA reservoir (ε_R), conduit (ε_CD), and contractile (ε_CT) strain were measured. RA stiffness was calculated as ratio of E/e' to ε_R. Echocardiographic data were compared with an age- and gender-matched group of 25 healthy volunteers. RA ε_R (49.3 ± 10.7 vs 59.6 ± 9.9%, p = 0.000) and ε_CD (26.8 ± 8.1 vs 34.3 ± 7.3%, p = 0.000) were significantly lower in SSc patients. No significant difference was found in ε_CT (22.9 ± 5.8 vs 25.3 ± 5.7%, p = 0.082). RA stiffness was significantly increased in SSc patients (0.11 ± 0.04 vs 0.08 ± 0.02, p = 0.001). 6MWT distance was 391 ± 95m. In stepwise multiple linear regression analysis RV wall thickness (r = -0.289, p = 0.030) and RA stiffness (r = -0.418, p = 0.002) became independent predictors of 6MWT distance. In conclusion, RA ε_R and ε_CD are impaired, while RA stiffness is increased in SSc compared with healthy subjects. Speckle tracking-derived RA stiffness is turned out to be one of the main determinants of the functional capacity in SSc patients.

Systemic sclerosis impacts right heart and cardiac autonomic nervous system

AIM

To evaluate the influence of systemic sclerosis (SSc) on right ventricular (RV) remodeling by two- and three-dimensional echocardiography (2DE and 3DE) and heart rate variability (HRV).

METHODS

Forty-five SSc patients and 35 age- and gender-matched healthy controls underwent clinical examination, 24-h Holter monitoring, and comprehensive 2DE and 3DE.

RESULTS

2DE RV global and RV free wall longitudinal strains, as well as 2DE RV endocardial, mid-myocardial, and epicardial longitudinal strains were lower in SSc subjects, who exhibited greater 3DE RV volumes but lower 3DE RV ejection fraction than controls. HRV indices were impaired in SSc subjects. These differences in RV global and free wall longitudinal strain, layer-specific strains, and ejection fraction, were associated with HRV indices independently of demographic, clinical, and echocardiographic parameters. Modified Rodnan Skin Score, clinical indicator of skin involvement in SSc, was associated with HRV parameters, RV layer-specific mechanics, and RV ejection fraction.

CONCLUSION

SSc affects RV function and mechanics of all myocardial layers, as well as cardiac autonomic nervous function. HRV indices are significantly associated with RV function, RV deformation, and skin involvement in SSc patients.

Cardiovascular Imaging Techniques in Systemic Rheumatic Diseases

The risk of cardiovascular (CV) events and mortality is significantly higher in patients with systemic rheumatic diseases than in the general population. Although CV involvement in such patients is highly heterogeneous and may affect various structures of the heart, it can now be diagnosed earlier and promptly treated. Various types of assessments are employed for the evaluation of CV risk such as transthoracic or transesophageal echocardiography, magnetic resonance imaging (MRI), and computed tomography (CT) to investigate valve abnormalities, pericardial disease, and ventricular wall motion defects. The diameter of coronary arteries can be assessed using invasive quantitative coronarography or intravascular ultrasound, and coronary flow reserve can be assessed using non-invasive transesophageal or transthoracic ultrasonography (US), MRI, CT, or positron emission tomography (PET) after endothelium-dependent vasodilation. Finally, peripheral circulation can be measured invasively using strain-gauge plethysmography in an arm after the arterial infusion of an endothelium-dependent vasodilator or non-invasively by means of US or MRI measurements of flow-mediated vasodilation of the brachial artery. All of the above are reliable methods of investigating CV involvement, but more recently, introduced use of speckle tracking echocardiography and 3-dimensional US are diagnostically more accurate.

Update on assessment and management of primary cardiac involvement in systemic sclerosis

Primary cardiac involvement is a common and severe complication of systemic sclerosis, which may affect all of the hearts' structural components, including pericardium, myocardium, endocardium, cardiac valves, and conduction system. While cardiac disease can be clinically silent and only diagnosed in autopsy, new imaging modalities such as speckle-tracking echocardiography and cardiovascular magnetic resonance may reveal various abnormal findings in the majority of patients. Cardiovascular magnetic resonance evaluation should include assessment of left and right ventricular function, inflammation (STIR T2-weighted sequences (T2-W) for edema detection), and fibrosis (T1-weighted sequences 15 min after Gd-DTPA contrast medium injection (late-gadolinium enhancement). Notably, cardiac disease is responsible for about one-fourth of systemic sclerosis-related deaths. Systematic studies for the assessment and therapy of systemic sclerosis-related cardiac complications, as well as relevant guidelines from the European League Against Rheumatism and the American College of Rheumatology, are currently lacking. However, research advances reviewed herein allow for a better understanding of the mechanisms that alter cardiac function. Implementation of such knowledge should reduce cardiac morbidity and mortality in systemic sclerosis patients.