Systemic sclerosis and the heart: current diagnosis and management

Abstract

Purpose of review: When present clinically, cardiac involvement in systemic sclerosis (SSc) is a major risk factor for death. It is therefore vitally important to understand the epidemiology, screening, diagnosis, and treatment of the cardiac manifestations of SSc.

Recent findings: The epidemiology of cardiac involvement in SSc has been the subject of several recent studies. Most importantly, the prevalence of overt left ventricular (LV) systolic dysfunction and its associated risk factors have been defined, and patients with diffuse cutaneous SSc appear to be most susceptible to direct cardiac involvement. From a diagnostic and screening standpoint, tissue Doppler echocardiography and natriuretic peptides have provided fresh insight into subclinical cardiac dysfunction in SSc. Newer techniques, such as speckle-tracking echocardiography, diffuse myocardial fibrosis imaging, and absolute myocardial perfusion imaging, are poised to further advance our knowledge. Lastly, there is now consistent observational data to suggest a central role for calcium channel blockers in the treatment of microvascular ischemia and prevention of overt LV systolic dysfunction, although randomized controlled trials are lacking.

Summary: Recent studies have improved our understanding of cardiac involvement in SSc. Nevertheless, key questions regarding screening, diagnosis, and treatment remain. Novel diagnostic techniques and multicenter studies should yield important new data, which will hopefully ultimately result in improved outcomes.

Figure 1. Advanced echocardiographic techniques for the evaluation of cardiac involvement in systemic sclerosis: tissue Doppler imaging vs. speckle-tracking echocardiography

Left panel: Differences between myocardial velocity and myocardial strain. Middle panel: Example of tissue velocities of basal RV free wall in a patient with SSc [open arrow points to peak systolic (S’) tissue velocity]. Right panel: Example of systolic strain curves of the RV derived from speckle-tracking echocardiography in the same patient with SSc (inset = 2D speckle-tracking image; arrow points to peak systolic strain of the basal RV free wall). In this case, peak systolic strain (−4.4%) was reduced (consistent with intrinsic RV systolic dysfunction) whereas peak systolic tissue velocity (12.3 cm/s) was preserved. RV systolic tissue velocity was normal despite abnormal RV function due to the tethering effect of normal LV systolic function (i.e. RV longitudinal velocity, but not strain, is somewhat dependent on LV systolic function as the LV ‘pulls’ the RV base toward the apex during systole). Thus, speckle-tracking strain analysis may be advantageous (compared with tissue Doppler imaging) for the detection of subclinical cardiac involvement.

Figure 2. Diffuse myocardial fibrosis quantification by cardiac magnetic resonance

Late gadolinium enhanced (LGE), mid-left ventricular short axis images and corresponding postcontrast T₁ mapping of the blood pool and myocardium in a normal control (left panel) and a patient with diffuse cutaneous SSc (right panel). Although LGE images demonstrate no focal areas of myocardial fibrosis, postcontrast myocardial T₁ mapping demonstrates faster recovery (shorter T₁) in the SSc patient. Precontrast and postcontrast T₁ values in the blood and myocardium are used to calculate the extracellular volume fraction (V_e). In the example shown, there is substantially greater diffuse myocardial fibrosis (higher V_e) in the SSc patient compared with normal despite similar appearance of the left ventricle.

Figure 3. Clinical algorithm for screening and diagnosis of cardiac involvement in systemic sclerosis

BNP, B-type natriuretic peptide; CAD, coronary artery disease; CMR, cardiac magnetic resonance; CPET, cardiopulmonary exercise testing; DLCO, carbon monoxide diffusing capacity; ILD, interstitial lung disease; JVP, jugular venous pulsations; LVEF, left ventricular ejection fraction; NT-proBNP, N-terminal pro-B-type natriuretic peptide; PA, pulmonary artery; PAH, pulmonary arterial hypertension; RV, right ventricle; TAPSE, tricuspid annular plane systolic excursion. *Differential diagnosis also includes noncardiac causes of natriuretic peptide evaluation including renal insufficiency, sepsis/critical illness, glucocorticoids, malignancy, and weight loss/cachexia.