Spectrum of Cardiovascular Involvement in Erdheim-Chester Disease Evaluated by Cardiac Computed Tomography
Erdheim Chester Disease (ECD) is a rare type of non-Langerhans histiocytosis characterized by the presence of foamy CD68+/CD1a-/S100- histocytes and associated fibrosis of various tissues. It typically presents in adulthood and predominantly affects males. Clinical manifestations are variable and include bone pain, exophthalmos, interstitial lung disease, renal failure, diabetes insipidus as well as cardiovascular and neurological involvement (Diamond et al, 2014).
Cardiovascular and neurological infiltration is associated with a poor prognosis, with 60% of ECD patients dying from cardiac complications, such as myocardial infarction, cardiac tamponade, and heart failure (Killu et al, 2013). Since early cardiac manifestations are often silent, advanced imaging techniques are the primary diagnostic modality to determine the site and degree of involvement. In addition to the prognostic value to be gained by cardiac imaging, elucidating the extent in which the heart is affected in ECD can guide management. In this monocentric study of 58 consecutive patients, we sought to further characterize the prevalence and spectrum of cardiovascular involvement in Erdheim-Chester disease through cardiac computed tomography.
Patients. Patients enrolled in NHGRI Clinical Protocol 11-HG-0207, “Clinical and Basic Investigations into Erdheim Chester disease” (NCT014117520), diagnosed with Erdheim Chester based on history and tissue examination, were prospectively imaged with cardiac computed tomography from October 2011 to December 2015. A total of 58 patients (75% male, age 52±11 years, range 19-72 years) obtained a contrast-enhanced, ECG-gated, cardiac CT on a 320-detector row Aquilion One scanner.
Metoprolol was administered if resting heart rate was greater than 65 beats/min in order to optimize imaging. Iodinated contrast was given through high flow IV to all except for 4 participants due to renal insufficiency.
Conclusion and Future Direction
Cardiovascular involvement of Erdheim Chester Disease is common (40%), and the most prevalent feature is pseudo-tumor involvement of the right atrioventricular sulcus, enveloping the right coronary artery. Nevertheless, other structures of the heart can be affected in a continuous manner with an expanding mass, resulting in a spectrum of involvement.
Our series supports the benefit of screening for cardiac involvement in these patients not only to get prognostic information but also to guide treatment. Future studies will focus on characterizing the prevalence of arrhythmias, valvular disease and coronary artery disease in Erdheim-Chester patients. We will also compare CT to other imaging techniques such as echocardiography and MRI. In addition, it will be interesting to ascertain how different therapies affect cardiac involvement and to establish how frequent cardiac surveillance should be in ECD patients.