Background: Cardiac involvement in Churg-Strauss syndrome (CSS) is not uncommon, but its frequency varies widely and may depend on the activity of the disease. Therefore, the cardiac involvement in CSS patients in clinical remission was assessed in the present study.
Methods and results: In 20 CSS patients in remission and 20 sex- and age-matched healthy controls, an ECG stress test, echocardiography, and 24-h ECG Holter monitoring were performed, together with cardiac magnetic resonance imaging (cMRI). Cardiac involvement was present in 90% (18/20) of CSS patients. Left ventricular ejection fraction (LVEF) was on average lower in the CSS group than in controls (P<0.05), with 7 patients showing systolic heart failure (LVEF <50%). cMRI changes included late gadolinium enhancement lesions in the LV in 89% of patients (17/19), present in all layers of the myocardium. Signs of ongoing inflammation (early gadolinium enhancement) and edema (T2-weighted imaging) were present in 6/19 patients. Holter monitoring revealed both supraventricular and ventricular arrhythmias more frequently in CSS patients when compared with controls (P<0.05). Absolute eosinophil count before the initiation of treatment was higher in rhythm disturbances (P<0.05), and inversely correlated with LV systolic function (rho -0.65).
Conclusions: Heart involvement in CSS patients who are in clinical remission is very common. It is characterized not only by fibrosis, but also by an active inflammatory process. The latter finding might influence therapeutic decisions in CSS patients in full clinical remission.