Background Systemic rheumatic diseases (SRDs) are associated with increased cardiovascular (CV) morbidity due to accelerated atherosclerosis. However, SRDs are also associated with cardiac vasculitis that may contribute to the increased CV risk. In the Feiring Heart Biopsy Study (FHBS) a high occurrence of inflammatory cell infiltrates (ICI) in the aorta of patients with coronary artery disease (CAD) and SRD were found and therefore we wanted to examine if this patient group also had a high occurrence of inflammation in the heart.
Objectives To examine the occurrence and extent of ICI and small vessel vasculitis in all layers of the right atrium (epicardium, myocardium and endocardium) in patients with CAD with and without SRDs.
Methods We examined biopsies from the right atrium taken in a standardized way during coronary artery bypass grafting from the edge of the openings for cannulation due to extracorporeal circulation from patients with and without SRD (matched for age, sex and acute coronary syndrome) included in FHBS (Hollan I, 2007). A 3-µm thick section from each paraffin fixed specimen was stained by hematoxylin and eosin and examined by light microscopy in a blinded manner. The number and extent of ICIs in the three layers of the heart wall were semi-quantified.
Conclusions In patients with CAD, vasculitis was not observed, but the occurrence of ICIs in the right atrium was high, mostly localized around small vessels. The ICIs occured in the epicardium, and the occurrence and extent of epicardial ICIs was similar in SRD and non-SRD patients. In the myocardium and endocardium, the ICIs occurred in a low frequency, and in the non-SRD group only (but the difference was not statistically significant). In theory, the observed ICIs might be secondary to or independent of cardiovascular disease (CVD), but the inflammation might also contribute to CAD by compromising of the function of epicardial coronary arteries. Interestingly, abnormalities in epicardium (increased mass of epicardial adipose tissue) are related to CV prognosis, and we propose that inflammation in the epicardium might be of particular importance. Our findings do not support the hypothesis that inflammation in the heart including small vessel cardiac vasculitis is more common in SRD than non-SRD patients. However, this possibility cannot be completely ruled out as the number of examined specimens were small, taken from apparently healthy tissue, and the right atrium was the only site sampled.
Disclosure of Interest None Declared