Prevalence of pericardial late gadolinium enhancement in patients after cardiac surgery: clinical and histological correlation

Abstract Funding Acknowledgements Type of funding sources: None. Background Opening of the pericardial sack during cardiac surgery induce usually, a mild inflammatory reaction. Late gadolinium enhancement of the pericardium (pLGE) still has been observed on cardiovascular magnetic resonance (CMR) in patients even long-time after cardiac surgery suggesting ongoing pericardial inflammation. Clinical relevance and histological correlation are unknown. We present a study evaluating the prevalence of pLGE and correlating it to clinical and histological findings. Materials and Methods 185 patients after cardiac surgery underwent CMR on a 1.5 or 3.0 T system. Presence (LGE+) or absence (LGE-) of pLGE was rated by 2 independent operators blinded to clinical characteristics. In case of discordance a third observer served as referee. Information on clinical symptoms were obtained at the time of CMR or from medical records. A pericardial biopsy was performed in 4 patients who underwent a second cardiac surgical intervention after CMR. Results Mean time between CMR and cardiac surgery was 158 ± 110 months. Pericardial LGE was observed in 83 patients (38%), two independent observers agreed in 73 (89%). The presence of LGE was not significant correlated to the type (p = 0.812) or duration of surgery (p = 0.734), nor the use of intrapericardial foreign material (p = 0.534). Two biopsies in LGE + patients showed mild inflammation and calcification, one biopsy in a LGE + patient showed the presence of fibrosis without inflammation while one biopsy in a LGE – patient was negative for inflammation. None of patients presented clinical signs for an active pericarditis. Discussion Presence of pericardial LGE is frequent in patient after cardiac surgery, however without clinical features of pericarditis. The CMR findings appear to be histologically correlated to the presence of fibrosis or mild chronic inflammation which remains to be confirmed in a larger patient population. Figure 1: Basal ventricular short axis view in LGE sequences showing the presence of LGE of the pericardium (Panel A, yellow arrows) compatible with mild inflammation present in histological findings, shown by the presence of T lymphocytes CD3+ (Panel B) and the presence of fibrin (Panel C) : (hematoxylin and eosin) and (Panel D) : (FAOG). Mid-ventricular short axis view in LGE sequences showing the presence of LGE of the pericardium (Panel E, yellow arrows), which is compatible with histological findings, showing the presence of granulomatous inflammation in a fibrinous pericardium (Panel F,H) : (hematoxylin and eosin) and (Panel G) : (fils polarized). Visible granuloma (Panel F).