Prevalence of Pericardial Late Gadolinium Enhancement in Patients After Cardiac Surgery: Clinical and Histological Correlations.

BACKGROUND: Pericardial late gadolinium enhancement (LGE) is usually associated with active pericarditis, but it is not infrequently found in patients after cardiac surgery even a long time after the intervention. The clinical relevance of this finding and its histological correlates are unknown. We sought to determine the prevalence of chronic pericardial LGE in patients after cardiac surgery. METHODS: All consecutive patients with previous cardiac surgery, who were referred to cardiovascular magnetic resonance between January 2017 and December 2021 were enrolled in the study. Cardiovascular magnetic resonance examination protocol was adapted to clinical indication but always included standard LGE acquisitions. Two independent observers blinded to clinical data assessed the presence of pericardial enhancement on LGE sequences. Fifteen patients underwent cardiac reintervention and pericardial biopsies were obtained. The primary study end point was to assess the prevalence of pericardial enhancement after cardiac surgery and identify possible determinants. The secondary end point was to correlate pericardial enhancement with clinical symptoms and histopathology. RESULTS: Two hundred four patients were included in the study. The median time between surgery and cardiovascular magnetic resonance was 160 months (35-226 months). Pericardial LGE was observed in 90 patients (44%). All patients were asymptomatic, and no specific treatment for pericarditis was started. All patients remained asymptomatic at a 1-year clinical follow-up. Pericardial LGE was significantly correlated with the number of previous surgeries (P=0.03). Pericardial fibrosis was detected in all 15 pericardial biopsy specimens; pericardial LGE was present in 7 patients (47%) who underwent biopsy. Histological signs of low-grade inflammation were detected in 6 patients (40%) with severe, circumferential pericardial LGE but in no patient without pericardial enhancement. CONCLUSIONS: Pericardial LGE is a frequent finding even several years after cardiac surgery. Its histological correlate is a chronic subclinical post--pericardiotomy inflammation. [ABSTRACT FROM AUTHOR]