Introduction: The management of even large pericardial effusions in asymptomatic patients is still a matter of debate. Aim of the present study is to explore, in a multicenter setting, the rate of post-cardiac injury syndromes (PCIS) and pericardial effusion recurrence after pericardial effusion drainage procedure. Material and Methods: This is a multicenter international retrospective study including a consecutive cohort of patients diagnosed with large, chronic and idiopathic pericardial effusions, prospectively evaluated from January 2003 to December 2021 who underwent a clinically indicated pericardial drainage procedure. Two separate end-points were recorded: 1) recurrence of pericardial effusion after drainage without any sign of pericardial inflammation 2) occurrence of PCIS, defined as the new onset of pericarditis 1 to 6 weeks after pericardial intervention. Results: 124 patients were enrolled (50 % female, mean age 64 years old). A mean follow-up of 29.6 ± 25.6 months was obtained in 110 patients (88 %). 110 patients were treated with pericardiocentesis (89 %), 25 with pleuro-pericardial windows (20 %), and 1 with pericardiectomy (1 %). PCIS occurred in 21 out of 124 patients followed for at least 6 weeks (16.9%). Recurrence of pericardial effusion after drainage without any sign of pericardial inflammation occurred in 68 out of 110 patients at a longer follow-up (61.8 %). At multivariate analysis only inflammatory cells in pericardial fluid was associated with PCIS and pericardiocentesis with pericardial effusion recurrency. Conclusion: Our data support the need of caution with the use of pericardiocentesis in asymptomatic patients with large pericardial effusion as it is often associated with pericardial effusion recurrence. Of interest the presence of inflammatory cells in the pericardial fluid is associated with PCIS after pericardial drainage procedures.
