Diagnosis of systemic inflammatory diseases among patients admitted for acute pericarditis with pericardial effusion.

Aims: Acute pericarditis may be the heralding manifestation of various systemic inflammatory diseases (SIDs). The aim of this study was to identify clinical indicators for SIDs in patients admitted for acute pericarditis with pericardial effusion.
Methods: All consecutive adult patients hospitalized in a Department of Internal Medicine over a 10-year period for acute pericarditis with pericardial effusion were retrospectively reviewed. Patients with cancer and tuberculosis were excluded. A structured clinical panel for extra-cardiac symptoms of SIDs was applied. SIDs were classified using current international criteria.
Results: Ninety-nine patients were admitted for acute pericarditis with pericardial effusion. After exclusion, 74 (49.7 ± 19.7 years, 56.7% women) patients were analyzed. Among them, 23 (23.2%) patients had a SID that was revealed by pericarditis in 12 cases. Systemic lupus erythematosus, undifferentiated connective-tissue disease, and Sjogren's syndrome accounted for 75% of the SID. Patients with SIDs were younger (P < 0.001), more frequently of female sex (P = 0.025), and had a higher frequency of extra-cardiac symptoms (P < 0.001) including arthralgia, myalgia, Raynaud phenomenon, and skin rash, as compared with patients with idiopathic pericarditis (n = 51). Overall, after exclusion of neoplasm and tuberculosis, the probability of SIDs in patients admitted with an acute pericarditis with pericardial effusion was 89.7% in patients younger than 50 who had extra-cardiac symptoms. Conversely, the probability fell to 8.4% in patients older than 50 with no extra-cardiac symptoms.
Conclusion: Both age and extra-cardiac symptoms suggest an underlying SID as a possible cause of acute pericarditis.