Temporal trends of clinical outcomes in patients hospitalized with acute pericarditis: analysis of the nationwide database in Japan

Abstract

Abstract Background Most patients with acute pericarditis are considered to have a good prognosis, but the short-term outcomes and whether they improve or worsen over time are unknown in large clinical databases. Purpose We sought to investigate in-hospital mortality and incidence of cardiac tamponade in patients hospitalized for acute pericarditis in Japan, as well as trends over time in these outcomes. Methods From the Japanese Registry of All Cardiac and Vascular Diseases database from 2016 to 2020, we analyzed 7,374 patients hospitalized for acute pericarditis at 871 certificated hospitals by Japanese Circulation Society. We included etiology of acute pericarditis by idiopathic, connective-tissue disease, and post-cardiac injury syndrome. The primary and secondary outcome was in-hospital mortality and incidence of cardiac tamponade, respectively. Cochran-Armitage test was performed. Results In Japanese acute pericarditis patients (mean age; 65.0 years, male 71.0%), the etiology was idiopathic 96.2%, connective-tissue disease 2.1%, and post-cardiac injury syndrome 1.7%. The mortality rate and incidence of cardiac tamponade were 2.2% and 5.3%, respectively. Secular trend in those rates remained unchanged over time (p-trend = 0.30 and 0.19). The rates of mortality and cardiac tamponade were 2.1% and 5.2% in idiopathic pericarditis, 1.3% and 10.5% in connective-tissue disease, and 7.0% and 3.9% in post-cardiac injury syndrome, respectively. Connective-tissue disease pericarditis was at higher risk of cardiac tamponade compared to idiopathic pericarditis (5.2 vs. 10.5%, P=0.004). In addition, compared to idiopathic pericarditis, postoperative cardiac pericarditis tended to have a higher mortality rate (2.1 vs. 7.0%, P<0.001). Conclusion The short-term prognosis of acute pericarditis did not change significantly over time. This finding that clinical outcomes differed depending on the underlying disease suggests to clinicians the importance of differential diagnosis.