Diagnosis of acute pericarditis and choice of treatment Acute pericarditis was diagnosed based on clinical recommendations. Baseline clinical and demographic data were recorded in all cases. In line with the current guidelines, diagnostic work-up included clinical history and examination, ECG, chest x-ray, echocardiography and routine blood tests including among others high-sensitivity cardiac troponin I and CRP.12 In patients with high risk features for secondary forms or complicated course13 additional tests will be performed at the discretion of the attending physician.