Serum cardiac troponin I and ST-segment elevation in patients with acute pericarditis

Objective ST-segment elevation in acute pericarditis is believed to be caused by superficial myocardial inflammation or epicardial injury. We used cardiac troponin I, a sensitive and specific marker of myocardial injury, to assess myocardial lesions in idiopathic acute pericarditis and its relationship to ST-segment elevation. Patients and Methods Sixty-nine consecutive patients (53 men, 48 +/- 17 years) with idiopathic acute pericarditis were included. We used an enzymoimmunoflurometric method to measure serum cardiac troponin I on admission (myocardial infarction threshold was 1.5 ng.ml(-1)). Results Cardiac troponin I was detectable in 34 patients (49%) and was beyond the 1.5 ng.ml(-1) threshold in 15 (22%). Coronary angiography performed in seven of these 15 patients was normal in all of them. ST-segment elevation was observed in 93% of the patients with cardiac troponin I >1.5 ng.ml(-1) vs 57% of those without (P<0.01). Sensitivity of ST-segment elevation to detect myocardial injury was 93% and specificity 43%. Patients with a cardiac troponin I increase higher than 1.5 ng.ml(-1) were more likely to have had a recent infection (66% vs 31%; P=0.01) and were younger (37 +/- 14 vs 52 +/- 16 years; P=0.002). There was no significant relationship with other parameters such as pericardial friction rub, fever, PR segment abnormalities, echocardiographic findings or C-reactive protein. Conclusion In patients with idiopathic acute pericarditis, an increase in cardiac troponin I is frequently observed, especially in younger patients and those with a recent infection. Although ST-segment elevation does not reliably indicate myocardial injury, a significant cardiac troponin I increase is only seen in these patients. (Eur Heart J 2000; 21: 832-836) (C) 2000 The European Society of Cardiology.