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

Abstract

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. (C) 2000 The European Society of Cardiology.