Clinical meaning and prognosis of the elevation degree of cardiac Troponin I in pericarditis of the adult: short-term and mid-term follow-up results

Introduction

The inflammatory process of acute pericarditis (Pc) may involve the epicardium and cause myocardial damage, as reflected by cardiac Troponin I (TnI) release. Studies performed with TnI demonstrated that the temporal pattern of this release is similar to that of an acute myocardial infarction (AMI); however, the true prognostic significance of TnI remains unknown in this setting.

Objective

To investigate the clinical and prognostic value of TnI release in adult with acute Pc.

Methods

From January 2000 to March 2006 we retrospectively studied 89 patients with the final diagnosis of acute myocarditis (Mc), of which 66 (74%) fulfilled at least two criteria of acute Pc (typical chest pain, pericardial friction rub, and/or alterations in the ECG). We only included those diagnosed with idiopathic or viral Pc with elevation of TnI over the level of cut for AMI in our hospital (≥ 0.6 ng/dl). We divided patients into tertiles according to the value of TnI (22 in each group). An echocardiographic (Echoc) study and a ECG monitorization was performed at admission in all. The coronariography was done in 24 (36%), which did not show lesions. The average follow-up was 24 ± 18 months and included Echoc in 61 (92%).

Results

Age 28 ± 9 years, 87% men; two (3%) patients had antecedents of idiopathic Pc and only one of Mc. The average of the peak of TnI was 17 ± 11 ng/dl, being the average of the values of TnI in each group of 6 ± 3 (first tertile), 15 ± 2 (second tertile) and 30 ± 11 ng/dl (third tertile). LVEF% was ≥ 55 in 61 (92%) and there were no differences in the age and sex between the three groups. The elevation of TnI did not correlate with the LVEF% (62 ± 5 vs 61 ± 4 vs 60 ± 7; P = 0.60). Only the values of TnI in the third tertile were associated with the elevation of the ST segment in ≥ 5 derivations (P = 0.001), and with abnormal ventricular wall motion (P = 0.046). There was no association with the presence of pericardial effusion, arrhythmias nor cardiac failure. During follow-up, two (3%) patients presented Mc, and three Pc without elevation of TnI. The remaining patients (92%) were asymptomatic and without cardiac dysfunction. The average LVEF% was >55% in all of them

Conclusion

In adults with acute Pc, the elevation degree of TnI is associated with the degree of elevation of the ST segment but it is not a negative prognosis indicator.