Abstract 10904: Undetectable Serum Cardiac Troponin I Does Not Preclude a Diagnosis of Giant Cell Myocarditis
Introduction: Giant cell myocarditis (GCM) is characterized by a fulminant and life-threatening course requiring prompt attention and advanced therapies. Suspicion for GCM is one of the only class I indications for performing an endomyocardial biopsy (EMB) for unexplained heart failure. GCM involves a polymorphous inflammatory cell infiltrate alongside myocyte damage, but may be missed due to the limitations of EMB. Elevated serum cardiac Troponin I (cTnI) is highly specific and sensitive for cardiac injury. Due to the destructive nature of GCM, cTnI would be expected to be elevated in this condition.
Hypothesis: We hypothesized that cTnI level is not predictive of GCM on EMB.
Methods: The Johns Hopkins Hospital EMB database was queried for acute myocarditis cases. Peak cTnI at time of presentation was obtained from the medical record.
Results: Six patients with GCM were identified (Table 1). Peak cTnI values were: <0.06, 0.09, 0.32, 1.8, 15.48 and 26.68 ng/mL. The patients with cTnI of <0.06 and 0.09 ng/mL had evidence of extensive myocyte necrosis on biopsy. Five patients required mechanical circulatory support and/or orthotopic heart transplant, four of whom passed away during index hospitalization. Thirty-seven cases of non-giant cell myocarditis were identified (Table 2). cTnI ranged from undetectable to 192 ng/mL (median 0.47 ng/mL; interquartile range: 6.52 ng/mL).
Conclusions: To our knowledge, no data exist on the role of cTnI in diagnosis and prognosis in GCM. Based on our experience, cTnI cannot be used as a screening tool or prognostic marker in GCM, nor should a negative or low-level troponin influence the decision to perform EMB.
Author Disclosures: N.A. Gilotra: None. N. Minkove: None. M.K. Bennett: None. R.J. Tedford: None. C. Steenbergen: None. M.K. Halushka: None. D.P. Judge: None. S.D. Russell: None.
- © 2015 by American Heart Association, Inc.