Abstract 14351: Prevalence of Myocarditis Among Chest Pain Patients With a Normal Ischemic Evaluation.

Background: Persistent chest pain after a normal ischemic evaluation is often a diagnostic dilemma. Although stress-echo, nuclear stress perfusion imaging and invasive coronary arteriography are commonly used for detection of coronary atherosclerosis, they are not well suited for diagnosing inflammatory heart disease. Cardiac MRI (CMR) is uniquely capable of detecting increased myocardial tissue water content (i.e. edema), a hallmark of myocardial inflammation. This study was designed to assess the value of CMR for detecting myocarditis in a cohort of patients with chest pain and a negative ischemic evaluation. Methods: An institutional cardiac imaging database was queried for all patients with chest pain who underwent CMR after a normal ischemic evaluation. Of 3,702 patients in the database, 1,527 patients with chest pain had a normal stress-echo, normal nuclear myocardial perfusion study(MPI), or normal CMR stress perfusion study. CMR findings of myocarditis included myocardial enhancement on T2 weighted imaging, early gadolinium enhancement, increased T1 relaxation time on T1 mapping, increased T2 relaxation time on T2 mapping and gadolinium enhancement on delayed imaging. At least 2 findings were required for a diagnosis of myocarditis. Results: Of 149 patients with a normal stress-echo, 10 (6.8%) had evidence of myocarditis. Of these 10 patients, nine (90%) were female. 29 out of 403 (7.2%) with a normal MPI had myocarditis. 63 of 924 patients (6.8%) with a normal CMR stress perfusion study, also had myocarditis on CMR. Conclusions: This retrospective analysis of a large institutional cardiac imaging database suggests that patients with a clinical presentation of chest pain, followed by a negative ischemic evaluation have a 7% prevalence of underlying myocarditis. Moreover, females with normal stress-echo results are more likely to have an undetected diagnosis of acute myocarditis. These findings stress the value of CMR for diagnosing myocarditis, especially when the more commonly used cardiac imaging modalities have failed to establish the etiology of chest pain. [ABSTRACT FROM AUTHOR]