Cor Vasa 2018, 60(6):e607-e614 | DOI: 10.1016/j.crvasa.2018.01.003

Should we fear infarct-like myocarditis?

Jan Duršpek^a,*, Jan Baxa^b, Jakub Šedivý^a, Daniel Rajdl^c, Milan Hromádka^a, Jan Lhotský^a, Richard Rokyta^a

^a Cardiology Department, University Hospital and Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic

^b Department of Radiology, University Hospital in Pilsen, Pilsen, Czech Republic

^c Institute of Clinical Biochemistry and Hematology, University Hospital in Pilsen, Pilsen, Czech Republic

Introduction: Infarct-like myocarditis is the most common presentation of acute myocarditis. A good prognosis is mentioned in the literature and several months of restricted physical activity is usually recommended.

Objectives: The aim of our study was to show the characteristic features and specificity of this particular presentation of myocarditis and to evaluate its prognosis, relative to physical activity, after hospital discharge.

Methodology: From 2012-2016, 73 patients with infarct-like myocarditis were hospitalized at the University Hospital of Pilsen and were evaluated by basic diagnostic parameters. Thirty-two patients from this group were involved in our prospective observational study where echocardiography (ECHO), magnetic resonance imaging (MRI) (including late gadolinium enhancement [LGE]), bicycle ergometry (BE) as well as troponin screening tests were regularly performed. One month after hospital discharge, all patients underwent bicycle ergometry without any load limitation. After the one-month follow-up, patients were allowed to increase physical exertion gradually to included job performance. None of the patients were professional athletes. During this observation time, 20 patients with different presentations of acute myocarditis were also admitted to hospital. These different presentations are discussed.

Results: None of the patients with infarct-like myocarditis had an early recurrence of the disease (i.e., within one year) or left ventricular (LV) systolic dysfunction (based on ECHO results). After one month, the LGE volume median had decreased by up to 53% and after six months it had decreased by up to 40% of the original value. After one and six months, hypersensitive troponin values were under the 99th percentile of the healthy population. The achieved exertion during BE, at the six-month follow-up (9.7 ± 2.2 METs) was statistically significantly better than after the one-month follow-up (8.9 ± 2.1 METs, p = 0.0023). On the last BE follow--ups (9.3 ± 2.1 METs), no significant change was seen (p = 0.2331). The average follow-up time was 2 years.

Conclusion: Infarct-like myocarditis has a specific feature that differs from other types of myocarditis. Infarct-like myocarditis has a good prognosis, which is independent of physical exertion starting one month after hospital discharge.

Keywords: Bicycle ergometry; Infarct like myocarditis; Late gadolinium enhancement; Magnetic resonance imaging; Prognosis

Received: December 11, 2017; Revised: January 6, 2018; Accepted: January 10, 2018; Published: December 1, 2018  Show citation