Global assessment of left ventricle longitudinal strain in patients after acute myocarditis: going further in left ventricular function

Abstract

Introduction: The assessment of prognosis following acute myocarditis is still a difficult task. Novel echocardiographic modalities, such as strain measurement added new parameters in evaluating left ventricular (LV) function. The aim of our study was to assess left ventricle (LV) function by longitudinal (L) strain (S) at midterm follow-up in patients after acute myocarditis. Methods: We included 31 subjects, among which 18 patients (pts) admitted consecutively in a tertiary center after an episode of acute myocarditis and 13 healthy controls. Definition of myocarditis was based on clinical, biochemical and cardiac magnetic resonance imaging information. At 12±7 months follow-up pts were revaluated using strain analysis by speckle tracking imaging. At this stage LV function was compared with the control group. Results: Among the patients with acute myocarditis 15 (83%) were men, 4 (22%) pts presented NYHA class III-IV at baseline and at the acute setting LV ejection fraction (EF) was 52±9%. Moderate LV dysfunction (EF <45%) was present in 3 (17%) pts. All pts showed late gadolinium enhancement (LGE), of which, 12 (66.7%) had a subepicardial pattern, and 6 (33.3%) presented subepicardial and intramural pattern. Extension of LGE was assessed in number of affected segments and 9 (50%) pts had less than 3 segments affected, 7 (40%) pts had between 4 and 7 and 2 (11%) pts had between 8 and 10. Oedema in T2 weight imaging was present in 11 (61.1%) pts. At 12±7 months follow-up all pts were revaluated. There were no changes in EF, regardless of LV function at presentation, extension of LGE or oedema in T2 weight imaging. Mean EF was 58±8% and speckle tracking strain analysis revealed GLS of -17.8±3.2%. Comparing these patients with the control group there was no difference regarding values mean EF (58±8% vs 61.8±3.5 p=0.1) neither GLS (-17.8±3.2% vs -18.7±1.8% p=0.9). There were also no differences when comparing GLS with extension LGE in MRI (p=0.36). Conclusions: In pts with myocarditis, LV function was similar to healthy individuals at one year follow-up. GLS, a marker of refined LV function, was normal despite the presence of LGE in MRI at the acute setting. Further studies are in order to better understand the prognostic role of late gadolinium enhancement in these patients.