Abstract 12952: Global Longitudinal Strain is Simple, Effective & Sensitive Assessment of Cardiac Chamber Function in Patients With Acute-phase Myocarditis

Abstract

Introduction: Myocarditis is an inflammatory disease process with growing clinical relevance in the current COVID-19 pandemic. Acute-phase myocarditis is known to result in subclinical changes in left ventricular (LV) function despite normal LV ejection fraction (LVEF), as assessed by myocardial deformation indices. The presence of right ventricular (RV) and left atrial (LA) subclinical dysfunction however has not been well described in current literature. Hypothesis: Myocarditis patients have subclinical impairment of LV, RV and LA function as assessed by global longitudinal strain (GLS) on speckle tracking echocardiography. Methods: Consecutive patients with clinical diagnosis of myocarditis admitted to our institution during 2013-2018 were assessed (n=76). Patients who did not meet appropriate diagnostic criteria (n=14), had impaired LVEF or prior cardiac disease (n=8) or poor transthoracic echocardiogram images (n=14) were excluded from analysis. Clinical and echocardiographic parameters were compared to age- , gender- and risk factor- matched controls. GLS was performed by two independent observers using vendor independent software (TomTec Arena, Germany v4.6). Results: The final cohort consisted 40 patients with myocarditis (age 44.3±16.7, 60% male) and 40 matched controls (44.5±16.6, 60% male). No significant differences in baseline clinical characteristics were observed between groups. No differences in LVEF, indexed LV mass, RV fractional area change, indexed LA volume or TR pressure gradient (p>0.05 for all) were demonstrated between the two groups. Patients with myocarditis had a lower mean LV strain (GLS%: -16.4±2.9 vs -19.7±2.7, p=0.0001), a lower mean RV Free Wall Strain (FWS) (GLS%: -22.1±4.1 vs -26.2±6.9, p=0.03) and a lower mean LA reservoir strain (GLS%: 27.5±4.6 vs. 33.7±6.3, p<0.0001) when compared to controls. Conclusions: Our results demonstrate the presence of significant subclinical global myocardial dysfunction despite normal traditional echocardiographic indices, in patients with acute-phase myocarditis. Routine assessment of GLS may identify such patients for early targeted cardiac therapy.