2D Left Ventricular Ejection Fraction
LVEF had a higher overall effect size compared to LVEDD, with a standard mean difference of |0.77| (95% CI: |0.26| - |1.28|, p≤0.01), with a higher degree of heterogeneity at 86%. Four out of the six studies demonstrated a statistically significant difference in LVEF between those with acute myocarditis when compared to controls. Importantly, Hsaio et al. demonstrated a significantly lower LVEF in myocarditis patients compared to controls (LVEF (%): 49±12 vs 64±4, p<0.01), with a large proportion with impaired systolic function and significantly higher wall motion index score(13). Furthermore, a subgroup analysis in this study for myocarditis patients with preserved LV function, also demonstrated significant difference in comparison to control populations (LVEF (%): 59±6 vs. 64±4; p=0.002)(13). Three other studies also demonstrated similar findings with statistically significant differences in LVEF, despite normal-range values(14-16). Two studies (Di Bella et al. 2018 and Caspar et al. 2017) demonstrated no significant differences in LVEF between myocarditis and control populations (61±4 vs 62±3, p=0.78 and 62.1±3.7 vs 63.5±3.8, p=0.099, respectively). Importantly, these studies did show significantly different LV-GLS values between these populations