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