Eleven RCTs (n=590 participants) were included for review. Study size ranged from 15 to 108 participants. Study quality was low to moderate: one study scored 1 on the Jadad scale, three scored 2, five scored 3, one scored 4 and one scored 5.
Statin treatment significantly improved left ventricular ejection fraction compared to standard medical treatment (WMD 3.35%, 95% CI 0.80 to 5.91, I2=99.6%; 10 studies, n=575). Significant benefits were observed on left ventricular end-diastolic diameter (WMD -3.77mm, 95% CI -6.24 to -1.31, I2=99.0%; four studies, n=306), left ventricular end systolic diameter (WMD -3.57mm, 95% CI -6.37 to -0.76, I2=97.2%; four studies, n=306), B-type natriuretic peptide (WMD -83.17 picograms/mL, 95% CI -121.29 to -45.05, I2 =96.3%; four studies, n=215) and New York Heart Association functional class (WMD -0.30, 95% CI -0.37 to -0.23, I2=72.4%; three studies, n=160) compared to control conditions.
Meta-regression showed that duration of follow-up was significantly associated with LVEF functioning (p=0.03). Sensitivity analysis that excluded one high-quality long-term study resulted in no benefit of statin on LVEF functioning. Removal of two studies individually resulted in statin having no benefit on LVEDD and LVESD. There was no evidence of publication bias.