Eleven studies comprising a total of 1244 patients reported the POAF in patients pretreated with atorvastatin or placebo^25-29,32-37 . Atorvastatin was correlated to a reduced prevalence of POAF (133/627 [21.2%] versus 201/617 [32.6%]). There was a statistically significant difference between the considered groups (OR 0.54; 95% CI: 0.41 to 0.70, p-value < 0,00001). There was severe heterogeneity observed between the 11 studies (I²= 65%) (Figure 9 ). However, If we only consider studies with ≥ 199 patients, the results are different (OR 0.74; 95% CI: 0.54 to 1.03, p-value = 0.08; I²= 83%) (Figure 10 ).