The expressions of ACADM (2.49 ± 0.34 vs. 1.81 ± 0.11, P = 0.065) and ECH1 (2.84 ± 0.30 vs. 2.07 ± 0.30, P = 0.129) proteins in the left atria were up-regulated in the MR patients with heart failure (n = 10) compared to patients with aortic valve disease and heart failure (n = 6), although the difference did not reach statistical significance (Fig. 2). This evidence concerns the gene ECH1 and aortic valve disorder.