Statistical Analysis 
The measurement data conforming to normal distribution and homogeneity of variance were tested by t-test, and the results showed that left ventricular diameter (LVD) (45.83±8.8mm) of the progression group was lower than that of the non-progression group (48.61±8.60mm), p=0.145<0.20. The mitral valve peak velocity in the progression group (2.07±0.62m/s) was higher than that in the non-progression group (1.83±0.58m/s), p=0.071<0.20. The aortic valve velocity was tested by the Mann-Whitney U test. The results showed that the average rank of the progression group was 93.82, the non-progression group was 68.02, U=954.50, p=0.005<0.20. Although compared the patients in the progression group with the non-progression group, Hypertension (1 case, 4% vs 12 cases, 10.1%, p=0.467>0.20), atrial fibrillation (17 cases, 68% vs 73 cases, 61.3%, p=0651>0.20), LVEF(55.95±4.38 vs 57.49±6.83, p=0.323>0.20), None of the above results were significant. Referring to the results of Mentias S, Matsuyama K et al [9-12], these possible clinical related variables were also included in multivariate regression analysis. The final results are shown in Table 5.
The results of the multivariable model have statistical significance, x²=34.637, p<0.001. Among the 9 variables, tricuspid ring annuloplasty, LVD, mitral prosthesis size, the presence of mild to moderate AVD before the operation, and aortic valve velocity were statistically significant (p<0.05). Compared with untreated, patients who received tricuspid ring annuloplasty had a 90% lower risk of progression events. In order to facilitate multivariable analysis, we classified LVD into three grades according to clinical reference values (<35mm, 35-50mm, >50mm). With each increase of one grade, the risk is reduced by 73%. Similarly, The aortic valve velocity was divided into three grades (<1.0m/kg, 1.0-1.7m/s, >1.7m/s). With each increase of one grade, the risk increased by 3.70 times. The risk increased by 2.40 times for each additional level of mitral prosthesis size (25# 27# 29#). The risk of patients who had mild to moderate AVD before the operation was 7.28 times higher than those without.