The effects of severe functional mitral regurgitation on right ventricular function in patients with advanced heart failure who were on waiting list for heart transplant

Background: This study aims to investigate the effects of severe functional mitral regurgitation on the parameters that reflect right ventricular function such as tricuspid annular plane systolic excursion and right ventricular stroke work index in potential heart transplant recipients. Methods: Between January 2015 and January 2017, a total of 282 consecutive patients (250 males, 32 females; mean age: 46 +/- 10 years; range, 18 to 66 years) with advanced heart failure who were referred for heart transplantation were retrospectively analyzed. The patients were divided into two groups as severe (n=84) and non-severe functional mitral regurgitation (n=198). Patients' medical histories, demographic characteristics, echocardiographic evaluations, and findings of right heart catheterization were recorded. Results: The two groups were similar in terms of left ventricular ejection fraction, the New York Heart Association functional class, Interagency Registry for Mechanically Assisted Circulatory Support profile, and the duration of heart failure (p>0.05). Both groups were also similar with respect to tricuspid annular plane systolic excursion and right ventricular stroke work index. Functional mitral regurgitation was the only statistically significant variable in the univariate analysis for tricuspid annular plane systolic excursion (odds ratio [OR]: 0.58; 95% confidence interval [CI] 0.34-0.97; p=0.04), with no significant effect in the multivariate analysis. In the univariate analysis for right ventricular stroke work index, pulmonary arterial systolic pressure (OR: 0.77; 95% CI 0.67-0.88; p<0.001) was a significant variable and also had a significant effect in the multivariate analysis (OR: 0.92; 95% CI 0.87-0.97; p=0.003). In the tertile analyses, there were no significant differences between the two groups with respect to tricuspid annular plane systolic excursion and right ventricular stroke work index. Conclusion: We found no significant difference in right ventricular functions between the severe and non-severe functional mitral regurgitation groups in patients with advanced heart failure who had relatively short follow-up. Right ventricle can maintain its normal function at early stage. Adaptive remodeling of right ventricle may have an effect on these findings. Severe functional mitral regurgitation may be associated with adverse effects on advanced heart failure by increasing the right ventricular afterload.