Mitral Regurgitation Severity and Echocardiographic Changes at 1-Year Postoperative: A Comparative Study of Surgical Aortic Valve Replacement Versus Transcatheter Aortic Valve Replacement

Background: Limited research exists on evolution of coexisting mitral valve regurgitation (MR) severity following transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) in patients with aortic stenosis (AS). In addition, very few studies have compared changes in echocardiographic measurements from preop to 1- year postop between TAVR and SAVR groups. This study aims to evaluate changes in MR severity and echocardiographic parameters at 1 year postop. Methods: Patients with AS and MR who underwent TAVR or SAVR from January 2000 to January 2023 were categorized based on preoperative MR severity. A Chi-square test and Fisher’s exact test, where appropriate were conducted to examine the association between demographics or comorbidities and mitral valve regurgitation severity. Survival between two groups was compared using Kaplan-Meier curves. A Mann-Whitney test was utilized to examine changes in echocardiographic parameters pre- and 1 year postop. Results: Of 165 patients, 80.0% underwent SAVR. In the SAVR group, 43 (32.6%) patients had coronary artery bypass grafting, 7 (5.3%) underwent mitral valve replacement (MVR), and 3 (2.3%) had endocarditis at surgery. Median age of TAVR patients with mild and moderate/severe MR was 80.0 and 83.5 years, respectively, compared to 71.0 and 76.5 years in SAVR group. Survival curves showed no significant difference between 2 procedures (p=0.0845). Within patients who underwent TAVR, a significantly higher proportion of patients with moderate/severe MR preop had congestive heart failure compared to patients with mild MR preop (100% vs 56.0%, p=0.031). For change in MR severity analysis, 25 patients were excluded due to missing follow-up echocardiographic data. Most patients with mild MR in both TAVR (79.2%) and SAVR (66.7%) groups experienced no change in MR severity. A higher percentage of those with moderate/severe MR showed grade improvement (62.5% in TAVR, 91.7% in SAVR without MVR, and 100% in SAVR with MVR). When comparing Echocardiographic parameters, there was no statistically significant difference between SAVR and TAVR groups, regarding Δ change from preop to 1-year postop measurements in median left ventricular ejection fraction (LVEF %) (0 vs 0, p=0.495), left ventricular internal diameter end diastolic (LVIDd cm) (0.01 vs 0.14, p=0.948), left ventricular internal diameter end systolic (LVIDs cm) (-0.34 vs 0.24, p=0.131), left ventricular outflow tract diameter (LVOTd cm) (-0.06 vs -0.10, p=0.838), left atrial dimension (LAd cm) (0.16 vs -0.25, p=0.262), and mitral valve E/A ratio (-0.001 vs 0.10, p=0.469). There were no significant differences in preop comorbidities or operative characteristics examined between improved and not improved MR groups. Conclusion: Patients with moderate/severe MR who underwent SAVR or TAVR predominantly experienced improved MR grade at one year postoperatively, whereas those with mild MR were likely to remain unchanged. Comparison of echocardiographic changes from preop to 1-year postop shows no significant difference between SAVR and TAVR groups. No predictive preop or operative characteristics were identified. Our findings provide valuable insights for decision-making in performing TAVR and SAVR on patients with AS and MR, particularly those with moderate to severe MR and multiple comorbidities, who may face higher risks from concomitant valve replacement procedures.