Right atrial structural remodeling predict worse outcomes in transcatheter mitral valve repair

Abstract

Background: In the current study, we assess the predictive role of right and left atrial volume indices (RAVI and LAVI) as well as the ratio of RAVI/LAVI (RLR) on mortality following transcatheter mitral valve repair (TMVr).

Methods: Transthoracic echocardiograms of 158 patients who underwent TMVr at a single academic medical center from 2011 to 2018 were reviewed retrospectively. RAVI and LAVI were calculated using Simpson's method. Patients were stratified based on etiology of mitral regurgitation (MR). Cox proportional-hazard regression was created utilizing MR type, STS-score, and RLR to assess the independent association of RLR with survival. Kaplan-Meier analysis was used to analyze the association between RAVI and LAVI with all-cause mortality. Hemodynamic values from preprocedural right heart catheterization were also compared between RLR groups.

Results: Among 123 patients included (median age 81.3 years; 52.5% female) there were 50 deaths during median follow-up of 3.0 years. Patients with a high RAVI and low LAVI had significantly higher all-cause mortality while patients with high LAVI and low RAVI had significantly improved all-cause mortality compared to other groups (p = 0.0032). RLR was significantly associated with mortality in patients with both functional and degenerative MR (p = 0.0038). Finally, Cox proportion-hazard modeling demonstrated that an elevated RLR above the median value was an independent predictor of all-cause mortality [HR = 2.304; 95% CI = 1.26-4.21, p = 0.006] when MR type and STS score were accounted for.

Conclusion: Patients with a high RAVI and low LAVI had significantly increased mortality than other groups following TMVr suggesting RA remodeling may predict worse outcomes following the procedure. Concordantly, RLR was predictive of mortality independent of MR type and preprocedural STS-score. These indices may provide additional risk stratification in patients undergoing evaluation for TMVr.

Keywords: Cardiac Remodeling; Echocardiography; LAVI; Mitraclip; Mitral Regurgitation; RAVI; RAVI/LAVI Ratio; Transcatheter Mitral Valve Repair.

Figure 1

Representative transthoracic echocardiogram images for RAVI/LAVI groups. All images are presented in apical four chamber view. Measurements were made by Simpson method of disc summation using AGFA Enterprise Imaging software. LAVI, left atrial volume indices; RAVI, right atrial volume indices.

Figure 2

Kaplan−Meier plot for TMVr patients by RAVI and LAVI above and below the median values. Red represents both RAVI and LAVI below median value; green represents RAVI less than median value, LAVI greater than median value; blue represents RAVI greater than median value, LAVI less than median value; purple represents both RAVI and LAVI above median values. Time on X‐axis is in years. Survival probability on Y‐axis calculated from all‐cause mortality (p = 0.0032). LAVI, left atrial volume indices; RAVI, right atrial volume indices; TMVr, transcatheter mitral valve repair. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 3

Kaplan−Meier plot for TMVr patients separated by RLR above or below median value of 0.6 and MR etiology. Red represents FMR patients with RLR less than 0.6. Purple represents FMR patients with RLR greater than 0.6. Yellow represents DMR patients with RLR less than 0.6. Blue represents DMR patients with RLR greater than 0.6. Time on X‐axis in years. Survival probability on Y‐axis calculated from all‐cause mortality (p = 0.0038). DMR, degenerative mitral regurgitation; FMR, functional mitral regurgitation; LAVI, left atrial volume indices; MR, mitral regurgitation; RAVI, right atrial volume indices; RLR, RAVI/LAVI ratio; TMVr, transcatheter mitral valve repair. [Color figure can be viewed at wileyonlinelibrary.com]