Plasma volume status predicting clinical outcomes in patients undergoing transcatheter edge-to-edge mitral valve repair

Abstract

Aims: Plasma volume status (PVS) is recognized as a marker of systemic congestion, but its clinical utility in patients with mitral regurgitation (MR) undergoing transcatheter edge-to-edge mitral valve repair (M-TEER) has not been well established. This study aimed to evaluate the prognostic significance of PVS in these patients.

Methods and results: Data from 3763 patients who underwent M-TEER were analysed from a Japanese multicentre registry. Patients were classified into functional MR (FMR) and degenerative MR (DMR) according to MR aetiology, and the median PVS values for each were calculated (FMR 12.7, DMR 14.4). The median value was used as the cut-off, stratifying the cohort into a high PVS group (n = 1882) and a low PVS group (n = 1881). All-cause mortality, cardiovascular death, and heart failure (HF) hospitalization between these two groups were compared up to 3 years in the overall, FMR, and DMR populations. The cumulative incidence rates of all-cause mortality, cardiovascular death, and HF hospitalization were higher in the high PVS group than in the low PVS group (47.0% vs. 22.2%, P < 0.001, 31.6% vs. 13.6%, P < 0.001, and 35.9% vs. 24.7%, P < 0.001, respectively). Similar trends in terms of all-cause mortality, cardiovascular death, and HF hospitalization were observed in the FMR and DMR cohorts (all P < 0.05). In the multivariate Cox regression analysis, the high PVS compared with the low PVS group was independently associated with the increased risk of all-cause death (hazard ratio [HR], 1.02; 95% confidence interval [CI], 1.01-1.03; P < 0.001), cardiovascular death (HR, 1.02; 95% CI, 1.01-1.03, P < 0.001) and HF hospitalization (HR, 1.02; 95% CI, 1.01-1.02, P < 0.001). An independent association between a high PVS and all-cause death, cardiovascular death, and HF hospitalization was also found in FMR and DMR sub-groups (all P < 0.05) while reducing MR severity to moderate or less after M-TEER was associated with improved outcomes in both the high and low PVS groups.

Conclusions: Preoperative PVS is a strong independent prognostic marker in patients undergoing M-TEER, correlating with increased risk of mortality and HF hospitalization. PVS may provide valuable clinical insights for patient stratification and management strategies in M-TEER patients.

Keywords: Heart failure; Mitral regurgitation; Plasma volume status; Transcatheter edge‐to‐edge mitral valve repair.

Figure 1

(A) Flowchart of the study design with patient distribution. (B) Distribution of plasma volume status (PVS) in the OCEAN‐Mitral registry cohort was divided into functional mitral regurgitation (FMR) and degenerative mitral regurgitation (DMR). (C) Kaplan–Meier curves showing cumulative all‐cause mortality, cardiovascular death, and heart failure hospitalization in patients with PVS stratified based on quartiles.

Figure 2

Kaplan–Meier curves showing the study endpoints in the plasma volume status (PVS) groups defined by two differential PVS classifications in functional mitral regurgitation (FMR) and degenerative mitral regurgitation (DMR) cohorts. (A) Kaplan–Meier curves showing cumulative all‐cause death in PVS stratified based on quartiles in the FMR cohort. (B) Kaplan–Meier curves showing cumulative cardiovascular death in PVS stratified based on quartiles in the FMR cohort. (C) Kaplan–Meier curves showing cumulative heart failure (HF) hospitalization in PVS stratified based on quartiles in the FMR cohort. (D) Kaplan–Meier curves showing cumulative all‐cause death in PVS stratified based on quartiles in the DMR cohort. (E) Kaplan–Meier curves showing cumulative cardiovascular death in PVS stratified based on quartiles in the DMR cohort. (F) Kaplan–Meier curves showing cumulative HF hospitalization in PVS stratified based on quartiles in the DMR cohort.

Figure 3

Results of multivariate Cox regression analysis in terms of all‐cause mortality, cardiovascular death, and heart failure (HF) hospitalization by overall, functional mitral regurgitation (FMR), and degenerative mitral regurgitation (DMR) cohorts.

Figure 4

Kaplan–Meier curves of all‐cause death showing in the plasma volume status (PVS) groups defined by two differential PVS classifications in clinical variables. (A) Kaplan–Meier curves showing cumulative all‐cause death in postprocedural residual mitral regurgitation (MR) ≥ +2 stratified based on quartiles in the high and low PVS cohort. (B) Kaplan–Meier curves showing cumulative all‐cause death in following preoperative number of medications. (C) Kaplan–Meier curves showing cumulative all‐cause death in preoperative diuretics stratified based on quartiles in the high and low PVS cohort.