Impact of Residual Transmitral Mean Pressure Gradient on Outcomes After Mitral Transcatheter Edge-to-Edge Repair

Abstract

Background: There is conflicting evidence regarding the effect of residual transmitral mean pressure gradient (TMPG) after mitral transcatheter edge-to-edge repair (M-TEER). Different TMPG cutoffs have been employed in prior studies with varying results.

Objectives: The purpose of this study was to examine the association between residual TMPG and M-TEER outcomes.

Methods: Consecutive patients undergoing M-TEER at our institution between 2014 and 2022 were included and divided based on quartiles of predischarge TMPG. Outcomes were assessed using Kaplan-Meier analysis and Cox proportional hazard models. We performed subgroup analyses according to mitral regurgitation (MR) mechanism. The primary outcome was all-cause mortality or heart failure hospitalization.

Results: We included 283 patients (age 76.7 ± 10.8 years, 42.8% women, 78.4% Caucasian, and baseline TMPG 2.4 ± 1.3 mm Hg). Higher baseline TMPG was a predictor of increased TMPG after M-TEER (coefficient 0.60 [95% CI: 0.40-0.70]; P < 0.001). In comparison with predischarge TMPG quartiles 1 to 3, those in quartile 4 (7.0 ± 1.1 mm Hg) had an increased risk of 3-year all-cause mortality or heart failure hospitalization (adjHR: 1.53 [95% CI: 1.03-2.26]; P = 0.034), as well as all-cause mortality alone (adjusted HR [adjHR]: 1.68 [95% CI: 1.09-2.60]; P = 0.020). Among patients with primary MR, similar findings were seen for the composite endpoint (adjHR: 2.08 [95% CI: 1.15-3.77]; P = 0.016), and all-cause mortality (adjHR: 2.70 [95% CI: 1.40-5.19]; P = 0.003). However, this association did not reach statistical significance in secondary MR.

Conclusions: In this single-center study, higher residual TMPG after M-TEER was associated with worse outcomes at intermediate- to long-term follow-up. The effect was mainly driven by increased mortality especially in patients with primary MR. Operators should strive to lower residual TMPG before the conclusion of the procedure.

Keywords: MVG; MitraClip; TEER; TMPG; mean gradient; mitral repair; outcomes.

Graphical abstract

Figure 1

Comparison of Baseline, Final Intraprocedural, Discharge, and 30-Day TMPG Among Patients With Different Quartiles of TMPG at Discharge The error bars represent 1 SD around the mean. TMPG = transmitral mean pressure gradient; TTE = transthoracic echocardiogram.

Central Illustration

Association Between Predischarge TMPG in Quartiles 1 to 4 and Outcomes After M-TEER Impact of transmitral mean pressure gradient (TMPG) on the primary composite outcome of all-cause mortality or heart failure hospitalization at 3 years after M-TEER in (A) all patients; (B) primary mitral regurgitation; and (C) secondary mitral regurgitation. Patients with mixed etiology were excluded from the subgroup analyses shown in (B and C) (N = 15). The panels show adjusted survival analyses stratified by quartiles 1 to 3 versus quartile 4. The variables used for multivariable adjustment are shown in Supplemental Tables 1 to 3. M-TEER = mitral transcatheter edge-to-edge repair.

Figure 2

Comparison of Primary Composite Outcome and Secondary Individual Endpoints After M-TEER According to Quartiles of TMPG The panels show unadjusted Kaplan-Meier curves with overall log-rank P values across the 4 quartiles, as well as the multivariable adjusted HRs comparing quartiles 1 to 3 versus quartile 4. M-TEER = mitral transcatheter edge-to-edge repair; other abbreviation as in Figure 1.

Figure 3

Comparison of Outcomes After M-TEER According to the Mechanism of MR, Including Primary MR and Secondary MR Patients with mixed etiology of mitral regurgitation were excluded from this analysis (N = 15). (A and B) Show unadjusted Kaplan-Meier curves with overall log-rank P values across the 4 quartiles, as well as the multivariable adjusted HRs comparing quartiles 1 to 3 versus quartile 4. MR = mitral regurgitation; other abbreviation as in Figure 2.