Contemporary Treatment and Outcomes of High Surgical Risk Mitral Regurgitation

Abstract

Before the development of transcatheter interventions, patients with mitral regurgitation (MR) and high surgical risk were often conservatively treated and subject to poor prognoses. We aimed to assess the therapeutic approaches and outcomes in the contemporary era. The study participants were consecutive high-risk MR patients from April 2019 to October 2021. Among the 305 patients analyzed, 274 (89.8%) underwent mitral valve interventions, whereas 31 (10.2%) received medical therapy alone. Of the interventions, transcatheter edge-to-edge mitral repair (TEER) was the most frequent (82.0% of overall), followed by transcatheter mitral valve replacement (TMVR) (4.6%). In patients treated with medical therapy alone, non-optimal morphologies for TEER and TMVR were shown in 87.1% and 65.0%, respectively. Patients undergoing mitral valve interventions experienced less frequent heart failure (HF) rehospitalization compared to those with medical therapy alone (18.2% vs. 42.0%, p < 0.01). Mitral valve intervention was associated with a lower risk of HF rehospitalization (HR 0.36 [0.18-0.74]) and an improved New York Heart Association class (p < 0.01). Most high-risk MR patients can be treated with mitral valve interventions. However, approximately 10% remained on medical therapy alone and were considered as unsuitable for current transcatheter technologies. Mitral valve intervention was associated with a lower risk of HF rehospitalization and improved functional status.

Keywords: contemporary management; mitral regurgitation; mitral valve intervention; optimal medical therapy alone.

Figure 1

Study flow chart. The present study included 274 patients (89.8%), who underwent mitral valve interventions and 31 (10.2%) were treated with medical therapy alone.

Figure 2

Contemporary therapeutic management of high surgical risk MR. Mitral valve intervention was performed in 89.8% of patients with high surgical risk, of which TEER was the most common approach. In contrast, 10.2% were treated with medical therapy alone (a). Among patients treated with medical therapy alone, 87.1% showed non-optimal valve morphology for TEER (b). Abbreviations: MR, mitral regurgitation; TEER, transcatheter edge-to-edge repair; and TMVR, transcatheter mitral valve replacement.

Figure 3

Details of non-optimal mitral valve morphology for TEER and TMVR. The details of non-optimal valve morphology were assessed for TEER by echocardiography (a). The details of CT assessment for TMVR are shown (b). Abbreviations: CT, computed tomography; LV, left ventricular; LVOT, left ventricular outflow tract; MAC, mitral annular calcification; TEER, transcatheter edge-to-edge mitral repair; and TMVR, transcatheter mitral valve replacement.

Figure 4

Representative cases of non-optimal valve morphologies for TEER. Red arrows indicate the MR jet in the lateral and medial segments (a). White arrow highlights the short length of the posterior leaflet with calcification (b). The red double-headed arrow depicts long coaptation height (c). The yellow double-headed arrow illustrates a long flail width (d). Abbreviations: MR, mitral regurgitation.

Figure 5

Representative cases of non-eligible valve morphologies for TMVR. Red arrows indicate severe mitral annular calcification (a). White curved outline and white arrows illustrate small neo-LVOT area. Blue curved line shape shows simulated transcatheter heart valve (b). Abbreviations: LVOT, left ventricular outflow tract and TMVR, transcatheter mitral valve replacement.

Figure 6

Heart failure rehospitalization and all-cause mortality within one year. The Kaplan–Meier curve depicts a lower cumulative event rate of heart failure rehospitalization in patients undergoing mitral valve interventions compared to patients treated with medical therapy (18.2% vs. 42.0%, p < 0.01) (a). In contrast, one-year all-cause mortality was similar between the groups (20.2% vs. 22.6%, p = 0.71) (b).

Figure 7

One-year heart failure hospitalization and all-cause mortality according to residual MR ≤ 2+, >2+ at discharge, and medical therapy alone. Patients with a reduction in MR to ≤2+ at discharge exhibited a lower event rate of heart failure rehospitalization compared to medical therapy alone (16.4% vs. 42.0%, p < 0.01) (a). However, patients with a residual MR > 2+ at discharge showed comparable outcomes with those treated with medical therapy alone (Heart failure rehospitalization: 29.9% vs. 42.0%, p = 0.28; all-cause mortality: 27.3% vs. 22.6%, p = 0.65) (b). Abbreviations: MR, mitral regurgitation.

Figure 8

Changes in NYHA functional class. Mitral valve intervention was associated with an improvement in the NYHA functional class from baseline to one-year follow-up (p < 0.01). Patients undergoing mitral valve interventions had lower NYHA functional scales compared to medical therapy alone within one-year follow-up (p < 0.01). Abbreviations: NYHA, New York Heart Association.

Figure 9

Changes in severity of MR and LV end-diastolic volume. At one year, patients undergoing mitral valve interventions had a lower severity of MR compared to medical therapy alone (p < 0.01) (a). Mitral valve intervention was associated with decreased LV end-diastolic volume from baseline to one-year follow-up (p < 0.01). LV end-diastolic volume within one year follow-up was similar between the two groups (94.9 mL [66.3, 132.3] vs. 93.3 mL [55.6, 144.7], p = 0.87) (b). Abbreviations: LV, left ventricular and MR, mitral regurgitation.