Hemodynamic Profiles and Clinical Response to Transcatheter Mitral Repair

Mismatch Between Residual Mitral Regurgitation and Left Atrial Pressure Predicts Prognosis After Transcatheter Edge-to-Edge Repair

BACKGROUND

The mechanism and impact of mismatch between residual mitral regurgitation (MR) and postprocedural left atrial pressure (LAP) after transcatheter edge-to-edge repair (TEER), which may adversely affect clinical outcome, is of great interest.

OBJECTIVES

This study aimed to examine the effect of hemodynamic mismatch after TEER on clinical outcomes in patients with heart failure due to severe MR and investigate the predictive factors for the mismatch using a prospective multicenter registry.

METHODS

We categorized 1,477 patients into optimal (residual MR grade ≤1 and postprocedural LAP ≤15 mm Hg), mismatched (residual MR grade >1 or postprocedural LAP >15 mm Hg), and poor (residual MR grade >1 and postprocedural LAP >15 mm Hg) groups and examined their prognosis. The primary endpoint was a composite of all-cause mortality and heart failure hospitalization.

RESULTS

There were 927 (62.7%), 459 (31.1%), and 91 (6.2%) patients categorized into optimal, mismatched, and poor groups, respectively. Cox regression analysis, referenced to the optimal group, revealed that the mismatched and poor groups exhibited a higher risk for the primary endpoint (HR: 1.55; 95% CI: 1.28-1.88; and HR: 1.95; 95% CI: 1.38-2.74, respectively). Six risk factors were identified as predictors of hemodynamic mismatch after TEER: body mass index, baseline left atrial volume index, atrial fibrillation, tricuspid annular plane systolic excursion value, preprocedural mean left atrial pressure, and postprocedural mean mitral valve pressure gradient.

CONCLUSIONS

Post-TEER hemodynamic mismatch between residual MR and postprocedural LAP was associated with a poor prognosis. Six readily accessible perioperative parameters predict the hemodynamic mismatch. (OCEAN-Mitral registry; UMIN000023653).

Impact of Left Atrial Pressure on Outcomes After Mitral Transcatheter Edge-to-Edge Repair

BACKGROUND

Increased left atrial pressure (LAP) has been associated with adverse outcomes after mitral transcatheter edge-to-edge repair (M-TEER). We sought to evaluate outcomes based on differences in postprocedural LAP measured after the final clip deployment.

METHODS

We included consecutive patients who underwent M-TEER at our institution between 2014 and 2022 with LAP monitoring. Patients were stratified into 3 groups according to tertiles of post-TEER mean LAP. Outcomes were assessed using Kaplan-Meier analysis and Cox proportional hazards models.

RESULTS

We included 273 patients (mean age, 76.8±10.8 years; 42.5% women; 78.4% White). The mean post-TEER LAP was 8.7±1.7 mm Hg in tertile 1 (n=85), 14.4±1.6 mm Hg in tertile 2 (n=95), and 21.9±3.8 mm Hg in tertile 3 (n=93). In comparison with tertile 1, both tertiles 2 and 3 were associated with increased risk of all-cause mortality or heart failure hospitalization at 2 years (adjusted hazard ratio [adjHR], 2.27 [95% CI, 1.25-4.12] and adjHR, 3.00 [95% CI, 1.59-5.64], respectively). Among patients with primary mitral regurgitation, higher LAP was associated with increased risk of 2-year all-cause mortality or heart failure hospitalization (tertile 2 versus 1: adjHR, 3.00 [95% CI, 1.37-6.56]; tertile 3 versus 1: adjHR, 5.52 [95% CI, 2.04-14.95]). However, in patients with secondary mitral regurgitation, neither being in tertile 2 (adjHR, 1.53 [95% CI, 0.55-4.24]) nor tertile 3 (adjHR, 2.18 [95% CI, 0.82-5.77]) were associated with the composite outcome compared with tertile 1. Any degree of LAP reduction following M-TEER was associated with lower mortality or heart failure hospitalization compared with no LAP reduction (adjHR, 0.59 [95% CI, 0.39-0.88]).

CONCLUSIONS

Elevated LAP after M-TEER was associated with increased 2-year risk of mortality or heart failure hospitalization. Exploration of reasons for elevated LAP after M-TEER and ways to lower it warrant further investigation.

A Novel Hemodynamic Index Characterizing Mitral Regurgitation Undergoing Transcatheter Edge-to-Edge Repair: The MPF

Background

Hemodynamic impact of residual mitral regurgitation (MR) after transcatheter edge-to-edge repair (TEER) is not always univocally measured by transesophageal echocardiographic (TEE) assessment alone. When analyzing TEER procedure result, operators often encounter discrepancy between TEE guidance and invasive hemodynamic monitoring.

Objectives

This study sought to investigate the role of invasive hemodynamic monitoring during mitral valve TEER procedure on top of TEE guidance.

Methods

We analyzed 78 patients with moderate-to-severe or severe MR who underwent TEER. Mitral pulse pressure fraction (MPF) was extracted from intraprocedural continuous left atrial pressure monitoring. Twenty-three patients with the same grade of MR not undergoing TEER were included as a control group. At follow-up, clinical and functional status in the majority of patients undergoing TEER were reassessed by NYHA classification and the 12-item Kansas City Cardiomyopathy Questionnaire (KCCQ).

Results

TEER significantly reduced MR burden on both TEE guidance and invasive hemodynamic monitoring. Post-TEER MPF was significantly reduced compared to both pre-TEER setting (P < 0.001) and control group (P < 0.001). At follow-up, while MR reduction assessed by TEE was associated with an improved functional status in terms of the 12-item KCCQ but not of NYHA classification, a greater reduction in MPF was associated with a significant amelioration of both NYHA classification (P = 0.036) and 12-item KCCQ (P = 0.032).

Conclusions

MPF could provide an immediate estimate of the real hemodynamic impact of MR and a prompt prediction of the functional improvement after TEER.

Mitral valve transcatheter edge-to-edge repair as a bridge to treat aortic dissecting aneurysm in a case of Marfan syndrome: a case report

Background

Marfan syndrome is an inherited disorder that manifests with various cardiovascular conditions. This case report discusses a patient with Marfan syndrome presenting with concurrent dissecting aortic aneurysm and acute mitral valve regurgitation (MR), exploring treatment strategies for this unique case.

Case summary

A 57-year-old man diagnosed with Marfan syndrome presented with progressive dyspnoea and awareness of orthopnoea. Acute heart failure (HF) due to acute MR associated with chordae rupture was diagnosed. However, contrast-enhanced CT revealed the coexistence of a massive dissecting aortic aneurysm, indicating surgical intervention. The dissecting aortic aneurysm extended over a large area. Given the high risk of simultaneous surgery with the mitral valve, a staged approach was adopted. Mitral valve transcatheter edge-to-edge repair (MV-TEER) was performed as the initial step to reduce the perioperative HF risk, followed by a planned two-stage surgery for the dissecting aortic aneurysm. This strategy effectively facilitated surgical intervention for the dissecting aortic aneurysm in the chronic phase after MV-TEER.

Discussion

Several reports showed the effectiveness of MV-TEER in cases of degenerative MR where surgical operation carries a high risk, but case report of MV-TEER in Marfan syndrome is rare. In recent years, the effectiveness of MV-TEER has also been reported as a 'bridge therapy' for heart transplantation. Mitral valve transcatheter edge-to-edge repair is considered a potential option to serve as a bridge to other invasive intervention.

Pulmonary venous flow patterns associated with long-term mitral transcatheter edge-to-edge outcomes

OBJECTIVE

Transcatheter edge-to-edge repair (TEER) is a prominent therapeutic option for mitral regurgitation (MR) patients. However, it lacks objective parameters to assess procedural efficacy. This study aims to investigate pulmonary venous (PV) flow as a surrogate for valvular hemodynamics and its associations to clinical outcomes.

METHODS

Consecutive MR patients who underwent TEER in our center from January 2020 to October 2021 were retrospectively investigated. PV flow parameters were measured before and after TEER, including velocity (cm/s), velocity time integral (VTI) (cm), and systolic/diastolic ratios. Primary outcomes were 1, 6, and 12 months heart failure hospitalizations (HFH) and 1 year all-cause mortality.

RESULTS

The cohort consisted of 80 patients. The mean age was 74.76 ± 10.13 years, 26 with primary and 54 with secondary MR. Systolic wave parameters improved significantly after TEER: mean peak velocity increased from 9.94 ± 31.95 to 35.74 ± 15.03 cm/s, and VTI from 3.62 ± 5.99 to 8.33 ± 4.72 cm. Furthermore, systolic to diastolic VTI and peak-velocities ratios showed significant improvement of 0.39 ± 0.63 to 0.81 ± 0.47 and 0.23 ± 0.66 to 0.91 ± 0.43, respectively. Using multivariable analysis, higher post-procedural SVTI was associated with less HFH: 1-month (OR = 0.72, CI [0.52,0.98]), 6-months (OR = 0.8, CI [0.66,0.97]), 1-year (OR = 0.85, CI [0.73,0.99]), as well as reduced 1-year mortality (OR = 0.64 95% CI [0.45,0.91]). Furthermore, compared to patients with SVTI ≥ 3, patients with SVTI < 3 had a higher risk for HFH at: 1-month (OR = 16.59, CI [1.48,186.02]), 6-months (OR = 12.2, CI [1.69,88.07]), and 1-year (OR = 8.61, CI [1.27,58.27]), as well as elevated 1-year mortality (OR = 8.07, 95% CI [1.04,62.28]).

CONCLUSION

PV flow was significantly improved following TEER, and several hemodynamic parameters were associated with HFH and mortality. These results may offer a basis for establishing future procedural goals to ensure better clinical outcomes.

Prognostic Value of Right Ventricular Afterload in Patients Undergoing Mitral Transcatheter Edge-to-Edge Repair

BACKGROUND

Pulmonary hypertension (PH) and secondary mitral regurgitation (MR) are associated with adverse outcomes after mitral transcatheter edge-to-edge repair. We aim to study the prognostic value of invasively measured right ventricular afterload in patients undergoing mitral transcatheter edge-to-edge repair.

METHODS AND RESULTS

We identified patients who underwent right heart catheterization ≤1 month before transcatheter edge-to-edge repair. The end points were all-cause mortality and a composite of mortality and heart failure hospitalization at 2 years. Using the receiver operating characteristic curve-derived threshold of 0.6 for pulmonary effective arterial elastance ([Ea], pulmonary artery systolic pressure/stroke volume), patients were stratified into 3 profiles based on PH severity (low elastance [HE]: Ea <0.6/mean pulmonary artery pressure (mPAP)) <35; High Elastance with No/Mild PH (HE-): Ea ≥0.6/mPAP <35; and HE with Moderate/Severe PH (HE+): Ea ≥0.6/mPAP ≥35) and MR pathogenesis (Primary MR [PMR])/low elastance, PMR/HE, and secondary MR). The association between this classification and clinical outcomes was examined using Cox regression. Among 114 patients included, 50.9% had PMR. Mean±SD age was 74.7±10.6 years. Patients with Ea ≥0.6 were more likely to have diabetes, atrial fibrillation, New York Heart Association III/IV status, and secondary MR (all P<0.05). Overall, 2-year cumulative survival was 71.1% and was lower in patients with secondary MR and mPAP ≥35. Compared with patients with low elastance, cumulative 2-year event-free survival was significantly lower in HE- and HE+ patients (85.5% versus 50.4% versus 41.0%, respectively, P=0.001). Also, cumulative 2-year event-free survival was significantly higher in patients with PMR/low elastance when compared with PMR/HE and patients with secondary mitral regurgitation (85.5% versus 55.5% versus 46.1%, respectively, P=0.005).

CONCLUSIONS

Assessment of the preprocedural cardiopulmonary profile based on mPAP, MR pathogenesis, and Ea guides patient selection by identifying hemodynamic features that indicate likely benefit from mitral-transcatheter edge-to-edge repair in PH or lack thereof.

Chordal force profile after neochordal repair of anterior mitral valve prolapse: An ex vivo study

Objective

This study aimed to biomechanically evaluate the force profiles on the anterior primary and secondary chordae after neochord repair for anterior valve prolapse with varied degrees of residual mitral regurgitation using an ex vivo heart simulator.

Methods

The experiment used 8 healthy porcine mitral valves. Chordal forces were measured using fiber Bragg grating sensors on primary and secondary chordae from A2 segments. The anterior valve prolapse model was generated by excising 2 primary chordae at the A2 segment. Neochord repair was performed with 2 pairs of neochords. Varying neochord lengths simulated postrepair residual mitral regurgitation with regurgitant fraction at >30% (moderate), 10% to 30% (mild), and <10% (perfect repair).

Results

Regurgitant fractions of baseline, moderate, mild, and perfect repair were 4.7% ± 0.8%, 35.8% ± 2.1%, 19.8% ± 2.0%, and 6.0% ± 0.7%, respectively (P < .001). Moderate had a greater peak force of the anterior primary chordae (0.43 ± 0.06 N) than those of baseline (0.19 ± 0.04 N; P = .011), mild (0.23 ± 0.05 N; P = .041), and perfect repair (0.21 ± 0.03 N; P = .006). In addition, moderate had a greater peak force of the anterior secondary chordae (1.67 ± 0.17 N) than those of baseline (0.64 ± 0.13 N; P = .003), mild (0.84 ± 0.24 N; P = .019), and perfect repair (0.68 ± 0.14 N; P = .001). No significant differences in peak and average forces on both primary and secondary anterior chordae were observed between the baseline and perfect repair as well as the mild and perfect repair.

Conclusions

Moderate residual mitral regurgitation after neochord repair was associated with increased anterior primary and secondary chordae forces in our ex vivo anterior valve prolapse model. This difference in chordal force profile may influence long-term repair durability, providing biomechanical evidence in support of obtaining minimal regurgitation when repairing mitral anterior valve prolapse.

Regional geometric differences between regurgitant and non-regurgitant mitral valves in patients with coronary artery disease

OBJECTIVE

Demonstrate that regional geometric differences exist between regurgitant and non-regurgitant mitral valves (MV's) in patients with coronary artery disease and due to the heterogenous and regional nature of ischemic remodeling in patients with coronary artery disease (CAD), that the available anatomical reserve and likelihood of developing mitral regurgitation (MR) is variable in non-regurgitant MV's in patients with CAD.

METHODS

In this retrospective, observational study intraoperative three-dimensional transesophageal echocardiographic data was analyzed in patients undergoing coronary revascularization with MR (IMR group) and without MR (NMR group). Regional geometric differences between both groups were assessed and MV reserve which was defined as the increase in antero-posterior (AP) annular diameter from baseline that would lead to coaptation failure was calculated in three zones of the MV from antero-lateral (zone 1), middle (zone 2), and posteromedial (zone 3).

MEASUREMENTS AND MAIN RESULTS

There were 31 patients in the IMR group and 93 patients in the NMR group. Multiple regional geometric differences existed between both groups. Most significantly patients in the NMR group had significantly larger coaptation length and MV reserve than the IMR group in zones 1 (p-value = .005, .049) and 2 (p-value = .00, .00), comparable between the two groups in zone 3 (p-value = .436, .513). Depletion of the MV reserve was associated with posterior displacement of the coaptation point in zones 2 and 3.

CONCLUSIONS

There are significant regional geometric differences between regurgitant and non-regurgitant MV's in patients with coronary artery disease. Due to regional variations in available anatomical reserve and the risk of coaptation failure in patients with CAD, absence of MR is not synonymous with normal MV function.

A case report of transcatheter repair of severe functional mitral regurgitation in cardiac amyloidosis

Background

Transcatheter therapy has become an alternative for functional mitral regurgitation (FMR) in patients at high surgical risk. However, the intervention of FMR in cardiac amyloidosis (CA) with transcatheter edge-to-edge repair (TEER) is controversial due to the potential risk of left atrial pressure (LAP) elevation.

Case summary

An 83-year-old woman with repeated heart failure (HF) and severe mitral regurgitation (MR) was referred to our centre for TEER. Pre-procedural transthoracic echocardiography (TTE) and transoesophageal echocardiography (TOE) confirmed the degree of MR and a functional aetiology. A peculiar LAP increase in this patient occurred immediately after successful TEER clip implantation and her n-terminal prohormone of brain natriuretic peptide significantly increased post-operatively. The diagnosis of CA was suspected and was subsequently established through endomyocardial biopsy. Aggressive anti-HF therapy was initiated and the patient was discharged after her HF symptoms were relieved. At 6-month follow-up, the patient was still alive and no episode of acute HF was experienced.

Discussion

Severe functional MR in CA treated with TEER has the potential risk of increasing LAP. During the short-term follow-up, TEER appears beneficial for left heart function (reduction of MR) but harmful for right heart function (increase of LAP). CA patients with severe FMR should be carefully evaluated about the benefits and potential harm of TEER intervention.