Reverse cardiac remodeling in patients undergoing combination therapy of transcatheter mitral valve repair

Aims

For patients with severe mitral valve regurgitation (MR), different kinds of transcatheter mitral valve repair (TMVr) exist, targeting the leaflets, annulus, and chordae. The concomitant combination (COMBO) therapy of TMVrs is rarely used as treatment, and there are very few publications about this therapeutic strategy. We evaluated the effect of COMBO-TMVr on the cardiac left chambers and clinical data, including survival.

Methods

We included 35 patients at high risk who underwent concomitant sequential transcatheter mitral valve edge-to-edge repair (M-TEER) and another TMVr for severe MR in our hospital between March 2015 and April 2018. Of these, 13 had adequate follow-up transthoracic echocardiography (TTE) up to around 1 year after the procedure.

Results

Survival for all patients was 83% at 1 year, 71% at 2 years, and 63% at 3 years, respectively. In the 13 patients with adequate TTE follow-up, M-TEER plus either Cardioband (n = 4), Carillon Mitral Contour System (n = 7), or Neochord (n = 2) were used, respectively. Ten patients had secondary, and three patients primary MR. After 1 year, changes [median (Q1, Q3)] of left ventricular (LV) end-systolic diameter of -9.9 cm (-11.1, 0.4), LV end-diastolic diameter of -3.3 cm (-8.5, 0.0), LV end-systolic volume (LVESV) of -17.4 mL (-32.6, -0.4), LV end-diastolic volume (LVEDV) of -13.5 mL (-15.9, -3.2), LV mass of -19.5 g (-24.2, -7.6), and left atrial volume (LAV) index (LAVi) of -16.4 mL (-23.3, -11.3) were observed. A significant reduction was also seen in the change ratios of LVESV, LVEDV, LV mass, and LAVi, respectively.

Conclusion

We found that COMBO therapy of TMVr seems feasible and may support reverse remodeling of left cardiac chambers during 1 year after the procedure in a cohort of patients at high risk.

Randomized Comparison of Transcatheter Edge-to-Edge Repair for Degenerative Mitral Regurgitation in Prohibitive Surgical Risk Patients

BACKGROUND

Severe symptomatic degenerative mitral regurgitation (DMR) has a poor prognosis in the absence of treatment, and new transcatheter options are emerging.

OBJECTIVES

The CLASP IID (Edwards PASCAL Transcatheter Valve Repair System Pivotal Clinical Trial) randomized trial (NCT03706833) is the first to evaluate the safety and effectiveness of the PASCAL system compared with the MitraClip system in patients with significant symptomatic DMR. This report presents the primary safety and effectiveness endpoints for the trial.

METHODS

Patients with 3+ or 4+ DMR at prohibitive surgical risk were assessed by a central screening committee and randomized 2:1 (PASCAL:MitraClip). Study oversight also included an echocardiography core laboratory and a clinical events committee. The primary safety endpoint was the composite major adverse event rate at 30 days. The primary effectiveness endpoint was the proportion of patients with mitral regurgitation (MR) ≤2+ at 6 months.

RESULTS

A prespecified interim analysis in 180 patients demonstrated noninferiority of the PASCAL system vs the MitraClip system for the primary safety and effectiveness endpoints of major adverse event rate (3.4% vs 4.8%) and MR ≤2+ (96.5% vs 96.8%), respectively. Functional and quality-of-life outcomes significantly improved in both groups (P < 0.05). The proportion of patients with MR ≤1+ was durable in the PASCAL group from discharge to 6 months (PASCAL, 87.2% and 83.7% [P = 0.317 vs discharge]; MitraClip, 88.5% and 71.2% [P = 0.003 vs discharge]).

CONCLUSIONS

The CLASP IID trial demonstrated safety and effectiveness of the PASCAL system and met noninferiority endpoints, expanding transcatheter treatment options for prohibitive surgical risk patients with significant symptomatic DMR.

Effects of MitraClip Therapy on Mitral Flow Patterns and Vortex Formation: An In Vitro Study

MitraClip transcatheter edge-to-edge repair is used to treat mitral regurgitation (MR). While MR is reduced, diastolic left ventricular flows are altered. An in vitro left heart simulator was used to assess a porcine mitral valve in the native, MR, and MR plus MitraClip cases. Velocity, vorticity, and Reynolds shear stress (RSS) were quantified by particle image velocimetry. Peak velocity increased from 1.20 m/s for native to 1.30 m/s with MR. With MitraClip, two divergent jets of 1.18 and 0.61 m/s emerged. Higher vorticity was observed with MR than native and lessened with MitraClip. MitraClip resulted in shear layer formation and downstream vortex formation. Native RSS decreased from 33 Pa in acceleration to 29 Pa at peak flow, then increased to 31 Pa with deceleration. MR RSS increased from 27 Pa in acceleration to 40 Pa at peak flow to 59 Pa during deceleration. MitraClip RSS increased from 79 Pa in acceleration to 162 Pa during peak flow, then decreased to 45 Pa during deceleration. After MitraClip, two divergent jets of reduced velocity emerged, accompanied by shear layers and recirculation. Chaotic flow developed, resulting in elevated RSS magnitude and coverage. Findings help understand consequences of MitraClip on left ventricular flow dynamics.

Impact of bleeding complications after transcatheter mitral valve repair

BACKGROUND

Bleeding in the context of cardiac catheterization is frequent and negatively impacts on short- and long-term patient outcome. We evaluated the clinical impact of in-hospital bleeding events after transcatheter mitral valve repair (TMVr) in the long-term follow- up.

METHODS

586 consecutive patients treated with first-time TMVr were enrolled in this registry. In-hospital MVARC (Mitral Valve Academic Research Council) bleedings were assessed and patients were grouped according to the incidence of a bleeding event. Multivariate logistic regression was used to identify significant independent predictors of MVARC bleeding. This study received approval by local ethics committee.

RESULTS

78 patients (13.3%) suffered from an MVARC bleeding event (Access site-related bleedings: 46.2%; GI tract bleeding: 35.9%; Other bleedings: 17.9%). Among these bleeding subgroups, neither relevant differences in baseline characteristics nor in severity of bleeding events were observed. Despite not being an independent predictor for overall death in the multivariate Cox regression analysis, MVARC bleeding was associated with prolonged hospital stay. The ORBIT bleeding score was the best match to predictors of any MVARC bleeding found in our cohort (c-score overall cohort: 0.68; c-score GI bleeding cohort: 0.72).

CONCLUSION

MVARC bleedings after TMVr are frequent findings but were only in half of the cases related to the access site. The ORBIT score could be useful for identification of patients at high risk for non-access site bleeding and especially GI bleeding.