Predictors and clinical impact of thrombosis after transcatheter mitral valve implantation using balloon-expandable bioprostheses

Transcatheter mitral valve implantation for native valve disease

Mitral regurgitation is the second most frequent heart valve disease in Europe and the most frequent in the US. Although surgery is the therapy of choice when intervention is indicated, transcatheter mitral valve repair or replacement are alternatives for patients who are not eligible for surgery. However, the development of transcatheter mitral valves is slower than expected. Although several transcatheter heart valves have been developed, only one has been commercialised. Indeed, most of these devices are being evaluated in clinical studies, with promising initial results. In this review, we propose an overview on transcatheter mitral valve replacement for the treatment of native mitral valve disease, from indication to results, including patients with severe annular calcification, and we provide you with a glimpse into the future of these therapies.

Emergent transcatheter mitral valve implantation: Early and mid-term outcomes

BACKGROUND

Transcatheter mitral valve implantation (TMVI) may be attractive to treat high-risk patients with mitral bioprosthesis or annuloplasty ring failure or severe mitral annular calcification.

AIM

To report the outcomes of patients after valve-in-valve/ring/mitral annular calcification TMVI using balloon expandable transcatheter aortic valves, according to the degree of urgency of the procedure.

METHODS

All patients who underwent TMVI in our centre from 2010 to 2021 were classified into three groups: elective, urgent or emergent/salvage TMVI.

RESULTS

A total of 157 patients were included: 129 (82.2%) had elective, 21 (13.4%) urgent and 7 (4.4%) had emergent/salvage TMVI. Patients with emergent/salvage TMVI had a higher EuroSCORE II: elective, 7.3%; urgent, 9.7%; emergent/salvage, 54.5% (P<0.0001). The indication for TMVI was bioprosthesis failure in all of the emergent/salvage group, in 13 of the urgent group (61.9%) and in 62 of the elective group (48.1%). Overall, the technical success rate of TMVI was 86%, and was similar in the three groups (elective, 86.1%; urgent, 95.2%; emergent/salvage, 71.4%). The cumulative survival rate at 2-year follow-up was lower in the emergent/salvage group than in the elective or urgent group (42.9% vs 71.2% for the elective group; 76.2% for the urgent group; log-rank test, P=0.012). The excess mortality in the emergent/salvage group occurred during the first month postprocedure. Thereafter, the 30-day landmark analysis did not show any more statistical difference between the three groups (log-rank test, P=0.94).

CONCLUSIONS

Emergent/salvage TMVI was associated with high early mortality, but 1-month survivors had similar outcomes to patients with elective/urgent TMVI. The degree of urgency of the procedure should not prevent TMVI in high-risk patients.

Mitral Valve-in-Ring Leaflet Thrombosis: A Multimodality Imaging Primer

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Echocardiography and CT help to detect mitral THVT.

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Hypoattenuated leaflet thickening on CT indicates mitral thrombosis.

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Duration of anticoagulation to prevent mitral transcatheter valve thrombosis is unclear.

Mitral valve-in-valve and valve-in-ring procedures: Midterm outcomes in a French nationwide registry

OBJECTIVES

Report contemporary outcomes in patients included in the Mitragister registry and treated with transcatheter mitral valve implantation for failed surgical annuloplasty rings or deteriorated bioprosthesis.

BACKGROUND

Midterm survival rates have been reported, but little is known about contemporary morbimortality endpoints.

METHODS

The primary safety outcome was the technical success rate. The primary efficacy composite endpoint was a composite of cardiovascular mortality and heart failure hospitalizations.

RESULTS

From 2016 to 2021, 102 patients (median age: 81 [74;84] years, 61% female, Euroscore II 11.0% [7.8;16.0]) undergoing valve-in-valve (ViV; n = 89) or valve-in-ring (ViR; n = 13) procedures were consecutively included. At baseline, ViR group patients had worse left ventricular ejection fraction (50% vs. 60%; p = 0.004) and more frequently severe regurgitation (46% vs. 15%; p = 0.014). The primary safety outcome was 95%: 77% and 98% in the ViR and ViV populations, respectively, (p = 0.014). At intermediate follow-up (6-12 months) clinical improvement was notable, 88% of the patients were in NYHA class ≤ II (vs. 25% at baseline; p < 0.001). At a mean follow-up of 17.1 ± 11.0 months, the primary efficacy composite reached 27%. By multivariate analysis, paravalvular leak (PVL) was the only independent predictor (hazard ratio: 2.39, 95% confidence interval: 1.08-5.29; p = 0.031) while ViR was not found statistically associated (p = 0.456).

CONCLUSIONS

This study confirms the safety and efficacy of the mitral ViV procedure. ViR patients appear at higher risk of procedural complications. The presence of PVL could be associated with markedly worse midterm prognosis. Whatever the intervention, procedural strategies to reduce PVL incidence remain to be assessed to prevent latter adverse outcomes.

Causes and predictors of mortality after transcatheter mitral valve implantation in patients with severe mitral annulus calcification

OBJECTIVES

To evaluate the causes and predictors of mortality after valve-in-mitral annulus calcification (MAC) transcatheter mitral valve implantation (TMVI).

BACKGROUND

Conventional surgical mitral valve replacement is associated with a high risk in patients with mitral valve disease associated with severe MAC. In this population, TMVI may be an attractive alternative option. However, its prognostic factors are poorly understood.

METHODS

All patients undergoing valve-in-MAC TMVI from 2013 to 2018 in our center were included. Indication for TMVI relied on the judgment of the local heart team. Patients were followed at 30 days and 1 year.

RESULTS

A total of 34 patients underwent valve-in-MAC TMVI. The mean age was 79 ± 11 years and 73% of patients were women. Their mean EuroSCORE 2 was 8 ± 7%. The transseptal approach was used in 79% of patients and a hybrid transatrial in 29%. Balloon expandable transcatheter heart valves were used in all the patients. Technical success was achieved in 76% of the patients. Thirty-day and 1-year all-cause mortality rates were 14.7% and 32.4%, respectively. The main two causes of 1-year mortality were congestive heart failure (8.8%) and infective endocarditis (5.9%). In multivariate analysis, the only predictor of 1-year mortality was the presence of periprothetic mitral regurgitation grade 2 (HR, 5.69; 95%CI, 1.59-27.88, p = 0.032).

CONCLUSION

Early and mid-term mortality remains high after valve-in-MAC TMVI and seems to be associated with the presence of paravalvular mitral regurgitation. However, whether the latter is a prognostic factor or marker remains to be determined to improve clinical outcomes in this high-risk population.