Incidence, clinical impact and treatment outcomes of valve thrombosis after transcatheter mitral valve implantation

Background

Transcatheter mitral valve implantation (TMVI) is a new treatment option for high-risk surgical patients with degenerated bioprosthesis (ViV), failed annuloplasty rings (ViR) and severe mitral annular calcification (ViMAC). However, limited data exist on transcatheter heart valve thrombosis.

Purpose

The aim of this study was to report the incidence, clinical impact and treatment outcomes of transcatheter heart valve (THV) thrombosis in patients undergoing TMVI.

Methods

All consecutive patients undergoing TMVI in our center between July 2010 and September 2019 were included. A transoesophageal echocardiography and a computed tomography (CT) were performed before hospital discharge and at each clinical visit, at 3 months, at 1 year and yearly after. THV thrombosis was defined as the presence of at least one thickened leaflet with restricted motion suggestive of thrombus confirmed by TOE and/or contrast CT. All patients received anticoagulation therapy with vitamin K antagonists (VKA) and a low dose of aspirin for the first 3 months.

Results

A total of 132 patients underwent TMVI (62 ViV, 36 ViR and 34 ViMAC). Among them, 16 (12.1%) patients had a THV thrombosis. Median age was 67 years old and 56.2% of patients were women. Median time to diagnosis of THV thrombosis was 78 days. Early THV thrombosis was observed in 7 (43.7%) and in 13 (81.2%) patients THV thrombosis occurred within the first 6 months after the procedure. 8 out 9 patients with subacute or late THV thrombosis were not anticoagulated or with subtherapeutic anticoagulation. No stroke or thromboembolic events occurred in these patients. No change in mitral gradient was observed in 14 out 16 patients. VKA were indicated in all patients. THV thrombosis resolved in all but one patient.

Conclusion

THV thrombosis is frequent after TMVI, occurs mainly within the first 6-months after the procedure, are mostly subclinical and resolves after optimization of anticoagulation treatment. An anticoagulation therapy for at least 6 months may be necessary.

Timing of THV thrombosis

Funding Acknowledgement

Type of funding source: None

Impact of mitral annular calcification associated mitral stenosis on clinical outcomes in patients undergoing transcatheter aortic valve implantation

Introduction

Mitral annular calcification (MAC) is a common finding in patient undergoing transaortic valve implantation (TAVI) and can cause significant mitral stenosis (MS).

Purpose

To assess the impact of MAC associated with significant MS (MAC-MS) on clinical outcomes following TAVR.

Methods

Consecutive patients undergoing TAVI in our institution between January 2008 and May 2018, were evaluated. All echocardiogram exams before intervention were analysed to identify the presence of MAC and MAC was confirmed on computed tomography (CT) scans. Patients were included in the MAC group if there was any calcification on the mitral annulus on CT scan. Severe MAC was considered as calcification of the mitral annulus involving over 50% of the circumference. Patients with a mitral mechanical valve or bioprosthesis and without CT scan available to confirm MAC were excluded (n=62). MAC-MS was defined as the association of MAC and a mean transmitral gradient over 5 mmHg.

Results

Among 1177 consecutive finally included patients, 504 (42.8%) had MAC and 85 had a MAC-MS (7.2%, 16.9% among the MAC population). Compared to MAC without MS (MAC non-MS group) and non-MAC patients, patients with MAC-MS were more frequently women (p<0.0001), had a greater BMI (p=0.002), more previous pacemaker implantation (p=0.035), smaller indexed aortic valve area and left ventricular end systolic diameter (p=0.019 and p=0.038). At 30-days after TAVR, there were no differences in stroke, major vascular complication and pacemaker implantation between groups. However, MAC-MS patients had higher rates of tamponade [Odd Ratio adjusted 3.12, 95% confidence interval (CI) 1.08–9.07, p=0.036] and mortality [Adjusted hazard Ratio (HRa) 2.83, 95% CI 1.39–5.76, p<0.005] after adjustment on baseline characteristics. At 1 year, patients with MAC-MS had a higher risk of death [19 (22.1%) vs. 142 (13%); HRa 1.83, 95% CI 1.14–3.03, p=0.01] compared to MAC non-MS and non-MAC patients. Severe MAC was not a predictor of 1 year mortality.

Conclusions

Mitral stenosis due to mitral annular calcification is infrequent in patient undergoing TAVI but is associated with higher early and mid-term mortality.

Funding Acknowledgement

Type of funding source: None

Transseptal transcatheter mitral valve implantation versus redo surgical mitral valve replacement for degenerated mitral bioprostheses

Background

The growing use of surgical bioprostheses raises concerns about a future reoperation for bioprosthesis degeneration. There are few data on outcome after transcatheter mitral valve-in-valve implantation (TMVI) compared with redo surgical mitral valve replacement (SMVR).

Purpose

To compare the feasibility, safety and outcomes of TMVI versus SMVR for degenerated mitral bioprosthesis in high-risk patients.

Methods

In our institution, 52 patients underwent TMVI by transseptal approach and 33 SMVR for degenerated mitral bioprosthesis. The composite endpoint of event-free survival included cardiovascular mortality, stroke, major bleeding, hospitalization for heart failure or mitral valve reintervention.

Results

Mean age and EuroSCORE II were higher in TMVI group vs. SMVR group (age 63±21 years vs. 51±15 years, p=0.002; EuroSCORE II 12.5±12.2% vs. 6.2±3.3%, p=0.001) (Table). In-hospital mortality was 3.8% after TMVI vs. 3.0% after SMVR (p=1.0).

Median follow-up was 2.2 years. At 5 years, survival was 69.7±9.4% after TMVI vs. 86.6±7.6% after SMVR (p=0.10) and event-free survival was lower after TMVI (40.1±9.9% vs 78.7±8.8% respectively, p=0.003) (Figure). In multivariate analysis, older age (p=0.02), neurologic history (p=0.05) and non-elective procedure (p<0.0001) were associated with lower event-free survival, while TMVI vs. SMVR was no longer significant (p=0.17). At last follow-up, 84% patients from TMVI group and 78% from SMVR group were NYHA I-II class. Mean mitral valve gradient and pulmonary artery systolic pressure were respectively 6.8±2.5 mmHg and 45±14 mmHg in TMVI group, and 4.8±2.0 mmHg and 37±11 mmHg in SMVR group.

Conclusion

TMVI is an alternative to SMVR in high-risk patients with degenerated mitral bioprosthesis. Comparison of mid-term results of the two techniques must take into account the differences in patient characteristics.

Event-free survival

Funding Acknowledgement

Type of funding source: None

Percutaneous aortic valve interventions in heart failure patients

The onset of symptoms of heart failure is a landmark in the natural history of aortic stenosis, and is associated with a dramatic reduction in survival. Aortic valve replacement markedly increases life-expectancy in such patients. However, the presence of heart failure and/or left ventricular dysfunction are strong predictors of poor acute and late mortality after cardiac surgery and the most frequent conditions leading to deny surgical aortic valve replacement in elderly patients. The last decade has witnessed the development of transcatheter aortic valve implantation (TAVI) and, consequently, the resurgence of percutaneous balloon aortic valvuloplasty (PBAV) and, both, are currently routine therapy for high-risk patients. These minimally invasive procedures are appealing therapeutic options for the subset of patients with heart failure and or/left ventricular systolic dysfunction. The available evidence on the results of PBAV and TAVI therapies in this setting is discussed and a management strategy is proposed.

[Percutaneous approaches to mitral valve disease]

Percutaneous approaches to mitral valve disease consist in modifications of existing surgical techniques, aiming to replicate the favourable outcomes of surgery, with less procedure-related risk, due to their less invasive nature. While some of these techniques are clearly indicated for the management of certain valve diseases, other appear as possible alternatives to surgery among patients deemed at high-risk or considered inoperable, or are still under clinical investigation. Major development of these percutaneous approaches is expected within the future, thus hopefully allowing treatment of a larger proportion of patients with mitral valve disease.

[Percutaneous exclusion of the left atrial appendage: perspectives]

With its high prevalence and well-known thromboembolic risk, atrial fibrillation (AF) is a crucial component of the 2010-2014 actions plan, ongoing in France to reduce the annual incidence of stroke. The stroke risk is stratified well with the CHA(2)DS(2)-VASc score. With the current guidelines, most patients with AF should be on oral anticoagulant regimen, a treatment recognized as effective but whose bleeding risks limit its use. In clinical practice, warfarin is often not prescribed in patients with high risk of stroke. Thus, the exploration of new ways in preventing thromboembolic events in patients with AF is needed. Beside new more convenient anticoagulant agents, the exclusion of the left atrial appendage recognized as main source of thrombi, may be an alternative in patients with both high risk of thrombotic and haemorrhagic events. Surgical experience showed that the results depend on the quality of the exclusion. For over the past 10 years, several percutaneous exclusion systems of the left atrial appendage have been developed. A randomized study (PROTECT AF) demonstrated the non-inferiority of the percutaneous exclusion in comparison with the warfarin. However, the place of this interventional therapy remains to be clarified, particularly the definition of the target population. This often multidisciplinary approach will have to be accompanied by a reduction of periprocedural complications, increase in rate of complete occlusion, and enough long clinical follow-up to assess the efficiency of this strategy.

[Echocardiography in the catheterization unit]

Non-coronary interventional cardiology has for about ten years been undergoing significant development, with the arrival of new percutaneous procedures in various domains. Some of them have already been well validated, notably percutaneous mitral comissurotomy, percutaneous closure of inter-atrial (IA) communications and patent foramen ovale, trans-septal catheterisation, and alcohol septal ablation of hypertrophic obstructive cardiomyopathy. Other interventional techniques are still in the validation phase, such as the techniques for percutaneous occlusion of the left atrium, percutaneous implantation of valvular prostheses, or the new approaches to percutaneous treatment of mitral valvulopathy. The rapid development of these techniques has benefited widely from the use of echocardiography in the catheter suite, providing a very precise clarification of the anatomy and continuous guidance during procedures. This echocardiographic guidance provides optimal results for the interventional procedure and reduces the incidence of complications.

[Treatment of intrastent restenosis by drug eluting stents: experience from one cardiology centre]

Many interventional treatments have been proposed for intrastent stenosis, in particular by drug-eluting stents, with encouraging results. The aim of this study was to assess the clinical outcome of patients with restenosis of an ordinary uncovered stent treated by a drug eluting stent in a prospective series. The register included 43 patients (50 intrastent restenoses) treated by a drug eluting stent (Cypher or Taxus). The restenosis lesion was focal in 32% of cases with an average length of 14.8 +/- 8 mm and diameter inferior to 2.5 mm in 48% of cases. A Cypher stent was implanted in 44% of cases and a Taxus stent in 56% of cases. After an average follow-up of 6.7 +/- 1.3 months, the major adverse cardiac event rate was 9.3%. It included one transmural infarct in a patient, due to stent thrombosis, and symptomatic restenoses in 3 patients (clinical restenosis rate: 7%). An angiographic control was performed in 15 patients (35%) identifying focal restenosis at the exit of the stent in the 3 symptomatic patients. As in previously reported studies, these results show that with well conducted platelet antiaggregant therapy, the treatment of intrastent restenosis with a drug eluting stent is effective with a low rate of adverse cardiovascular events which compares favourably with previously proposed techniques of management.

[Intracardiac echography]

The role of echocardiography during non-coronary interventions is of increasing importance. They include percutaneous closure of atrial septal defects (ASD) or patent foramen ovale (PFO), percutaneous balloon mitral valvuloplasty (PMV), septal alcoholization, or interventional procedures managing arrhythmia. In all cases, echographic monitoring enables to guide the procedures, optimize and assess their results and avoid complications. This role could even increase with the development of other interventional techniques such as left auricle appendage exclusion or the percutaneous treatment of valvular diseases. This article reviews this new approach and its value in interventional cardiology.

[A pitfall of transseptal catheterisation for percutaneous mitral commissurotomy: interruption of the inferior vena cava with azygos continuation]

Transseptal catheterisation is a widely used technique in interventional cardiology. The authors report the case of a 37 year old woman admitted for percutaneous mitral commissurotomy of a symptomatic rheumatic mitral stenosis in whom transseptal catheterisation was impossible because of a rare congenital anomaly: interruption of the inferior vena cava with azygos vein continuation.

[Feasibility of percutaneous exclusion of the left atrial appendage: results of 11 cases]

Atrial fibrillation is associated with a risk of cerebral embolism, the only proven effective prevention of which is anticoagulant therapy. There is no known alternative in cases with contra-indications to this treatment. Percutaneous exclusion of the left atrial appendage by the implantation of a prosthesis (PLAATO System, ev3 Inc., Plymouth, Minnesota) is a new approach to the prevention of these complications. The authors report the results observed in a series of 11 consecutive patients (7 men, mean age 72 +/- 9 years) in whom this procedure was proposed. All patients had atrial fibrillation for over 3 months, were at high risk and had contra-indications to oral anticoagulants. The implantation of the prosthesis was performed after treatment with aspirin and clopidogrel, under general anaesthesia radioscopy and transoesophageal echocardiographic guidance with success in 9 cases (1 implantation refused in the catheter laboratory and 1 failure). The only complication observed was transient ST elevation treated by emergency angioplasty. The echographic and angiographic criteria of success of left atrial appendage exclusion were fulfilled in all implanted patients. The hospital course was uncomplicated. One recurrence of stroke was observed at the second month: transoesophageal echocardiography confirmed the absence of thrombosis, of migration of the prosthesis and its impermeability in all the patients. After 7 +/- 5 months' follow-up, no other adverse event was observed. This new procedure is technically feasible. Despite encouraging results, its long-term efficacy in the prevention of thromboembolic complications of atrial fibrillation remains to be demonstrated.

[Angioplasty of saphenous vein grafts in the acute phase of myocardial infarction. Short and mid-term results]

The impact of the progress of interventional cardiology on the improved prognosis of myocardial infarction due to occlusion of a saphenous vein bypass graft is not well known. The aim of this study was to report the modalities and results at short and medium term of revascularisation by angioplasty of venous grafts in the acute phase of myocardial infarction. Out of a total of 870 consecutive patients treated by angioplasty in the first 6 hours of myocardial infarction with persistent ST elevation between 1990 and 2002, 16 (2%) had acute occlusion of a saphenous vein graft. Twelve of the 16 patients had previous myocardial infarction; perfusion was obtained in 7 patients. The attempt failed in 9 patients because of "no-reflow" (n=5), the extensive nature of the thrombosis (n=2) and technical failure (n=2). Three patients died in hospital, all after failed angioplasty. At 6 months, of the 13 survivors of the hospital period, 2 had been readmitted for a revascularisation procedure. At 2 years, 3 patients had died, 2 were readmitted for recurrent myocardial infarction and 8 patients remained free of a major cardiovascular event. Reperfusion by angioplasty of an occluded saphenous vein graft in the acute phase of myocardial infarction remains imperfect and the prognosis at short and medium term is poor.

[Myocardial infarction and disseminated lupus erythematosus]

Myocardial infarction is an underestimated complication of disseminated lupus erythematosus (DLE). Its features, treatment and prognosis are poorly understood. From June 1988 to December 2002, out of 1572 consecutive patients admitted during the first hours of acute myocardial infarction with ST elevation, 7 (5 women, aged 38 +/- 7 years) had DLE. The commonest risk factor was smoking (N = 4). There was a higher incidence of anterior infarction (N = 5). The infarct occurred 7 +/- 5 years after diagnosis of DLE. There were other complications of DLE in all cases. Three patients had antiphospholipid syndromes. The culprit artery was usually the left anterior descending (N = 5). The lesions included stenosing atheroma (N = 5) and extensive thrombosis (N = 5). The coronary disease was usually limited to a single vessel (N = 5). Revascularisation procedures include pre-hospital thrombolysis (N = 3) followed by immediate angioplasty (N = 2) or primary angioplasty (N = 4). TIMI grade 3 flow was obtained in all cases, 278 +/- 162 min after the onset of symptoms. The clinical course was characterised by acute reocclusion in 3 patients, recurrent in 2 patients with an antiphospholipid syndrome, and death in 1 case. Acute myocardial infarction occurs in already complicated cases of DLE, in young patients, associating atherosclerosis and extensive thrombosis. The risk of early reocclusion after reperfusion is high, especially in cases with the antiphospholipid syndrome.