Incidence, characteristics and functional implications of cerebral embolic lesions after the MitraClip procedure

Strategy to optimize PeriproCeduraL AnticOagulation in structural transseptal interventions: Design and rationale of the STOP CLOT trial

BACKGROUND

Both transcatheter edge-to-edge repair (TEER) of mitral regurgitation or left atrial appendage closure (LAAC) require periprocedural anticoagulation with unfractionated heparin (UFH) that is administered either before or immediately after transseptal puncture (TSP). The optimal timing of UFH administration (before or after TSP) is unknown. The Strategy To Optimize PeriproCeduraL AnticOagulation in Structural Transseptal Interventions trial (STOP CLOT Trial) was designed to determine if early anticoagulation is effective in reducing ischemic complications without increasing the risk of periprocedural bleeding.

METHODS

The STOP CLOT trial is a multicenter, prospective, double-blind, placebo-controlled, randomized trial. A total of 410 patients scheduled for TEER or LAAC will be randomized 1:1 either early UFH administration (iv. bolus of 100 units/kg UFH or placebo, given after obtaining femoral vein access and at least 5 minutes prior to the start of the TSP) or late UFH administration (iv. bolus of 100 units/kg UFH or placebo given immediately after TSP). Prespecified preliminary statistical analysis will be performed after complete follow-up of the first 196 randomized subjects. To ensure blinding, a study nurse responsible for randomization and UFH/placebo preparation is not involved in the care of the patients enrolled into the study. The primary study endpoint is a composite of (1) major adverse cardiac and cerebrovascular events (death, stroke, TIA, myocardial infarction, or peripheral embolization) within 30 days post-procedure, (2) intraprocedural fresh thrombus formation in the right or left atrium as assessed with periprocedural transesophageal echocardiography, or (3) occurrence of new ischemic lesions (diameter ≥4 mm) on brain magnetic resonance imaging performed 2 to 5 days after the procedure. The safety endpoint is the occurrence of moderate or severe bleeding complications during the index hospitalization.

CONCLUSIONS

Protocols of periprocedural anticoagulation administration during structural interventions have never been tested in a randomized clinical trial. The Stop Clot trial may help reach consensus on the optimal timing of initiation of periprocedural anticoagulation.

CLINICAL TRIALS REGISTRATION NUMBER

The study protocol is registered at ClinicalTrials.gov, identifier NCT05305612.

Cerebral embolic protection during transcatheter heart interventions

Stroke remains a devastating complication of transcatheter aortic valve replacement (TAVR), with the incidence of clinically apparent stroke seemingly fixed at around 3% despite TAVR's significant evolution during the past decade. Embolic showers of debris (calcium, atheroma, valve material, foreign material) are captured in the majority of patients who have TAVR using a filter-based cerebral embolic protection device (CEPD). Additionally, in systematic brain imaging studies, the majority of patients receiving TAVR exhibit new cerebral lesions. Mechanistic studies have shown reductions in the volume of new cerebral lesions using CEPDs, yet the first randomised trial powered for periprocedural stroke within 72 hours of a transfemoral TAVR failed to meet its primary endpoint of showing superiority of the SENTINEL CEPD. The present review summarises the clinicopathological rationale for the development of CEPDs, the evidence behind these devices to date and the emerging recognition of cerebral embolisation in many non-TAVR transcatheter procedures. Given the uniqueness of each of the various CEPDs under development, specific trials tailored to their designs will need to be undertaken to broaden the CEPD field, in addition to evaluating the role of CEPD in non-TAVR transcatheter heart interventions. Importantly, the cost-effectiveness of these devices will require assessment to broaden the adoption of CEPDs globally.

New Perspective on Pathophysiology and Management of Functional Mitral Regurgitation

Functional mitral regurgitation (FMR) occurs as a result of global or segmental left ventricular (LV) dysfunction or left atrial dilatation, leading to mitral annular dilatation, papillary muscle displacement, mitral valve (MV) leaflet tethering, and leaflet remodeling. The prevalence of FMR continues to rise in the United States. Even mild FMR is associated with adverse clinical outcomes. Echocardiography is the primary imaging modality used to assess the type and severity of mitral regurgitation. FMR treatment depends on the etiology. Evidence-based pharmacologic and cardiac resynchronization therapies for underlying LV dysfunction remain the mainstay of treatment. Patients who remain symptomatic despite optimal medical therapy can be considered for surgical or percutaneous MV intervention. This article reviews the pathophysiology, imaging evaluation, and therapeutic options of FMR, highlighting the most recent developments in a rapidly evolving field.

Cerebrovascular Events After Transcatheter Edge-to-Edge Repair and Guideline-Directed Medical Therapy in the COAPT Trial

BACKGROUND

Little is known regarding the risk of cerebrovascular events (CVE) in patients with heart failure and severe secondary mitral regurgitation treated with transcatheter edge-to-edge repair (TEER).

OBJECTIVES

The study sought to examine the incidence, predictors, timing, and prognostic impact of CVE (stroke or transient ischemic attack) in the COAPT (Cardiovascular Outcomes Assessment of the Mitraclip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial.

METHODS

A total of 614 patients with heart failure and severe secondary mitral regurgitation were randomized to TEER plus guideline-directed medical therapy (GDMT) vs GDMT alone.

RESULTS

At 4-year follow-up, 50 CVEs occurred in 48 (7.8%) of the 614 total patients enrolled in the COAPT trial; Kaplan-Meier event rates were 12.3% in the TEER group and 10.2 in the GDMT alone group (P = 0.91). Within 30 days of randomization, CVE occurred in 2 (0.7%) patients randomized to TEER and 0% randomized to GDMT (P = 0.15). Baseline renal dysfunction and diabetes were independently associated with increased risk of CVE, while baseline anticoagulation was associated with a reduction of CVE. A significant interaction was present between treatment group and anticoagulation such that TEER compared with GDMT alone was associated with a reduced risk of CVE among patients with anticoagulation (adjusted HR: 0.24; 95% CI: 0.08-0.73) compared with an increased risk of CVE in patients without anticoagulation (adjusted HR: 2.27; 95% CI: 1.08-4.81; P_interaction = 0.001). CVE was an independent predictor of death within 30 days after the event (HR: 14.37; 95% CI: 7.61, 27.14; P < 0.0001).

CONCLUSIONS

In the COAPT trial, the 4-year rate of CVE was similar after TEER or GDMT alone. CVE was strongly associated with mortality. Whether anticoagulation is effective at reducing CVE risk after TEER warrants further study. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Trial] and COAPT CAS [COAPT); NCT01626079).

Cerebral embolisation during transcatheter edge-to-edge repair of the mitral valve with the MitraClip system: a prospective, observational study

BACKGROUND

New ischaemic brain lesions on magnetic resonance imaging (MRI) are reported in up to 86% of patients after transcatheter edge-to-edge repair of the mitral valve (TEER-MV). Knowledge of the exact procedural step(s) that carry the highest risk for cerebral embolisation may help to further improve the procedure.

AIMS

The aim of this study was to identify the procedural step(s) that are associated with an increased risk of cerebral embolisation during TEER-MV with the MitraClip system. Furthermore, the risk of overt stroke and silent brain ischaemia after TEER-MV was assessed.

METHODS

In this prospective, pre-specified observational study, all patients underwent continuous transcranial Doppler examination during TEER-MV to detect microembolic signals (MES). MES were assigned to specific procedural steps: (1) transseptal puncture and placement of the guide, (2) advancing and adjustment of the clip in the left atrium, (3) device interaction with the MV, and (4) removal of the clip delivery system and the guide. Neurological examination using the National Institutes of Health Stroke Scale (NIHSS) and cerebral MRI were performed before and after TEER-MV.

RESULTS

Fifty-four patients were included. The number of MES differed significantly between the procedural steps with the highest numbers observed during device interaction with the MV. Mild neurological deterioration (NIHSS ≤3) occurred in 9/54 patients. New ischaemic lesions were detected in 21/24 patients who underwent MRI. Larger infarct volume was significantly associated with neurological deterioration.

CONCLUSIONS

Cerebral embolisation is immanent to TEER-MV and predominantly occurs during device interaction with the MV. Improvements to the procedure may focus on this procedural step.

Asymptomatic Stroke in the Setting of Percutaneous Non-Coronary Intervention Procedures

Advancements in clinical management, pharmacological therapy and interventional procedures have strongly improved the survival rate for cardiovascular diseases (CVDs). Nevertheless, the patients affected by CVDs are more often elderly and present several comorbidities such as atrial fibrillation, valvular heart disease, heart failure, and chronic coronary syndrome. Standard treatments are frequently not available for “frail patients”, in particular due to high surgical risk or drug interaction. In the past decades, novel less-invasive procedures such as transcatheter aortic valve implantation (TAVI), MitraClip or left atrial appendage occlusion have been proposed to treat CVD patients who are not candidates for standard procedures. These procedures have been confirmed to be effective and safe compared to conventional surgery, and symptomatic thromboembolic stroke represents a rare complication. However, while the peri-procedural risk of symptomatic stroke is low, several studies highlight the presence of a high number of silent ischemic brain lesions occurring mainly in areas with a low clinical impact. The silent brain damage could cause neuropsychological deficits or worse, a preexisting dementia, suggesting the need to systematically evaluate the impact of these procedures on neurological function.

Magnetic Resonance Imaging for Cerebral Micro-embolizations During Minimally Invasive Mitral Valve Surgery

The role of aortic clamping techniques on the occurrence of neurological complications after right mini-thoracotomy mitral valve surgery is still debated. Brain injuries can occur also as silent cerebral micro-embolizations (SCM), which have been linked to significant deficits in physical and cognitive functions. Aims of this study are to evaluate the overall rate of SCM and to compare endoaortic clamp (EAC) with trans-thoracic clamp (TTC). Patients enrolled underwent a pre-operative, a post-operative, and a follow-up MRI. Forty-three patients were enrolled; EAC was adopted in 21 patients, TTC in 22 patients. Post-operative SCM were reported in 12 cases (27.9%). No differences between the 2 groups were highlighted (23.8% SCM in the EAC group versus 31.8% in the TTC). MRI analysis showed post-operative SCM in nearly 30% of selected patients after right mini-thoracotomy mitral valve surgery. Subgroup analysis on different types of aortic clamping showed comparable results. CLINICAL RELEVANCE: The rate of SCM reported in the present study on patients undergoing minimally invasive MVS and RAP is consistent with data in the literature on patients undergoing cardiac surgery through median sternotomy and antegrade arterial perfusion. Moreover, no differences were reported between EAC and TTC: both the aortic clamping techniques are safe, and the choice of the surgical setting to adopt can be really done according to the patient's characteristics.

Complications Following MitraClip Implantation

Purpose of Review

To provide a detailed overview of complications associated with MitraClip therapy and its development over time with the aim to alert physicians for early recognition of complications and to offer treatment strategies for each complication, if possible.

Recent Findings

The MitraClip system (MC) is the leading transcatheter technique to treat mitral regurgitation (MR) and has been established as a safe procedure with very low adverse event rates compared to mitral surgery at intermediate to high risk or in secondary MR. Lately, the fourth MC generation has been launched with novel technical features to facilitate device handling, decrease complication rates, and allow the treatment of even complex lesions.

Summary

Although the complication rate is low, adverse events are associated with increased morbidity and mortality. The most common complications are bleeding, acute kidney failure, procedure-induced mitral stenosis, and an iatrogenic atrial septal defect with unknown clinical impact.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11886-021-01553-9.

Cerebral Protection Devices during Transcatheter Interventions: Indications, Benefits, and Limitations

Purpose of Review

Stroke remains a devastating complication of cardiovascular interventions. This review is going to discuss stroke rates and outcomes in different cardiovascular procedures with a highlight on the current evidence for the use of cerebral protection devices (CPD).

Recent Findings

Depending on the quality of neurological assessment, stroke occurs in up to 9.1% after TAVI, 3.9% after mitral clipping, 3.1% in LAAO patients, 0.4% after PCIs, and 1.8% after catheter ablation. CPDs are available for routine use. They are easy to use in most anatomies, feasible, and safe. Data on clinical impact and stroke reduction from RCTs are still missing.

Summary

Most evidence for the routine use of CPDs exists in TAVI patients, who are at the highest risk. The PROTECTED TAVI RCT will shed more light on the clinical impact of CPD-use in TAVI patients. In other cardiovascular procedures like mitral clipping, PCIs, and ablation, the current data do not support the routine use of CPDs in these patients.

Cerebrovascular events after transcatheter mitral valve interventions: a systematic review and meta-analysis

Objective

Current guidelines support the use of transcatheter mitral valve interventions to treat some selected high-risk patients with significant mitral valvulopathy. As with any other interventional cardiac procedure, concerns have been raised about cerebrovascular event. The aim of this systematic review and meta-analysis was to determine the incidence of cerebrovascular events following (1) transcatheter mitral valve edge-to-edge repair with mitral valve clip and (2) transcatheter mitral valve replacement (TMVR).

Methods

We conducted a systematic review of studies reporting the cerebrovascular adverse events after transcatheter mitral valve edge-to-edge repair and TMVR procedures. The primary endpoint was the incidence of cerebrovascular events as defined by the Mitral Valve Academic Research Consortium. An event that occurred within 30 days or during index hospitalisation was defined as periprocedural; otherwise it was defined as non-periprocedural. This study was designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Aggregated study-level data were pooled using a random effect model. The quality of each study was appraised with the Hawker checklist, a method of systematically reviewing research from different paradigms.

Results

Sixty studies totalling 28 155 patients undergoing edge-to-edge repair with mitral valve clip were included in the analysis. Periprocedural stroke and non-periprocedural stroke rates were 0.9% (95% CI 0.6 to 1.1) and 2.4% (95% CI 1.6 to 3.2), respectively. For TMVR procedures, 26 studies including 1910 patients were analysed. The estimated periprocedural stroke incidence was 1% (95% CI 0.5 to 1.8) compared with 7% (95% CI 0.8 to 18.5) for non-periprocedural stroke.

Conclusions

Transcatheter mitral valve interventions are associated with low rates of cerebrovascular events. The exact mechanisms of these complications are still poorly understood given the relative paucity of good quality data.

Trial registration number

CRD42019117257.

Cerebral Embolic Risk During Transcatheter Mitral Valve Interventions: An Unaddressed and Unmet Clinical Need?

As new transcatheter mitral valve (MV) interventions continuously evolve, potential procedure-related adverse events demand careful investigation. The risk of cerebral embolic damage is ubiquitous in any left-sided structural heart intervention (and potentially linked to long-term neurocognitive sequelae); therefore, efforts to evaluate these aspects in the field of catheter-based MV procedures are justified. Given the peculiarities of MV anatomy, MV disease, and MV procedures, the lessons learned from other transcatheter heart interventions (i.e., transcatheter aortic valve replacement) cannot be directly translated to MV applications. Through a systematic assessment of available evidence, the authors present and discuss procedure- and patient-related factors potentially associated with cerebral embolic risk during catheter-based MV interventions. Given the paucity of available data in this field, future large, dedicated studies are needed to understand whether cerebral embolic injury represents a real clinical issue during MV procedures.

A sentinel in Mitraclip intervention: Catch the enemy!

Cerebral ischemic lesions occurring during transcatheter valve interventions are common feared complications and the use of filter device seems to reduce their incidence. We report the case of an 84-year old female patient with severe mitral regurgitation undergoing MitraClip. During the trans-esophageal echocardiography (TEE)-guided procedure was detected the presence of a little fibrin strand adherent to the steerable guide catheter for which we decided to implant the Claret CE Pro (Claret Medical, Inc. Santa Rosa, CA, USA) cerebral protection device and to continue the procedure during which the thrombus disappeared. At the end of the procedure a big thrombus was detected in the distal filter. The histologic analysis of the debris captured by the filters showed the presence of a thrombus, compatible with the image identified by TEE.

Formation of a left atrial thrombus during percutaneous mitral valve edge-to-edge repair induced by acute reduction of mitral regurgitation

Percutaneous mitral valve repair (PMVR) using the MitraClip system (Abbott, Abbott Park, IL, USA) is an innovative method allowing treatment of mitral regurgitation (MR) for patients that are not accessible by conventional operation. Thrombogenicity in the left atrium (LA) in general is increased in the presence of atrial fibrillation and mitral valve disease. We observed in a patient who underwent PMVR an acute change in thrombogenicity in the LA with thrombus formation in the left atrial appendix (LAA) immediately after clip placement. Thrombus formation occurred under verified therapeutic anticoagulation using unfractionated heparin. To our knowledge this is the first patient with documented acute and solid intra-interventional thrombus formation. The observation implies that acute reduction of mitral valve regurgitation and changes in hemodynamics within the LA enhances the risk of thrombus formation. <Learning objective: Percutaneous mitral valve repair is associated with acute changes in the thrombogenicity within the left atrium despite adequate periinterventional anticoagulation.>.

The Effects of Mitral Valve Repair on Memory Performance, Executive Function, and Psychological Measures in Patients With Heart Failure

OBJECTIVES

Heart failure (HF) is a prevalent disease that remains costly and associated with a high mortality rate. HF is also associated with poor neurocognitive functioning. For the treatment for HF patients with severe mitral regurgitation, the MitraClip device has emerged as a promising interventional tool that reduces the mitral valve leakage and thus increases cardiac output. Currently, there is only limited knowledge on changes in cognitive and psychosocial functioning before and after the MitraClip intervention.

METHODS

Cognitive function (memory and executive function) and psychosocial measures (depression, anxiety, and quality of life) were assessed before and after the MitraClip intervention in 24 HF patients and 23 healthy participants (comparison group).

RESULTS

MitraClip intervention in HF patients was followed by improvements in figural long-term memory (p = .003) and executive function (planning ability, p < .001) relative to the comparison group. In addition, the intervention resulted in a significant improvement in depression (p = .002), anxiety (p = .003) and quality of life scores (physical p = .017, mental p = .013) as well as improved 6-minute walk test results over time (p = .002).

CONCLUSIONS

The presented data provide evidence of a significant improvement in memory and executive function as well as in depression, anxiety, and quality of life scores in patients with chronic HF after MitraClip intervention. Further research is needed to shed light on the long-term development of cognitive function, psychosocial well-being, and clinical parameters after MitraClip intervention and how these factors depend on one another.

Transcatheter mitral valve repair with the MitraClip(®) can be performed without general anesthesia and without conscious sedation

BACKGROUND

General anesthesia is known to be associated with an increased risk for complications, especially in elderly and multi-morbid patients, the primary target population of the MitraClip(®) technique. The aim is to assess whether general anesthesia and even conscious sedation can be avoided during the MitraClip(®) procedure.

METHODS

A total of 91 consecutive patients who underwent MitraClip(®) implantation [median 77 years, (IQR 72-83), 40 % female] were retrospectively analyzed. The first 26 patients were treated in general anesthesia. Afterwards, local anesthesia was chosen as primary anesthetic approach. Altogether, 28 (31 %) patients received general anesthesia, local anesthesia was performed in 35 (38 %) patients with sedation and in 28 (31 %) patients without sedation.

RESULTS

The respective patient groups were similar regarding their baseline characteristics. Procedural success (successful implantation of at least one clip and post-procedure MR grade ≤2) was achieved in 89 % with no difference between the groups (93 % in general anesthesia, 89 % in local anesthesia with sedation, 86 % in local anesthesia without sedation, p = ns). No difference regarding hospital complications was noted. Local anesthesia with and without sedation was associated with less necessity for ICU/IMC stay (100 % in general anesthesia, 14 % in local anesthesia with sedation, 14 % in local anesthesia without sedation; p < 0.0001). One-year estimated survival was not significantly different among the groups (63, 82 and 75 %; p = ns).

CONCLUSIONS

Transcatheter mitral valve repair with the MitraClip(®) can be performed without general anesthesia and even without conscious sedation with similar procedural success and complication rates.