Topographical distribution of perioperative cerebral infarction associated with transcatheter aortic valve implantation

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.

Stroke prevention during and after transcatheter aortic valve implantation: From cerebral protection devices to antithrombotic management

Since its conception, transcatheter aortic valve implantation (TAVI) has undergone important improvements both in the implantation technique and in transcatheter devices, allowing an enthusiastic adoption of this therapeutic approach in a wide population of patients previously without a surgical option and managed conservatively. Nowadays, patients with severe symptomatic aortic stenosis are typically managed with TAVI, regardless of their risk to surgery, improving the prognosis of patients and thus achieving an exponential global expansion of its use. However, thromboembolic and hemorrhagic complications remain a latent concern in TAVI recipients. Both complications can appear simultaneously in the periprocedural period or during the follow-up, and when minor, they resolved without apparent sequelae, but in a relevant percentage of cases, they are devastating, overshadowing the benefit achieved with TAVI. Our review outlines the etiology and incidence of thromboembolic complications associated with TAVI, the main current strategies for their prevention, and the implications of its pharmacological management at the follow-up in a TAVI population, mostly frail and predisposed to bleeding complications.

Stroke after transcatheter aortic valve replacement: A severe complication with low predictability

OBJECTIVES

We aimed to describe stroke and transient ischemic attacks (TIAs) after transcatheter aortic valve replacement (TAVR) and to identify associated risk factors.

BACKGROUND

Stroke/TIA after TAVR is a major complication.

METHODS

A total of 1919 concomitant patients underwent TAVR in a single center from 2007 to 2017. Pre-, intra-, and postprocedural data were collected prospectively in a database and analyzed retrospectively. Stroke and TIA were documented according to the Valve Academic Research Consortium-II criteria. Logistic regression was used to determine risk factors for stroke after TAVR.

RESULTS

Mean age was 79.5 ± 6.8 years, mean logistic EuroScore was 17.6% ± 12.8%, and 51.8% (n = 994) of the patients were female. Stroke/TIA occurred in 76 patients (3.9%), 1.9% were disabling, and 1.6% nondisabling. The predominant type of stroke were territorial ischemic lesions (82.4%), with primary bleeding in 4.4% and border zone infarctions in 4.4%. Left-sided lesions were more common (45.6% left sided vs. 25% right sided) and 13.2% of the lesions were bilateral (4.4% no finding and 11.8% missing data). In multivariate logistic regression, prior stroke (odds ratio [OR] = 1.83, p = 0.046) and initial experience (first 300 TAVR implanted at our center) were identified as independent risk factors for stroke/TIA during the first 30 days (OR = 1.95, p = 0.045). Overall, the occurrence of stroke had a highly significant impact on a 30-day mortality (13.2% vs. 4.9% in patients without stroke (p = 0.005).

CONCLUSION

Stroke within the first 30 days after TAVR severely impairs 30-day survival. We identified prior stroke and initial experience as significant independent risk factors for the occurrence of stroke after TAVR.

Anemia and risk of periprocedural cerebral injury detected by diffusion-weighted magnetic resonance imaging in patients undergoing transcatheter aortic valve replacement

BACKGROUND

Anemia is prevalent in patients undergoing transcatheter aortic valve replacement (TAVR) and has been linked to impaired outcomes after the procedure. Few studies have evaluated the impact of anemia and new ischemic lesions post TAVR.

METHODS

We prospectively enrolled 158 patients who received TAVR in our center. Anemia was defined according to the World Health Organization criteria as hemoglobin <12 g/dL in women and <13 g/dL in men. All patients underwent diffusion-weighted magnetic resonance imaging (DW-MRI) procedure before and within 4-7 days after TAVR.

RESULTS

Anemia was present in 85 (53.8%) patients who underwent TAVR, and 126 (79.7%) patients had 718 new DW-MRI positive lesions with a mean of 4.54±5.26 lesions per patient. The incidence of new ischemic lesions was 81.2% in patients with anemia versus 78.1% in patients without anemia (P=0.629). Moreover, anemic patients had bigger total volume/lesions in the anterior cerebral artery/middle cerebral artery (ACA/MCA) and MCA regions compared to the non-anemic patients (31.89±55.78 mm3 vs. 17.08±37.39 mm3, P=0.049; and 54.54±74.72 mm3 vs. 33.75±46.03 mm3, P=0.034). Anemia was independently associated with the volume/lesion in the ACA/MCA (β=16.796, 95% confidence interval [95% CI] 2.001 to 31.591, P=0.026) and in the MCA zone (β=0.020, 95% CI 0.001 to 0.040, P=0.041).

CONCLUSIONS

Patients with pre-procedural anemia may have bigger total volume/lesions in the ACA/MCA and MCA regions compared to the non-anemic patients. Whether the consequences of bigger total volume/lesions impact neurological and cognitive outcomes remains to be investigated.

"Tailor-made" Total Cerebral Protection during Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) is an alternative treatment to surgical aortic valve replacement for treating severe aortic stenosis. With the increased use of TAVI, the risk of cerebrovascular complications during the procedure has become an emerging problem. We evaluated the safety and feasibility of our total cerebral protection methods using embolic protection devices (EPDs) for carotid artery stenting. We collected the results of cases in which the clinical team determined that our protection method was necessary among patients undergoing TAVI from May to October 2019 in our medical center. We applied this method to patients who had a potentially high risk of cerebrovascular events during the procedure. The methods of protection were selected comprehensively based on the potential of collateralization of brain perfusion when some arteries were blocked with a balloon, accessibility of the brain arteries, and the ability to cover the brain arteries with devices. Five patients, aged 83.8 ± 1.8 years, were included in the study. Technical success was achieved in all five patients. No cases showed any new neurological symptoms after the procedures; however, head MRI on the day after showed new ischemic lesions in three of five cases (60%). In all cases, emboli were found in the collected filters. This report demonstrates protection of the entire perfusion area in each case using EPDs in patients at high risk of intraoperative embolism. The methods we used were feasible and can potentially reduce cerebrovascular events following TAVI.

Increased Intima-Media Thickness of the Ascending Aorta May Predict Neurological Complications Associated with TAVI

OBJECTIVES

Neurological complications associated with transcatheter aortic valve implantation (TAVI) are important due to its morbidity and mortality risks. The purpose of this study was to investigate the importance of the features of the aortic valve and ascending aorta to predict the neurological complications associated with TAVI.

METHODS

The patients for whom the heart team decided to perform TAVI were included in the study. In order to assess possible neurological complications, cerebral diffusionweighted magnetic resonance imaging(MRI) was performed pre- and post-operatively. The diameter of the patients' aortic root and ascending aorta, aortic valve scores, intima media thickness of the ascending aorta were measured from their transesophageal echocardiography records.

RESULTS

A total of 108 patients constituted the study population. 31 patients were found to develop a new lesion (MR+) detected on MRI after TAVI, while 76 patients did not have any new lesions (MR-). The groups did not have any significant differences in their aortic valve features and scores. However, AA-IMT was found to be higher in the MR+ group (1.8mm [1.6-2.3] vs 1.4mm [1.2-1.8] interquartile range). The multivariate logistic regression analysis conducted to detect new lesions revealed that AA-IMT led to a significantly increased risk.

CONCLUSION

The features of the ascending are more important than the demographic characteristics of patients and features of the native valve in predicting new lesions on MRI scans and thus neurological events after TAVI.

Reduction of Cerebral Emboli: In vitro Study with a Novel Cerebral Embolic Protection Device

Aim

To assess the efficacy of the TriGUARD 3™, a novel cerebral embolic protection (CEP) device in reducing cerebral embolization by deflecting embolic debris away from the cerebral circulation using a quantitative in vitro model.

Methods and Results

This in vitro study assessed the ability of a cerebral embolic protection device to deflect embolic debris, by measuring the percent of particles and air bubbles, 200 µm and 300 µm in size, from entering the cerebral circulation compared to unprotected controls. A 3D printed silicone model of the ascending aorta, the aortic arch with its three major cerebral arteries and the descending aorta was connected to a custom-made simulator that mimics physiological pulsatile flow patterns of the left ventricle. Comparative analyses were used to assess the efficacy of the cerebral embolic protection device to deflect particles and air bubbles away from the major cerebral arteries. The percent of particles and air bubbles entering the major cerebral arteries was significantly lower with cerebral embolic protection compared to unprotected controls (p<0.0001). Cerebral protection resulted in 97.4–100% reduction in air bubble counts, and 97.4–97.8% reduction in particle counts compared to unprotected controls.

Conclusion

This in vitro study used simulated physiologic flow conditions in an aortic arch model to demonstrate >97% efficacy of the TriGUARD 3 CEP device, in reducing cerebral embolization of particulate and air bubbles of 200 µm to 300 µm in size.

Cerebral Infarction after Transcatheter Aortic Valve Implantation in Japan: Retrospective Analysis at a Single High-Volume Center

BACKGROUND

Perioperative cerebral infarction is one of the concerning complications after transcatheter aortic valve implantation in patients with aortic stenosis. Several studies have reported on this complication; however, those included only Caucasians and analyzed a small number of cases. Here, we report on the characteristics and risk factors of symptomatic cerebral infarction after transcatheter aortic valve implantation in a single, high-volume center in Japan.

METHODS

We included 308 consecutive patients who underwent transcatheter aortic valve implantation in our facility between 2013 and 2016. We retrospectively analyzed the occurrence, characteristics, and prognoses of symptomatic cerebral infarction within 7 days after the procedure and statistically compared the risk factors between patients with or without cerebral infarction.

RESULTS

Five patients (1.6%) suffered from symptomatic cerebral infarction, which was usually recognized just after the procedure, with mild symptoms. Long-term prognoses tended to be good unless other factors influenced disability. Comorbidities, such as carotid artery stenosis and peripheral artery disease, were significantly higher in patients with cerebral infarction (P = .036 and .002, respectively); in addition, coronary artery disease and longer anesthesia duration (indicating challenging catheter procedures) tended to be associated with cerebral infarction (P = .080 and .069, respectively).

CONCLUSIONS

Symptomatic cerebral infarction occurred in 1.6% of patients after transcatheter aortic valve implantation in a single, high-volume center in Japan; the infarctions were of mild severity tending toward good long-term prognoses. We speculate arterial embolism from atherosclerotic large arteries, especially from the aortic arch, during catheter procedures might be the mechanistic basis of cerebral infarction.

Cerebral Embolic Protection in TAVI: Friend or Foe

Cerebrovascular accidents including stroke or transient ischaemic attack are one of the most feared complications after transcatheter aortic valve implantation. Transcatheter aortic valve implantation procedures have been consistently associated with silent ischaemic cerebral embolism as assessed by diffusion-weighted MRI. To reduce the risk of cerebrovascular accidents and silent emboli, cerebral embolic protection devices were developed with the aim of preventing procedural debris reaching the cerebral vasculature. The authors summarise the available data regarding cerebral embolic protection devices and its clinical significance.

Neuron-Specific Enolase and Matrix Metalloproteinase 9 Signal Perioperative Silent Brain Infarction During or After Transcatheter Aortic Valve Implantation

Magnetic resonance imaging (MRI) studies have consistently identified a high incidence of silent brain infarction (SBI) after cardiac intervention. The frequent occurrence, objective measurement and clinical sequelae of SBI have seen interest in their detection for both research and clinical purposes. However, MRI is expensive, time-consuming, unsafe in acutely-ill patients, and not always available, limiting its use as a routine screening tool. For this purpose, a blood biomarker of SBI would be the "Holy Grail." By performing targeted profiling of serologic biomarkers this study aimed to assess their potential as screening tools for perioperative SBI. This is a nested case-control study of 20 prospectively recruited patients undergoing transcatheter aortic valve implantation under general anesthesia. Clinical and diffusion-weighted MRI assessments were performed at baseline and on day 3 postprocedure to identify the presence (cases) or absence (controls) of new SBI. Blood was collected at baseline and 24, 48, and 72 hours postprocedure and analyzed for S100 calcium-binding protein B, neuron specific enolase (NSE), matrix metalloproteinase 9 (MMP 9), and glial fibrillary acidic protein. Best-fit polynomial curves using a smoothing model were generated for each biomarker and inferential testing at a predefined 24-hour postprocedure timepoint detected a significant difference for MMP 9 (72,435; SEM: 25,030; p = 0.027). Longitudinal regression revealed a statistically significant case-control difference for both NSE (mean: 10,747; SEM: 3,114) and MMP 9 (63,842; SEM: 16,173). In conclusion, NSE and MMP 9 are present in higher levels following SBI and warrant further investigation for their utility as screening tools.