Neurological damage after transcatheter aortic valve implantation compared with surgical aortic valve replacement in intermediate risk patients

Impact of surgical aortic valve replacement and transcatheter aortic valve implantation on cardiovascular and cerebrovascular controls: A pilot study

Surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI) are options in severe aortic valve stenosis (AVS). Cardiovascular (CV) and cerebrovascular (CBV) control markers, derived from variability of heart period, systolic arterial pressure, mean cerebral blood velocity and mean arterial pressure, were acquired in 19 AVS patients (age: 76.8 ± 3.1 yrs, eight males) scheduled for SAVR and in 19 AVS patients (age: 79.9 + 6.5 yrs, 11 males) scheduled for TAVI before (PRE) and after intervention (POST, <7 days). Left ventricular function was preserved in both groups. Patients were studied at supine resting (REST) and during active standing (STAND). We found that: (i) both SAVR and TAVI groups featured a weak pre-procedure CV control; (ii) TAVI ensured better CV control; (iii) cerebral autoregulation was working in PRE in both SAVR and TAVI groups; (iv) SAVR and TAVI had no impact on the CBV control; (v) regardless of group, CV and CBV control markers were not influenced by STAND in POST. Even though the post-procedure preservation of both CV and CBV controls in TAVI group might lead to privilege this procedure in patients at higher risk, the missing response to STAND suggests that this advantage could be insignificant.

Cerebral Protection in Trans-Catheter Aortic Valve Replacement: Review and Contemporary Assessment of Randomized Trial Data

As the population has aged and as aortic valve therapies have evolved, the use of trans-catheter aortic valve replacement (TAVR) has grown dramatically over the past decade. A well-known complication of percutaneous cardiac intervention is embolic phenomena, and TAVR is among the highest risk procedures for clinical and subclinical stroke. As indications for TAVR expand to lower-risk and ultimately younger patients, the long-term consequences of stroke are amplified. Cerebral embolic protection (CEP) devices have taken a on unique preventative role following the Food and Drug Administration approval of the SentinelTM Cerebral Protection System (CPS). More recently, the PROTECTED TAVR study has spurred extensive debate in the neuro-cardiac community. In this review we describe the contemporary literature regarding stroke risk associated with TAVR, the history and role of CEP devices, a PROTECTED TAVR sub-group analysis, and implications for next steps in the field. Lastly, we explore the unique need for CEP in a younger TAVR population, as well as directions for future research.

Early Detection of Risk of Neo-Sinus Blood Stasis Post-Transcatheter Aortic Valve Replacement Using Personalized Hemodynamic Analysis

Background

Despite the demonstrated benefits of transcatheter aortic valve replacement (TAVR), subclinical leaflet thrombosis and hypoattenuated leaflet thickening are commonly seen as initial indications of decreased valve durability and augmented risk of transient ischemic attack.

Methods

We developed a multiscale patient-specific computational framework to quantify metrics of global circulatory function, metrics of global cardiac function, and local cardiac fluid dynamics of the aortic root and coronary arteries.

Results

Based on our findings, TAVR might be associated with a high risk of blood stagnation in the neo-sinus region due to the lack of sufficient blood flow washout during the diastole phase (e.g., maximum blood stasis volume increased by 13, 8, and 2.7 fold in the left coronary cusp, right coronary cusp, and noncoronary cusp, respectively [N = 26]). Moreover, in some patients, TAVR might not be associated with left ventricle load relief (e.g., left ventricle load reduced only by 1.2 % [N = 26]) and diastolic coronary flow improvement (e.g., maximum coronary flow reduced by 4.94%, 15.05%, and 23.59% in the left anterior descending, left circumflex coronary artery, and right coronary artery, respectively, [N = 26]).

Conclusions

The transvalvular pressure gradient amelioration after TAVR might not translate into adequate sinus blood washout, optimal coronary flow, and reduced cardiac stress. Noninvasive personalized computational modeling can facilitate the determination of the most effective revascularization strategy pre-TAVR and monitor leaflet thrombosis and coronary plaque progression post-TAVR.

Silent Brain Infarction, Delirium, and Cognition in Three Invasive Cardiovascular Procedures: a Systematic Review

Silent brain infarctions (SBIs) are brain lesions noted on neuroimaging that are not associated with clinical symptoms. SBIs are associated with a number of vascular risk factors and are common following invasive cardiovascular procedures such as atrial fibrillation (AF) ablation, coronary artery bypass graft (CABG), and transcatheter aortic valve replacement (TAVR). Although not eliciting signs of clinical stroke, SBIs are associated with increased frailty, and motor and mood features. Less is known, however, about the relationship between SBI, cognition, and delirium following invasive cardiac procedures and most investigations into these relationships have been reported in large-scale epidemiological studies. In the current paper, we conducted a systematic review to evaluate evidence of a relationship between SBI, delirium, and cognitive decline following CABG, AF ablation, and TAVR. Twenty studies met inclusion criteria. In general, our review identified conflicting results for each cardiac procedure, with some studies suggesting a relationship between SBI, cognitive impairment, and delirium, whereas others showed no relationship between SBI, cognitive impairment, and delirium. Potential reasons for this discrepancy as well as suggestions for future research are discussed.

Predictive Model for Thrombus Formation After Transcatheter Valve Replacement

PURPOSE

Leaflet thrombosis is a significant adverse event after transcatheter aortic valve (TAV) replacement (TAVR). The purpose of our study was to present a semi-empirical, mathematical model that links patient-specific anatomic, valve, and flow parameters to predict likelihood of leaflet thrombosis.

METHODS

The two main energy sources of neo-sinus (NS) washout after TAVR include the jet flow downstream of the TAV and NS geometric change in volume due to the leaflets opening and closing. Both are highly dependent on patient anatomic and hemodynamic factors. As rotation of blood flow is prevalent in both the sinus of Valsalva and then the NS, we adopted the vorticity flux or circulation (Г) as a metric quantifying overall washout. Leaflet thrombus volumes were segmented based on hypo-attenuating leaflet thickening (HALT) in post-TAVR patient's gated computed tomography. Г was assessed using dimensional scaling as well as computational fluid dynamics (CFD) respectively and correlated to the thrombosis volumes using sensitivity and specificity analysis.

RESULTS

Г in the NS, that accounted for patient flow and anatomic conditions derived from scaling arguments significantly better predicted the occurrence of leaflet thrombus than CFD derived measures such as stasis volumes or wall shear stress. Given results from the six patient datasets considered herein, a threshold Г value of 28.0 yielded a sensitivity and specificity of 100% where patients with Gamma < 28 developed valve thrombosis. A 10% error in measurements of all variables can bring the sensitivity specificity down to 87%.

CONCLUSION

A predictive model relating likelihood of valve thrombosis using Г in the NS was developed with promising sensitivity and specificity. With further studies and improvements, this predictive technology may lead to alerting physicians on the risk for thrombus formation following TAVR.

The Efficacy and Safety of Hybrid Ablations for Atrial Fibrillation

OBJECTIVES

This study sought to comprehensively determine the procedural safety and midterm efficacy of hybrid ablations.

BACKGROUND

Hybrid ablation of atrial fibrillation (AF) (thoracoscopic ablation followed by catheter ablation) has been used for patients with nonparoxysmal AF; however, accurate data regarding efficacy and safety are still limited.

METHODS

Patients with nonparoxysmal AF underwent thoracoscopic, off-pump ablation using the COBRA Fusion radiofrequency system (Estech) followed by a catheter ablation 3 months afterward. The safety of the procedure was assessed using sequential brain magnetic resonance and neuropsychological examinations at baseline (1 day before), postoperatively (2-4 days for brain magnetic resonance imaging or 1 month for neuropsychological examination), and at 9 months after the surgical procedure. Implantable loop recorders were used to detect arrhythmia recurrence. Arrhythmia-free survival (the primary efficacy endpoint) was defined as no episodes of AF or atrial tachycardia while off antiarrhythmic drugs, redo ablations or cardioversions.

RESULTS

Fifty-nine patients (age: 62.5 ± 10.5 years) were enrolled, 37 (62.7%) were men, and the mean follow-up was 30.3 ± 10.8 months. Thoracoscopic ablation was successfully performed in 55 (93.2%) patients. On baseline magnetic resonance imaging, chronic ischemic brain lesions were present in 60% of patients. New ischemic lesions on postoperative magnetic resonance imaging were present in 44.4%. Major postoperative cognitive dysfunction was present in 27.0% and 17.6% at 1 and 9 months postoperatively, respectively. The probability of arrhythmia-free survival was 54.0% (95% CI: 41.3-66.8) at 1 year and 43.8% (95% CI: 30.7-57.0) at 2 years.

CONCLUSIONS

The thoracoscopic ablation is associated with a high risk of silent cerebral ischemia. The midterm efficacy of hybrid ablations is moderate.

Valve Academic Research Consortium 3: updated endpoint definitions for aortic valve clinical research

Aims 

The Valve Academic Research Consortium (VARC), founded in 2010, was intended to (i) identify appropriate clinical endpoints and (ii) standardize definitions of these endpoints for transcatheter and surgical aortic valve clinical trials. Rapid evolution of the field, including the emergence of new complications, expanding clinical indications, and novel therapy strategies have mandated further refinement and expansion of these definitions to ensure clinical relevance. This document provides an update of the most appropriate clinical endpoint definitions to be used in the conduct of transcatheter and surgical aortic valve clinical research.

Methods and results 

Several years after the publication of the VARC-2 manuscript, an in-person meeting was held involving over 50 independent clinical experts representing several professional societies, academic research organizations, the US Food and Drug Administration (FDA), and industry representatives to (i) evaluate utilization of VARC endpoint definitions in clinical research, (ii) discuss the scope of this focused update, and (iii) review and revise specific clinical endpoint definitions. A writing committee of independent experts was convened and subsequently met to further address outstanding issues. There were ongoing discussions with FDA and many experts to develop a new classification schema for bioprosthetic valve dysfunction and failure. Overall, this multi-disciplinary process has resulted in important recommendations for data reporting, clinical research methods, and updated endpoint definitions. New definitions or modifications of existing definitions are being proposed for repeat hospitalizations, access site-related complications, bleeding events, conduction disturbances, cardiac structural complications, and bioprosthetic valve dysfunction and failure (including valve leaflet thickening and thrombosis). A more granular 5-class grading scheme for paravalvular regurgitation (PVR) is being proposed to help refine the assessment of PVR. Finally, more specific recommendations on quality-of-life assessments have been included, which have been targeted to specific clinical study designs.

Conclusions 

Acknowledging the dynamic and evolving nature of less-invasive aortic valve therapies, further refinements of clinical research processes are required. The adoption of these updated and newly proposed VARC-3 endpoints and definitions will ensure homogenous event reporting, accurate adjudication, and appropriate comparisons of clinical research studies involving devices and new therapeutic strategies.

Valve Academic Research Consortium 3: Updated Endpoint Definitions for Aortic Valve Clinical Research

AIMS

The Valve Academic Research Consortium (VARC), founded in 2010, was intended to (i) identify appropriate clinical endpoints and (ii) standardize definitions of these endpoints for transcatheter and surgical aortic valve clinical trials. Rapid evolution of the field, including the emergence of new complications, expanding clinical indications, and novel therapy strategies have mandated further refinement and expansion of these definitions to ensure clinical relevance. This document provides an update of the most appropriate clinical endpoint definitions to be used in the conduct of transcatheter and surgical aortic valve clinical research.

METHODS AND RESULTS

Several years after the publication of the VARC-2 manuscript, an in-person meeting was held involving over 50 independent clinical experts representing several professional societies, academic research organizations, the US Food and Drug Administration (FDA), and industry representatives to (i) evaluate utilization of VARC endpoint definitions in clinical research, (ii) discuss the scope of this focused update, and (iii) review and revise specific clinical endpoint definitions. A writing committee of independent experts was convened and subsequently met to further address outstanding issues. There were ongoing discussions with FDA and many experts to develop a new classification schema for bioprosthetic valve dysfunction and failure. Overall, this multi-disciplinary process has resulted in important recommendations for data reporting, clinical research methods, and updated endpoint definitions. New definitions or modifications of existing definitions are being proposed for repeat hospitalizations, access site-related complications, bleeding events, conduction disturbances, cardiac structural complications, and bioprosthetic valve dysfunction and failure (including valve leaflet thickening and thrombosis). A more granular 5-class grading scheme for paravalvular regurgitation (PVR) is being proposed to help refine the assessment of PVR. Finally, more specific recommendations on quality-of-life assessments have been included, which have been targeted to specific clinical study designs.

CONCLUSIONS

Acknowledging the dynamic and evolving nature of less-invasive aortic valve therapies, further refinements of clinical research processes are required. The adoption of these updated and newly proposed VARC-3 endpoints and definitions will ensure homogenous event reporting, accurate adjudication, and appropriate comparisons of clinical research studies involving devices and new therapeutic strategies.

Incidence and Risk Factors for Silent Brain Infarction After On-Pump Cardiac Surgery: A Meta-analysis and Meta-regression of 29 Prospective Cohort Studies

BACKGROUND

Silent brain infarction (SBI) happens at a considerable rate after on-pump cardiac surgery. Though termed silent, SBI is related to unfavorable clinical outcomes including higher incidence of future stroke and neurocognitive impairment in the general population. The risk factors of SBI have not been fully identified in both individual studies and several meta-analyses addressing the topic. In this meta-analysis, we aimed to conduct meta-regression analysis for the first time to explore risk factors for SBI after on-pump cardiac surgery.

METHODS

This meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Medline, Embase, Central, Web of Science, and Wiley databases were searched for relevant studies. Preoperative patient baseline characteristics and intraoperative surgical parameters were extracted from included studies. For meta-regression, a P value of less than 0.1 was considered statistically significant in both univariable and multivariable analyses.

RESULTS

Twenty-nine studies with 1478 patients were included in this meta-analysis. The summarized SBI rate after on-pump cardiac surgery was 37% (95% CI 0.27-0.47, P < 0.0001). Heterogeneity between studies was significant (I2 = 94.9%, P < 0.0001). In multivariable meta-regression, we found that age (coefficient 0.014, 95% CI 0.001-0.029, P = 0.043), diabetes (coefficient 0.006, 95% CI - 0.001 to 0.013, P = 0.075), and proportion of CABG (coefficient - 0.001, 95% CI - 0.003 to 0.0003, P = 0.096) were significantly associated with SBI incidence.

CONCLUSION

From the meta-regression, we concluded that advanced age and diabetes were related to increased SBI incidence after on-pump cardiac surgery, while CABG procedure alone was associated with less SBI onset. Studies with more accurate diagnoses of SBI are required to add more conclusive evidence to the field.

A randomized trial comparing axillary versus innominate artery cannulation for aortic arch surgery

BACKGROUND

Cerebral protection remains the cornerstone of successful aortic surgery; however, there is no consensus as to the optimal strategy.

OBJECTIVE

To compare the safety and efficacy of innominate to axillary artery cannulation for delivering antegrade cerebral protection during proximal aortic arch surgery.

METHODS

This randomized controlled trial (The Aortic Surgery Cerebral Protection Evaluation CardioLink-3 Trial, ClinicalTrials.gov Identifier: NCT02554032), conducted across 6 Canadian centers between January 2015 and June 2018, allocated 111 individuals to innominate or axillary artery cannulation. The primary safety outcome was neuroprotection per the appearance of new severe ischemic lesions on the postoperative diffusion-weighted-magnetic resonance imaging. The primary efficacy outcome was the difference in total operative time. Secondary outcomes included 30-day all-cause mortality and postoperative stroke.

RESULTS

One hundred two individuals (mean age, 63 ± 11 years) were in the primary safety per-protocol analysis. Baseline characteristics between the groups were similar. New severe ischemic lesions occurred in 19 participants (38.8%) in the axillary versus 18 (34%) in the innominate group (P for noninferiority = .0009). Total operative times were comparable (median, 293 minutes; interquartile range, 222-411 minutes) for axillary versus (298 minutes; interquartile range, 231-368 minutes) for innominate (P for superiority = .47). Stroke/transient ischemic attack occurred in 4 (7.1%) participants in the axillary versus 2 (3.6%) in the innominate group (P = .43). Thirty-day mortality, seizures, delirium, and duration of mechanical ventilation were similar in both groups.

CONCLUSIONS

diffusion-weighted magnetic resonance imaging assessments indicate that antegrade cerebral protection with innominate cannulation is safe and affords similar neuroprotection to axillary cannulation during aortic surgery, although the burden of new neurological lesions is high in both groups.

Cerebral Blood Flow in Patients with Severe Aortic Valve Stenosis Undergoing Transcatheter Aortic Valve Implantation

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is a minimally invasive, life‐saving treatment for patients with severe aortic valve stenosis that improves quality of life. We examined cardiac output and cerebral blood flow in patients undergoing TAVI to test the hypothesis that improved cardiac output after TAVI is associated with an increase in cerebral blood flow.

DESIGN

Prospective cohort study.

SETTING

European high‐volume tertiary multidisciplinary cardiac care.

PARTICIPANTS

Thirty‐one patients (78.3 ± 4.6 years; 61% female) with severe symptomatic aortic valve stenosis.

MEASUREMENTS

Noninvasive prospective assessment of cardiac output (L/min) by inert gas rebreathing and cerebral blood flow of the total gray matter (mL/100 g per min) using arterial spin labeling magnetic resonance imaging in resting state less than 24 hours before TAVI and at 3‐month follow‐up. Cerebral blood flow change was defined as the difference relative to baseline.

RESULTS

On average, cardiac output in patients with severe aortic valve stenosis increased from 4.0 ± 1.1 to 5.4 ± 2.4 L/min after TAVI (P = .003). The increase in cerebral blood flow after TAVI strongly varied between patients (7% ± 24%; P = .41) and related to the increase in cardiac output, with an 8.2% (standard error = 2.3%; P = .003) increase in cerebral blood flow per every additional liter of cardiac output following the TAVI procedure.

CONCLUSION

Following TAVI, there was an association of increase in cardiac output with increase in cerebral blood flow. These findings encourage future larger studies to determine the influence of TAVI on cerebral blood flow and cognitive function.

Silent Brain Infarcts Following Cardiac Procedures: A Systematic Review and Meta-Analysis

Background

Silent brain infarcts (SBI) are increasingly being recognized as an important complication of cardiac procedures as well as a potential surrogate marker for studies on brain injury. The extent of subclinical brain injury is poorly defined.

Methods and Results

We conducted a systematic review and meta‐analysis utilizing studies of SBIs and focal neurologic deficits following cardiac procedures. Our final analysis included 42 studies with 49 separate intervention groups for a total of 2632 patients. The prevalence of SBIs following transcatheter aortic valve implantation was 0.71 (95% CI 0.64‐0.77); following aortic valve replacement 0.44 (95% CI 0.31‐0.57); in a mixed cardiothoracic surgery group 0.39 (95% CI 0.28‐0.49); coronary artery bypass graft 0.25 (95% CI 0.15‐0.35); percutaneous coronary intervention 0.14 (95% CI 0.10‐0.19); and off‐pump coronary artery bypass 0.14 (0.00‐0.58). The risk ratio of focal neurologic deficits to SBI in aortic valve replacement was 0.22 (95% CI 0.15‐0.32); in off‐pump coronary artery bypass 0.21 (95% CI 0.02‐2.04); with mixed cardiothoracic surgery 0.15 (95% CI 0.07‐0.33); coronary artery bypass graft 0.10 (95% CI 0.05‐0.18); transcatheter aortic valve implantation 0.10 (95% CI 0.07‐0.14); and percutaneous coronary intervention 0.06 (95% CI 0.03‐0.14). The mean number of SBIs per patient was significantly higher in the transcatheter aortic valve implantation group (4.58 ± 2.09) compared with both the aortic valve replacement group (2.16 ± 1.62, P=0.03) and the percutaneous coronary intervention group (1.88 ± 1.02, P=0.03).

Conclusions

SBIs are a very common complication following cardiac procedures, particularly those involving the aortic valve. The high frequency of SBIs compared with strokes highlights the importance of recording this surrogate measure in cardiac interventional studies. We suggest that further work is required to standardize reporting in order to facilitate the use of SBIs as a routine outcome measure.

Meta-Analysis of Prevalence and Risk Factors for Cognitive Decline and Improvement After Transcatheter Aortic Valve Implantation

Changes to cognition, both decline and improvement, are commonly reported after transcatheter aortic valve implantation (TAVI). However, previous systematic reviews and meta-analyses have missed these subgroups by assessing whole-group-averages for cognitive outcomes. We sought to pool estimates to identify the prevalence of cognitive decline and improvement after TAVI, as well as associated factors for these outcomes. A systematic review identified 15 articles appropriate for meta-analysis. When robust cognitive change definitions were employed, the pooled prevalence of incident cognitive impairment up to 1-, 1 to 6-, and ≥6-months post-TAVI was 7%, 14%, and 12%, respectively. For cognitive improvement, the prevalence from 1 to 6 months and ≥6 months after TAVI was estimated to be 19% and 11%, respectively. Two factors were associated with these cognitive outcomes: (1) using a cerebral embolic protection device was associated with decreased prevalence of cognitive decline up to 1-week post-TAVI; (2) baseline cognitive impairment had a large association with post-TAVI cognitive improvement. In conclusion, cognitive decline and cognitive improvement are experienced by approximately 7% to 19% of patients after TAVI, respectively. Those with the lowest cognitive performance pre-TAVI appear to have the most to gain in terms of cognitive improvement post-TAVI. Identifying further predictive factors for cognitive decline and improvement post-TAVI will facilitate a personalized-medicine approach for cognitive care and prognosis.

Incidence and Distribution of Cerebral Embolism After Cardiac Surgery According to the Systemic Perfusion Strategy - A Diffusion-Weighted Magnetic Resonance Imaging Study

BACKGROUND

Stroke is a major concern in minimally invasive cardiac surgery, so we investigated the incidence and risk factors of cerebral embolism according to the systemic perfusion strategy under thorough imaging assessment.

METHODS AND RESULTS

Between November 2011 and May 2015, 315 cardiac surgery patients who underwent preoperative computed tomography angiography (CTA) as a routine evaluation were enrolled. The incidence and distribution of cerebral embolism were analyzed with routine postoperative brain diffusion-weighted magnetic resonance imaging (DW-MRI) examination. Anterograde perfusion was used in 103 patients (group A), and retrograde perfusion was performed in 212 patients (group R). Operative deaths, incidence of clinical stroke (group A: 0%, group R: 0.5%, P=0.77), and rate of cerebral embolism (group A: 35.9%, group R: 26.4%, P=0.08) were comparable. The median number of new embolic lesions detected by MRI per patient (group A: 2, group R: 2, P=0.16), maximal diameter of the lesion (group A: 6.5 mm, group R: 6.0 mm, P=0.97), and anatomic distribution of the lesion were similar between groups. In the multivariate analysis, hypertension, emergency status, atherosclerosis grade 3 or 4 (intimal thickening >4 mm), and cardiopulmonary bypass time were independent risk factors for postoperative cerebral embolism, but retrograde perfusion was not.

CONCLUSIONS

According to the results of postoperative DW-MRI, retrograde perfusion itself might not increase the incidence of postoperative cerebral embolism in properly selected cardiac surgery patients undergoing routine preoperative CTA examination.

Transcatheter aortic valve replacement for pure aortic valve regurgitation: "on-label" versus "off-label" use of TAVR devices

INTRODUCTION

Transcatheter aortic valve replacement (TAVR) has become the mainstay of treatment for aortic stenosis in patients with high surgical risk. Pure aortic regurgitation (PAR) is considered a relative contraindication for TAVR; however, TAVR is increasingly performed in PAR patients with unfavorable risk profile. Herein, we aim to summarize available data on TAVR for PAR with special emphasis on "on-label" versus "off-label" TAVR devices.

METHODS AND RESULTS

Pubmed was searched for studies of patients undergoing TAVR for PAR. Primary outcome was 30 day-mortality. Pooled estimated event rates were calculated. Twelve studies including a total of 640 patients were identified until December 2017. Among these, 208 (33%) patients were treated with devices with CE-mark approval for PAR ("on-label"; JenaValve and J valve). Overall, the procedural success rate was 89.9% (95% CI 81.1-96.1%; I² 80%). Major bleeding was reported in 6.4% (95% CI 2.9-10.8%; I² 48%). All-cause mortality at 30 days was 10.4% (95% CI 7.1-14.2%; I² 20%). Stroke occurred in 2.2% (95% CI 0.9-3.9%; I² 0%). A permanent pacemaker was required in 10.7% (95% CI 7.3-14.6%; I² 23%). At 30 days after TAVR, ≥ moderate AR post-interventional was observed in 11.5% (95% CI 2.9-23.6%; I² 90%). In the "on-label"-group, success rate was 93.0% (95% CI 85.9-98.1%; I² 52%). 30-day-mortality was 9.1% (95% CI 3.7-16.0%; I² 36%). More than trace AR was present in 2.8% (95% CI 0.1-7.6%; I² 0%). Compared to first-generation devices, second-generation devices were associated with significantly lower 30-day-mortality (r = - 0.10; p = 0.02), and significantly higher procedural success rates (r = 0.28; p < 0.001). Compared to other second-generation devices, the use of J valve or JenaValve was not associated with altered mortality (r = 0.04; p = 0.50), rates of > trace residual AR (r = - 0.05; p = 0.65) but with a significantly higher procedural success (r = 0.15; p = 0.042).

CONCLUSION

Based on this summary of available observational data TAVR for PAR is feasible and safe in patients deemed inoperable. First-generation TAVR devices are associated with inferior outcome and should be avoided. The "on-label" use of PAR-certified TAVR devices is associated with a significantly higher procedural success rate and might be favorable compared to other second-generation devices.

Meta-Analysis Comparing the Frequency of Stroke After Transcatheter Versus Surgical Aortic Valve Replacement

Stroke is one of the most feared complications of aortic valve replacement. Although the outcomes of transcatheter aortic valve implantation (TAVI) improved substantially over time, concerns remained about a potentially higher incidence of stroke with TAVI compared with surgical replacement (SAVR). However, comparative data are sparse. We performed a meta-analysis comparing the incidence of stroke among patients undergoing TAVI versus SAVR. Of the 5067 studies screened, 28 eligible studies (22 propensity-score matched studies and 6 randomized trials) were analyzed. Primary endpoints were 30-day stroke and disabling stroke. Secondary endpoints were 1-year stroke and disabling stroke. A total of 23,587 patients were included, of whom 47.27% underwent TAVI and 52.72% underwent SAVR. For each endpoint, pooled estimates of odds ratio (OR) with 95% confidence interval (CI) were calculated. The pooled estimates for stroke (2.7% vs 3.1%, OR 0.86; 95% CI 0.72 to 1.02; p=0.08) and disabling stroke (2.5% vs 2.9%, OR 0.96; 95% CI 0.57 to 1.62; p=0.89) were comparable following TAVI versus SAVR at 30 days. Similarly, the pooled estimates for stroke (5.0% vs 4.6%, OR 1.01; 95% CI 0.79 to 1.28; p=0.96) and disabling stroke (4.1% vs 4.5%, OR 0.92; 95% CI 0.92 to 1.39; p=0.71) were similar at 1 year. A sensitivity analysis including only RCTs yielded similar results. Our meta-analysis documents comparable rates of strokes and disabling strokes following TAVI or SAVR both at 30 days and 1 year.

Cerebrovascular Events After Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) has emerged as an alternative less invasive treatment for patients with symptomatic severe aortic stenosis. Despite the technological development and knowledge improvement in recent years, neurological complications remain a concern, especially with the expansion of the technique toward younger and lower risk patients. Clinical cerebrovascular events have an important impact on patients' morbidity and mortality with a multifactorial origin. While cerebral microembolizations during TAVI is a universal phenomenon and embolic protection devices have been developed in an attempt to reduce them, their clinical utility remains unclear. We review the current evidence on cerebrovascular events associated with TAVI and potential preventive strategies.

Neuroprotective measures throughout the TAVI pathway

Aortic stenosis (AS) is the most common clinical valvular heart disorder that warrants active treatment. Symptomatic and severe AS is associated with increased morbidity and mortality if left untouched. Transcatheter aortic valve implantation (TAVI) is an innovative therapeutic modality approved initially for patients with prohibitive surgical risk and subsequently became a mainstream practice and the preferred treatment modality for many patients with severe AS at high and moderate surgical risk. Consistently global TAVI volumes have increased and indications continue to widen toward younger and lower-risk patients. However, periprocedural stroke is one of the most feared complications of TAVI, and when clinically evident, it is often associated with significant increase in mortality, physical disability, social isolation and financial costs. Furthermore, even when clinically overt stroke is not evident following TAVI, highly sensitive imaging modalities have demonstrated new post-procedural ischemic lesions in most patients. Although little is known about the long-term clinical significance of these lesions, there are strong signals showing they might be related with reduced subsequent neurocognitive function. This review provides a comprehensive contemporary insight of the definitions, incidence and temporal trends of stroke in TAVI patients, as well as the mechanisms, etiologies and risk factors for such neurological events. Furthermore, an integrated approach of neuroprotective measures targeted to reduce the incidence of stroke during each phase of the periprocedural TAVI pathway is suggested with a special focus on the role of embolic protective devices.

Task-related changes in degree centrality and local coherence of the posterior cingulate cortex after major cardiac surgery in older adults

OBJECTIVES

Older adults often display postoperative cognitive decline (POCD) after surgery, yet it is unclear to what extent functional connectivity (FC) alterations may underlie these deficits. We examined for postoperative voxel-wise FC changes in response to increased working memory load demands in cardiac surgery patients and nonsurgical controls.

EXPERIMENTAL DESIGN

Older cardiac surgery patients (n = 25) completed a verbal N-back working memory task during MRI scanning and cognitive testing before and 6 weeks after surgery; nonsurgical controls with cardiac disease (n = 26) underwent these assessments at identical time intervals. We measured postoperative changes in degree centrality, the number of edges attached to a brain node, and local coherence, the temporal homogeneity of regional functional correlations, using voxel-wise graph theory-based FC metrics. Group × time differences were evaluated in these FC metrics associated with increased N-back working memory load (2-back > 1-back), using a two-stage partitioned variance, mixed ANCOVA.

PRINCIPAL OBSERVATIONS

Cardiac surgery patients demonstrated postoperative working memory load-related degree centrality increases in the left dorsal posterior cingulate cortex (dPCC; p < .001, cluster p-FWE < .05). The dPCC also showed a postoperative increase in working memory load-associated local coherence (p < .001, cluster p-FWE < .05). dPCC degree centrality and local coherence increases were inversely associated with global cognitive change in surgery patients (p < .01), but not in controls.

CONCLUSIONS

Cardiac surgery patients showed postoperative increases in working memory load-associated degree centrality and local coherence of the dPCC that were inversely associated with postoperative global cognitive outcomes and independent of perioperative cerebrovascular damage.

Cognitive Outcomes After Transcatheter Aortic Valve Implantation: A Metaanalysis

OBJECTIVES

To quantitatively summarize changes in cognitive performance in individuals with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI).

DESIGN

Metaanalysis.

PARTICIPANTS

Individuals undergoing TAVI (N = 1,065 (48.5% male) from 18 studies, average age ≥80).

MEASUREMENTS

The MEDLINE, EMBASE, and Cochrane Central databases were searched for original peer-reviewed reports assessing cognitive performance using standardized cognitive tests before and after TAVI. Data were extracted for cognitive scores before TAVI; perioperatively (within 7 days after TAVI); 1, 3, and 6 months after TAVI, and 12 to 34 months after TAVI (over the long term). Standardized mean differences (SMDs) were generated using random-effects models for changes in cognition at each time point. Metaregression analyses were conducted to assess the association between population and procedural characteristics and cognitive outcomes. Risk of bias was assessed.

RESULTS

There were no significant changes from baseline in perioperative cognitive performance (SMD = 0.05, 95% confidence interval (CI) = -0.08-0.18; z = 0.75, P = .46), although overall cognitive performance had improved significantly 1 month after TAVI (SMD = -0.33, 95% CI = -0.50 to -0.16; z = 3.83, P < .001). There were no differences in cognitive performance 3 and 6 months after TAVI or over the long term. Cognitive outcomes were not associated with any covariates in regression analyses.

CONCLUSION

Cognitive performance is preserved after TAVI, suggesting TAVI is not detrimental to cognition.

Axillary versus innominate artery cannulation for antegrade cerebral perfusion in aortic surgery: design of the Aortic Surgery Cerebral Protection Evaluation (ACE) CardioLink-3 randomised trial

INTRODUCTION

Neurological injury remains the major cause of morbidity and mortality following open aortic arch repair. Systemic hypothermia along with antegrade cerebral perfusion (ACP) is the accepted cerebral protection approach, with axillary artery cannulation being the most common technique used to establish ACP. More recently, innominate artery cannulation has been shown to be a safe and efficacious method for establishing ACP. Inasmuch as there is a lack of high-quality data comparing axillary and innominate artery ACP, we have designed a randomised, multi-centre clinical trial to compare both cerebral perfusion strategies with regards to brain morphological injury using diffusion-weighted MRI (DW-MRI).

METHODS AND ANALYSIS

110 patients undergoing elective aortic surgery with repair of the proximal arch requiring an open distal anastamosis will be randomised to either the innominate artery or the axillary artery cannulation strategy for establishing unilateral ACP during systemic circulatory arrest with moderate levels of hypothermia. The primary safety endpoint of this trial is the proportion of patients with new radiologically significant ischaemic lesions found on postoperative DW-MRI compared with preoperative DW-MRI. The primary efficacy endpoint of this trial is the difference in total operative time between the innominate artery and the axillary artery cannulation group.

ETHICS AND DISSEMINATION

The study protocol and consent forms have been approved by the participating local research ethics boards. Publication of the study results is anticipated in 2018 or 2019. If this study shows that the innominate artery cannulation technique is non-inferior to the axillary artery cannulation technique with regards to brain morphological injury, it will establish the innominate artery cannulation technique as a safe and potentially more efficient method of antegrade cerebral perfusion in aortic surgery.

TRIAL REGISTRATION NUMBER

NCT02554032.

In-hospital mortality in propensity-score matched low-risk patients undergoing routine isolated surgical or transfemoral transcatheter aortic valve replacement in 2014 in Germany

AIMS

Recent randomized trials have documented the superiority of TAVR-particularly via transfemoral access-over SAVR in patients with severe aortic stenosis considered to have a high or intermediate operative risk of death. We sought to assess in-hospital outcomes of patients with severe aortic stenosis and a low risk of operative mortality undergoing routine surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR).

METHODS AND RESULTS

We performed a propensity-score matched comparison of all patients undergoing first-time treatment by SAVR or transfemoral TAVR (TF-TAVR) in 2014 in Germany who had a logistic EuroSCORE (logES) ≤ 10%, considered to reflect low surgical risk. The primary endpoint of our analysis was in-hospital mortality. Of 7624 SAVR and 9969 TF-TAVR procedures, 6844 (89.8%) and 2751 patients (27.6%), respectively, were considered low risk with a logES between 1.505 and 10.0%. Matching yielded 805 TF-TAVR/SAVR patient pairs with identical propensity scores and no difference in pertinent baseline characteristics, except for the logES, which was significantly higher in TF-TAVR patients (6.8 ± 1.7 vs. 4.2 ± 1.3% in SAVR patients, P < 0.001). Observed in-hospital mortalities were 1.7% (95% confidence interval, 1.1-3.0%) in SAVR and 2.0% (1.3-3.3%) in TF-TAVR patients (P = 0.85).

CONCLUSION

Our finding of no difference in in-hospital mortality in propensity-score matched low-surgical-risk patients treated by SAVR or TF-TAVR in a routine clinical setting indicates that TF-TAVR can be offered safely to individual patients, despite their operative risk being low. This finding needs to be confirmed in a randomized trial.

Neurological Injury in Intermediate-Risk Transcatheter Aortic Valve Implantation

BACKGROUND

The application of transcatheter aortic valve implantation (TAVI) to intermediate-risk patients is a controversial issue. Of concern, neurological injury in this group remains poorly defined. Among high-risk and inoperable patients, subclinical injury is reported on average in 75% undergoing the procedure. Although this attendant risk may be acceptable in higher-risk patients, it may not be so in those of lower risk.

METHODS AND RESULTS

Forty patients undergoing TAVI with the Edwards SAPIEN-XT™ prosthesis were prospectively studied. Patients were of intermediate surgical risk, with a mean±standard deviation Society of Thoracic Surgeons score of 5.1±2.5% and a EuroSCORE II of 4.8±2.4%; participant age was 82±7 years. Clinically apparent injury was assessed by serial National Institutes of Health Stroke Scale assessments, Montreal Cognitive Assessments (MoCA), and with the Confusion Assessment Method. These identified 1 (2.5%) minor stroke, 1 (2.5%) episode of postoperative delirium, and 2 patients (5%) with significant postoperative cognitive dysfunction. Subclinical neurological injury was assessed using brain magnetic resonance imaging, including diffusion-weighted imaging (DWI) sequences preprocedure and at 3±1 days postprocedure. This identified 68 new DWI lesions present in 60% of participants, with a median±interquartile range of 1±3 lesions/patient and volumes of infarction of 24±19 μL/lesion and 89±218 μL/patient. DWI lesions were associated with a statistically significant reduction in early cognition (mean ΔMoCA -3.5±1.7) without effect on cognition, quality of life, or functional capacity at 6 months.

CONCLUSIONS

Objectively measured subclinical neurological injuries remain a concern in intermediate-risk patients undergoing TAVI and are likely to manifest with early neurocognitive changes.

CLINICAL TRIAL REGISTRATION

URL: http://www.anzctr.org.au. Australian & New Zealand Clinical Trials Registry: ACTRN12613000083796.

Transcatheter aortic valve replacement: perioperative stroke and beyond

INTRODUCTION

The definition of stroke has changed over time, from a clinical only-based diagnosis to a more complex classification, including both clinical and imaging-based criteria, in part due to widespread use of magnetic resonance imaging (MRI). The increasing number of transcatheter aortic valve replacement (TAVR) procedures in patients with severe aortic valvular stenosis who are considered high-risk surgical candidates has influenced our view on the diagnosis, interpretation, and significance of perioperative stroke during these procedures. Areas covered: In this perspective, we summarize changes in the definition and diagnostic criteria for stroke and transient ischemic attacks. We examine how the introduction of MRI and standardized cognitive tests has affected our understanding of the safety of TAVR procedures. Finally, we review the growing evidence regarding the role of cerebral protection technology during TAVR procedures on cognitive function. Expert commentary: Standardized MRI-based protocols and prospective evaluation of neurologic deficits with a battery of cognitive assessment tests are needed to ensure accurate recognition of postprocedural clinical events in patients undergoing TAVR procedures and to confirm the effectiveness of embolic protection technology.

Serial Changes in Cognitive Function Following Transcatheter Aortic Valve Replacement

BACKGROUND

Data regarding the mid- to long-term cognitive trajectory of transcatheter aortic valve (TAVR) recipients are scarce.

OBJECTIVES

Changes in global cognition and specific cognitive domains up to 1 year post-TAVR were evaluated.

METHODS

Fifty-one patients (median age 80.0 [interquartile range: 72.0 to 85.0] years; 37% women) underwent TAVR and prospective assessment of cognitive function using the Montreal Cognitive Assessment (MoCA) at baseline, short-term (30 days), and 1 year post-TAVR. Processing speed and executive cognitive functions were further evaluated with the digit-symbol substitution test (DSST), Trail Making Tests (TMT), and verbal fluency tests at the same time points. Cognitive decline (CD) was determined by changes in mean scores and as a rate using practice-corrected reliable change index (RCI).

RESULTS

The baseline mean total MoCA score was 22.71 ± 3.84. Twenty patients (39.2%) were considered cognitively impaired using a cutoff of <23 of 30 points. Mean total MoCA score improved at short-term post-TAVR and remained stable at 1 year (p = 0.022). On the basis of the RCI of total MoCA score, 4 patients (7.8%) presented with short-term CD, which persisted at 1 year in 1 patient (2.0%). Four patients (7.8%) exhibited cognitive improvement at 1 year, increasing to 15% among those with baseline cognitive impairment. No significant changes were observed over time in the mean DSST, TMT, and verbal fluency test scores. On the basis of the RCI, 10 of 40 patients (25%) presented with a reduction in performance of at least 1 test at 30 days that persisted at 1 year in 4 patients (10%).

CONCLUSIONS

TAVR was associated with global improvement in cognitive status, more pronounced among those with cognitive impairment pre-TAVR. However, early decline in some complex cognitive functions was observed in one-quarter of TAVR recipients, persisting at 1 year in 10% of patients.