Clinical and prognostic implications of existing and new-onset atrial fibrillation in patients undergoing transcatheter aortic valve implantation

Late Bleeding Events in Patients Undergoing Percutaneous Coronary Intervention in the Workup Pre-TAVR

BACKGROUND

In patients undergoing percutaneous coronary intervention (PCI) in the work-up pre-transcatheter aortic valve replacement (TAVR), the incidence and clinical impact of late bleeding events (LBEs) remain largely unknown.

OBJECTIVES

This study sought to determine the incidence, clinical characteristics, associated factors, and outcomes of LBEs in patients undergoing PCI in the work-up pre-TAVR.

METHODS

This was a multicenter study including 1,457 consecutive patients (mean age 81 ± 7 years; 41.5% women) who underwent TAVR and survived beyond 30 days. LBEs (>30 days post-TAVR) were defined according to the Valve Academic Research Consortium-2 criteria.

RESULTS

LBEs occurred in 116 (7.9%) patients after a median follow-up of 23 (IQR: 12-40) months. Late bleeding was minor, major, and life-threatening or disabling in 21 (18.1%), 63 (54.3%), and 32 (27.6%) patients, respectively. Periprocedural (<30 days post-TAVR) major bleeding and the combination of antiplatelet and anticoagulation therapy at discharge were independent factors associated with LBEs (P ≤ 0.02 for all). LBEs conveyed an increased mortality risk at 4-year follow-up compared with no bleeding (43.9% vs 36.0; P = 0.034). Also, LBE was identified as an independent predictor of all-cause mortality after TAVR (HR: 1.39; 95% CI: 1.05-1.83; P = 0.020).

CONCLUSIONS

In TAVR candidates with concomitant significant coronary artery disease requiring percutaneous treatment, LBEs after TAVR were frequent and associated with increased mortality. Combining antiplatelet and anticoagulation regimens and the occurrence of periprocedural bleeding determined an increased risk of LBEs. Preventive strategies should be pursued for preventing late bleeding after TAVR, and further studies are needed to provide more solid evidence on the most safe and effective antithrombotic regimen post-TAVR in this challenging group of patients.

Outcomes of transcatheter aortic valve replacement in patients with and without atrial fibrillation: Insight from national inpatient sample

BACKGROUND

Atrial fibrillation (AF) is one of the most frequent rhythm disturbance encountered in the population in general. Our study aims to evaluate the in-hospital outcomes of TAVR with AF.

METHODS

We used National Inpatient Sample database from 2011 to 2018. Baseline characteristics and in-hospital outcomes were evaluated in TAVR based on AF status or not in both unmatched and propensity-matched cohorts.

RESULTS

A total of 215,938 patients underwent TAVR during our study period and out of these AF was encountered in 89,587 (41.5%) patients. AF patients undergoing TAVR had a higher mean age and had an increased burden of key co-morbidities in the unmatched cohort. With propensity matched 1:1 analysis, AF had higher mortality as compared to no-AF group (2.4% vs. 2.1%, p < 0.01). The rate of cardiogenic shock (2.9% vs 2.1%), respiratory complications (9.9% vs 8.2%), acute kidney injury (15.6% vs 12.0%), vascular complications (5.0% vs 4.7%), and blood transfusion (10.4% vs 8.6%) was higher in TAVR patients with AF. A lower proportion of patients had routine discharge to home for TAVR with AF (80.8% vs 74.4%). Cost of hospitalization (23,0171[SD, 20,5242] vs 210,608[28,4203]) and length of stay (5.7[SD, 11.8] vs 4.29[7.2] days) were considerably higher in patients undergoing TAVR with AF.

CONCLUSION

Patients undergoing TAVR with concomitant AF tended to have increased mortality, complications, length, and cost of stay compared to non-AF patients.

Direct oral anticoagulants in patients with atrial fibrillation and bioprosthetic valve replacement: A meta-analysis

OBJECTIVES

This systematic review and meta-analysis compares direct oral anticoagulants (DOACs) versus vitamin K antagonists (VKAs) in patients with atrial fibrillation and bioprosthetic valve replacement or repair (BVR).

BACKGROUND

The optimal anticoagulation therapy for patients with atrial fibrillation and a history of bioprosthetic valve replacement or repair (BVR) is not well understood.

METHODS

We performed a systematic literature review to identify clinical studies that compared anticoagulation therapies for patients with atrial fibrillation and BVR. The primary outcomes of stroke, major bleeding, and mortality were reported as random effects risk ratio (RR) with 95% confidence interval. No prior ethical approval was required since all data is public.

RESULTS

Our search yielded 101 potential studies. We included six studies reporting on 1911 patients. There was a lower risk of stroke and major bleeding in patients with atrial fibrillation after BVR treated with DOACs when compared to VKAs with risk ratios of 0.44 (95% CI 0.24-0.82, p < 0.01) and 0.53 (95% CI 0.34-0.83, p < 0.01), respectively. There was no statistically significant difference in mortality between patients with atrial fibrillation after BVR treated with DOACs compared to patients treated with VKAs with a risk ratio of 1.12 (95% CI 0.73-1.74, p = 0.60).

CONCLUSION

This systematic review and meta-analysis suggests that DOACs are superior to VKAs with respect to stroke and major bleeding in patients with atrial fibrillation and BVR.

Arrhythmic burden in patients with new-onset persistent left bundle branch block after transcatheter aortic valve replacement: 2-year results of the MARE study

AIMS

We determined the incidence and type of arrhythmias at 2-year follow-up in patients with new-onset persistent left bundle branch block (LBBB) following transcatheter aortic valve replacement (TAVR).

METHODS AND RESULTS

Multicentre prospective study including 103 consecutive patients with new-onset persistent LBBB post-TAVR (SAPIEN XT/3: 53; CoreValve/Evolut R: 50). An implantable cardiac monitor (Reveal XT, Reveal Linq) was implanted before hospital discharge and patients had continuous monitoring for up to 2 years. Arrhythmic events were adjudicated in a central core lab. 1836 new arrhythmic events (tachyarrhythmias: 1655 and bradyarrhythmias: 181) occurred at 2 years. Of these, 283 (15%) occurred beyond 1 year (tachyarrhythmias 212, bradyarrhythmias 71) in 33 (36%) patients, without differences between valve type. Most late (>1 year) arrhythmic events were asymptomatic (94%) and led to a treatment change in 17 (19%) patients. A total of 71 late bradyarrhythmias [high-degree atrioventricular block (HAVB): 3, severe bradycardia: 68] were detected in 17 (21%) patients. At 2 years, 18 (17%) patients had received a permanent pacemaker (PPM) or implantable cardiac-defibrillator. PPM implantation due to HAVB predominated in the early phase post-TAVR, with only 1 HAVB event requiring PPM implantation after 1 year.

CONCLUSION

Patients with new-onset LBBB post-TAVR exhibited a very high burden of arrhythmic events within the 2 years post-procedure. While new tachyarrhythmic events were homogeneously distributed over time, the vast majority of new HAVB episodes leading to PPM implantation occurred early after the procedure. These results should help to guide the management of this challenging group of patients. (clinicaltrials.gov: NCT02153307).

Heart failure following transcatheter aortic valve replacement

Introduction: Over the past decade, the number of transcatheter aortic valve replacement (TAVR) procedures has increased exponentially. Despite major improvements in both device and successes, the rate of hospital readmission after TAVR remains high, with heart failure (HF) decompensation being one of the most important causes.Areas covered: This review provides an overview of the current status of HF following TAVR, including details about its incidence, clinical impact, contributing factors, and current and future treatment perspectives.Expert opinion: HF decompensation has been identified as the most common cause of rehospitalization following TAVR, and it has been associated with a negative prognosis. Multiple preexisting factors including low flow status, cardiac amyloidosis, myocardial fibrosis, multivalvular disease, pulmonary hypertension, coronary artery disease, and atrial fibrillation have been associated with an increased risk of HF events. Also, multiple post-procedural factors like the occurrence of significant paravalvular leaks, severe prosthesis-patient mismatch, and conduction disturbances have also contributed to increase this risk . Thus, reducing HF events in TAVR recipients would require a multifactorial and multidisciplinary effort including the optimization of the medical treatment and close follow-up and treatment of residual or concomitant valvular disease and conduction disturbance issues. Future studies in this challenging group of patients are warranted.

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.

Ambulatory Electrocardiogram Monitoring in Patients Undergoing Transcatheter Aortic Valve Replacement: JACC State-of-the-Art Review

Transcatheter aortic valve replacement (TAVR) has changed the treatment of patients with severe aortic stenosis. However, the occurrence of conduction disturbances has not decreased significantly over time and remains the main drawback of the procedure. In addition, new-onset atrial fibrillation is the most frequent tachyarrhythmia during the hospitalization period and is associated with worse clinical outcomes. However, little is known regarding the incidence and clinical impact of arrhythmic events beyond the periprocedural TAVR period. Ambulatory electrocardiogram (AECG) monitoring has recently emerged as a tool to unravel the complex issue of arrhythmic disorders (bradyarrhythmias and tachyarrhythmias) before and after TAVR. To date, the preliminary results from the initial experience using AECG monitoring systems showed the safety, usefulness, and potential clinical implications of this diagnostic tool in TAVR recipients. This review provides an overview of the current status, clinical implications, and future perspectives of AECG monitoring in the TAVR setting.

Optimal antithrombotic therapy after transcatheter aortic valve replacement in patients with atrial fibrillation

Atrial fibrillation (AF) is prevalent in patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). Depending on the timing of AF detection, it is usually categorized as pre-existing AF or new-onset AF. Antiplatelet therapy, rather than a vitamin K antagonist, may be considered as the primary treatment for patients without an indication for oral anticoagulants who undergo TAVR. However, the optimal postprocedural antithrombotic regimen for patients with AF undergoing TAVR remains unknown. In this review, we briefly introduce the management strategies of antithrombotic therapy and list the evidence from related studies to elucidate the optimal antithrombotic management for patients with AF undergoing TAVR.

Comparing anticoagulation therapy alone versus anticoagulation plus single antiplatelet drug therapy after transcatheter aortic valve implantation in patients with an indication for anticoagulation: a systematic review and meta-analysis

PURPOSE

This meta-analysis compared the efficacy and safety of oral anticoagulation (OAC) therapy alone versus OAC plus single antiplatelet therapy (SAPT) in patients with an indication for chronic OAC (mostly due to atrial fibrillation) after transcatheter aortic valve implantation (TAVI).

METHODS

A systematic literature search was performed in the PubMed, Embase, and Cochrane Library databases to identify relevant studies. Data was extracted from the eligible studies and outcomes expressed as relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

Five studies comprising 1344 patients with an indication for chronic OAC and undergoing TAVI were included. Of the 1344 patients, 480 patients received OAC therapy alone and 864 patients received OAC plus SAPT. There were no significant differences between OAC alone versus OAC plus SAPT in all-cause mortality (RR = 1.05, 95% CI 0.84-1.30, p = 0.69) and ischemic stroke (RR = 0.95, 95% CI 0.95-1.61, p = 0.86). However, OAC alone was associated with significantly lower risks of all bleeding events (RR = 0.62, 95% CI 0.49-0.69, p < 0.0001) and major and/ life-threatening bleeding events (RR = 0.57, 95% CI 0.42-0.76, p = 0.0002) compared to OAC plus SAPT.

CONCLUSION

In patients with an indication for chronic anticoagulation, post-TAVI antithrombotic therapy with OAC alone compared to OAC plus SAPT may be not significantly different in reducing all-cause mortality and ischemic stroke, but has an important benefit in a significantly lower risk of all bleeding and major and/life-threatening bleeding events.

Anticoagulation With or Without Antiplatelet Therapy Following Transcatheter Aortic Valve Replacement for Patients With Atrial Fibrillation: A Meta-Analysis

BACKGROUND

Although current guidelines recommend oral anticoagulants (OAC) with or without antiplatelet therapy (APT) following transcatheter aortic valve replacement (TVAR) in patients with an indication for long-term anticoagulation therapy, the optimal antithrombotic strategy remains unknown in these population. Herein, we conducted a meta-analysis comparing the outcome of OAC alone versus OAC with APT following TAVR in patients with atrial fibrillation (AF).

METHODS

MEDLINE and EMBASE were searched through May 2020 to identify clinical trials that investigated OAC alone versus OAC with APT following TAVR in patients with AF. From each study, we extracted the hazard ratios (HRs) or risk ratios of major or life threatening bleeding, stroke, all-cause mortality and cardiovascular mortality.

RESULTS

1 randomized controlled trial and 3 observational studies were identified, which enrolled a total of 2032 patients with AF who underwent TAVR assigned to the OAC group (n = 722) or OAC with APT group (n = 1310). Pooled analyses demonstrated the rate of major or life threatening bleeding was significantly lower in the OAC group compared to the OAC with APT group (HR [95% Confidence Interval [CI] = 0.54 [0.38-0.77], P = .0006]). However, the rate of stroke was similar in both groups (HR [95% CI] = 1.22 [0.80-1.87], P = .36). All-cause and cardiovascular mortalities were also similar in both groups.

CONCLUSIONS

We observed that OAC with APT following TAVR in patients with AF increased the risk of bleeding compared to OAC alone without decreasing the risk of stroke.

The effect of P wave indices on new onset atrial fibrillation after trans-catheter aortic valve replacement

OBJECTIVES

Data is scarce regarding the relation between P wave indices and new onset atrial fibrillation (NOAF) after trans-catheter aortic valve replacement (TAVR).

AIMS

The present study aimed to find out certain characteristics of P wave that may predict NOAF after TAVR procedure.

METHOD

Patients with severe calcific aortic stenosis who had undergone TAVR procedure between 2013 and 2019 in two centers were investigated. P wave abnormalities that have been resumed to reflect impaired atrial conduction; partial and advanced inter atrial block (IAB), P-wave terminal force in lead V1, P wave dispersion, reduced amplitude of P- wave in lead I, P wave peak time in D2 and V1 were evaluated on pre- procedural 12 derivation surface electrocardiography (ECG). The relationship between these parameters and incidence of NOAF during index hospitalization was evaluated.

RESULTS

A total of 227 consecutive patients (median age 79 [74-83]; 134 [59%] female) were included in the study. NOAF occurred in 46 (20.3%) patients. P wave duration, P wave dispersion, number of patients with partial and advanced IAB, left atrium diameter, STS score were higher in NOAF patients. Use of general anesthesia and history of prior open heart surgery were also more frequent in NOAF group. In multivariable logistic regression analysis; advanced IAB (OR 6.413 [2.555-16.095] p < 0.01), P wave dispersion (OR 3.544 [1.431-8.780] p = 0.006) and use of general anesthesia (OR 2.736 [1.225-6.109] p = 0.014) were independent predictors of NOAF.

CONCLUSION

Among P wave abnormalities evaluated on pre-procedural 12-derivation surface ECG, advanced IAB and P wave dispersion may predict NOAF after TAVR procedure.

Antithrombotic Therapy and Cardiovascular Outcomes After Transcatheter Aortic Valve Replacement in Patients With Atrial Fibrillation

OBJECTIVES

The study sought to determine the patterns of antithrombotic therapy and association with clinical outcomes in patients with atrial fibrillation (AF) and CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category) score ≥2 following transcatheter aortic valve replacement (TAVR).

BACKGROUND

The impact of antithrombotic regimens on clinical outcomes in patients with AF and severe aortic stenosis treated with TAVR is unknown.

METHODS

In the randomized PARTNER II (Placement of Aortic Transcatheter Valve II) trial and associated registries, 1,621 patients with prior AF and CHA2DS2-VASc score ≥2 comprised the study cohort. Outcomes were analyzed according to antithrombotic therapy.

RESULTS

During the 5-year enrollment period, 933 (57.6%) patients were discharged on oral anticoagulant therapy (OAC). Uninterrupted antiplatelet therapy (APT) for at least 6 months or until an endpoint event was used in 544 of 933 (58.3%) of patients on OAC and 77.5% of patients not on OAC. At 2 years, patients on OAC had a similar rate of stroke (6.6% vs. 5.6%; p = 0.53) and the composite outcome of death or stroke (29.7% vs. 31.8%; p = 0.33), compared with no OAC. OAC with APT was associated with a reduced rate of stroke (5.4% vs. 11.1%; p = 0.03) and death or stroke (29.7% vs. 40.1%; p = 0.01), compared with no OAC or APT. Following adjustment, OAC with APT and APT alone were both associated with reduced rates of stroke compared with no OAC or APT (hazard ratio for OAC+APT: 0.43, 95% confidence interval: 0.22 to 0.85; p = 0.015; hazard ratio for APT alone: 0.32, 95% confidence interval: 0.16 to 0.65; p = 0.002), while OAC alone was not.

CONCLUSIONS

Among patients with prior AF undergoing TAVR, antiplatelet with or without anticoagulant therapy was associated with a reduced risk of stroke at 2 years, implicating multifactorial stroke mechanisms in this population.

Adjuvant Antithrombotic Therapy in TAVR

PURPOSE OF REVIEW

Transcatheter aortic valve replacement (TAVR) has developed into an important alternative to surgical aortic valve replacement (SAVR) for patients with severe aortic stenosis (AS). Adjuvant antithrombotic therapies are commonly used during and after TAVR to decrease the risk of valve thrombosis and thromboembolic cerebrovascular events (CVEs) but consequently increase the risk of bleeding. This article reviews the past and current clinical data regarding adjuvant antithrombotic therapies in TAVR.

RECENT FINDINGS

Cerebrovascular and bleeding events during and after TAVR are associated with substantial morbidity and mortality. Bivalirudin, a direct thrombin inhibitor, has been shown to be safe alternative to unfractionated heparin (UFH) as procedural anticoagulation during TAVR; however, sparse evidence exists to guide use of antiplatelet and anticoagulant therapies in patients after TAVR. Multiple studies comparing different antithrombotic regimens in the post-TAVR setting are currently underway. Current guidelines recommend intra-procedural anticoagulation with UFH for during TAVR and with dual antiplatelet therapy (DAPT) after TAVR. There is a need to better understand the role of adjuvant antithrombotic therapies in TAVR. The results of ongoing studies are needed to develop evidence-based guidance for the use of adjuvant antithrombotic therapies after TAVR.

Warfarin and Antiplatelet Therapy Versus Warfarin Alone for Treating Patients With Atrial Fibrillation Undergoing Transcatheter Aortic Valve Replacement

OBJECTIVES

The study sought to examine the risk of ischemic events and bleeding episodes associated with differing antithrombotic strategies in patients undergoing transcatheter aortic valve replacement (TAVR) with concomitant atrial fibrillation (AF).

BACKGROUND

Guidelines recommend antiplatelet therapy (APT) post-TAVR to reduce the risk of stroke. However, data on the efficacy and safety of this recommendation in the setting of a concomitant indication for oral anticoagulation (due to atrial fibrillation [AF]) with a vitamin K antagonist (VKA) are scarce.

METHODS

A multicenter evaluation comprising 621 patients with AF undergoing TAVR was undertaken. Post-TAVR prescriptions were used to determine the antithrombotic regimen used according to the following 2 groups: monotherapy (MT) with VKA (n = 101) or multiple antithrombotic therapy (MAT) with VKA plus 1 or 2 antiplatelet agents (aspirin or clopidogrel; n = 520). Endpoint definitions were in accordance with Valve Academic Research Consortium-2 criteria. The rate of stroke, major adverse cardiovascular events (stroke, myocardial infarction, or cardiovascular death), major or life-threatening bleeding events, and death were assessed by a Cox multivariate model regression survival analysis according to the antithrombotic regime used.

RESULTS

During a median follow-up of 13 months (interquartile range: 3 to 31 months) there were no differences between groups in the rate of stroke (MT: 5%, MAT: 5.2%; adjusted hazard ratio [HR]: 1.25; 95% confidence interval [CI]: 0.45 to 3.48; p = 0.67), major adverse cardiovascular events (MT: 13.9%, MAT: 16.3%; adjusted HR: 1.33; 95% CI: 0.75 to 2.36; p = 0.33), and death (MT 22.8%, MAT: 19.2%; adjusted HR: 0.93; 95% CI: 0.58 to 1.50; p = 0.76). A higher risk of major or life-threatening bleeding was found in the MAT group (MT: 14.9%, MAT: 24.4%; adjusted HR: 1.85; 95% CI: 1.05 to 3.28; p = 0.04). These results remained similar when patients receiving VKA plus only 1 antiplatelet agent (n = 463) were evaluated.

CONCLUSIONS

In TAVR recipients prescribed VKA therapy for AF, concomitant antiplatelet therapy use appears not to reduce the incidence of stroke, major adverse cardiovascular events, or death, while increasing the risk of major or life-threatening bleeding.

Anticoagulation for prosthetic heart valves: unresolved questions requiring answers

PURPOSE OF REVIEW

The efficacy of anticoagulation for valvular prostheses is the result of a delicate balance between the risk of thromboembolic (TE) events and bleeding. Here, we review data on anticoagulation for valve prostheses with a focus on clinical trials that address key unanswered questions.

RECENT FINDINGS

There are several unanswered questions in the field of prosthetic valve anticoagulation, including: optimal TE prophylaxis in the short term for bioprostheses, optimal TE prophylaxis following transcatheter aortic valve implantation, the safety and efficacy of lower levels of anticoagulation with the bileaflet mechanical prosthesis, the role of aspirin for patients with mechanical prostheses, and the management of anticoagulation for mechanical valves in pregnancy. Other areas of study include the role, if any, of nonwarfarin oral anticoagulants for prosthetic TE prophylaxis as well as self-INR monitoring. Finally, we briefly mention studies of newer anticoagulants, such as novel vitamin K antagonists and antisense oligonucleotides, that are on the horizon.

SUMMARY

Optimal antithrombotic management is a key issue for patients with valvular prostheses, and the publication of recent trials has provided much-needed guidance. We highlight areas of progress, in addition to the major unanswered questions for which well-designed, prospective clinical trials are forthcoming.

Antithrombotic therapy following transcatheter aortic valve implantation: what challenge do we face?

The issue of stroke and bleeding events following transcatheter aortic valve implantation (TAVI) and its relation with antithrombotic regimens before, during and after the procedure is increasingly recognized as an important issue. While dedicated trials are ongoing, there is no clear evidence at present on the best antithrombotic regimen in the context of TAVI. In this article, we will go through the mechanisms involved in embolic and bleeding complications of TAVI, and we will discuss the key aspects of antithrombotic treatment in patients undergoing TAVI.

Arrhythmia Burden in Elderly Patients With Severe Aortic Stenosis as Determined by Continuous Electrocardiographic Recording

Background—

This study sought to evaluate the prevalence of previously undiagnosed arrhythmias in candidates for transcatheter aortic valve replacement (TAVR) and to determine the impact on therapy changes and arrhythmic events after the procedure.

Methods and Results—

A total of 435 candidates for TAVR underwent 24-hour continuous ECG monitoring the day before the procedure. Newly diagnosed arrhythmias were observed in 70 patients (16.1%) before TAVR: paroxysmal atrial fibrillation (AF)/atrial tachycardia (AT) in 28, advanced atrioventricular block or severe bradycardia in 24, nonsustained ventricular tachycardia in 26, and intermittent left bundle-branch block in 3 patients. All arrhythmic events but one were asymptomatic and led to a therapy change in 43% of patients. In patients without known AF/AT, the occurrence of AF/AT during 24-hour ECG recording was associated with a higher rate of 30-day cerebrovascular events (7.1% versus 0.4%; P =0.030). Among the 53 patients with new-onset AF/AT after TAVR, 30.2% had newly diagnosed paroxysmal AF/AT before the procedure. In patients who needed permanent pacemaker implantation after the procedure (n=35), 31.4% had newly diagnosed advanced atrioventricular block or severe bradycardia before TAVR. New-onset persistent left bundle-branch block after TAVR occurred in 37 patients, 8.1% of whom had intermittent left bundle-branch block before the procedure.

Conclusions—

Newly diagnosed arrhythmias were observed in approximately a fifth of TAVR candidates, led to a higher rate of cerebrovascular events, and accounted for a third of arrhythmic events after the procedure. This high arrhythmia burden highlights the importance of an early diagnosis of arrhythmic events in such patients to implement the appropriate therapeutic measures earlier.

Atrial fibrillation, stroke, and mortality rates after transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is considered a suitable treatment for patients with severe symptomatic aortic stenosis and high operative risk. Our aim was to evaluate the effect of preprocedural and new-onset atrial fibrillation (NOAF) on mortality and stroke in patients who underwent TAVI. We performed a single-center study of 380 consecutive patients enrolled to a TAVI registry. NOAF was defined as postprocedural atrial fibrillation (AF) occurring within 30 days after the procedure. Patients were followed up for a mean of 528 ± 364 days. During follow-up, 19 (5%) new episodes of stroke occurred, of whom 6 and 18 cases occurred within 30 days and 1 year, respectively. Overall mortality during the follow-up was 68 (20%), of those 12 and 58 patients died within 30 days and 1 year, respectively. NOAF occurred in 31 (8.2%) patients and was not associated with higher stroke or mortality rates at 30 days or 1 year of follow-up. Notably, compared with patients without previous AF, patients with previous AF at baseline had increased rates of stroke and mortality at 1-year follow-up (2.1% vs 9.6%, p = 0.01, and 8.2% vs 34.9%, p <0.01; respectively). In multivariate analysis, AF at baseline but not NOAF was a significant predictor of mortality throughout the follow-up period (HR 2.2, 95% confidence interval 1.3 to 3.8, p = 0.003, and HR 1.5, 95% confidence interval 0.5 to 4.1, p = 0.390, respectively). In conclusion, previous AF at baseline but not NOAF significantly increases stroke and mortality rates after TAVI. The inclusion of AF into future TAVI risk stratification scores should be strongly considered.

Stroke after transcatheter aortic valve replacement: incidence, risk factors, prognosis, and preventive strategies

The first transcatheter aortisc valve replacement (TAVR) was performed in 2002, and has been proven beneficial in inoperable and high-risk patients for open heart surgery. Stroke occurrence after TAVR, both periprocedure and at follow-up, has not been well described. We sought to review incidence, pathophysiology, predictors, prognosis, and current preventive strategies of cerebrovascular accidents (CVAs) after TAVR. Studies were selected from a Medline search if they contained clinical outcomes data after TAVR. Acute and subacute CVAs after TAVR have been reported in 3% to 6% of patients. Approximately 45% of CVAs occur within 2 days after TAVR; 28% between 3 and 10 days; 4% between 10 and 30 days; and 10.5% occur from 1 month to 2 years. Clinically silent cerebral embolisms have been reported, with an incidence greatly exceeding that of overt CVAs. Underlying pathophysiologic mechanisms for CVAs can be broadly categorized into embolic and nonembolic causes, as well as procedural and postprocedural (early and late). Important predictors of early CVAs are small aortic valve area, atrial fibrillation, and balloon postdilation, whereas late CVAs are mostly influenced by chronic atrial fibrillation, prior cerebrovascular disease, and transapical approach. Following stroke, patients exhibit increased morbidity and mortality. A multilevel approach for the prevention of CVAs includes improved interventional techniques, embolic protection devices, antithrombotic treatment, close monitoring, and aggressive management of modifiable risk factors. Technology advances notwithstanding stroke morbidity and mortality remains steady. The significance of silent cerebral embolism on prognosis remains uncertain, and optimal medical treatment during and after TAVR should be further investigated.

Advanced chronic kidney disease in patients undergoing transcatheter aortic valve implantation: insights on clinical outcomes and prognostic markers from a large cohort of patients

AIM

The aim of this study was to determine the effects of advanced chronic kidney disease (CKD) on early and late outcomes after transcatheter aortic valve implantation (TAVI), and to evaluate the predictive factors of poorer outcomes in such patients.

METHODS AND RESULTS

This was a multicentre study including a total of 2075 consecutive patients who had undergone TAVI. Patients were grouped according the estimated glomerular filtration rate as follows: CKD stage 1-2 (≥60 mL/min/1.73 m(2); n = 950), stage 3 (30-59 mL/min/1.73 m(2); n = 924), stage 4 (15-29 mL/min/1.73 m(2); n = 134) and stage 5 (<15 mL/min/1.73 m² or dialysis; n = 67). Clinical outcomes were evaluated at 30-days and at follow-up (median of 15 [6-29] months) and defined according to the VARC criteria. Advanced CKD (stage 4-5) was an independent predictor of 30-day major/life-threatening bleeding (P = 0.001) and mortality (P = 0.027), and late overall, cardiovascular and non-cardiovascular mortality (P < 0.01 for all). Pre-existing atrial fibrillation (HR: 2.29, 95% CI: 1.47-3.58, P = 0.001) and dialysis therapy (HR: 1.86, 95% CI: 1.17-2.97, P = 0.009) were the predictors of mortality in advanced CKD patients, with a mortality rate as high as 71% at 1-year follow-up in those patients with these 2 factors. Advanced CKD patients who had survived at 1-year follow-up exhibited both a significant improvement in NYHA class (P < 0.001) and no deterioration in valve hemodynamics (P = NS for changes in mean gradient and valve area over time).

CONCLUSIONS

Advanced CKD was associated with a higher rate of early and late mortality and bleeding events following TAVI, with AF and dialysis therapy determining a higher risk in these patients. The mortality rate of patients with both factors was unacceptably high and this should be taken into account in the clinical decision-making process in this challenging group of patients.

Long-term prognostic value and serial changes of plasma N-terminal prohormone B-type natriuretic peptide in patients undergoing transcatheter aortic valve implantation

Little is known about the usefulness of evaluating cardiac neurohormones in patients undergoing transcatheter aortic valve implantation (TAVI). The objectives of this study were to evaluate the baseline values and serial changes of N-terminal prohormone B-type natriuretic peptide (NT-proBNP) after TAVI, its related factors, and prognostic value. A total of 333 consecutive patients were included, and baseline, procedural, and follow-up (median 20 months, interquartile range 9 to 36) data were prospectively collected. Systematic NT-proBNP measurements were performed at baseline, hospital discharge, 1, 6, and 12 months, and yearly thereafter. Baseline NT-proBNP values were elevated in 86% of the patients (median 1,692 pg/ml); lower left ventricular ejection fraction and stroke volume index, greater left ventricular mass, and renal dysfunction were associated with greater baseline values (p <0.01 for all). Higher NT-proBNP levels were independently associated with increased long-term overall and cardiovascular mortalities (p <0.001 for both), with a baseline cut-off level of ∼2,000 pg/ml best predicting worse outcomes (p <0.001). At 6- to 12-month follow-up, NT-proBNP levels had decreased (p <0.001) by 23% and remained stable up to 4-year follow-up. In 39% of the patients, however, there was a lack of NT-proBNP improvement, mainly related to preprocedural chronic atrial fibrillation, lower mean transaortic gradient, and moderate-to-severe mitral regurgitation (p <0.01 for all). In conclusion, most patients undergoing TAVI presented high NT-proBNP levels, and a lack of improvement was observed in >1/3 of the patients after TAVI. Also, higher NT-proBNP levels predicted greater overall and cardiac mortalities at a median follow-up of 2 years. These findings support the implementation of NT-proBNP measurements for the clinical decision-making process and follow-up of patients undergoing TAVI.