Changes in Coagulation and Platelet Activation Markers Following Transcatheter Left Atrial Appendage Closure

Single versus dual antiplatelet therapy following percutaneous left atrial appendage closure-A systematic review and meta-analysis

BACKGROUND

In the last few years, percutaneous LAA occlusion (LAAO) has become a plausible alternative in atrial fibrillation (AF) patients with contraindications to anticoagulation therapy. Nevertheless, the optimal antiplatelet strategy following percutaneous LAAO remains to be defined.

METHODS

Studies comparing single antiplatelet therapy (SAPT) versus dual antiplatelet therapy (DAPT) following LAAO were systematically searched and screened. The outcomes of interest were ischemic stroke, device-related thrombus (DRT) and major bleeding. A random-effect meta-analysis was performed comparing outcomes in both groups. The moderator effect of baseline characteristics on outcomes was evaluated by univariate meta-regression analyses.

RESULTS

Sixteen observational studies with 3255 patients treated with antiplatelet therapy (SAPT, n = 1033; DAPT, n = 2222) after LAAO were included. Mean age was 74.5 ± 8.3 years, mean CHA2DS2-VASc and HAS-BLED scores were 4.3 ± 1.5 and 3.2 ± 1.0, respectively. At a weighted mean follow-up of 12.7 months, the occurrence of stroke (RR 1.33; 95% CI 0.64-2.77; p =.44), DRT (RR 1.52; 95% CI 0.90-2.58; p =.12), and the composite of stroke and DRT (RR 1.26; 95% CI 0.67-2.37; p =.47) did not differ significantly between SAPT and DAPT groups. The rate of major bleedings was also not different between groups (RR 1.41; 95% CI 0.64-3.12; p =.39).

CONCLUSIONS

Among AF patients at high bleeding risk undergoing percutaneous LAAO, a post-procedural minimalistic antiplatelet strategy with SAPT did not significantly differ from DAPT regimens regarding the rate of stroke, DRT and major bleeding.

Best anticoagulation strategy with and without appendage occlusion for stroke-prophylaxis in postablation atrial fibrillation patients with cardiac amyloidosis

INTRODUCTION

Both atrial fibrillation (AF) and amyloidosis increase stroke risk. We evaluated the best anticoagulation strategy in AF patients with coexistent amyloidosis.

METHODS

Consecutive AF patients with concomitant amyloidosis were divided into two groups based on the postablation stroke-prophylaxis approach; group 1: left atrial appendage occlusion (LAAO) in eligible patients and group 2: oral anticoagulation (OAC). Group 1 patients were further divided into Gr. 1A: LAAO + half-does NOAC (HD-NOAC) for 6 months followed by aspirin 81 mg/day and Gr. 1B: LAAO + HD-NOAC. In group 1 patients, with complete occlusion at the 45-day transesophageal echocardiogram, patients were switched to aspirin, 81 mg/day at 6 months. In case of leak, or dense "smoke" in the left atrium (LA) or enlarged LA, they were placed on long-term half-dose (HD) NOAC. Group 2 patients remained on full-dose NOAC during the whole study period.

RESULTS

A total of 92 patients were included in the analysis; group 1: 56 and group 2: 36. After the 45-day TEE, 31 patients from group 1 remained on baby-aspirin and 25 on HD NOAC. At 1-year follow-up, four stroke, one TIA and six device-thrombus were reported in group 1A, compared to none in patients in group 1B (5/31 vs. 0/25, p = .03). No bleeding events were reported in group 1, whereas group 2 had five bleeding events (one subdural hematoma, one retinal hemorrhage, and four GI bleedings). Additionally, one stroke was reported in group 2 that happened during brief discontinuation of OAC.

CONCLUSION

In patients with coexistent AF and amyloidosis, half-dose NOAC following LAAO was observed to be the safest stroke-prophylaxis strategy.

Challenges and advances in device-related thrombus in left atrial appendage occlusion

Oral anticoagulation therapy (OAC) is a mainstay for mitigating stroke and other embolic events in patients with atrial fibrillation (AF). Despite the demonstrated efficacy of OAC in reducing events, many patients are unable to tolerate OAC due to bleeding risks. Left atrial appendage occlusion (LAAO) devices were developed as implantable technologies to moderate stroke risk in patients with intolerance to OAC. Despite clinical data supporting near-comparable protection against thromboembolic events with OAC, device-related thrombus formation has emerged as a critical complication following LAAO that remains a potential limitation to the safety and efficacy of LAAO. Improved biocompatibility of LAAO devices with fluoropolymers, a well-established stent-coating technology used to reduce thrombus formation and promote endothelialization, may optimize outcomes after LAAO.

Perioperative Treatment with Rivaroxaban and Dabigatran on Changes of Coagulation and Platelet Activation Biomarkers following Left Atrial Appendage Closure

Insufficient data exist regarding the investigation of the impact of novel oral anticoagulants (NOACs) on coagulation activation biomarkers in the context of left atrial appendage closure (LAAC) and device-related thrombosis (DRT). The study was designed to investigate the changes and presence of coagulation activation biomarkers between different antithrombotic strategies following LAAC. A total of 120 nonvalvular atrial fibrillation patients intolerant of long-term anticoagulants, who underwent successful WATCHMAN closure implantation, were enrolled (rivaroxaban, n = 82; dabigatran, n = 38). Blood samples were obtained from left atrium (LA) and left atrial appendage (LAA) during the operation and fasting blood samples on the same day of LAAC and 45 days after discharge. The biochemical indicators, thrombin-antithrombin complex (TAT), soluble P-selectin (sP-selectin), von Willebrand factor (vWF), and CD40 ligand (CD40L), were measured by enzyme-linked immunosorbent assay. The primary endpoints of this study were the efficacy and safety characteristics of different antithrombotic strategies, including DRT incidence, stroke or transient ischemic attack, systemic embolism, and clinical major and nonmajor bleeding complications during the follow-up of 180 days. The results revealed that TAT, vWF, sP-selectin, and CD40L levels in vein were significantly reduced by 2.4% (p = 0.043), 5.0% (p < 0.001), 8.7% (p < 0.001), and 2.5% (p = 0.043) from their baseline levels after rivaroxaban treatment. Conversely, no significant changes were detected in the dabigatran group. Furthermore, the plasma levels of platelet activation biomarkers (CD40L and sP-selectin) in both LA and LAA groups were significantly lower after anticoagulation with rivaroxaban, as compared to dabigatran treatment (CD40L: 554.62 ± 155.54 vs. 445.02 ± 130.04 for LA p = 0.0013, 578.51 ± 156.28 vs. 480.13 ± 164.37 for LAA p = 0.0052; sP-selectin: 2849.07 ± 846.69 vs. 2225.54 ± 799.96 for LA p = 0.0105, 2915.52 ± 1402.40 vs. 2203.41 ± 1061.67 for LAA p = 0.0022). Notably, the present study suggests that rivaroxaban may be more effective in the prevention of DRT for patients undergoing LAAC.

Short-term antiplatelet versus anticoagulant therapy after left atrial appendage closure: a systematic review and meta-analysis

This meta-analysis compared the efficacy and safety of different antithrombotic regimens after left atrial appendage closure (LAAC). PubMed, Embase, Medline, Cochrane Library databases were systematically searched from their inception to March 2023. Patients were divided into short-term oral anticoagulation (OAC) group and antiplatelet therapy (APT) group. The incidence of events were performed using RevMan 5.4. The events including device-related thrombus (DRT), ischemic stroke/systemic embolization (SE), major bleeding, any bleeding, any major adverse event and all-cause mortality. Subgroup analysis were based on OAC alone or OAC plus single antiplatelet therapy (SAPT) in OAC group. Oral anticoagulants include warfarin and direct oral anticoagulant (DOAC). Fourteen studies with 35,166 patients were included. We found that the incidence of DRT (OR = 0.49, 95% CI 0.36-0.66, P＜0.0001) and all-cause mortality (OR = 0.71, 95% CI 0.57-0.89, P = 0.002) were significantly lower in OAC group than APT group. However, there was no statistical differences in the incidence rates of ischemic stroke/SE (OR = 0.77, 95% CI 0.49-1.20, P = 0.25), major bleeding (OR = 0.84, 95% CI 0.55-1.27, P = 0.84), any bleeding (OR = 0.83, 95% CI 0.56-1.22, P = 0.34) and any major adverse event (OR = 0.56, 95% CI 0.30-1.03, P = 0.06) in the two groups. Subgroup analysis found that the incidence of DRT, all-cause mortality and any major adverse event in OAC monotherapy were lower than that in APT group (P＜0.05), but not statistically different from other outcome. The incidence of DRT, all-cause mortality, any major adverse event and any bleeding in DOAC were significantly better than APT group (P＜0.05). While warfarin only has better incidence of DRT than APT (P＜0.05), there was no statistical difference between the two groups in other outcome (P＞0.05). The incidence of DRT was significantly lower than APT group (P＜0.05), major bleeding were higher, and the rest of the outcome did not show any statistically significant differences(P＞0.05) when OAC plus SAPT. Based on the existing data, short-term OAC may be favored over APT for patients who undergo LAAC. DOAC monotherapy may be favored over warfarin monotherapy or OAC plus APT, when selecting anticoagulant therapies.

Left Atrial Appendage Occlusion and Post-procedural Antithrombotic Management

Left atrial appendage occlusion (LAAO) is an established alternative to oral anticoagulation for stroke prevention in atrial fibrillation. Antithrombotic therapy is used in the post-procedural period to prevent device-related thrombosis (DRT). The risk of DRT is considered highest in the first 45-90 days after device implantation, based on animal studies of the device healing process. Clinically applied antithrombotic regimens vary greatly across studies, continents, and centers. This article gives an overview of the evidence behind current antithrombotic regimens, ongoing randomized trials, and future post-procedural management.

Antithrombotic Therapy for Patients Undergoing Cardiac Electrophysiological and Interventional Procedures: JACC State-of-the-Art Review

Electrophysiological and interventional procedures have been increasingly used to reduce morbidity and mortality in patients experiencing cardiovascular diseases. Although antithrombotic therapies are critical to reduce the risk of stroke or other thromboembolic events, they can nonetheless increase the bleeding hazard. This is even more true in an aging population undergoing cardiac procedures in which the combination of oral anticoagulants and antiplatelet therapies would further increase the hemorrhagic risk. Hence, the timing, dose, and combination of antithrombotic therapies should be carefully chosen in each case. However, the maze of society guidelines and consensus documents published so far have progressively led to a hazier scenario in this setting. Aim of this review is to provide-in a single document-a quick, evidenced-based practical summary of the antithrombotic approaches used in different cardiac electrophysiology and interventional procedures to guide the busy clinician and the cardiac proceduralist in their everyday practice.

Effectiveness and safety of short-term anticoagulant regimens after left atrial appendage occlusion: A systematic review and meta-analysis

INTRODUCTION

Left atrial appendage occlusion (LAAO) provides an alternative for poor candidates of long-term oral anticoagulant (OAC) therapy; however, anticoagulant therapy after surgical procedures has limited use due to associated uncertainties. We aimed to evaluate the effectiveness and safety of the short-term use of direct oral anticoagulant (DOAC) and warfarin after LAAO.

METHOD

Electronic databases such as PubMed, Embase, Medline, and Cochrane Library databases were searched up to November 11, 2022. Our study compared DOAC therapy and warfarin in patients after LAAO. A meta-analysis was conducted with the Review Manager software (version 5.4).

RESULTS

The meta-analysis included 13 cohort studies with a total of 32,607 patients. Our findings indicated that the incidence of stroke/TIA/SE, peri-device leaks>5 mm, device-related thrombosis, and all-cause mortality were not significantly different between the two groups after LAAO (P > 0.05). The DOAC group had a significantly lower incidence of major bleeding (OR = 0.83, 95 % CI: 0.74-0.94, P = 0.003), any bleeding (OR = 0.34, 95 % CI: 0.23-0.51, P < 0.001), stroke/TIA/SE and major bleeding (OR = 0.57, 95 % CI: 0.34-0.95, P = 0.03), and any major adverse event (OR = 0.89, 95 % CI:0.82-0.97, P = 0.010) than the warfarin group. The subgroup analysis revealed that the rate of stroke/TIA/SE was similar in the two groups in terms of the different regions, follow-up time, study type, anticoagulant strategy, and bleeding risk. The incidence of major bleeding in the DOAC group was significantly lower than that in the warfarin group in North America, as well as at follow-up period ≤6 months, retrospective cohort, HAS-BLED average score ≥ 3. In addition, the risk of major bleeding was higher with the combination of OAC and single antiplatelet therapy (SAPT) than with OAC alone. Finally, in the North American region, retrospective cohort, and HAS-BLED average score ≥ 3, the incidence of any serious adverse event in the DOAC group was still significantly lower than that in the warfarin group.

CONCLUSION

Compared to warfarin, DOAC reduced the risk of major bleeding and any serious adverse event in patients after LAAO. This advantage was particularly notable in North America and high-risk populations for bleeding. In addition, the incidence of device-related thrombosis, peri-device leaks, stroke/TIA/SE and all-cause mortality were similar in both groups. The risk of major bleeding was lower in patients taking OAC alone compared with those taking OAC plus SAPT, without increasing the risk of thrombosis.

Network Meta-Analysis of Initial Antithrombotic Regimens After Left Atrial Appendage Occlusion

BACKGROUND

The optimal antithrombotic therapy following left atrial appendage occlusion (LAAO) in patients with nonvalvular atrial fibrillation (AF) remains uncertain.

OBJECTIVES

In this study, the authors sought to compare the efficacy and safety of various antithrombotic strategies after LAAO.

METHODS

We searched the Medline, Cochrane, EMBASE, LILACS, and ClinicalTrials.gov databases for studies reporting outcomes after LAAO, stratified by antithrombotic therapy prescribed at postprocedural discharge. Direct oral anticoagulants (DOACs), vitamin K antagonists (VKAs), single antiplatelet therapy (SAPT), dual antiplatelet therapy (DAPT), DOAC plus SAPT, VKA plus SAPT, and no antithrombotic therapy were analyzed. We performed a frequentist random effects model network meta-analysis to estimate the OR and 95% CI for each comparison. P-scores provided a ranking of treatments.

RESULTS

Forty-one studies comprising 12,451 patients with nonvalvular AF were included. DAPT, DOAC, DOAC plus SAPT, and VKA were significantly superior to no therapy to prevent device-related thrombosis. DOAC was associated with lower all-cause mortality than VKA (OR: 0.39; 95% CI: 0.17-0.89; P = 0.03). Compared with SAPT, DAPT was associated with fewer thromboembolic events (OR: 0.50; 95% CI: 0.29-0.88; P = 0.02), without a difference in major bleeding. In the analysis of P-scores, DOAC monotherapy was the strategy most likely to have lower thromboembolic events and major bleeding.

CONCLUSIONS

In this network meta-analysis comparing initial antithrombotic therapies after LAAO, monotherapy with DOAC had the highest likelihood of lower thromboembolic events and major bleeding. DAPT was associated with a lower incidence of thromboembolic events compared with SAPT and may be a preferred option in patients unable to tolerate anticoagulation.

Antithrombotic Management After Left Atrial Appendage Closure: Current Evidence and Future Perspectives

Left atrial appendage closure is an alternative to chronic oral anticoagulation to prevent embolic events related to nonvalvular atrial fibrillation. After device implantation, antithrombotic treatment is prescribed to prevent device-related thrombosis, a dreadful complication associated with an increased risk of ischemic events. However, the optimal antithrombotic treatment after left atrial appendage closure, effective on both device-related thrombus prevention and bleeding risk mitigation, remains to be determined. In more than 10 years experience with left atrial appendage closure, a wide range of antithrombotic treatments have been used, mostly in observational studies. In this review, we analyzed the body of evidence for each antithrombotic regimen after left atrial appendage closure to provide tools to guide the physician choice and describe future perspectives in the field.

Left atrial appendage occlusion combined with cryoballoon or radiofrequency ablation: One-year follow-up comparison

Background

A one-stop procedure involving catheter ablation and left atrial appendage occlusion (LAAO) is an option for high-risk atrial fibrillation patients. Few studies have reported the efficacy and safety of cryoballoon ablation (CBA) combined with LAAO, and no studies have compared the combination of LAAO with CBA or radiofrequency ablation (RFA).

Methods

A total of 112 patients were enrolled in the present study; 45 patients received CBA combined with LAAO (group 1), and 67 patients received RFA combined with LAAO (group 2). Patient follow-up was performed for 1 year to detect peri-device leaks (PDLs) and safety outcomes (defined as a composite of peri-procedural and follow-up adverse events).

Results

The number of PDLs at the median 59 days follow-up was comparable between the two groups (33.3% in group 1 vs. 37.3% in group 2, p = 0.693). Safety outcomes were also comparable between the two groups (6.7% in group 1 vs. 7.5% in group 2, p = 1.000). Multivariable regression showed that PDLs risk and safety outcomes were all similar between the two groups. Subgroup analysis of PDLs indicated no significant differences. Follow-up safety outcomes were related to anticoagulant medication, and patients without PDLs were more likely to discontinue antithrombotic therapy. The total procedure and ablation times were all significantly shorter for group 1.

Conclusion

When compared with left atrial appendage occlusion combined with radiofrequency, left atrial appendage occlusion combined with cryoballoon ablation has the same risk of peri-device leaks and safety outcomes, but the procedure time was significantly reduced.

Left atrial appendage occlusion

Prevention of stroke represents a goal of primary importance in health systems due to its associated morbidity and mortality. As several patient groups with increased stroke rates have been identified, multiple approaches have been developed and implemented: oral anticoagulation (OAC) for patients with atrial fibrillation, surgical and percutaneous revascularisation in patients with carotid disease, device closure for patients with patent foramen ovale, and now, left atrial appendage occlusion (LAAO) for selected patients with non-valvular atrial fibrillation (NVAF). The latter group of patients are the focus of this review which evaluates the pathophysiology, selection of patients, procedural performance, outcomes of treatment both during and post-procedure, adjunctive therapy, complications, and longer-term outcomes.

Reduced- or Half-Dose Rivaroxaban Following Left Atrial Appendage Closure: A Feasible Antithrombotic Therapy in Patients at High Risk of Bleeding?

The optimal antithrombotic strategy after percutaneous left atrial appendage closure (LAAC) has not yet been established. The advisability of administering low-dose direct oral anticoagulation after LAAC to patients at high risk of bleeding is uncertain. Thus, in the present study, we evaluated the safety and effectiveness of reduced-(15 mg) or half-dose rivaroxaban (10 mg) versus warfarin regarding real-world risks of thromboembolism, bleeding, and device-related thrombosis (DRT) after LAAC. Patients with non-valvular atrial fibrillation and HASBLED ≥ 3 who had undergone successful LAAC device implantation from October 2014 to April 2020 were screened and those who had received 10 mg or 15 mg rivaroxaban or warfarin therapy were enrolled. The patients were followed up 45 days and 6 months after LAAC to evaluate outcomes, including death, thromboembolism, major bleeding, and DRT. Of 457 patients with HASBLED ≥ 3 who had undergone LAAC, 115 had received warfarin and 342 rivaroxaban (15 mg: N = 164; 10 mg: N = 178). There were no significant differences in the incidence of thromboembolism or DRT between the warfarin and both doses of rivaroxaban groups (all p > 0.05). The incidence of major bleeding was significantly higher in the warfarin group than in either the reduced- or half-dose rivaroxaban groups (warfarin vs. rivaroxaban 15 mg: 2.6% vs. 0%, p = 0.030; warfarin vs. rivaroxaban 10 mg: 2.6% vs. 0%, p = 0.038). Either reduced- or half-dose rivaroxaban may be an effective and safe alternative to warfarin therapy in patients with LAAC and who are at high risk of bleeding, the risk of thromboembolism being similar and of major bleeding lower for both doses of rivaroxaban.

Impact and predictors of device-related thrombus after percutaneous left atrial appendage closure

Device-related thrombus (DRT) is a known complication occurring in up to 7% of patients undergoing percutaneous left atrial appendage closure (LAAC). Since the target population of LAAC is generally ineligible for oral anticoagulant therapies, DRT raises important concerns. The aim of this review will be to summarize available evidence on DRT after LAAC focusing on its possible impact on outcomes. Recent findings showed a tighter association between DRT and neurological ischemic events. Antithrombotic regimen adopted after LAAC may have a protective effect against DRT. Many patient-related and procedural factors have been identified as possible predictors of DRT. A tailored approach, which takes into account DRT, is needed in the patient selection for LAAC and in the postprocedural follow-up.

Massive Device-Related Thrombus After LAA Occlusion: Intraoperative Insights Into Mechanism

In patients with a contraindication to oral anticoagulation, the left atrial appendage occlusion devices are an approved alternative. Device-related thrombus is a recognized complication, but underlying mechanisms are incompletely understood. In this case series, the authors describe potentially the same mechanism of thrombosis with intraoperative images of incomplete endothelialization. (Level of Difficulty: Intermediate.).

Device-related thrombus following left atrial appendage occlusion

Thrombus formation on intracardiac devices remains a subject of importance, with rates in the 2-5% range. Device-related thrombus (DRT) following left atrial appendage occlusion is an area of particular concern considering its association with embolic events. DRT continues to present numerous questions, including the optimal definition, incidence, risk factors, monitoring, therapy, and clinical outcomes - all subjects of ongoing assessment. Herein, we discuss these considerations, building upon the relevant historical context and pathophysiologic insights while discussing the future considerations in this rapidly evolving field.

Early Discontinuation of Antithrombotic Treatment Following Left Atrial Appendage Closure

Although antithrombotic treatment is recommended after left atrial appendage closure (LAAC), some patients require discontinuation of antithrombotic treatment after LAAC without evidence on the safety of such a strategy. We sought to evaluate outcomes of patients who had early antithrombotic treatment discontinuation after LAAC. This is a multicenter study including 1,082 patients who underwent successful LAAC. Early discontinuation of antithrombotic treatment was defined as discontinuation of all antiplatelet/anticoagulant treatment within 6 months following the procedure. A propensity-matched analysis was used to compare outcomes of patients with and without early antithrombotic treatment discontinuation. A total of 148 patients (13.7%) had early antithrombotic treatment discontinuation. In the entire population, antithrombotic treatment discontinuation patients exhibited a lower CHA₂DS₂-VASc score (p <0.001) and a higher rate of previous gastrointestinal bleeding episodes (p = 0.01) compared with patients without discontinuation. After a median follow-up of 2.1 (1,1-3.1) years after antithrombotic treatment discontinuation, the rates of death, ischemic stroke, and major bleeding were 12.1, 0.6, and 3.3 per 100 patient-years. In 119 matched pairs with similar baseline characteristics, antithrombotic treatment discontinuation patients had a similar risk of death (hazard ratio [HR] 1.06, 95% confidence interval [CI] 0.65 to 1.71, p = 0.82), ischemic stroke (HR 0.39, 95% CI 0.04 to 3.79, p = 0.42) and major bleeding (HR 1.48, 95% CI 0.56 to 3.88, p = 0.43) compared with those without discontinuation. In conclusion, antithrombotic treatment was discontinued in 1 of 7 selected patients within 6 months after LAAC, and this was not associated with an increased risk of death or thromboembolic events after a median follow-up of 2 years. These data support the safety of shorter periods of antithrombotic therapy after LAAC in high bleeding risk patients based on clinician judgment. Further trials are warranted.

Percutaneous left atrial appendage closure in patients with primary hemostasis disorders and atrial fibrillation

BACKGROUND OR PURPOSE

We report our single-center experience with percutaneous left atrial appendage closure (LAAC) in patients with non-valvular atrial fibrillation (NVAF) and primary hemostasis disorders (HD).

METHODS

Consecutive patients with primary HD who underwent a percutaneous LAAC were included. Baseline characteristics, procedural data, and clinical outcomes were prospectively collected and compared with the overall LAAC cohort without HD.

RESULTS

Since 2013, among 229 LAAC, 17 patients (7%) had a primary HD: thrombocytopenia (n = 5), myelodysplastic syndrome (n = 6), von Willebrand syndrome (n = 4), type A hemophilia (n = 1), and dysfibrinogenemia (n = 1). The HD population's age ranged from 61 to 87 years, and the median CHA₂DS₂VASc was 5. Periprocedural plasmatic management was required in 47% of patients. The immediate LAAC implantation success rate was 100%. Patients received a direct oral anticoagulant (DOA) (n = 9), dual antiplatelet (n = 6), aspirin (n = 1), or no therapy (n = 1) during the first six postoperative weeks, followed with single antiplatelet (n = 16) or no therapy (n = 1) during lifelong. After 20 months, the technical success rate and procedural success rate were 100% and 94%. Zero device-/procedure-related complication and only one life-threatening bleeding occurred. Compared to patients without HD (n = 212), a baseline history of bleeding was less frequent (53% vs 91%, p < 0.001), and more patients received a perioperative blood transfusion (47% vs 4%, p < 0.001) in the HD group. The efficacy and safety outcomes did not differ between HD and non-HD cohorts.

CONCLUSIONS

Percutaneous LAAC in primary HD carriers appeared as safe and as effective as in overall LAAC population for stroke and bleeding prevention at midterm follow-up. Percutaneous left atrial appendage closure in patients with atrial fibrillation and primary hemostasis disorders. The percutaneous LAAC in primary hemostasis disorders and AF carriers requires a multidisciplinary approach. Cardiologist, anesthesiologist, and hematologist discussion is a cornerstone to assess anticoagulant contraindication, LAAC feasibility, periprocedural management, and follow-up (high). This multidisciplinary care is illustrated by the case of a 61-year-old male with hemophilia type A and recurrent hemarthrosis. Pre-LAAC assessment confirmed procedural indication and cactus LAA anatomy (left). After plasmatic management with factor VIII infusion, a WATCHMAN™ no. 21 was successfully implanted (middle). During follow-up, without antithrombotic regime, no ischemic or hemorrhagic complication occurred (right). LAA, left atrial appendage; LAAC, left atrial appendage closure; TEE, transesophageal echocardiography. Percutaneous LAAC in primary HD carriers appeared as safe and as effective as in overall LAAC population for stroke and bleeding prevention at midterm follow-up.

Half-Dose Direct Oral Anticoagulation Versus Standard Antithrombotic Therapy After Left Atrial Appendage Occlusion

OBJECTIVES

This study evaluated the long-term efficacy of a standard antithrombotic strategy versus half-dose direct oral anticoagulation (DOAC) after Watchman implantation.

BACKGROUND

No consensus currently exists on the selection of the most effective antithrombotic strategy to prevent device-related thrombosis (DRT) in patients undergoing endocardial left atrial appendage closure.

METHODS

After successful left atrial appendage closure, consecutive patients were prescribed a standard antithrombotic strategy (SAT) or long-term half-dose DOAC (hdDOAC). The primary composite endpoint was DRT and thromboembolic (TE) and bleeding events.

RESULTS

Overall, 555 patients (mean age 75 ± 8 years, 63% male; median 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 4 [interquartile range (IQR): 3-6]; median HAS-BLED [hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol] score 3 [IQR: 2-4]) were included. Patients were categorized into 2 groups (SAT: n = 357 vs hdDOAC: n = 198). Baseline clinical characteristics were similar between groups. The median follow-up duration was 13 months (IQR: 12-15 months). DRT occurred in 12 (2.1%) patients, all in the SAT group (3.4% vs 0.0%; log-rank P = 0.009). The risk of nonprocedural major bleeding was significantly more favorable in the hdDOAC group (0.5% vs. 3.9%; log-rank P = 0.018). The rate of the primary composite endpoint of DRT and TE and major bleeding events was 9.5% in SAT patients and 1.0% in hdDOAC patients (HR: 9.8; 95% CI: 2.3-40.7; P = 0.002).

CONCLUSIONS

After successful Watchman implantation, long-term half-dose DOAC significantly reduced the risk of the composite endpoint of DRT and TE and major bleeding events compared with a standard, antiplatelet-based, antithrombotic therapy.

Low Dose of Direct Oral Anticoagulants after Left Atrial Appendage Occlusion

The optimal antithrombotic strategy following left atrial appendage occlusion (LAAO) is not yet clearly established. Low-dose non-vitamin K antagonist oral anticoagulants (NOAC) might represent a valid alternative, but data regarding their usage is scarce. The aim of this study was to examine the efficacy and safety of low-dose NOAC compared to single (SAPT) or dual antiplatelet therapies (DAPT) after LAAO. We included consecutive patients with non-valvular atrial fibrillation who underwent LAAO and received low-dose apixaban, SAPT, or DAPT at discharge. The primary objective of this study included an efficacy endpoint (thromboembolic events and device related thrombosis (DRT)) and a safety endpoint (incidence of major bleeding) within the first three months after LAAO. A total of 139 patients were included. This group involved SAPT in 26 (18%), DAPT in 73 (53%), and apixaban in 40 (29%) patients. Follow-up at three-months showed no significant differences in the primary efficacy endpoint (2 (8%) SAPT, 3 (4%) DAPT and 0 (0%) apixaban; p value = 0.25). In contrast, the primary safety endpoint occurred more frequently in DAPT patients (7 (10%) DAPT, 0 (0%), SAPT and 0 with apixaban; p value = 0.03). Combining both efficacy and safety outcomes, low dose apixaban had a lower rate of events (2 (8%) with SAPT, 9 (12%) with DAPT and 0 (0%) with apixaban; p = 0.046). Low-dose apixaban after LAAO may be a valid alternative to DAPT and SAPT as depicted by the reduction in the occurrence of major bleedings and combined DRT/major bleedings respectively. Randomized data will be necessary to validate this strategy.

Short-term direct oral anticoagulation or dual antiplatelet therapy following left atrial appendage closure in patients with relative contraindications to chronic anticoagulation therapy

BACKGROUND

Biological data suggest that short-term anticoagulation would be more effective than dual antiplatelet therapy (DAPT) to reduce the thrombotic risk following left atrial appendage closure (LAAC). This study sought to assess the safety and efficacy of direct oral anticoagulation (DOAC) versus DAPT immediately post-LAAC.

METHODS

Multicenter study including 592 consecutive patients with relative contraindication to chronic anticoagulation who underwent LAAC and received either DAPT or DOAC for 1-3 months. Each patient receiving DOAC was matched with 2 patients on DAPT based on propensity-score (propensity-matched population of 285 patients). Outcomes recorded were death, stroke, non-procedural related severe bleeding, serious adverse event (SAE: composite of death, stroke, bleeding) and early (within 3 months post-LAAC) device-related thrombosis (DRT).

RESULTS

Early outcomes (within 3-month post-LAAC) did not significantly differ between groups, but a numerically higher rate of early death (3.7% vs. 1.1%), non-procedural related severe bleeding (7.4% vs. 3.2%), and SAE (11.1% vs. 5.3%) were observed in patients receiving DAPT. After a median follow-up of 22 (8-38) months, similar outcomes were observed in DAPT and DOAC groups regarding death (HR: 1.18; 95% CI: 0.58-2.37; p = 0.652), stroke (HR: 1.01; 95% CI: 0.22-5.45; p = 0.908), non-procedural related severe bleeding (HR: 1.68; 95% CI: 0.69-4.12; p = 0.257), and SAE (HR: 1.28; 95% CI: 0.73-2.24; p = 0.383). DRT was identified in 4 patients (2.6%) receiving DAPT versus 0 patient receiving DOAC (p = 0.162).

CONCLUSIONS

Short-term DOAC following LAAC in patients with contraindications to chronic anticoagulation was safe and tended to associate with a lower rate of SAE and DRT compared to DAPT.

Antiplatelet and Antithrombotic Therapy After Patent Foramen Oval and Atrial Septal Defect Closure

Pathologies of the atrial septum include different interatrial communications varying from patent foramen ovale (PFO) to actual defects. Atrial septal defects (ASDs) may be localized within the fossa ovalis such as the secundum type ASD or outside the region of fossa ovalis, such as the ostium primum defect and sinus venosus defect. Over the last decades, the percutaneous closure of interatrial shunts has become a feasible and safe method. During these procedures, the delicate balance between thrombotic risk, device sealing process and bleeding risk is crucial. In this review, we sought to describe current available data on the antiplatelet and antithrombotic management of patients after percutaneous ASD or PFO closure.

Meta-analysis of postoperative antithrombotic therapy after left atrial appendage occlusion

Objective

This meta-analysis explored the safety and effectiveness of different anticoagulant regimens after left atrial appendage occlusion (LAAO).

Methods

Databases, such as PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Library, were searched to identify eligible studies according to the inclusion criteria. The incidences of events, including device-related thrombus (DRT) formation, stroke, systemic thromboembolism, bleeding, cardiovascular mortality, and all-cause mortality, were analyzed using R version 3.2.3.

Results

The screening retrieved 32 studies, including 36 study groups and 4,474 patients. The incidence of outcomes after LAAO was calculated via meta-analysis. In the subgroup analysis, the rates of DRT formation, cardiovascular mortality, and all-cause mortality were significantly different among different antithrombotic methods. Single antiplatelet therapy was associated with the highest rate of adverse events, followed by dual antiplatelet therapy (DAPT). Vitamin K antagonists (VKAs) and new oral anticoagulants (NOACs) carried lower rates of adverse events.

Conclusions

Anticoagulant therapy had better safety and efficacy than antiplatelet therapy. Thus, for patients with nonabsolute anticoagulant contraindications, anticoagulant therapy rather than DAPT should be actively selected. NOACs displayed potential for further development, and these treatments might represent alternatives to VKAs in the future.

Safety and Efficacy of Single Versus Dual Antiplatelet Therapy After Left Atrial Appendage Occlusion

The optimal antiplatelet strategy after left atrial appendage (LAA) occlusion able to protect from device-related thrombosis, paying the lowest price in terms of bleeding increase, is unclear. In a real-world, observational study we performed a head-to-head comparison of single versus dual antiplatelet therapy (SAPT vs DAPT) in patients who underwent LAA occlusion. We included 610 consecutive patients, stratified according to the type of post-procedural antiplatelet therapy (280 on SAPT and 330 on DAPT). Primary outcome measure was the incidence of the net composite end point including Bleeding Academic Research Consortium classification 3-5 bleeding, major adverse cardiovascular events or device-related thrombosis at 1-year follow-up. The use of SAPT compared with DAPT was associated with similar incidence of the primary net composite end point (9.3% vs 12.7% p = 0.22), with an adjusted hazard ratio (HR) of 0.69, 95% confidence interval 0.41 to 1.15; p = 0.15) at multivariate analysis. However, SAPT significantly reduced Bleeding Academic Research Consortium classification 3-5 bleeding (2.9% vs 6.7%, p = 0.038; adjusted HR 0.37, 0.16 to 0.88; p = 0.024). The occurrence of ischemic events (major adverse cardiovascular events or device-related thrombosis) was not significantly different between the 2treatment strategies (7.8% vs 7.4%; adjusted HR 1.34, 0.70 to 2.55; p = 0.38). In patients who underwent LAA occlusion, post-procedural use of SAPT instead of DAPT was associated with reduction of bleeding complications, with no significant increase in the risk of thrombotic events. These hypothesis-generating findings should be confirmed in a specific, randomized study.

Short-Term Oral Anticoagulation Versus Antiplatelet Therapy Following Transcatheter Left Atrial Appendage Closure

Background:

The impact of antithrombotic therapy on coagulation system activation after left atrial appendage closure (LAAC) remains unknown. This study sought to compare changes in coagulation markers associated with short-term oral anticoagulation (OAC) versus antiplatelet therapy (APT) following LAAC.

Methods:

Prospective study including 78 atrial fibrillation patients undergoing LAAC with the Watchman device. F1+2 (prothrombin fragment 1+2) and TAT (thrombin-antithrombin III) were assessed immediately before the procedure, and at 7, 30, and 180 days after LAAC.

Results:

Forty-eight patients were discharged on APT (dual: 31, single: 17) and 30 on OAC (direct anticoagulants: 26, vitamin K antagonists: 4), with no differences in baseline-procedural characteristics between groups except for higher spontaneous echocardiography contrast in the OAC group. OAC significantly reduced coagulation activation within 7 days post-LAAC compared with APT (23% [95% CI, 5%–41%] versus 82% [95% CI, 54%–111%] increase for F1+2, P =0.007; 52% [95% CI, 15%–89%] versus 183% [95% CI, 118%–248%] increase for TAT, P =0.048), with all patients in both groups progressively returning to baseline values at 30 and 180 days. Spontaneous echocardiography contrast pre-LAAC was associated with an enhanced activation of the coagulation system post-LAAC (144 [48–192] versus 52 [24–111] nmol/L, P =0.062 for F1+2; 299 [254–390] versus 78 [19–240] ng/mL, P =0.002 for TAT). Device-related thrombosis occurred in 5 patients (6.4%), and all of them were receiving APT at the time of transesophageal echocardiography (10.2% versus 0% if OAC at the time of transesophageal echocardiography, P =0.151). Patients with device thrombosis exhibited a greater coagulation activation 7 days post-LAAC ( P =0.038 and P =0.108 for F1+2 and TAT, respectively).

Conclusions:

OAC (versus APT) was associated with a significant attenuation of coagulation system activation post-LAAC. Spontaneous echocardiography contrast pre-LAAC associated with enhanced coagulation activation post-LAAC, which in turn increased the risk of device thrombosis. These results highlight the urgent need for randomized trials comparing OAC versus APT post-LAAC.