Perioperative Safety and Efficacy of Different Anticoagulation Strategies With Direct Oral Anticoagulants in Pulmonary Vein Isolation: A Meta-Analysis

Venous vascular closure system vs. figure-of-eight suture following atrial fibrillation ablation: the STYLE-AF Study

AIMS

Simplified ablation technologies for pulmonary vein isolation (PVI) are increasingly performed worldwide. One of the most common complications following PVI are vascular access-related complications. Lately, venous closure systems (VCSs) were introduced into clinical practice, aiming to reduce the time of bed rest, to increase the patients' comfort, and to reduce vascular access-related complications. The aim of the present study is to compare the safety and efficacy of using a VCS to achieve haemostasis following single-shot PVI to the actual standard of care [figure-of-eight suture and manual compression (MC)].

METHODS AND RESULTS

This is a prospective, multicentre, randomized, controlled, open-label trial performed at three German centres. Patients were randomized 1:1 to undergo haemostasis either by means of VCS (VCS group) or of a figure-of-eight suture and MC (F8 group). The primary efficacy endpoint was the time to ambulation, while the primary safety endpoint was the incidence of major periprocedural adverse events until hospital discharge. A total of 125 patients were randomized. The baseline characteristics were similar between the groups. The VCS group showed a shorter time to ambulation [109.0 (82.0, 160.0) vs. 269.0 (243.8, 340.5) min; P < 0.001], shorter time to haemostasis [1 (1, 2) vs. 5 (2, 10) min; P < 0.001], and shorter time to discharge eligibility [270 (270, 270) vs. 340 (300, 458) min; P < 0.001]. No major vascular access-related complication was reported in either group. A trend towards a lower incidence of minor vascular access-related complications on the day of procedure was observed in the VCS group [7 (11.1%) vs. 15 (24.2%); P = 0.063] as compared to the control group.

CONCLUSION

Following AF ablation, the use of a VCS results in a significantly shorter time to ambulation, time to haemostasis, and time to discharge eligibility. No major vascular access-related complications were identified. The use of MC and a figure-of-eight suture showed a trend towards a higher incidence of minor vascular access-related complications.

Catheter ablation of atrial fibrillation: anticipating and avoiding complications

INTRODUCTION

Atrial fibrillation (AF) ablation is being performed more frequently and more widely at more centers. This stems from several factors including 1) demographic forces leading to an increased prevalence of the arrhythmia; 2) greater availability of ambulatory monitoring making diagnosis more frequent; 3) relative inefficacy of medications; and 4) improved safety and efficacy of the procedure. Ablation has become much more streamlined and reproducible than a decade ago, but life-threatening complications may still arise.

AREAS COVERED

This review will focus on awareness, avoidance, and early recognition and management of complications of AF ablation. This literature review is challenged by differing approaches to ablation of AF both within a center and between centers, the rapid improvement of technology making the outcomes associated with a therapeutic strategy begun a few years prior relatively obsolete, as well as the heterogeneity of the population being studied.

EXPERT OPINION

Newer technologies are on the horizon which will allow us to ablate AF with increasing efficacy, efficiency, and hopefully safety. Such new technology and changing usage mandate vigilance to avoid complications.

Interrupted versus uninterrupted anticoagulation therapy for catheter ablation in adults with arrhythmias

BACKGROUND

The management of anticoagulation therapy around the time of catheter ablation (CA) procedure for adults with arrhythmia is critical and yet is variable in clinical practice. The ideal approach for safe and effective perioperative management should balance the risk of bleeding during uninterrupted anticoagulation while minimising the risk of thromboembolic events with interrupted therapy.

OBJECTIVES

To compare the efficacy and harms of interrupted versus uninterrupted anticoagulation therapy for catheter ablation (CA) in adults with arrhythmias.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and SCI-Expanded on the Web of Science for randomised controlled trials on 5 January 2021. We also searched three registers on 29 May 2021 to identify ongoing or unpublished trials. We performed backward and forward searches on reference lists of included trials and other systematic reviews and contacted experts in the field. We applied no restrictions on language or publication status.

SELECTION CRITERIA

We included randomised controlled trials comparing uninterrupted anticoagulation with any modality of interruption with or without heparin bridging for CA in adults aged 18 years or older with arrhythmia.

DATA COLLECTION AND ANALYSIS

Two review authors conducted independent screening, data extraction, and assessment of risk of bias. A third review author resolved disagreements. We extracted data on study population, interruption strategy, ablation procedure, thromboembolic events (stroke or systemic embolism), major and minor bleeding, asymptomatic thromboembolic events, cardiovascular and all-cause mortality, quality of life (QoL), length of hospital stay, cost, and source of funding. We used GRADE to assess the certainty of the evidence.  MAIN RESULTS: We identified 12 studies (4714 participants) that compared uninterrupted periprocedural anticoagulation with interrupted anticoagulation. Studies performed an interruption strategy by either a complete interruption (one study) or by a minimal interruption (11 studies), of which a single-dose skipped strategy was used (nine studies) or two-dose skipped strategy (two studies), with or without heparin bridging. Studies included participants with a mean age of 65 years or greater, with only two studies conducted in relatively younger individuals (mean age less than 60 years). Paroxysmal atrial fibrillation (AF) was the primary type of AF in all studies, and seven studies included other types of AF (persistent and long-standing persistent). Most participants had CHADS2 or CHADS2-VASc demonstrating a low-moderate risk of stroke, with almost all participants having normal or mildly reduced renal function. Ablation source using radiofrequency energy was the most common (seven studies). Ten studies (2835 participants) were conducted in East Asian countries (Japan, China, and South Korea), while the remaining two studies were conducted in the USA. Eight studies were conducted in a single centre. Postablation follow-up was variable among studies at less than 30 days (three studies), 30 days (six studies), and more than 30 days postablation (three studies). Overall, the meta-analysis showed high uncertainty of the effect between the interrupted strategy compared to uninterrupted strategy on the primary outcomes of thromboembolic events (risk ratio (RR) 1.76, 95% confidence interval (CI) 0.33 to 9.46; I2 = 59%; 6 studies, 3468 participants; very low-certainty evidence). However, subgroup analysis showed that uninterrupted vitamin A antagonist (VKA) is associated with a lower risk of thromboembolic events without increasing the risk of bleeding. There is also uncertainty on the outcome of major bleeding events (RR 1.10, 95% CI 0.59 to 2.05; I2 = 6%; 10 studies, 4584 participants; low-certainty evidence). The uncertainty was also evident for the secondary outcomes of minor bleeding (RR 1.01, 95% CI 0.46 to 2.22; I2 = 87%; 9 studies, 3843 participants; very low-certainty evidence), all-cause mortality (RR 0.34, 95% CI 0.01 to 8.21; 442 participants; low-certainty evidence) and asymptomatic thromboembolic events (RR 1.45, 95% CI 0.85 to 2.47; I2 = 56%; 6 studies, 1268 participants; very low-certainty evidence). There was a lower risk of the composite endpoint of thromboembolic events (stroke, systemic embolism, major bleeding, and all-cause mortality) in the interrupted compared to uninterrupted arm (RR 0.23, 95% CI 0.07 to 0.81; 1 study, 442 participants; low-certainty evidence). In general, the low event rates, different comparator anticoagulants, and use of different ablation procedures may be the cause of imprecision and heterogeneity observed.

AUTHORS' CONCLUSIONS

This meta-analysis showed that the evidence is uncertain to inform the decision to either interrupt or continue anticoagulation therapy around CA procedure in adults with arrhythmia on outcomes of thromboembolic events, major and minor bleeding, all-cause mortality, asymptomatic thromboembolic events, and a composite endpoint of thromboembolic events (stroke, systemic embolism, major bleeding, and all-cause mortality).  Most studies in the review adopted a minimal interruption strategy which has the advantage of reducing the risk of bleeding while maintaining a lower level of anticoagulation to prevent periprocedural thromboembolism, hence low event rates on the primary outcomes of thromboembolism and bleeding. The one study that adopted a complete interruption of VKA showed that uninterrupted VKA reduces the risk of thromboembolism without increasing the risk of bleeding. Hence, future trials with larger samples, tailored to a more generalisable population and using homogeneous periprocedural anticoagulant therapy and ablation source are required to address the safety and efficacy of the optimal management of anticoagulant therapy prior to ablation.

Meta-analysis of controlled studies on minimally interrupted vs. continuous use of non-vitamin K antagonist oral anticoagulants in catheter ablation for atrial fibrillation

Aims

At present, there are no guideline recommendations for minimally interrupted use of non-vitamin K antagonist oral anticoagulants (mi-NOAC) during catheter ablation (CA) for atrial fibrillation (AF). Current evidence is predominantly based on observational studies, with continuous use of vitamin K antagonist in the control arm. This quantitative summary reflects the first high-level evidence on contemporary regimens, with continuous NOAC use (c-NOAC) as the current gold standard.

Methods and results

Meta-analysis (Pubmed, Embase, and Web of Science) on prospective, controlled studies comparing contemporary mi-NOAC (without bridging) with c-NOAC. Net adverse clinical events (major bleeding, thrombo-embolic events) were the primary outcome. In addition, we analysed total bleeding, minor bleeding, and silent cerebral embolism.

Eight studies (six randomized, two observational) with 2168 patients were summarized. The primary endpoint occurred in 1.0% (18/1835): 1.1% (11/1005) vs. 0.8% (7/830) for the mi-NOAC and c-NOAC groups, respectively; odds ratio (OR) 1.20 [95% confidence interval (CI) 0.49–2.92, P = 0.64]. The OR for total bleeding on mi-NOAC was 1.26 (95% CI 0.97–1.63, P = 0.07). ORs for minor bleeding and silent cerebral embolism were 1.17 (95% CI 0.80–1.70, P = 0.34) and 2.62 (95% CI 0.54–12.61, P = 0.12), respectively.

Conclusion

This synopsis provides a quantitative synthesis of high-level evidence on a contemporary strategy of mi-NOAC in CA for AF, and overall clinical outcomes were not different from continuous NOAC use. Despite preprocedural interruption, there was no sign of lower bleeding rates. Additional higher volume datasets are warranted for more precise treatment effect estimations of this everyday alternative anticoagulation strategy in AF ablation.

An update on antithrombotic therapy in atrial fibrillation patients in long-term ambulatory setting after percutaneous coronary intervention: where do we go from here?

INTRODUCTION

In the treatment of patients with atrial fibrillation (AF) who undergo percutaneous coronary intervention (PCI), it is unclear which combination of antithrombotic drugs is preferable and which is the optimal duration of treatment.

AREAS COVERED

The authors review the available evidence in this area resulting from single studies and meta-analyses. In the absence of direct head-to-head comparisons between different non-vitamin K oral anticoagulants (NOAC), the authors review the available studies with NOACS in these patients and derived indirect comparisons.

EXPERT OPINION

In patients with AF who undergo PCI, a dual antithrombotic strategy which includes a NOAC plus single antiplatelet therapy with a P2Y12 inhibitor (preferably clopidogrel) should be considered as the preferred treatment option in most cases. Oral anticoagulation associated with dual antiplatelet therapy (triple antithrombotic therapy) should be offered for no longer than 30 days to patients with very high thrombotic and low hemorrhagic risk. It is unclear whether the dual antithrombotic strategy should be continued beyond 12 months in patients at high risk of thrombotic events. Additional data from adequately powered controlled studies are needed to support the long-term efficacy of this strategy and to establish the best patient-tailored approach in this complex scenario.

Differences in activated clotting time and total unfractionated heparin dose during pulmonary vein isolation in patients on different anticoagulation therapy

Background

Periprocedural pulmonary vein isolation (PVI) anticoagulation requires balancing between bleeding and thromboembolic risk. Intraprocedural anticoagulation is monitored by activated clotting time (ACT) with target value >300 s, and there are no guidelines specifying an initial unfractionated heparin (UFH) dose.

Methods

We aimed to assess differences in ACT values and UFH dosage during PVI in patients on different oral anticoagulants. We conducted an international, multi‐center, registry‐based study. Consecutive patients with atrial fibrillation (AF) undergoing PVI, on uninterrupted anticoagulation therapy, were analyzed. Before transseptal puncture, UFH bolus of 100 IU/kg was administered regardless of the anticoagulation drug.

Results

Total of 873 patients were included (median age 61 years, IQR 53–66; female 30%). There were 248, 248, 189, 188 patients on warfarin, dabigatran, rivaroxaban, and apixaban, respectively. Mean initial ACT was 257 ± 50 s, mean overall ACT 295 ± 45 s and total UFH dose 158 ± 60 IU/kg. Patients who were receiving warfarin and dabigatran compared to patients receiving rivaroxaban and apixaban had: (i) significantly higher initial ACT values (262 ± 57 and 270 ± 48 vs. 248 ± 42 and 241 ± 44 s, p < .001), (ii) significantly higher ACT throughout PVI (309 ± 46 and 306 ± 44 vs. 282 ± 37 and 272 ± 42 s, p < .001), and (iii) needed lower UFH dose during PVI (140 ± 39 and 157 ± 71 vs. 171 ± 52 and 172 ± 70 IU/kg).

Conclusion

There are significant differences in ACT values and UFH dose during PVI in patients receiving different anticoagulants. Patients on warfarin and dabigatran had higher initial and overall ACT values and needed lower UFH dose to achieve adequate anticoagulation during PVI than patients on rivaroxaban and apixaban.

Appropriate intraprocedural initial heparin dosing in patients undergoing catheter ablation for atrial fibrillation receiving uninterrupted non-vitamin-K antagonist oral anticoagulant treatment

Background

To clarify the appropriate initial dosage of heparin during radiofrequency catheter ablation (RFCA) in patients with atrial fibrillation (AF) receiving uninterrupted nonvitamin K antagonist oral anticoagulant (NOAC) treatment.

Methods

A total of 187 consecutive AF patients who underwent their first RFCA in our center were included. In the warfarin group (WG), an initial heparin dose of 100 U/kg was administered (control group: n = 38). The patients who were on NOACs were randomly divided into 3 NOAC groups (NG: n = 149), NG110, NG120, and NG130, and were administered initial heparin doses of 110 U/kg, 120 U/kg, and 130 U/kg, respectively. During RFCA, the activated clotting time (ACT) was measured every 15 min, and the target ACT was maintained at 250–350 s by intermittent heparin infusion. The baseline ACT and ACTs at each 15-min interval, the average percentage of measurements at the target ACT, and the incidence of periprocedural bleeding and thromboembolic complications were recorded and analyzed.

Results

There was no significant difference in sex, age, weight, or baseline ACT among the four groups. The 15 min-ACT, 30 min-ACT, and 45 min-ACT were significantly longer in the WG than in NG110 and NG120. However, no significant difference in 60 min-ACT or 75 min-ACT was detected. The average percentages of measurements at the target ACT in NG120 (82.2 ± 23.6%) and NG130 (84.8 ± 23.7%) were remarkably higher than those in the WG (63.4 ± 36.2%, p = 0.007, 0.003, respectively). These differences were independent of the type of NOAC. The proportion of ACTs in 300–350 s in NG130 was higher than in WG (32.4 ± 31.8 vs. 34.7 ± 30.6, p = 0.735). Severe periprocedural thromboembolic and bleeding complications were not observed.

Conclusions

For patients with AF receiving uninterrupted NOAC treatment who underwent RFCA, an initial heparin dosage of 120 U/kg or 130 U/kg can provide an adequate intraprocedural anticoagulant effect, and 130 U/kg allowed ACT to reach the target earlier.

Trial registration: Registration number: ChiCTR1800016491, First Registration Date: 04/06/2018 (Chinese Clinical Trial Registry http://www.chictr.org.cn/index.aspx).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02032-3.

Direct Oral Anticoagulants Plasma Levels Measurement: Clinical Usefulness from Trials and Real-World Data

Measurement of direct oral anticoagulants (DOACs) activity is not routinely necessary. Indeed, evaluation of DOACs plasmatic concentration is discouraged for the majority of patients, due to the lack of outcome data supporting this approach. Nevertheless, DOAC measurements may be useful in emergency situations such as serious bleeding events, need for urgent invasive procedures, and acute ischemic stroke or in managing anticoagulation in "special populations" not adequately studied in clinical trials, for example the very elderly or those at the extremes of body weight. The aim of this review is to describe and summarize the methods for DOACs activity evaluation and the settings in which their plasma level measurement may be indicated, analyzing indications from scientific societies and evidence from clinical trials, as well as real world data on the usefulness of DOACs plasma levels "monitoring."

Percutaneous Occlusion of the Left Atrial Appendage with Thrombus Irresponsive to Antithrombotic Therapy

We analyzed clinical experience with percutaneous closure of instances of left atrial appendage with thrombus (LAAT) irresponsive to antithrombotic therapy in patients treated in three high-volume cardiology centers. Clinical and procedural data regarding consecutive patients who underwent percutaneous left atrial appendage closure (PLAAC) due to LAAT were retrospectively analyzed. The study population consisted of 17 patients (11 men; 68 ± 14 years; CHA₂DS₂VASC 4.7 ± 1.9; HASBLED 3 (0-5)) with LAAT confirmed by transesophageal echocardiography, and included 5 patients with mechanical heart valves. Most of the patients (94.1%) received anticoagulation therapy before PLAAC. All LAATs were located in distal portions of the appendage and occupied less than 30% of its volume. Occluding-device implantation was successful in 17 patients; in one, a residual leak was disclosed. Appropriate positioning of occluders required more than 1 attempt in 6 individuals (35.3%); in 3 others (17.6%), the subjects' devices had contact with thrombi. No procedural complications were noted. Midterm follow-up (median: 10 months) revealed no procedure-related complications or clinically diagnosed thromboembolism. Transesophageal echocardiography (TEE) performed after six months revealed device-related thrombus in one patient. We concluded that LAAT irresponsive to antithrombotic therapy might be effectively treated with PLAAC, even in patients with mechanical-valve prostheses.

Interrupted or Uninterrupted Oral Anticoagulants in Patients Undergoing Atrial Fibrillation Ablation

BACKGROUND AND PURPOSE

The safety and efficacy of uninterrupted, minimally interrupted (one dose skipped) or completely interrupted (24 h skipped) oral anticoagulant therapy in patients with atrial fibrillation (AF) ablation are poorly defined. We conducted a network meta-analysis to explore the effect of interrupted or uninterrupted oral anticoagulants in patients with AF undergoing ablation.

METHODS

The Cochrane Library, PubMed and Embase databases were systematically searched for studies comparing uninterrupted, minimally interrupted or completely interrupted non-vitamin K antagonist oral anticoagulants (NOACs) with continuous or interrupted warfarin in patients undergoing AF ablation.

RESULTS

Twelve randomized clinical trials (RCTs) with a total of 5597 patients with AF undergoing catheter ablation were included. For thromboembolism, minimally interrupted NOACs (OR 0.03, 95% CI 0.01-0.35), uninterrupted NOACs (OR 0.04, 95% CI 0.01-0.23) and continuous VKAs (OR 0.05, 95% CI 0.01-0.21) were better than interrupted warfarin. The risk of total bleeding appeared higher in the completely interrupted NOAC group compared with the minimally interrupted NOACs (OR 2.74, 95% CI 1.18-6.37), uninterrupted NOACs (OR 2.15, 95% CI 1.05-4.38) and uninterrupted warfarin (OR 2.04, 95% CI 1.02-4.08). To reduce the risk of total bleeding, minimally interrupted NOACs (OR 0.15, 95% CI 0.08-0.27), uninterrupted NOACs (OR 0.19, 95% CI 0.14-0.42) and uninterrupted warfarin (OR 0.24, 95% CI 0.15-0.39) were better than interrupted warfarin. In the event of major bleeding, there was no significant difference in the interrupted NOAC, uninterrupted NOAC, interrupted VKA and uninterrupted VKA groups.

CONCLUSIONS

These three NOAC strategies may have similar safety and efficacy in terms of thromboembolism and major bleeding complications. The total bleeding risk of completely interrupted oral anticoagulants is higher than that of uninterrupted and minimally interrupted NOACs. For thromboembolism, minimally interrupted NOACs, uninterrupted NOACs and continuous VKAs were better than interrupted warfarin.

Activated clotting time on the day of atrial fibrillation ablation for minimally interrupted and uninterrupted direct oral anticoagulation therapy: Sequential changes, differences among direct oral anticoagulants, and ablation safety outcomes

Background

Activated clotting time (ACT)–guided heparinization is used during atrial fibrillation (AF) ablation. Differences in sensitivity to ACT assays have been identified among different direct oral anticoagulants (DOACs).

Objective

We aimed to examine ACT just before ablation (pre‐ACT) for different ablation start times (9:00, 11:00, 13:00, or 15:00) and ablation safety outcomes in minimally interrupted (min‐Int) and uninterrupted (Unint) DOAC regimens and examine differences in pre‐ACT values among four DOACs.

Methods

Consecutive patients were randomized into the min‐Int (n = 307) or Unint (n = 277) groups. DOACs examined were apixaban, dabigatran, edoxaban, and rivaroxaban.

Results

No sequential changes in pre‐ACT values were observed for each DOAC used and for all four DOACs combined in the min‐Int and Unint groups. There was no meaningful difference in pre‐ACT at each ablation start time between the groups. Clinically significant differences in overall pre‐ACT were not obtained between the groups (138 ± 24 vs 142 ± 23 seconds). The pre‐ACT (baseline) value for dabigatran was on average 29 seconds higher than that for the other three DOACs. The min‐Int and Unint groups showed similar thromboembolic (0% vs 0%) and bleeding event rates (major, 1% vs 0%; all, 3.5% vs 2.5%).

Conclusion

The pre‐ACT did not show a sequential change in the min‐Int and Unint groups. No notable differences in the time‐dependent change in pre‐ACT between the groups were observed. Variations in baseline ACT suggest the need for moderate adjustment of ACT for adequate modification of heparin dose for the other three DOACs. Both regimens provided similar acceptable AF ablation safety outcomes.