Incidence of Device-Related Thrombosis in Watchman Patients Undergoing a Genotype-Guided Antithrombotic Strategy.

OBJECTIVES: This study sought to report the incidence of device-related thrombosis (DRT) and thromboembolic (TE) events when an alternative to clopidogrel is prescribed in loss-of-function (LOF) allele carriers of the cytochrome P450 2C19 (CYP2C19) gene. BACKGROUND: LOF polymorphisms of the CYP2C19 gene are associated with reduced hepatic bioactivation of clopidogrel. METHODS: A total of 1,002 Watchman patients were included. Six hundred forty-five patients underwent CYP2C19 genetic testing; among patients with clopidogrel resistance, clopidogrel was replaced by either prasugrel (pilot cohort) or half dose direct oral anticoagulant ([DOAC]/Group 1), both in combination with aspirin. We compared the incidence of DRT/TE events among genotyped patients and a control group which received standard dual antiplatelet therapy (DAPT) (Group 2; n = 357). All reported events occurred during a timeframe between 45- and 180-day follow-up transesophageal echocardiograms, when the 2 different antithrombotic strategies (genotype-guided vs standard DAPT) were adopted. RESULTS: In the pilot cohort (n = 244), bleeding events occurred in 10.2% of patients who received aspirin plus prasugrel, leading to early discontinuation of the prasugrel-based protocol. DOAC Group 1 patients (n = 401), 25.7% were reduced metabolizers, and clopidogrel was replaced by half dose direct oral anticoagulant. DRT was documented in 1 (0.2%) patient of Group 1 and 7 (1.96%) patients of Group 2 (log-rank P = 0.021). The composite endpoint of DRT/TE events was significantly lower among patients receiving a genotype-guided antithrombotic strategy (0.75% vs 3.10%; log-rank P = 0.017). CONCLUSIONS: In Watchman patients, a genotype-based antithrombotic strategy with aspirin plus half dose DOAC in reduced clopidogrel metabolizers was superior to standard DAPT with respect to DRT/TE events.

Thromboembolic Risk in Atrial Fibrillation Patients With Left Atrial Scar Post-Extensive Ablation: A Single-Center Experience.

OBJECTIVES: This study evaluated the association of the post-ablation scar with stroke risk in patients undergoing atrial fibrillation (AF) ablation. BACKGROUND: Late gadolinium enhancement-cardiac magnetic resonance studies have reported a direct association between pre-ablation left atrial scar and thromboembolic events in patients with AF. METHODS: Consecutive patients with AF were classified into 2 groups based on the type of ablation performed at the first procedure. Group 1 involved limited ablation (isolation of pulmonary veins, left atrial posterior wall, and superior vena cava); and group 2 involved extensive ablation (limited ablation + ablation of nonpulmonary vein triggers from all sites except left atrial appendage). During the repeat procedure, post-ablation scar (region with bipolar voltage amplitude <0.5 mV) was identified by using 3-dimensional voltage mapping. RESULTS: A total of 6,297 patients were included: group 1, n = 1,713; group 2, n = 4,584. Group 2 patients were significantly older and had more nonparoxysmal AF. Nineteen (0.3%) thromboembolic events were reported after the first ablation procedure: 9 (1.02%) in group 1 and 10 (0.61%) in group 2 (p = 0.26). At the time of the event, all 19 patients were experiencing arrhythmia. Median time to stroke was 14 (interquartile range: 9 to 20) months in group 1 and 14.5 (interquartile range: 8 to 18) months in group 2. Post-ablation scar data were derived from 2,414 patients undergoing repeat ablation. Mean scar area was detected as 67.1 ± 4.6% in group 2 and 34.9 ± 8.8% in group 1 at the redo procedure (p < 0.001). CONCLUSIONS: Differently from the cardiac magnetic resonance-detected pre-ablation scar, scar resulting from extensive ablation was not associated with increased risk of stroke compared with that from the limited ablation.

Use of a Novel Septal Occluder Device for Left Atrial Appendage Closure in Patients With Postsurgical and Postlariat Leaks or Anatomies Unsuitable for Conventional Percutaneous Occlusion.

BACKGROUND: Interventional therapies aiming at excluding the left atrial appendage (LAA) from systemic circulation have been established as a valid alternative to oral anticoagulation in patients at high thromboembolic risk. However, their efficacy on stroke prophylaxis may be compromised owing to incomplete LAA closure. Additionally, the need for an alternative thromboembolic prevention may remain unmet in patients with contraindications to oral anticoagulation whose appendage anatomy is unsuitable for some conventional devices commercially available. We aimed at evaluating the feasibility of LAA closure with the novel Gore Cardioform Septal Occluder in patients with incomplete appendage ligation or anatomic features which do not meet the manufacturer's requirements for Watchman deployment. METHODS: Twenty-one consecutive patients (mean age: 72±6 years; 85.7% males; CHA2DS2-VASc: 4.5±1.4; HAS-BLED: 3.6±1.0) were included. Transesophageal echocardiography was performed within 2 months to assess for residual LAA patency. RESULTS: Fourteen patients had incomplete LAA closure following surgical (n=6) or Lariat ligation (n=8). In 7 patients with an appendage anatomy unsuitable for Watchman deployment, the mean maximal landing zone size and LAA depth were 14.4±1.3 and 18.6±2.8 mm. Successful Cardioform Septal Occluder deployment was achieved in all patients. No peri-procedural complications were documented. Procedure and fluoroscopy times were 46±13 and 14±5 minutes. Follow-up transesophageal echocardiography after 58±9 days revealed complete LAA closure in all patients. CONCLUSIONS: Transcatheter LAA closure via a Cardioform Septal Occluder device might be a valid alternative in patients with residual leaks following failed appendage ligation or whose LAA anatomy does not meet the minimal anatomic criteria to accommodate a Watchman device. Graphic Abstract: A graphic abstract is available for this article.

Epicardial Ablation Complications.

The percutaneous epicardial approach has become an adjunctive tool for electrophysiologists to treat disparate cardiac arrhythmias, including accessory pathways, atrial tachycardia, and particularly ventricular tachycardia. This novel technique prompted a strong impulse to perform epicardial access as an alternative strategy for pacing and defibrillation, left atrial appendage exclusion, heart failure with preserved ejection fraction, and genetically engineered tissue delivery. However, because of the incremental risk of major complications compared with stand-alone endocardial ablation, it is still practiced in a limited number of highly experienced centers across the world.

Common and rare susceptibility genetic variants predisposing to Brugada syndrome in Thailand.

BACKGROUND: Mutations in SCN5A are rarely found in Thai patients with Brugada syndrome (BrS). Recent evidence suggested that common genetic variations may underlie BrS in a complex inheritance model. OBJECTIVE: The purpose of this study was to find common and rare/low-frequency genetic variants predisposing to BrS in persons in Thailand. METHODS: We conducted a genome-wide association study (GWAS) to explore the association of common variants in 154 Thai BrS cases and 432 controls. We sequenced SCN5A in 131 cases and 205 controls. Variants were classified according to current guidelines, and case-control association testing was performed for rare and low-frequency variants. RESULTS: Two loci were significantly associated with BrS. The first was near SCN5A/SCN10A (lead marker rs10428132; odds ratio [OR] 2.4; P = 3 × 10-10). Conditional analysis identified a novel independent signal in the same locus (rs6767797; OR 2.3; P = 2.7 × 10-10). The second locus was near HEY2 (lead marker rs3734634; OR 2.5; P = 7 × 10-9). Rare (minor allele frequency [MAF] <0.0001) coding variants in SCN5A were found in 8 of the 131 cases (6.1% in cases vs 2.0% in controls; P = .046; OR 3.3; 95% confident interval [CI] 1.0-11.1), but an enrichment of low-frequency (MAF<0.001 and >0.0001) variants also was observed in cases, with 1 variant (SCN5A: p.Arg965Cys) detected in 4.6% of Thai BrS patients vs 0.5% in controls (P = 0.015; OR 9.8; 95% CI 1.2-82.3). CONCLUSION: The genetic basis of BrS in Thailand includes a wide spectrum of variant frequencies and effect sizes. As previously shown in European and Japanese populations, common variants near SCN5A and HEY2 are associated with BrS in the Thai population, confirming the transethnic transferability of these 2 major BrS loci.

Non-pulmonary vein triggers in nonparoxysmal atrial fibrillation: Implications of pathophysiology for catheter ablation.

Rhythm control of persistent atrial fibrillation (AF) patients represents a challenge for the modern interventional cardiac electrophysiologist; as a matter of fact, there is still divergence regarding the best ablative approach to adopt in this population. Different investigational endpoints, variability of techniques and tools, significant technological evolution, and the lack of universally accepted pathophysiological models engendered a considerable heterogeneity in terms of techniques and outcomes, so much that the treatment of persistent subtypes of AF commonly still relies mainly on pulmonary vein (PV) isolation. The purpose of the present review is to report the current experimental and clinical evidence supporting the importance of mapping and ablating non-PV triggers and describe our institutional approach for the ablation of nonparoxysmal AF.

Recurrent Atrial Fibrillation with Isolated Pulmonary Veins: What to Do.

When patients have symptomatic recurrent atrial tachyarrhythmias after 2 months following pulmonary vein antral isolation, a repeat ablation should be considered. Patients might present with isolated pulmonary veins posterior wall. In these patients, posterior wall isolation is extended, and non-pulmonary vein triggers are actively sought and ablated. Moreover, in those with non-paroxysmal atrial fibrillation or a known higher prevalence of non-pulmonary vein triggers, empirical isolation of the superior vena cava, coronary sinus, and/or left atrial appendage might be performed. In this review, we will focus on ablation of non-pulmonary vein triggers, summarizing our current approach for their mapping and ablation.

Closure of the left atrial appendage using percutaneous transcatheter occlusion devices.

Closure of the left atrial appendage (LAA) using percutaneous transcatheter occlusion devices is used for stroke prevention as an alternative for patients with a high risk and contraindications for long-term oral anticoagulation use. In this manuscript, we will discuss the practical aspects of four among the available devices that provide percutaneous intravascular closure of the LAA: Watchman, Amulet, WaveCrest, and LAmbre.

Catheter ablation is preferred over surgery for persistent atrial fibrillation.

There are important limitations that can hinder outcomes of surgical ablation in nonparoxysmal patients with atrial fibrillation (AF), which is the typical AF population undergoing concomitant cardiac surgery for valve or ischemic heart disease. Incomplete lesions with recovered conduction or gaps as well as arrhythmias originating from areas not targeted by surgical ablation are commonly seen at the time of recurrence. Therefore, while it might be reasonable to perform AF surgery in this cohort, it is important to know these limitations and establish adequate postoperative rhythm monitoring to detect recurrences, which can be effectively addressed by catheter ablation.

Clinical Implications and Management Strategies for Left Atrial Appendage Leaks.

Left atrial appendage (LAA) is the dominant source of systemic thromboembolic (TE) events in patients with nonvalvular atrial fibrillation (AF). In patients with significant bleeding risk, various LAA exclusion strategies have been developed as an alternative to pharmacologic TE prophylaxis. Nevertheless, in a relatively small percentage of patients, incomplete LAA closure can be documented, either at the time of procedure or during follow-up. This persistent patency can potentially jeopardize an effective stroke prophylaxis. Hereby, we report an update on the current clinical implications of LAA leaks and how to manage them.

The Subtle Journey of a Right Atrial Lead: Hemopneumothorax Due to Subacute Pacemaker Lead Perforation.

We report an unusual case of subacute right atrial perforation by a screw-in pacemaker lead that migrated into the right lung causing hemopneumothorax 2 weeks after the procedure. After transvenous simple manual traction and minithoracotomy repair of the right atrial wall, the lead was repositioned without any complications. (Level of Difficulty: Beginner.).