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.

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.

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.