Relationship between body mass index and left atrial appendage thrombus in nonvalvular atrial fibrillation

Treatment of Persistent Left Atrial Appendage Thrombus in Patients with Atrial Fibrillation on Adequate Oral Anticoagulation: Pathways of Care for All-comers and Heart Failure Patients

In patients with AF, the presence of left atrial/left atrial appendage (LA/LAA) thrombus is related to an increased risk of thromboembolic events. Anticoagulation therapy, either with vitamin K antagonists or novel oral anticoagulants (NOACs) is therefore mandatory in AF with LA/LAA thrombus in order to lower the risk of stroke or other systemic embolic events. Despite the efficacy of these treatments, some patients will have persistent LAA thrombus remaining or may have contraindications to oral anticoagulation. Currently, little is known about the occurrence, risk factors and resolution rate of LA/LAA thrombus in patients who are already under optimal chronic oral anticoagulation, including vitamin K antagonists or NOACs. The common action in clinical practice in this scenario is switching from one to another anticoagulant drug exhibiting a different mechanism of action. Repeated cardiac imaging is then advised within several weeks to visually verify thrombus dissolution. Finally, there is a substantial scarcity of data on the role and optimal use of NOACs after LAA occlusion. The aim of this review is to critically evaluate data and provide up-to-date information on the best antithrombotic strategies in this challenging clinical scenario.

The risk factors of thrombus formation and the effect of catheter ablation on repetitive thrombus formation in patients with atrial fibrillation: a single center retrospective study in China

BACKGROUND

Atrial fibrillation (AF) predisposes patients to the formation of atrial thrombi. The CHA₂DS₂-VASc score does not include all risk factors for atrial thrombosis. The present study is designed to explore the influencing factors of thrombus formation in patients with AF and to investigate the effect of catheter ablation (CA) on recurrent thrombosis in patients with a history of intracardiac thrombus.

METHODS

(1) This study consisted of 1726 patients that underwent CA, among which 58 patients had a history of intracardiac thrombus prior to CA. The risk factors for thrombus formation were explored by comparing the baseline clinical characteristics of patients with and without atrial thrombus. (2) The left atrial appendage flow velocity (LAAFV) in patients with a history of intracardiac thrombus who were willing to undergo transesophageal echocardiography (TEE) at the latest follow-up were examined, and comparisons of the LAAFV was made before and after CA.

RESULTS

The median follow-up period is 13 months. Persistent AF was found to be the only independent risk factor affecting the formation of atrial thrombus among the investigated factors (OR 3.152; 95%CI 1.806-5.500; p < 0.001). Twenty-seven patients agreed to undergo TEE during follow-up, no clinical ischemic stroke events were recorded, no recurrent intracardiac thrombus formation was detected in patients, 15 patients maintained sinus rhythm (55.6%) during follow-up; successful CA significantly increased LAAFV (difference between latest evaluation prior to CA 17.46 ± 14.81 cm/s, p < 0.001).

CONCLUSIONS

Persistent AF is the only independent risk factor for thrombus formation. Successful CA may improve the LAAFV and thereby decrease the risk of intracardiac thrombus formation.

Increased Body Mass Index and Risk of Left Atrial Thrombus in Nonvalvular Atrial Fibrillation Patients-Data from the Left Atrial Thrombus on Transesophageal Echocardiography (LATTEE) Registry

An increased body mass index (BMI) is associated with a higher incidence of atrial fibrillation (AF) and a higher risk of thromboembolic complications in AF patients. The aim of this study was to investigate the effect of BMI on the risk of left atrial thrombi (LATs) in patients with nonvalvular AF/atrial flutter (AFl) (NV AF/AFl). Patients diagnosed with NVAF/AFl (between November 2018 and May 2020) were selected from the multicenter, prospective, observational Left Atrial Thrombus on Transesophageal Echocardiography (LATTEE) registry that included AF/AFl patients referred for cardioversion or ablation followed by transesophageal echocardiography. A total of 2816 AF/AFl patients (63.6% males; mean age 65.8 years; mean BMI 29.8 kg/m2) were included in the study. Two hundred and twenty-two of them (7.9%) had LATs. Compared with normal-weight patients, those with BMIs ≥ 25 kg/m2 more frequently presented clinical factors potentially provoking LATs, such as non-paroxysmal AF/AFl (p = 0.04), hypertension (p < 0.001), and diabetes (p < 0.001); had higher CHA2DS2 scores (p < 0.001); and had larger LA dimensions (LA diameter and LA area) (p < 0.001 for both parameters). On the other hand, they showed some features negatively related to thromboembolic risk; for example, they were younger (p < 0.001) and were more often male (p = 0.002). In addition, patients with abnormal BMIs were more likely to be smokers (p = 0.006) and to be treated with oral anticoagulants (p = 0.005). Despite these differences in the prevalence of thromboembolic risk factors, the incidence of LATs was not increased in patients with abnormal body weight (overweight and obese compared to normal-weight patients) in this large real-life cohort of AF/AFl patients. This is probably due to the balanced composition regarding the prevalence of positive and negative thromboembolic risk factors.

Apixaban Use in Obese Patients: A Review of the Pharmacokinetic, Interventional, and Observational Study Data

Abstract

Relatively little is known about the influence of extreme body weight on the pharmacokinetics (PK), pharmacodynamics (PD), efficacy, and safety of drugs used in many disease states. While direct oral anticoagulants (DOACs) have an advantage over warfarin in that they do not require routine drug monitoring, some may regard this convenience as less compelling in obese patients. Some consensus guidelines discourage using DOACs in patients weighing > 120 kg or with a body mass index > 35–40 kg/m², given a sparsity of available data in this population and the concern that fixed dosing in obese patients might lead to decreased drug exposure and lower efficacy. Per the prescribing information, apixaban does not require dose adjustment in patients weighing above a certain threshold (e.g., ≥ 120 kg). Data from healthy volunteers and patients with nonvalvular atrial fibrillation (NVAF) or venous thromboembolism (VTE) have shown that increased body weight has a modest effect on apixaban’s PK. However, the paucity of exposure data in individuals > 120 kg and the lack of guideline consensus on DOAC use in obese patients continue to raise concerns about potential decreased drug exposure at extreme weight. This article is the first to comprehensively review the available PK data in obese individuals without NVAF or VTE, and PK, PD, efficacy, effectiveness, and safety data for apixaban in obese patients with either NVAF or VTE, including subgroup analyses across randomized controlled trials and observational (real-world) studies. These data suggest that obesity does not substantially influence the efficacy, effectiveness, or safety of apixaban in these patients.

Trial Registration ARISTOTLE: NCT00412984; AVERROES: NCT00496769; AMPLIFY: NCT00643201; AMPLIFY-EXT: NCT00633893; ADVANCE-1: NCT00371683; ADVANCE-2: NCT00452530; ADVANCE-3: NCT00423319

Video abstract

Atrial thrombi in elective patients considered for atrial fibrillation rhythm control: Risk factors and prognostic value

The prognostic value of atrial thrombi (AT) among elective patients with atrial fibrillation (AF) referred for a rhythm control strategy is unclear. In this study, clinical variables were correlated with the presence of AT and long term survival among 205 patients submitted to transesophageal echocardiography before elective AF cardioversion or ablation. Atrial thrombi were present in 7.8% of cases and were significantly associated with reduced survival. Obesity was the only independent clinical predictor of AT [OR 4.27 (1.15-15.79), p = 0.03]. In patients with AF, AT appear to be associated with adverse outcomes, possibly indicating more advanced atrial cardiomyopathy.

Frequency of atrial thrombus formation in patients with atrial fibrillation under treatment with non-vitamin K oral anticoagulants in comparison to vitamin K antagonists: a systematic review and meta-analysis

BACKGROUND

To assess the frequency of left atrium/left atrial appendage (LA/LAA) thrombus under treatment with non-vitamin K oral anticoagulants (NOACs) in comparison with vitamin K antagonists (VKAs) in patients with non-valvular atrial fibrillation (AF).

METHODS

PubMed, Web of Science™, EMBASE and the Cochrane Library databases were searched for studies comparing NOACs with VKAs in AF patients who underwent diagnostic transoesophageal echocardiography (TEE).

RESULTS

A total of four trials were considered eligible and were included in the meta-analysis. Four RCTs comprising n = 2397 AF patients (NOACs: n = 1412, VKAs: n = 985) were included in the meta-analysis. The frequency of LA/LAA thrombus formation under treatment with NOACs was similar to VKAs [odds ratio (OR) 1.14, 95% confidence intervals (95% CIs) 0.97-1.65, p = 0.48]. Both treatment groups revealed an approximately 5% frequency of thrombus formation, although a precise calculation is not possible due to Simpson paradox. Indications of heterogeneity between the included trials were not found (χ2 test p = 0.99, I2 = 0%).

CONCLUSIONS

The findings of this meta-analysis suggest that NOACs are similar to VKAs regarding the frequency of LA/LAA thrombus in patients with AF. An unknown number of patients in the original studies did not receive sufficient anticoagulation for at least 3 weeks prior to TEE examination, and therefore the present results should be interpreted with caution. Systematic review registration- http://www.crd.york.ac.uk/PROSPERO . Unique identifier: PROSPERO CRD42017059293.

Morphological features of the left atrial appendage in consecutive coronary computed tomography angiography patients with and without atrial fibrillation

The majority of intracardiac thrombi form in the left atrial appendage (LAA). Enlargement of this structure, together with certain morphological features, may indicate a predisposition to the formation of thrombi and subsequent cardioembolic stroke. Thus far, studies on LAA morphology have largely focused on those patients with atrial fibrillation (AF). Taking a different approach, we investigated the variation in LAA morphology in a consecutive patient population with and without AF. We evaluated 808 consecutive patients (529 females; mean age 52.5±9.9 years) who underwent coronary artery computed tomography angiography (CCTA), the majority of whom (749) had no history of AF. We assessed the length, lobe number, and morphological classification of their LAAs. Demographic data and medical histories were collated from medical records and then correlated with LAA morphology. The proportions of each of the four morphological classes of LAA for the overall vs. non-AF population were: WindSock, 62.3/61.5%; Cactus, 18.6/18.8%; ChickenWing, 10.0/10.0%; and CauliFlower, 9.2/9.6%. Age (p<0.001; r = 0.156) and female gender (p<0.001) were both found to be associated with an increased body surface area (BSA)-related LAA length. Male patients were more likely to manifest multi-lobed (p = 0.003) LAAs, and overweight patients with a greater number of multi-lobed LAA morphological classes (p = 0.010). No associations with morphological LAA features could be found for patients with diabetes, hypertension, or dyslipidemia. Nor did the size of the left atrium exhibit any correlation with BSA-related LAA length. In the overall and non-AF populations, aging and female gender were associated with longer BSA-indexed LAAs.

Relation of Body Mass Index With Adverse Outcomes Among Patients With Atrial Fibrillation: A Meta-Analysis and Systematic Review

BACKGROUND

Several studies have investigated the impact of body mass index (BMI) on the prognosis of atrial fibrillation, but the results remain controversial. We sought to estimate the association of BMI with atrial fibrillation-related outcomes.

METHODS AND RESULTS

We systematically searched the Cochrane Library, PubMed, and Elsevier databases for all studies reporting associations between BMI and atrial fibrillation-related outcomes. Relative risks (RRs) and 95% CIs were extracted and pooled. Nine studies with 49 364 participants were included. Underweight BMI was associated with an increased risk of stroke or systemic embolism (RR 1.67, 95% CI 1.12-2.49), all-cause mortaliity (RR 2.61, 95% CI 2.21-3.09), and cardiovascular death (RR 2.49, 95% CI 1.38-4.50). Nevertheless, the pooled RRs of overweight and obese patients were lower than those of normal-weight patients for stroke or systemic embolism (overweight: RR 0.91, 95% CI 0.80-1.04; obese: RR 0.84, 95% CI 0.72-0.98; grade 1 obesity: RR 0.89, 95% CI 0.71-1.11; grade 2 obesity: RR 0.64, 95% CI 0.45-0.91; grade 3 obesity: RR 0.82, 95% CI 0.54-1.25), all-cause death (overweight: RR 0.78, 95% CI 0.62-0.96; obese: RR 0.84, 95% CI 0.64-1.10; grade 1 obesity: RR 0.64, 95% CI 0.57-0.73; grade 2 obesity: RR 0.70, 95% CI 0.47-1.03; grade 3 obesity: RR 0.72, 95% CI 0.59-0.88), and cardiovascular death (overweight: RR 0.79, 95% CI 0.58-1.08; obese: RR 0.99, 95% CI 0.79-1.24).

CONCLUSIONS

Underweight BMI is associated with an increased risk of stroke or systemic embolism, cardiovascular death, and all-cause death in Asian patients with atrial fibrillation, whereas in all atrial fibrillation patients, overweight and obese BMI was not associated with increased risks of these outcomes.

Impact of Body Mass Index on the Prognosis of Japanese Patients With Non-Valvular Atrial Fibrillation

Obesity is a risk factor for atrial fibrillation (AF); however, obesity is associated with lower mortality in patients with established AF, a phenomenon known as the obesity paradox. Previous studies reported inconsistent results regarding effects of body weight on risk of cardiogenic embolism in patients with AF. To determine relation between body mass index (BMI) and prognosis among Japanese patients with nonvalvular AF (NVAF), a post hoc analysis was conducted using observational data in the J-RHYTHM Registry. Subjects were categorized as underweight (BMI <18.5), normal (18.5 to 24.9), overweight (25.0 to 29.9), or obese (≥30 kg/m(2)). End points included thromboembolism, major hemorrhaging, all-cause mortality, and cardiovascular mortality. Of the 7,406 patients with NVAF, 6,379 patients (70 ± 10 years old; BMI, 23.6 ± 3.9 kg/m(2)) having baseline BMI data constituted the study group. During the 2-year follow-up period, 111 patients had thromboembolism, 124 experienced major hemorrhage, and 159 died. Multivariate analysis with the Cox proportional hazards model showed that none of the BMI categories were independent predictors of thromboembolism. However, being underweight was an independent predictor of all-cause mortality (hazard ratio [HR] 2.45; 95% confidence interval [CI] 1.62 to 3.69; p <0.001) and cardiovascular mortality (HR 3.00, 95% CI 1.52 to 5.91, p = 0.001) when normal weight was used as the reference. Additionally, being overweight was a predictor of lower all-cause mortality (HR 0.60, 95% CI 0.37 to 0.95, p = 0.029). In conclusion, being underweight is associated with higher risks of all-cause and cardiovascular mortality compared with having a normal weight. Being overweight or obese is not associated with increased mortality among Japanese patients with NVAF.