Left atrial appendage morphology predicts the formation of left atrial appendage thrombus.

BACKGROUND: Nonchicken wing left atrial appendage (LAA) morphology is associated with higher risk for stroke in patients with atrial fibrillation (AF) than chicken wing (CW) morphology. OBJECTIVE: Assess whether LAA morphology predicts the formation of LAA thrombus independent of age, sex, presenting rhythm, left ventricular ejection fraction (LVEF), or anticoagulant use. METHODS: A cross-sectional analysis was performed on patients prospectively enrolled in the Vanderbilt LAA Registry or presenting for transesophageal echocardiogram (TEE) between January 1, 2015, and November 1, 2017 (n = 306). Two physicians independently reviewed TEEs interpreted as having LAA thrombus. Determination of LAA morphology, ejection velocity, and presence of thrombus (n = 102) were based on 0°, 45°, 90°, and 135° TEE views. The control cohort (n = 204) included consecutive AF patients undergoing TEE without LAA thrombus. RESULTS: LAA morphology in patients with LAA thrombus was: 35% windsock, 47% broccoli, and 12% CW. Windsock (odds ratio [OR], 4.0; 95% confidence interval [CI]: 1.7-9.3, p = .001) and broccoli (OR, 6.6; 95% CI: 2.6-16.6; p < .001) morphology were higher risk for thrombus compared to CW. Female sex predicted higher-odds for LAA thrombus (OR, 2.6; 95% CI: 1.4-4.8; p = .002) as did LAA-EV < 20 cm/s (OR, 11.12; 95% CI: 5.6-22.1). Anticoagulation use (OR, 0.5; 95% CI: 0.3-0.9; p = .03) and higher LVEF (OR, 0.95; 95% CI: 0.93-0.98; p < .001) were associated with lower risk. In patients with a CW morphology who had LAA thrombus, 4 of the 7 had an LAA-EV < 20 cm/s and acute systolic heart failure with LVEF < 30% or active malignancy. In multivariable linear regression analysis controlling for presenting rhythm, anticoagulant use, age, sex, and LVEF, CW morphology appears relatively protective from LAA thrombus (p = .001). CONCLUSION: CW LAA morphology appears relatively protective against the formation of LAA thrombus.

Feasibility of left atrial appendage device closure following chronically failed surgical ligation.

BACKGROUND: Incomplete surgical left atrial appendage occlusion (S-LAAO) with a narrow neck has been shown to predict an increased rate of embolic stroke. Patients with a previously attempted S-LAAO were systematically excluded from all clinical trials of LAA closure devices. OBJECTIVE: The purpose of this study was to evaluate the feasibility of Watchman LAA device closure for patients referred with chronically incomplete S-LAAO. METHODS: A prospective single-arm feasibility cohort evaluated only subjects undergoing Watchman LAA closure following incomplete S-LAAO. Patients referred and implanted were followed in the Vanderbilt LAA Registry. Preprocedure computed tomographic angiography and transesophageal echocardiography (TEE) were performed to evaluate suitability for closure, with 45-day follow-up TEE postimplant. RESULTS: All attempted LAA closures after incomplete S-LAAO were successful (n = 6). Mean age was 76.3 ± 7 years. Mean CHADS2Vasc score was 3.8 ± 0.8, and HAS-BLED score was 3.5 ± 0.5. At 45-day follow up, all subjects had complete device seal with no thrombus on device and had transitioned to clopidogrel plus aspirin. Three subjects had narrow ostial necks with a maximum diameter ≤9 mm. In all cases, the 4.7-mm Watchman access sheath was able to cross the ostial stricture. Mean occluder size implanted was 28 ± 4 mm. Mean LAA dimension by TEE in the 45° and 135° views for depth was 31 mm and ostial diameter was 11 × 16 mm, below the minimum Watchman indication for use of 17 mm. No major intraoperative complications occurred. CONCLUSION: Watchman LAA closure seems to be feasible in patients with chronically incomplete S-LAAO, including subjects with a narrow neck ≤9 mm in width.

Non-pulmonary vein mediated atrial fibrillation: A novel sub-phenotype.

BACKGROUND: Atrial fibrillation (AF) is a mechanistically heterogeneous disorder, and the ability to identify sub-phenotypes ("endophenotypes") of AF would assist in the delivery of personalized medicine. We used the clinical response to pulmonary vein isolation (PVI) to identify a sub-group of patients with non-PV mediated AF and sought to define the clinical associations. METHODS: Subjects enrolled in the Vanderbilt AF Ablation Registry who underwent a repeat AF ablation due to arrhythmia recurrence were analyzed on the basis of PV reconnection. Subjects who had no PV reconnection were defined as "non-PV mediated AF". A comparison group of subjects were identified who had AF that was treated with PVI-only and experienced no arrhythmia recurrence >12 months. They were considered a group enriched for "PV-mediated AF". Univariate and multivariable binary logistic regression analysis was performed to investigate clinical associations between the PV and non-PV mediated AF groups. RESULTS: Two hundred and twenty nine subjects underwent repeat AF ablation and thirty three (14%) had no PV reconnection. They were compared with 91 subjects identified as having PV-mediated AF. Subjects with non-PV mediated AF were older (64 years [IQR 60,71] vs. 60 [52,67], P = 0.01), more likely to have non-paroxysmal AF (82% [N = 27] vs. 35% [N = 32], P<0.001), and had a larger left atrium (LA) (4.2cm [3.6,4.8] vs. 4.0 [3.3,4.4], P = 0.04). In univariate analysis, age (per decade: OR 1.56 [95% CI: 1.04 to 2.33], P = 0.03), LA size (per cm: OR 1.8 [1.06 to 3.21], P = 0.03) and non-paroxysmal AF (OR 8.3 [3.10 to 22.19], P<0.001) were all significantly associated with non-PV mediated AF. However, in multivariable analysis only non-paroxysmal AF was independently associated with non-PV mediated AF (OR 7.47 [95% CI 2.62 to 21.29], P<0.001), when adjusted for age (per decade: OR 1.25 [0.81 to 1.94], P = 0.31), male gender (OR 0.48 [0.18 to 1.28], P = 0.14), and LA size (per 1cm: 1.24 [0.65 to 2.33], P = 0.52). CONCLUSIONS: Non-paroxysmal AF was the only clinical variable found to be independently associated with non-PV mediated AF. We demonstrated that analysis of AF ablation outcomes data can serve as a tool to successfully identify a sub-phenotype of subjects who have non-PV mediated AF. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov ID # NCT02404415.

Digoxin and short term mortality after acute STEMI: Results from the MAGIC trial.

BACKGROUND: The safety of digoxin has been a subject of debate for decades, most recently among patients with atrial fibrillation (AF). Digoxin has been used during the acute phase of ST elevation myocardial infarction (STEMI) complicated with AF or heart failure. Data about digoxin in this setting are scarce. HYPOTHESIS: We hypothesize that digoxin maybe associated with increased mortality when used during the acute phase of ST segment myocardial infarction. METHODS: We investigated the association between digoxin and mortality in patients enrolled in the MAGnesium In Coronaries (MAGIC) study, which evaluated the efficacy of early magnesium administration in STEMI. Multiple Cox proportional hazards models were examined to assess the aforementioned association after correction for clinical characteristics and comorbidities. RESULTS: After excluding 639 (10.3%) patients for missing data, we analyzed the remaining 5574 patients. There were 852 (15.3%) deaths during the one month follow-up and 170 (3.0%) patients on digoxin concomitantly, among which 42 patients (24.7%) died. There was a statistically significant association between digoxin and increased mortality in the unadjusted statistical analysis; however, this association disappeared after correction for clinical characteristics and comorbidities in the primary multivariable analysis (estimated hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.62-1.19, p=0.372) and in three additional multivariable analyses. CONCLUSION: Digoxin use as a new or preexisting medication during the acute phase of STEMI in the MAGIC trial was not associated with a significant increase in mortality after correcting for clinical characteristics and comorbidities.