Outcomes for Atrial Fibrillation Patients with Silent Left Atrial Thrombi Detected by Transesophageal Echocardiography

Impact of left atrial appendage flow velocity on thrombus resolution and clinical outcomes in patients with atrial fibrillation and silent left atrial thrombi: insights from the LAT study

AIMS

Blood stasis is crucial in developing left atrial (LA) thrombi. LA appendage peak flow velocity (LAAFV) is a quantitative parameter for estimating thromboembolic risk. However, its impact on LA thrombus resolution and clinical outcomes remains unclear.

METHODS AND RESULTS

The LAT study was a multicentre observational study investigating patients with atrial fibrillation (AF) and silent LA thrombi detected by transoesophageal echocardiography (TEE). Among 17 436 TEE procedures for patients with AF, 297 patients (1.7%) had silent LA thrombi. Excluding patients without follow-up examinations, we enrolled 169 whose baseline LAAFV was available. Oral anticoagulation use increased from 85.7% at baseline to 97.0% at the final follow-up (P < 0.001). During 1 year, LA thrombus resolution was confirmed in 130 (76.9%) patients within 76 (34-138) days. Conversely, 26 had residual LA thrombi, 8 had thromboembolisms, and 5 required surgical removal. These patients with failed thrombus resolution had lower baseline LAAFV than those with successful resolution (18.0 [15.8-22.0] vs. 22.2 [17.0-35.0], P = 0.003). Despite limited predictive power (area under the curve, 0.659; P = 0.001), LAAFV ≤ 20.0 cm/s (best cut-off) significantly predicted failed LA thrombus resolution, even after adjusting for potential confounders (odds ratio, 2.72; 95% confidence interval, 1.22-6.09; P = 0.015). The incidence of adverse outcomes including ischaemic stroke/systemic embolism, major bleeding, or all-cause death was significantly higher in patients with reduced LAAFV than in those with preserved LAAFV (28.4% vs. 11.6%, log-rank P = 0.005).

CONCLUSION

Failed LA thrombus resolution was not rare in patients with AF and silent LA thrombi. Reduced LAAFV was associated with failed LA thrombus resolution and adverse clinical outcomes.

Comparison of Long-Term Outcomes Between Combination Antiplatelet and Anticoagulant Therapy and Anticoagulant Monotherapy in Patients With Atrial Fibrillation and Left Atrial Thrombi

Background: Anticoagulation for patients with atrial fibrillation (AF) complicated by left atrial thrombi (LAT) is a frequent cause of bleeding complications, but risk factors remain unknown.

Methods and Results: Of 3,139 AF patients who underwent transesophageal echocardiography, 82 with LAT under anticoagulation were included in this study. Patients treated with combination antiplatelet and anticoagulant therapy (n=31) were compared with those receiving anticoagulant monotherapy (n=51) to investigate the effects of antiplatelet agents during anticoagulation on bleeding complications. Over a mean (±SD) follow-up of 878±486 days, bleeding events occurred more frequently in the combination therapy than monotherapy group (58% vs. 20%; P<0.001), but there was no significant difference in embolic events (6.5% vs. 3.9%; P=0.606). Kaplan-Meier analysis also showed a significantly higher rate of bleeding events in the combination therapy group, but no significant difference in the rate of embolic events. Inverse probability of treatment weighting revealed that combination therapy was independently associated with an increased risk of bleeding (hazard ratio [HR] 2.98, 95% confidence interval [CI] 1.14–7.89, P=0.026), but not with the risk of embolic events (HR 0.30, 95% CI 0.04–2.59, P=0.275). Net clinical benefit analysis was almost negative for combination therapy vs. monotherapy.

Conclusions: In patients with AF and LAT, combination therapy was significantly associated with an increased risk of bleeding events, but not with a reduced risk of embolic events.

Long-term left atrial thrombi after mitral valve replacement

The aim of this study was to evaluate the risk factors and characteristics of long-term postoperative left atrial (LA) thrombi after mitral valve replacement. Transthoracic echocardiography (TTE) file of 3117 consecutive patients with mitral valve replacement history was reviewed (between Jan 2006 and Feb 2019). 45 LA thrombi cases (1.4%) was identified and matched to 180 thrombi-free cases by random sampling. The median detection time of LA thrombi was 58 months (IQR, 17-144) after MV replacement. Distribution of LA thrombi included roof (n = 10), posterior wall (n = 9), appendage (n = 7), lateral wall (n = 6), anterior wall (n = 2), septum (n = 1) and multiple site (n = 10). All thrombi were sessile and immobile. The independent predictors for LA thrombi development by stepwise multiple regression analysis were the larger LA size (> 55 mm), the increased of mitral valve pressure gradient (MVPG > 6 mmHg), and the reduced of left ventricular ejection fraction (LVEF < 50%). Long-term thrombi incidence after mitral valve replacement is somewhat low. In individuals with mitral prosthetic valves, larger LA size, increased MVPG and reduced LVEF were three promising independent predictors of the insistence of LA thrombi. Furthermore, LA thrombi were sessile, immobile and widespread in the long-term postoperative period after mitral valve replacement. Close monitoring should be applied in these patients with thrombi risk.

Effect of Extensive Ablation on Recurrence in Patients with Persistent Atrial Fibrillation Treated with Pulmonary Vein Isolation (EARNEST-PVI) trial: Design and rationale

BACKGROUND

Although extensive substrate modification in addition to pulmonary vein isolation (PVI) has been recommended in catheter ablation for persistent atrial fibrillation (AF), recent randomized controlled trials have not demonstrated efficacy of such additional ablations.

METHODS AND STUDY DESIGN

The Osaka Cardiovascular Conference will conduct a multicenter, randomized, open-label trial aiming to examine whether PVI alone is non-inferior to PVI plus additional ablation such as linear ablation and/or complex fractionated atrial electrogram ablation in patients with persistent AF. The primary outcome is recurrence of AF documented by scheduled or symptom-driven electrocardiogram tests during a 1-year follow-up period after the index ablation. The key secondary endpoints include all-cause death, occurrence of symptomatic stroke, complications related to the procedure, and quality of life assessment using the 36-item Short-Form Health Survey. The clinical impact of the presence or absence of AF trigger foci, and their origins in cases with them, on the results of catheter ablation will also be investigated as an exploratory endpoint. A total of 512 patients will be enrolled and followed up to 1 year.

CONCLUSIONS

The EARNEST-PVI trial is a randomized controlled trial designed to assess whether PVI alone is non-inferior to extended substrate ablation for patients with persistent AF undergoing a first catheter ablation.

Left atrial appendage thrombus detected by transesophageal examination with linear endoscopic ultrasound

Linear endoscopic ultrasound (L-EUS) is mainly performed to assess pancreaticobiliary and mediastinal diseases. In this report, transesophageal observation with L-EUS revealed an LAA thrombus that was not detected by transthoracic echocardiography. This report highlights a novel potential role for L-EUS in the detection of cardiovascular diseases including LAA thrombi.