Project description:ObjectivesIn this study, the authors sought to perform a meta-analysis of controlled studies assessing the relationship between left atrial appendage (LAA) electrical isolation (EI) and recurrent atrial fibrillation (AF).BackgroundLAA triggers could play an important role in AF and can be treated with complete EI of the LAA via surgical or percutaneous approaches.MethodsWe conducted a meta-analysis of all controlled studies published as of November 21, 2016, assessing the relationship between left atrial appendage electrical isolation (LAAEI) and recurrent AF. The primary endpoint was atrial tachycardia (AT) or AF recurrence after the post-procedure blanking period. The association between LAAEI and AT/AF was estimated using random-effects modeling. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the DerSimonian and Laird method.ResultsWe identified 7 studies including 1,037 patients; LAAEI was performed in 566 patients (55%). LAAEI was associated with a significantly lower rate of AT/AF recurrence in the primary analysis (OR: 0.38; 95% CI: 0.16 to 0.90; p = 0.02). The association between LAAEI and recurrent AT/AF was strongest in a sensitivity analysis restricted to studies of percutaneous LAAEI (OR: 0.22; 95% CI: 0.11 to 0.46; p < 0.001; 5 studies, n = 623). LAAEI was not associated with thromboembolism (OR: 0.50; 95% CI: 0.18 to 1.39; p = 0.18; 5 studies, n = 767), although these studies either incorporated LAA occlusion (3 studies, n = 552 patients) or follow-up echocardiography to assess LAA function (2 studies, n = 215 patients) to inform antithrombotic strategies.ConclusionsLAAEI is associated with a significant reduction in recurrent AT/AF. Randomized trials are required to confirm the efficacy and long-term safety of LAAEI and to determine the optimal concomitant antithrombotic strategy.
Project description:Percutaneous left atrial appendage (LAA) closure is being increasingly used as a treatment strategy to prevent stroke in patients with atrial fibrillation (AF) who have contraindications to anticoagulants. Several approaches and devices have been developed in the last few years, each with their own unique set of advantages and disadvantages. In this article, the published studies on surgical and percutaneous approaches to LAA closure are reviewed, focusing on stroke mechanisms in AF, LAA structure and function relevant to stroke prevention, practical differences in procedural approach, and clinical considerations surrounding management.
Project description:Among patients with ischemic stroke and atrial fibrillation, which ones are at high risk of recurrent stroke is unclear. This study aimed to determine whether left atrial size was associated with long-term risk of stroke recurrence in patients with nonvalvular atrial fibrillation. In this multicenter prospective cohort study, nonvalvular atrial fibrillation patients hospitalized for acute ischemic stroke were enrolled and followed up after discharge. Indexed-left atrial diameter was obtained by dividing left atrial diameter by body surface area. Cause-specific and subdistribution hazard ratios of recurrent stroke were estimated by Cox proportional hazards and Fine-Gray models, respectively. Risk prediction was evaluated by integrated discrimination improvement and net reclassification improvement. In total, 1611 patients (77.8±10.2 [mean±SD] years, 44.5% female) were included. During follow-up for 2.40±1.63 (mean±SD) years, 251 patients had recurrent stroke and 514 patients died. An increased indexed-left atrial diameter (per 1 cm/m2) was significantly associated with elevated risk of stroke recurrence (hazard ratio 1.60, 95% CI 1.30-1.98). The association was maintained when death was regarded as the competing risk and in 1464 patients who were treated with anticoagulants (hazard ratio 1.59, 95% CI 1.27-2.00). Risk prediction for recurrent stroke was significantly improved by adding indexed-left atrial diameter to the baseline model composed of the factors in the CHADS2 score or those in the CHA2DS2-VASc score. These findings suggest that left atrial enlargement is associated with an increased risk of recurrent stroke in nonvalvular atrial fibrillation patients with ischemic stroke.
Project description:BackgroundThe results of studies evaluating the left atrial appendage (LAA) function and structure as predictors of atrial fibrillation (AF) recurrence after catheter ablation (CA) are contradictory. Therefore, we performed a meta-analysis to assess whether the LAA function and structure can predict the recurrence of AF after CA.MethodsThe PubMed, EMBASE, Web of Science, and Cochrane library databases were used to conduct a comprehensive literature search. Finally, 37 studies encompassing 11 LAA parameters were included in this meta-analysis.ResultsCompared with those in the non-recurrence group, the recurrence group had increased LAA volume (SMD 0.53, 95% CI [0.36, 0.71] p < 0.00001), LAA volume index, LAA orifice area, and LAA orifice short/long axis and decreased LAA emptying flow velocity (SMD -0.54, 95% CI [-0.68, -0.40], P < 0.00001), LAA filling flow velocity, and LAA ejection fraction, while there was no significant difference in LAA morphology or LAA depth.ConclusionLarge LAA structure of pre-ablation (LAA volume, orifice area, orifice long/short axis, and volume index) and decreased LAA function of pre-ablation (LAA emptying flow velocity, filling flow velocity, ejection fraction, and LASEC) increase the odds of AF recurrence after CA.Systematic review registration[https://www.crd.york.ac.uk/prospero/], identifier [CRD42022324533].
Project description:BackgroundLeft atrial volume index (LAVI) of >34 mL/m2 is the cutoff value for identifying an enlarged left atrium. The definition of left atrial (LA) reverse remodeling after atrial fibrillation (AF) ablation is undetermined. We hypothesized that patients with LA dilatation who achieve normal LA volume (LAVI<34 mL/m2) after AF ablation have better long-term outcomes than those who do not. Furthermore, we investigated whether patients with a normal LA volume can also achieve normal LA function with AF ablation.MethodsWe enrolled 140 AF patients with baseline LAVI of ≥34 mL/m2, without AF recurrence for 1 year after the initial AF ablation. We acquired conventional and speckle-tracking echocardiographic parameters within 24 hour and at 1 year after the procedure. To define the normal range of LA function, age- and sex-matched controls without a history of AF were also enrolled.ResultsAfter restoration of sinus rhythm, LA structural and functional parameters significantly improved, and 75 patients (54%) had normal LA volume. During a median follow-up of 44 (31-61) months, 32 patients (23%) experienced a late recurrence of AF (AF recurrence >1 year). Patients who achieved normal LA volume after AF ablation had fewer late recurrences than those who did not (P < .01). However, LA abnormalities, especially LA dysfunction, persisted in AF patients even when the LA volume was normalized compared with controls.ConclusionPatients who achieved normal LA volume had better long-term outcomes of AF ablation than those who did not; however, LA abnormalities persisted even after successful ablation of AF.
Project description:BackgroundIndigenous Australians experience a greater burden of AF. Whether this is in-part due to differences in arrhythmogenic structures that appear to contribute to AF differences amongst other ethnicities is not known.MethodsWe studied forty individuals matched for ethnicity and other AF risk factors. Computed tomography imaging was used to characterise left atrial (LA), pulmonary vein (PV), and left atrial appendage (LAA) anatomy.ResultsThere were no significant differences in LA diameters or volumes between Indigenous and non-Indigenous Australians. Similarly, we could not detect any consistent differences in PV number, morphology, diameters, or ostial characteristics according to ethnicity. LAA analyses suggested that Indigenous Australians may have a greater proportion of non chickenwing LAA type, and a tendency for eccentric, oval-shaped LAA ostia; however, there were no other differences seen with regards to LAA volume or depth. Indexed values for LA, PV and LAA anatomy corrected for body size were broadly similar.ConclusionsIn a cohort of individuals matched for AF risk factors, we could find no strong evidence of ethnic differences in LA, PV, and LAA characteristics that may explain a predisposition of Indigenous Australians for atrial arrhythmogenesis. These findings, in conjunction with our previous data showing highly prevalent cardiometabolic risk factors in Indigenous Australians with AF, suggest that it is these conditions that are more likely responsible for the AF substrate in these individuals. Continued efforts should therefore be directed towards risk factor management in an attempt to prevent and minimise the effects of AF in Indigenous Australians.