Oclusão do apêndice atrial esquerdo por cateter: racional, técnica e indicações clínicas / Left atrial appendage occlusion: rationale, techniques and clinical indications

A fibrilação atrial (FA) está associada ao acidente vascular cerebral (AVC) embólico fatal ou de grande repercussão clínica. Apesar da eficácia da anticoagulação oral, muitos pacientes não podem ser tratados por apresentarem sangramento importante. Pacientes com FA e alto risco de AVC embólico e história de hemorragia intracraniana, doença renal crônica terminal e sangramento gastrintestinal recorrente são candidatos para oclusão do apêndice atrial esquerdo (AAE). Estudos clínicos controlados adicionais serão necessários para identificar as melhores técnicas e os pacientes que terão maior benefício com a oclusão do AAE. Apesar da necessidade de mais dados, a oclusão do AAE deve ser atualmente considerada em pacientes com FA, alto risco de AVC e contraindicação para anticoagulação oral. Neste artigo existe uma revisão do racional, das indicações e das próteses para oclusão do AAE disponíveis no Brasil

Atrial fibrillation (AF) is associated with disabling or fatal thromboembolic stroke. Despite the efficacy of oral anticoagulation, many patients are not treated due to significant bleeding. Patients with AF and high risk of stroke, and prior intracranial bleeding, end-stage renal disease and recurrent gastrointestinal bleeding are candidates for left atrial appendage (LAA) occlusion. Additional randomized trials are needed to identify the best methods and the patients who will benefit from LAA occlusion. Despite the need for more data, LAA occlusion should currently be considered in patients with AF, high risk of stroke and contraindications to long-term oral anticoagulation. In this article, we review the rationale, indications, and prostheses for LAA occlusion available in Brazi

Atrial Strain and Strain Rate: A Novel Method for the Evaluation of Atrial Stunning / Strain Atrial e Strain Rate: Novo Método para Avaliar Atordoamento Atrial

Abstract Background: Atrial fibrillation (AF) is the most common arrhythmia seen in adults. Atrial stunning is defined as the temporary mechanical dysfunction of the atrial appendage developing after AF has returned to sinus rhythm (SR). Objectives: We aimed to evaluate atrial contractile functions by strain and strain rate in patients with AF, following pharmacological and electrical cardioversion and to compare it with conventional methods. Methods: This study included 41 patients with persistent AF and 35 age-matched control cases with SR. All the AF patients included in the study had transthoracic and transesophageal echocardiography performed before and after. Septum (SEPsSR), left atrium (LAsSR) and right atrium peak systolic strain rate (RAsSR) were defined as the maximum negative value during atrial contraction and septum (SEPε), left atrium (LAε) and right atrium peak systolic strain (RAε) was defined as the percentage of change. Parameters of two groups were compared. Results: In the AF group, 1st hour and 24th hour LAε, RAε, SEPε, LAsSR, RAsSR, SEPsSR found to be significantly lower than in the control group (LAε: 2.61%±0.13, 3.06%±0.19 vs 6.45%±0.27, p<0.0001; RAε: 4.03%±0.38, 4.50%±0.47 vs 10.12%±0.64, p<0.0001; SEPε: 3.0%±0.22, 3.19%±0.15 vs 6.23%±0.49, p<0.0001; LAsSR: 0.61±0.04s-1, 0.75±0.04s- 1 vs 1.35±0.04s-1, p<0.0001; RAsSR: 1.13±0.06s-1, 1.23±0.07s-1 vs 2.10±0.08s- 1, p<0.0001; SEPsSR: 0.76±0.04s- 1, 0.78±0.04s- 1 vs 1.42±0.06 s- 1, p<0.0001). Conclusion: Atrial strain and strain rate parameters are superior to conventional echocardiographic parameters for the evaluation of atrial stunning in AF cases where SR has been achieved.

Resumo Fundamento: A fibrilação atrial (FA) é a arritmia mais comum em adultos. Define-se atordoamento atrial como a disfunção mecânica temporária do apêndice atrial que se desenvolve depois de reversão da FA ao ritmo sinusal (RS). Objetivos: Avaliar as funções atriais contráteis através de strain atrial e strain rate em pacientes com FA, após cardioversão farmacológica e elétrica, assim como compará-los com os métodos convencionais. Métodos: Este estudo incluiu 41 pacientes com FA persistente e 35 controles com RS e pareados por idade. Todos os pacientes com FA incluídos neste estudo foram submetidos a ecocardiografia transtorácica e transesofágica antes e após. Strain rates de pico sistólico do septo (SEPsSR), do átrio esquerdo (LAsSR) e do átrio direito (RAsSR) foram definidas como o máximo valor negativo durante contração atrial. Strains de pico sistólico do septo (SEPε), do átrio esquerdo (LAε) e do átrio direito (RAε) foram definidas como porcentagem de mudança. Resultados: No grupo com FA, os parâmetros LAε, RAε, SEPε, LAsSR, RAsSR e SEPsSR da 1a hora e da 24a hora foram significativamente mais baixos que no grupo controle (LAε: 2,61%±0,13; 3,06%±0,19 vs 6,45%±0,27; p<0,0001; RAε: 4,03%±0,38; 4,50%±0,47 vs 10,12%±0,64; p<0,0001; SEPε: 3,0%±0,22; 3,19%±0,15 vs 6,23%±0,49; p<0,0001; LAsSR: 0,61±0,04s-1; 0,75±0,04s-1 vs 1,35±0,04s-1; p<0,0001; RAsSR: 1,13±0,06s-1; 1,23±0,07s-1 vs 2,10±0,08s-1; p<0,0001; SEPsSR: 0,76±0,04s-1; 0,78±0,04s-1 vs 1,42±0,06 s-1; p<0,0001). Conclusão: Os parâmetros strain atrial e strain rate são superiores aos parâmetros ecocardiográficos convencionais para avaliar atordoamento atrial em pacientes com FA que reverteram ao RS.

Left Atrial Function Following Surgical Ablation of Atrial Fibrillation: Prospective Evaluation Using Dual-Source Cardiac Computed Tomography

PURPOSE: The Maze procedure has shown excellent efficacy in the elimination of atrial fibrillation (AF); however, little is known about the quality of functional recovery in the left atrium (LA) following successful sinus rhythm conversion by the Maze procedure. MATERIALS AND METHODS: We prospectively enrolled 12 patients (aged 52.5+/-10.1 years, 1 female) with valvular AF undergoing mitral valve surgery combined with the Maze procedure. Parameters of LA function in three anatomic compartments [anterior, posterior, and LA appendage (LAA)] were evaluated using electrocardiography-gated dual-source cardiac CT at one month and at six months after surgery. Twelve subjects matched by age, gender, and body surface area served as controls. RESULTS: At one month after surgery, ejection fraction (EF) and emptying volume (EV) of the LA were 14.9+/-7.4% and 21.3+/-9.7 mL, respectively, and they were significantly lower than those of the control group (EF, 47.9+/-11.2%; EV, 46.0+/-10.7%; p<0001). These values did not significantly change throughout late periods (p=0.22 and 0.21, respectively). Functional contributions of the anterior, posterior, and appendage compartments (EV of each compartment/overall EV) were 80.4%, -0.9%, and 20.5%, respectively, for those with LAA preservation (n=6); 100.1%, -0.1%, and 0% for those with LAA resection (n=6; p<0.05); and 62.2%, 28.2%, and 9.7% in the control subjects (p<0.001). CONCLUSION: Contractile functions of the LA significantly decreased after the Maze procedure. Functional contributions of three compartments of the LA were also altered. The influence of LAA preservation on postoperative LA functions needs to be evaluated through studies of larger populations.

Oclusão percutânea do apêndice atrial esquerdo e do forame oval patente no mesmo procedimento sem necessidade de punção transeptal / Percutaneous occlusion of left atrial appendage and patent foramen ovale in the same procedure avoiding transeptal puncture

A oclusão do apêndice atrial esquerdo tem sido realizada com sucesso para a prevenção de fenômenos embólicos em pacientes com fibrilação atrial, como alternativa à anticoagulação oral. O acesso atrial, através de forame oval ou comunicação interatrial tipo ostium secundum, tem sido evitado em função da crença de que o posicionamento do dispositivo é dificultado pela disposição mais alta do forame no septo interatrial. Neste manuscrito, relatamos um caso em que foram ocluídos, sequencialmente, o apêndice atrial esquerdo e o forame oval sem a necessidade de punção transeptal, que simplificou e tornou mais seguro o procedimento.

Left atrial appendage occlusion has been successfully employed to prevent embolic events in patients with atrial fibrillation as an alternative to oral anticoagulation. Left atrial access through the patent foramen ovale or ostium secundum atrial septal defect has been discouraged due to the fear that entering the septum in a higher position through the foramen would prevent adequate device positioning. In this manuscript we report a case in which the left atrial appendage and the foramen ovale were sequentially occluded avoiding transseptal puncture, making the procedure simpler and faster.

Oclusão Percutânea do Apêndice Atrial Esquerdo com Prótese Watchman® / Left Atrial Appendage Closure With the WatchmanTM Device

Introdução: O acidente vascular cerebral secundário à fibrilação atrial tem sido associado a taxas de mortalidade e de incapacidade permanente elevadas, porquanto sua prevenção eficaz é importante. O tratamento com varfarina diminui em 60% o risco de acidente vascular cerebral; todavia, até metade dos pacientes com fibrilação atrial não faz uso da anticoagulação. A oclusão do apêndice atrial esquerdo surgiu como estratégia alternativa para prevenção do acidente vascular cerebral. Métodos: Foram selecionados pacientes com fibrilação atrial, escore de CHA2DS2-VASc ≥ 2, não elegíveis para anticoagulação, para se submeterem ao fechamento percutâneo do apêndice atrial esquerdo com a prótese Watchman®. O procedimento foi realizado sob anestesia geral e guiado por ecocardiografia transesofágica. Resultados: Dos 11 pacientes selecionados, 2 não foram tratados por apresentarem trombo pré ou durante o procedimento, antes do implante do dispositivo. A idade foi de 74 ± 5,1 anos, 66,6% eram do sexo masculino, com escores CHA2DS2-VASc de 4 ± 1,4 e HAS-BLED de 3,4 ± 1,1, 77% tinham contraindicação ou condições sociais desfavoráveis para utilizarem a anticoagulação. O sucesso técnico foi de 100%, sendo alcançada a oclusão completa em todos os casos, com tempo médio de fluoroscopia de 22,1 ± 10,8 minutos e ausência de complicações hospitalares. No seguimento de 78,3 ± 41,5 dias, não ocorreram desfechos clínicos, mas um paciente apresentou trombo no dispositivo e recebeu anticoagulação por 3 meses. Conclusões: A oclusão percutânea do apêndice atrial esquerdo com dispositivo Watchman® é factível e pode ser uma alternativa atrativa na prevenção de acidente vascular cerebral nos pacientes com fibrilação atrial e limitação para anticoagulação.

Background: Stroke secondary to atrial fibrillation has been associated to a high risk of permanent, severe disability, and high early mortality, and therefore its effective prevention is of paramount importance. Warfarin therapy reduces the risk of stroke by 60%, however, half of the patients with atrial fibrillation do not receive anticoagulation. Left atrial appendage closure has emerged as an alternative strategy for stroke prevention. Methods: Patients with atrial fibrillation and CHADSVASc score ≥ 2, not eligible for anticoagulation, were submitted to left atrial appendage closure using the WatchmanTM device. The procedure was performed under general anesthesia and was guided by transesophageal echocardiography. Results: Of the 11 selected patients, 2 were not treated due to thrombi presented prior or during the procedure and before device implantation. Mean age was 74 ± 5.1 years, 66% were male, CHA2DS2-VASc score was 4 ± 1.4, HASBLED score was 3.4 ± 1.1, 77% had contraindications or had unfavorable social conditions for anticoagulation. Technical success was 100% and complete occlusion was obtained in all of the cases, with a mean fluoroscopic time of 22.1 ± 10.8 minutes, and no hospital complications. At a follow-up of 78.3 ± 41.5 days, there were no clinical events but one patient had thrombus formation on the device and received anticoagulation for 3 months. Conclusions: Left atrial appendage closure with the WatchmanTM device is feasible and may be a good alternative therapy for stroke prevention in patients with atrial fibrillation and restrictions for anticoagulation.

Characteristics of Pulmonary Vein Enlargement in Non-Valvular Atrial Fibrillation Patients with Stroke

PURPOSE: The association between pulmonary vein (PV) dilatation and stroke in non-valvular atrial fibrillation (AF) patients remains unknown. MATERIALS AND METHODS: We examined the left atrium (LA) and PV in control (n=138) and non-valvular AF patients without (AF group, n=138) and with non-hemorrhagic stroke (AF with stroke group, n=138) using computed tomography. RESULTS: The LA, LA appendage (LAA), and all PVs were larger in the AF than control patients. The orifice areas of the LAA (5.6+/-2.2 cm2 vs. 4.7+/-1.7 cm2, p<0.001), left superior PV (3.8+/-1.5 cm2 vs. 3.4+/-1.2 cm2, p=0.019), and inferior PV (2.3+/-1.0 cm2 vs. 1.8+/-0.7 cm2, p<0.001) were larger in the AF with stroke than in the AF only group. However, right PVs were not different between the two groups. In a multivariate analysis, the orifice areas of the left superior PV [odds ratio (OR) 1.25, 95% confidence interval (CI) 1.03-1.51, p=0.02], left inferior PV (OR 1.97, 95% CI 1.41-2.75, p<0.001), and LAA (OR 1.30, 95% CI 1.13-1.50, p<0.001) were independent predictors of stroke. CONCLUSION: Compared to the right PVs, the left PVs and LAA exhibited more significant enlargement in patients with AF and stroke than in patients with AF only. This finding suggests that the remodeling of left-sided LA structures might be related to stroke.

Early Experience Using a Left Atrial Appendage Occlusion Device in Patients with Atrial Fibrillation

PURPOSE: Atrial fibrillation (AF) is one of the major risk factors for ischemic stroke, and 90% of thromboembolisms in these patients arise from the left atrial appendage (LAA). Recently, it has been documented that an LAA occlusion device (OD) is not inferior to warfarin therapy, and that it reduces mortality and risk of stroke in patients with AF. MATERIALS AND METHODS: We implanted LAA-ODs in 5 Korean patients (all male, 59.8+/-7.3 years old) with long-standing persistent AF or permanent AF via a percutaneous trans-septal approach. RESULTS: 1) The major reasons for LAA-OD implantation were high risk of recurrent stroke (80%), labile international neutralizing ratio with hemorrhage (60%), and 3/5 (60%) patients had a past history of failed cardioversion for rhythm control. 2) The mean LA size was 51.3+/-5.0 mm and LAA size was 25.1x30.1 mm. We implanted the LAA-OD (28.8+/-3.4 mm device) successfully in all 5 patients with no complications. 3) After eight weeks of anticoagulation, all patients switched from warfarin to anti-platelet agent after confirmation of successful LAA occlusion by trans-esophageal echocardiography. CONCLUSION: We report on our early experience with LAA-OD deployment in patients with 1) persistent or permanent AF who cannot tolerate anticoagulation despite significant risk of ischemic stroke, or 2) recurrent stroke in patients who are unable to maintain sinus rhythm.

Oclusão percutânea do apêndice atrial na fibrilação atrial com risco embólico / Percutaneous occlusion of the left appendage in atrial fibrillation

Fundamentos: A fibrilação atrial está associada a maior risco de eventos embólicos. O apêndice atrial esquerdoé a principal fonte de trombos.Objetivos: Avaliar a segurança e descrever a técnica de oclusão por cateter do apêndice atrial esquerdo.Métodos: Dois pacientes (um masculino com 79 anos e outro feminino com 91 anos) com fibrilação atrial, alto risco tromboembólico e contraindicação à anticoagulação foram submetidos à oclusão do apêndice atrial por viapercutânea. Resultados: Em ambos os casos, a prótese foi liberada sem fluxo residual, com completa exclusão da circulação e sem complicações. Os pacientes foram mantidos com dupla antiagregação plaquetária por três meses. Conclusões: A oclusão percutânea do apêndice atrialesquerdo é um novo e efetivo método para prevenção de eventos embólicos em pacientes com fibrilação atrial.

Predictors of left atrial appendage clot: a transesophageal echocardiographic study of left atrial appendage function in patients with severe mitral stenosis.

BACKGROUND: The purpose of this study was to prospectively evaluate a large group of consecutive, non-anticoagulated patients with severe rheumatic mitral stenosis and to analyze the left atrial appendage function in relation to left atrial appendage clot and spontaneous echo contrast formation. METHODS AND RESULTS: We prospectively studied left atrial appendage function in 200 consecutive patients with severe mitral stenosis who underwent transesophageal echocardiography and correlated it with spontaneous echo contrast and left atrial appendage clot. The mean age was 30.2 +/- 9.4 years. Fifty-five (27.5%) patients were in atrial fibrillation. Left atrial appendage clot was present in 50 (25%) patients and 113 (56.5%) had spontaneous echo contrast. The older age, increased duration of symptoms, atrial fibrillation, spontaneous echo contrast, larger left atrium, depressed left atrial appendage function and type II and III left atrial appendage flow patterns correlated significantly (p<0.05) with the left atrial appendage clot. Left atrial appendage ejection fraction was significantly less in patients with clot (21.8 +/- 12.8% v. 39.1 +/- 13.2%, p<0.0001) and in those with spontaneous echo contrast (30.3 +/- 16.2 % v. 40.3 +/- 11.8%, p<0.001). Left atrial appendage filling (18.0 +/- 11.7 v. 27.6 +/- 11.8 cm/s, p <0.0001) and emptying velocities (15.4 +/- 7.0 v. 21.5 +/- 9.6 cm/s, p<0.001) and filling (1.4 +/- 1.0 v. 2.5 +/- 1.4 cm, p<0.0001) and emptying (1.5 +/- 1.2 v. 2.1 +/- 1.2 cm, p <0.05) velocity time integrals were also significantly lower in patients with clot as compared to those without clot. On multivariate regression analysis, atrial fibrillation (odds ratio 6.68, 95% CI 1.85-24.19, p=0.003) and left atrial appendage ejection fraction (odds ratio 1.06, 95% CI 1.00 - 1.11, p=0.04) were the only two independent predictors of clot formation. Incidence of clot was 62.59% in patients with left atrial appendage ejection fraction < or = 25% as compared to 10.4% in those having left atrial appendage ejection fraction >25%. Similarly patients with spontaneous echo contrasthadlower filling (21.7 +/- 11.5 v. 29.4 +/- 12.7 cm/s, p<0.0001) and emptying (17.0 +/- 8.1 v. 23.9 +/- 10.9 cm/s, p<0.0001) velocities, as well as filling (1.9 +/- 1.3 v. 2.7 +/- 1.3 cm, p<0.01) and emptying (1.7 +/- 1.0 v. 2.3 +/- 1.4 cm, p<0.01) velocity time integrals as compared to patients without spontaneous echo contrast. In a subgroup of the patients with normal sinus rhythm, the left atrial appendage ejection fraction was significantly less in patients with clot compared to those without clot (31.2 +/- 13.2 v. 41.3 +/- 11.5 %, p<0.01). CONCLUSIONS: In the patients with severe mitral stenosis, besides atrial fibrillation, a subgroup of patients in normal sinus rhythm with depressed left atrial appendage function (left atrial appendage ejection fraction < or = 25%) had a higher risk of clot formation in left atrial appendage and these patients should be routinely anticoagulated for prevention of clot formation.