Heart Team for Left Appendage Occlusion without the Use of Antithrombotic Therapy: The Epicardial Perspective.

BACKGROUND: Left atrial appendage occlusion is an increasingly proposed treatment for patients with atrial fibrillation and poor tolerance to anticoagulants. All endovascular devices require antithrombotic therapy. Anatomical and clinical variables predisposing to device-related thrombosis, as well as post-procedural peri-device leaks, could mandate the continuation or reintroduction of aggressive antithrombotic treatment. Because of the absence of foreign material inside the heart, epicardial appendage closure possibly does not necessitate antithrombotic therapy, but data of large series are missing. METHODS: Multidisciplinary team evaluation for standalone totally thoracoscopic epicardial appendage closure was done in 180 consecutive patients with atrial fibrillation and poor tolerance to antithrombotic therapy. One hundred and fifty-two patients consented (male 66.1%, mean age 76.1 ± 7.4, CHA2DS2VASc mean 5.3 ± 1.6, HASBLED mean 3.8 ± 1.1). Indications were cerebral hemorrhage (48%), gastro-intestinal bleeding (33.3%), and other bleeding (20.7%). No antithrombotic therapy was prescribed from the day of surgery to the latest follow up. RESULTS: Procedural success was 98.7%. At a mean follow up of 38.2 ± 18.8 months, cardioembolic and bleeding events were 1.3% and 0.6%, respectively. Among patients with a history of blood transfusions (41.1%), none needed further transfusions or treatment post procedure. CONCLUSION: Epicardial appendage occlusion without any antithrombotic therapy appears to be safe and effective. This strategy could be advised when minimization of bleeding risk concomitant to stroke prevention is needed.

Epicardial standalone left atrial appendage clipping for prevention of ischemic stroke in patients with atrial fibrillation contraindicated for oral anticaogulation.

INTRODUCTION: The most appropriate treatment for stroke prevention in standalone atrial fibrillation patients with a high CHADS2VASC score contraindicated for oral anticoagulation (OAC) or novel OAC (NOAC) still needs to be defined. Percutaneous left atrial appendage (LAA) closure devices are available, but because of their endocardial positioning need a period of antiplatelet therapy (APT). This study aimed to evaluate the safety and efficacy of epicardial left atrial appendage clipping in patients contraindicated for (N)OAC and APT. METHODS AND RESULTS: We describe a standalone totally thoracoscopic LAA clipping of forty-five consecutive patients with nonvalvular atrial fibrillation (NVAF; 32 males; age, 73.1 ± 7.4 years; CHADVASC, 6.5 ± 1.1; HAS-BLED 4.9 ± 0.9) with absolute contraindications to (N)OAC. The patients were selected by a multidisciplinary Heart Team. Sixty percent had a previous ischemic stroke and 51% a history of the hemorrhagic event and 22% both. All patients were implanted with an LAA epicardial clip, guided by preoperative computed tomography and intraoperative transesophageal echocardiography. The mean procedural duration was 52.3 ± 12.6 minutes with postprocedural extubation interval of 22.8 ± 14.6 minutes. No procedure-related complications occurred. Intraprocedural transesophageal echocardiography (TEE) showed complete LAA occlusion in all patients. At a mean follow-up of 16.4 ± 9.1 months (range, 2-34), with all patients off (N)OAC or APT, no ischemic stroke or hemorrhagic complications occurred. computed tomography or TEE at follow-up demonstrated a correct LAA occlusion in all with mean stumps of 3.3 ± 2.8 mm. CONCLUSION: Thoracoscopic epicardial closure of the LAA with the AtriClip PRO2 device is a potentially safe and efficient treatment for stroke prevention in patients with NVAF contraindicated for anticoagulant therapy or APT.

Multicentre experience with the second-generation subcutaneous implantable cardioverter defibrillator and the intermuscular two-incision implantation technique.

INTRODUCTION: The recently developed second-generation subcutaneous implantable cardioverter defibrillator (S-ICD) and the intermuscular two-incision implantation technique demonstrate potential favorable features that reduce inappropriate shocks and complications. However, data concerning large patient populations are lacking. The aim of this multicentre prospective study was to evaluate the safety and outcome of second-generation S-ICD using the intermuscular two-incision technique in a large population study. METHODS AND RESULTS: The study population included 101 consecutive patients (75% male; mean age, 45 ± 13 years) who received second-generation S-ICD (EMBLEM; Boston Scientific, Marlborough, MA) implantation using the intermuscular two-incision technique as an alternative to the standard implantation technique. Twenty nine (29%) patients were implanted for secondary prevention. Twenty four (24%) patients had a previously implanted transvenous ICD. All patients were implanted without any procedure-related complications. Defibrillation testing was performed in 80 (79%) patients, and ventricular tachycardia was successfully converted at less than or equal to 65 J in 98.75% (79/80) of patients without pulse generator adjustments. During a median follow-up of 21 ± 10 months, no complications requiring surgical revision or local or systemic device-related infections were observed. Ten patients (9.9%) received appropriate and successful shocks for ventricular arrhythmias. Three (2.9%) patients experienced inappropriate shocks due to oversensing the cardiac signal (n = 1), noncardiac signal (n = 1), and a combination of both cardiac and noncardiac signals (n = 1), with one patient requiring device explantation. No patients required device explantation due to antitachycardia pacing indications. CONCLUSIONS: According to our multicentre study, second-generation S-ICD implanted with the intermuscular two-incision technique is an available safe combination and appears to be associated with a low risk of complications, such as inappropriate shocks.

Left atrial model reconstruction in atrial fibrillation ablation: reliability of new mapping and complex impedance systems.

AIMS: The effectiveness of atrial fibrillation (AF) ablation relies on detailed knowledge of the anatomy of the left atrium (LA) and pulmonary veins (PVs). It is common to combine computed tomography/magnetic resonance (CT/MR) with imaging by electroanatomical (EA) mapping systems. The aim of this study was to evaluate the accuracy of LA anatomical reconstruction by 'One Model' and 'VeriSense' tools (Ensite Velocity 3.0, St Jude Medical), compared with CT/MR imaging. METHODS AND RESULTS: Seventy-two patients with AF underwent pre-procedural imaging (97% CT-scan, 3% MR imaging) and transcatheter ablation of PVs. Operators were blinded to CT/MR imaging. Electrical Coupling Index (ECI) was used to recognize venous structures when the circular catheter could not. The LA 'One Model' map was obtained without complications; all 124 main left PVs and 144 main right PVs were detected. Nine of 9 intermediate right PVs and 30 of 30 early branches were detected, whereas 1 of the 27 early branches on the right inferior PVs was missed. Comparison between LA intervein distances measured on the roof (RO) and the posterior wall (PW) showed a high correspondence between the EA model and CT/MR imaging (RO CT/MR imaging vs. EA: 32 ± 7 vs. 32 ± 7 mm; PW CT/MR imaging vs. EA: 36 ± 6 vs. 36 ± 7 mm). The EA model yielded slightly larger PV ostia diameters, owing to the distortion caused by catheter pressure. CONCLUSIONS: Recent 3D mapping tools allow outstanding anatomical rendering and are key in complex ablation procedure set-up. This study shows that 3D anatomical reconstruction of LA, PVs, and their variable branches is not only safe and fast but also accurate and reliable.

Intermuscular Two-Incision Technique for Subcutaneous Implantable Cardioverter Defibrillator Implantation: Results from a Multicenter Registry.

BACKGROUND: The traditional technique for subcutaneous implantable cardioverter defibrillator (S-ICD) implantation, which involves three incisions and a subcutaneous pocket, is associated with possible complications, including inappropriate interventions. The aim of this prospective multicenter study was to evaluate the efficacy and safety of an alternative intermuscular two-incision technique for S-ICD implantation. METHODS: The study population included 36 consecutive patients (75% male, mean age 44 ± 12 years [range 20-69]) who underwent S-ICD implantation using the intermuscular two-incision technique. This technique avoids the superior parasternal incision for the lead placement and consists of creating an intermuscular pocket between the anterior surface of the serratus anterior and the posterior surface of the latissimus dorsi muscles instead of a subcutaneous pocket. RESULTS: All patients were successfully implanted in the absence of any procedure-related complications with a successful 65-J standard polarity defibrillation threshold testing, except in one, who received a second successful shock after pocket revision. During a mean follow-up of 10 months (range 3-30), no complications requiring surgical revision were observed. At device interrogation, stable sensing without interferences was observed in all patients. Two patients (5.5%) experienced appropriate and successful shock on ventricular fibrillation and in four patients (11%), a total of seven nonsustained self-terminated ventricular tachycardias were correctly detected. No inappropriate interventions were observed. CONCLUSIONS: Our experience suggests that the two-incision intermuscular technique is a safe and efficacious alternative to the current technique for S-ICD implantation that may help reducing complications including inappropriate interventions and offer a better cosmetic outcome, especially in thin individuals.

Pace mapping of Koch's triangle reduces risk of atrioventricular block during ablation of atrioventricular nodal reentrant tachycardia.

INTRODUCTION: Slow pathway (SP) ablation of AV nodal reentrant tachycardia (AVNRT) can be complicated by second- to third-degree AV block. We assessed the usefulness of pace mapping of Koch's triangle in preventing this complication. METHODS AND RESULTS: Nine hundred nine consecutive patients undergoing radiofrequency ablation of AVNRT were analyzed. Group 1 (n=487) underwent conventional slow pathway ablation. Group 2 (n=422) underwent ablation guided by pace mapping of Koch's triangle, which located the anterogradely conducting fast pathway (AFP) based on the shortest St-H interval obtained by stimulating the anteroseptal, midseptal, and posteroseptal aspects of Koch's triangle. In group 2, AFP was anteroseptal in 384 (91%), midseptal in 33 (7.8%), and posteroseptal or absent in 5 (1.2%). In 32 of 33 patients with midseptal AFP, slow pathway ablation was performed strictly in the posteroseptal area. In 4 of 5 patients with posteroseptal or no AFP, retrograde fast pathway was ablated. Two patients refused ablation. Persistent second- to third-degree AV block was induced in 7 (1.4%) of 487 group 1 patients versus 0 (0%) of 422 group 2 patients (P=0.038). Ablation was successful in all patients in whom ablation was performed. CONCLUSION: Pace mapping of Koch's triangle identifies patients in whom the AFP is absent or is abnormally close to the slow pathway. In these cases, guiding ablation helps to avoid AV block.

Radiofrequency ablation of atrioventricular nodal reentrant tachycardia: the risk of intraprocedural, late and long-term atrioventricular block. The Veneto Region multicenter experience.

BACKGROUND: Radiofrequency ablation of either the fast or the slow pathway in atrioventricular nodal reentrant tachycardia (AVNRT) can be complicated by transient or permanent atrioventricular (AV) block. Little is known about the possibility of AV block occurring during the first weeks after the procedure and nothing about the risk of AV block during the long-term follow-up. METHODS: To clarify these latter points, from February 1990 to December 2000 we enrolled 510 consecutive patients (56 males, 454 females, mean age 55 +/- 16 years) with AVNRT. The target of ablation was the fast pathway in 29 patients (group A) and the slow pathway in 474 (group B), while in 7 (group C) the slow pathway was targeted after unsuccessful fast pathway ablation. Follow-up was available for 488/510 (95.6%). The length of follow-up was 8.2 +/- 2.4 years in group A, 3.4 +/- 2.4 years in group B (83 group B patients had a follow-up > 6 years: 7.3 +/- 0.8 years), and 7.3 +/- 2.4 years in group C. RESULTS: The success rates were 93, 99 and 100% in the three groups respectively. Intraprocedural II-III degree AV block occurred in 6/29 patients (20%) of group A, in 11/474 patients (2.3%) of group B and in 3/7 patients (42%) of group C. In all patients of groups A and C, the II-III degree AV block was transient. In contrast, in 6/474 patients of group B (1.2%, 2 II degree and 4 III degree AV block) the block still persisted at the end of the procedure. Within 7 days of the procedure, a late persistent II-III degree AV block developed in 1/29 patients (3.4%, 1 III degree) of group A, in 1/474 patients (0.2%, 1 II degree) of group B and in 0/7 patients of group C. In 1 out of 6 patients of group B who developed an intraprocedural persistent AV block, 1:1 conduction resumed within the first week. A definitive pacemaker was implanted for permanent III degree AV block in 1/29 patients of group A (3.4%), in 4/474 patients (0.8%) of group B and in 0/7 patients of group C. In the remaining 2/474 group B patients with permanent II degree AV block, a pacemaker was not implanted. During follow-up, no patient presented with a II-III degree AV block related to the ablation. In group B, 2 patients received a pacemaker implant for reasons unrelated to the ablation (1 sick sinus syndrome, 1 progressive intraventricular conduction disease). CONCLUSIONS: The risk of permanent AV block in patients who undergo fast or slow pathway ablation is low and limited to the procedure or to the days immediately after the procedure, and there is no risk of II-III degree AV block during long-term follow-up.