Clinical and electrophysiological predictors of device-detected new-onset atrial fibrillation during 3 years after cardiac surgery

Postoperative atrial fibrillation (POAF) after cardiac surgery is an independent predictor of stroke and mortality late after discharge. We aimed to determine the burden and predictors of early (up to 5th postoperative day) and late (after 5th postoperative day) new-onset atrial fibrillation (AF) using implantable loop recorders (ILRs) in patients undergoing open chest cardiac surgery Seventy-nine patients without a history of AF undergoing cardiac surgery underwent peri-operative high-resolution mapping of electrically induced AF and were followed 36 months after surgery using an ILR (Reveal XTTM). Clinical and electrophysiological predictors of late POAF were assessed. POAF occurred in 46 patients (58%), with early POAF detected in 27 (34%) and late POAF in 37 patients (47%). Late POAF episodes were short-lasting (mostly between 2 min and 6 h) and showed a circadian rhythm pattern with a peak of episode initiation during daytime. In POAF patients, electrically induced AF showed more complex propagation patterns than in patients without POAF. Early POAF, right atrial (RA) volume, prolonged PR time, and advanced age were independent predictors of late POAF

Effectiveness and safety of simultaneous hybrid thoracoscopic and endocardial catheter ablation of lone atrial fibrillation

BACKGROUND: We evaluated the safety and effectiveness of the hybrid thoracoscopic endocardial epicardial technique for the treatment of lone atrial fibrillation. METHODS: Between 2009 and 2012, a cohort of 78 consecutive patients (median age 60.5 years, 77% male) underwent ablation of atrial fibrillation (AF) as a stand-alone procedure using a thoracoscopic, hybrid epicardial-endocardial technique. All patients underwent continuous 7-day Holter monitoring at 3 months, 6 months, 1 year and yearly thereafter. All patients reached 1-year follow-up. Median follow-up was 24 months [interquartile range 12-36]. RESULTS: No death or conversion to cardiopulmonary bypass occurred. No patient demonstrated paralysis of the phrenic nerve. Overall, the incidence of perioperative complications was 8% (n=6). At the end of follow-up, sixty-eight patients (87%) were in sinus rhythm (SR) with no episode of AF, atrial flutter or atrial tachycardia lasting longer than 30 seconds and off antiarrhythmic drugs (ADD). Among patients with long-standing persistent AF, 15 (100%) were in SR and off AAD. Success rates were 82% (n=28) in persistent and 76% (n=22) in paroxysmal AF (P=0.08). No patient died and no thromboembolic/bleeding events or procedure-related complications occurred during the follow-up. CONCLUSIONS: Thoracoscopic hybrid epicardial endocardial technique proved to be effective and safe in the treatment of LAF and to represent an important new suitable option to treat stand-alone AF. Our findings need to be confirmed by further larger studies

Guideline adherence in antithrombotic treatment after concomitant ablation surgery in atrial fibrillation patients

OBJECTIVES: We investigated real-life oral anticoagulation (OAC) treatment after surgical ablation and examined its adherence to current recommendations. We also explored factors related to OAC use preoperatively and at follow-up. METHODS: One hundred and fifteen patients with atrial fibrillation (AF) were evaluated during 12-month follow-up after surgery. Patients were divided into two categories according to the congestive heart failure, hypertension, age ≥75 years, diabetes and prior stroke [or transient ischaemic attack or thromboembolism] (CHADS(2)) score: 60 patients were assigned to the high-risk group (CHADS(2) score ≥2) and 55 to the low-risk group (CHADS(2) score ≤1). OAC use was defined as guideline adherent, undertreatment or overtreatment. RESULTS: Baseline overall guideline adherence was 62%. OAC was underprescribed in high-risk patients and overprescribed in low-risk patients (both, P < 0.001). The only factor associated with OAC use after logistic regression analysis were age >75 years (P = 0.01) and preoperative AF > paroxysmal (P = 0.013). Overall guideline adherence at 12-month follow-up showed a trend towards a better adherence in the sinus rhythm (SR) subgroup (74% vs 55%, P = 0.02). OAC was underprescribed in high-risk patients and overprescribed in low-risk patients (both P < 0.001). After logistic regression analysis, preoperative OAC use (P = 0.007) and other indications for OAC (P = 0.01) were predictors of anticoagulation treatment. CONCLUSIONS: Real-life OAC prescription in AF patients showed a moderate guideline adherence, with high-risk patients being undertreated and low-risk patients being overtreated. These findings stress the importance that antithrombotic treatment in patients undergoing AF surgery needs to be critically re-evaluated

Galectin-3 marks activated macrophages in failure-prone hypertrophied hearts and contributes to cardiac dysfunction

BACKGROUND: Inflammatory mechanisms have been proposed to be important in heart failure (HF), and cytokines have been implicated to add to the progression of HF. However, it is unclear whether such mechanisms are already activated when hypertrophied hearts still appear well-compensated and whether such early mechanisms contribute to the development of HF. METHODS AND RESULTS: In a comprehensive microarray study, galectin-3 emerged as the most robustly overexpressed gene in failing versus functionally compensated hearts from homozygous transgenic TGRmRen2-27 (Ren-2) rats. Myocardial biopsies obtained at an early stage of hypertrophy before apparent HF showed that expression of galectin-3 was increased specifically in the rats that later rapidly developed HF. Galectin-3 colocalized with activated myocardial macrophages. We found galectin-3-binding sites in rat cardiac fibroblasts and the extracellular matrix. Recombinant galectin-3 induced cardiac fibroblast proliferation, collagen production, and cyclin D1 expression. A 4-week continuous infusion of low-dose galectin-3 into the pericardial sac of healthy Sprague-Dawley rats led to left ventricular dysfunction, with a 3-fold differential increase of collagen I over collagen III. Myocardial galectin-3 expression was increased in aortic stenosis patients with depressed ejection fraction. CONCLUSIONS: This study shows that an early increase in galectin-3 expression identifies failure-prone hypertrophied hearts. Galectin-3, a macrophage-derived mediator, induces cardiac fibroblast proliferation, collagen deposition, and ventricular dysfunction. This implies that HF therapy aimed at inflammatory responses may need to be targeted at the early stages of HF and probably needs to antagonize multiple inflammatory mediators, including galectin-

Epicardial and endocardial electrophysiological guided thoracoscopic surgery for atrial fibrillation: A multidisciplinary approach of atrial fibrillation ablation in challenging patients

AbstractIntroductionPatients with atrial fibrillation (AF) with enlarged atria or previous pulmonary vein isolation (PVI) are challenging patients for catheter ablation. Thoracoscopic surgery is an effective treatment for these patients but comes at the cost of an increase in adverse events. Recently, electrophysiological (EP) guided approaches to thoracoscopic surgery have been described which consist of EP guidance by measurement of conduction block across ablation lines. In this study we describe the efficacy and safety of EP-guided thoracoscopic surgery for AF in patients with enlarged atria and/or prior failed catheter ablation.Methods & resultsA total of 72 patients were included. Two different approaches to EP-guided thoracoscopic surgery were implemented: epicardial or endocardial EP-guidance at the time of surgery. Residual intraoperative conduction requiring additional ablation was detected with epicardial or endocardial mapping techniques in 50% and 11%, respectively. Additional epicardial or endocardial ablation was performed until bidirectional block was confirmed. Follow-up consisted of an ECG and a 24h Holter at 3, 6 and 12months after the procedure. A total of 57 patients (79%) had freedom of AF and were off anti-arrhythmic drugs at one year follow-up (30 paroxysmal (83%), 27 persistent AF (75%)). Adverse events occurred in 13 patients (6 major). None of our patients died and all events were reversible.ConclusionEP-guidance of thoracoscopic surgery can be safely performed both epicardially and endocardially and is associated with a high rate of long-term maintenance of sinus rhythm in patients with enlarged atria and/or a previously failed ablation

Quantification of epicardial adipose tissue in patients undergoing hybrid ablation for atrial fibrillation

OBJECTIVES: Epicardial adipose tissue volume (EAT-V) has been linked to atrial fibrillation (AF) recurrences after catheter ablation. We retrospectively studied the association between atrial EAT-V and outcome after hybrid AF ablation (epicardial surgical and endocardial catheter ablation). METHODS: On preoperative cardiac computed tomography angiography scans, the left atrium and right atrium were manually delineated using the open source Image J. With custom-made automated software, the number of pixels in the regions of interest on each slice was calculated. On the basis of the Hounsfield units, pixel size and slice thickness, EAT-V was computed and normalized in relation to the body surface area (BSA) and the myocardial tissue volume. RESULTS: Eighty-five patients were included. Left atrial and right atrial EAT-V normalized to BSA were not significantly different between paroxysmal and persistent AF [0.84 (0.51-1.50) vs 0.81 (0.57-1.18), 1.74 (1.02-2.56) vs 1.55 (1.26-2.18), all P = 0.9], neither between the acute conduction block and no acute conduction block in the epicardial box lesion [0.92 (0.55-1.39) vs 0.72 (0.55-1.24), P = 0.5, right atrium not applicable], nor between the sinus rhythm and arrhythmia recurrence after 12 months [0.88 (0.55-1.48) vs 0.63 (0.47-1.10), 1.61 (1.11-2.50) vs 1.55 (1.20-2.20), all P > 0.1]. Left atrial EAT-V normalized to myocardial tissue volume was not different between the groups. CONCLUSIONS: This study could neither confirm that EAT-V was predictive of recurrence of supraventricular arrhythmias in patients undergoing a hybrid AF ablation, nor that EAT-V was different between patients with paroxysmal AF and persistent and long-standing persistent AF. This suggests that EAT-V might not affect the outcome in surgical ablation procedures and therefore should not influence preoperative or intraoperative decision-making