Severe Periprocedural Complications After Ablation for Atrial Fibrillation: An International Collaborative Individual Patient Data Registry.

BACKGROUND: Catheter ablation for atrial fibrillation (AF) including pulmonary vein isolation and possibly further substrate ablation is the most common electrophysiological procedure. Severe complications are uncommon, but their detailed assessment in a large worldwide cohort is lacking. OBJECTIVES: The aim of this study was to determine the incidence of periprocedural severe complications and to provide a detailed characterization of the diagnostic evaluation and management of these complications in patients undergoing AF ablation. METHODS: Individual patient data were collected from 23 centers worldwide. Limited data were collected for all patients who underwent catheter ablation, and an expanded series of data points were collected for patients who experienced severe complications during periprocedural follow-up. Incidence, predictors, patient characteristics, management details, and overall outcomes of patients who experienced ablation-related complications were investigated. RESULTS: Data were collected from 23 participating centers at which 33,879 procedures were performed (median age 63 years, 30% women, 71% radiofrequency ablations). The incidence of severe complications (n = 271) was low (tamponade 6.8‰, stroke 0.97‰, cardiac arrest 0.41‰, esophageal fistula 0.21‰, and death 0.21‰). Age, female sex, a dilated left atrium, procedure duration, and the use of radiofrequency energy were independently associated with the composite endpoint of all severe complications. Among patients experiencing tamponade, 13% required cardiac surgery. Ninety-three percent of patients with complications were discharged directly home after a median length of stay of 5 days (Q1-Q3: 3-7 days). CONCLUSIONS: This large worldwide collaborative study highlighted that tamponade, stroke, cardiac arrest, esophageal fistula, and death are rare after AF ablation. Older age, female sex, procedure duration, a dilated left atrium, and the use of radiofrequency energy were associated with severe complications in this multinational cohort. One in 8 patients with tamponade required cardiac surgery.

Voltage and propagation mapping: New tools to improve successful ablation of atrioventricular nodal reentry tachycardia.

INTRODUCTION: Mapping system is useful in ablation of atrioventricular nodal reentry tachycardia (AVNRT) and localization of anatomic variances. Voltage mapping identifies a low voltage area in the Koch triangle called low-voltage-bridge (LVB); propagation mapping identifies the collision point (CP) of atrial wavefront convergence. We conducted a prospective study to evaluate the relationship between LVB and CP with successful site of ablation and identify standard value for LVB. MATERIALS AND METHODS: Three-dimensional (3D) maps of the right atria were constructed from intracardiac recordings using the ablation catheter. Cut-off values on voltage map were adjusted until LVB was observed. On propagation map, atrial wavefronts during sinus rhythm collide in the site representing CP, indicating the area of slow pathway conduction. Ablation site was selected targeting LVB and CP site, confirmed by anatomic position on fluoroscopy and atrioventricular ratio. RESULTS: Twenty-seven consecutive patients were included. LVB and CP were present in all patients. Postprocedural evaluation identified standard cut-off of 0.3-1 mV useful for LVB identification. An overlap between LVB and CP was observed in 23 (85%) patients. Procedure success was achieved in all patient with effective site at first application in 22 (81%) patients. There was a significant correlation between LVB, CP, and the site of effective ablation (p = .001). CONCLUSION: We found correlation between LVB and CP with the site of effective ablation, identifying a voltage range useful for standardized LVB identification. These techniques could be useful to identify ablation site and minimize radiation exposure.

Can specific ECG markers identify a pharmacologically induced type 1 Brugada pattern? Insights from a large, single-center cohort.

BACKGROUND: In patients with a type 2 or 3 Brugada pattern, the pharmacological (IC drugs) induction of a type 1 pattern confirms the diagnosis of Brugada syndrome. OBJECTIVE: To evaluate the value of various ECG markers in predicting IC drug test results. METHODS: We retrospectively analysed 443 consecutive patients referred to our Center (from January 2010 to December 2019) to undergo Ajmaline/Flecainide testing; all had a type 2 or 3 Brugada pattern or were relatives with Brugada syndrome. Clinical parameters and ECG markers (r1V1 and SV6 duration and amplitude, QRSV1/QRSV6 duration, V1 and V2 ST amplitude) were independently evaluated for their association to pharmacological test positivity, and a logistic regression model was applied. RESULTS: The drug test was positive in 151 (34%) patients. On multivariate logistic regression analysis, age > 45 years, female gender, HR >60 bpm, QRSV1/QRSV6 duration >1 and non-isoelectric pattern in V2 were associated with a positive test. The percentage of patients who tested positive increased according to the presence of the above ECG markers (from 11.3% in the absence to 57.6% in the presence of both factors). During long-term follow-up, the clinical event rate was higher in patients with predictive ECG markers and very low in those without. CONCLUSIONS: In our population we confirmed the ability of QRSV1/QRSV6 duration >1 and of a non-isoelectric pattern in V2 to predict a pharmacologically induced type 1 Brugada pattern. Patients with neither of these ECG markers had a rather low event rate during follow-up.

Evaluation of Pulmonary Vein Fibrosis Following Cryoballoon Ablation of Atrial Fibrillation: A Semi-Automatic MRI Analysis.

Current guidelines recommend the use of cardiac magnetic resonance imaging (MRI) for the management of atrial fibrillation (AF). However, the widespread use of cardiac MRI in clinical practice is difficult to achieve. The aim of the present study is to assess whether cardiac MRI can be adopted to identify ablation-induced fibrosis, and its relationship with AF recurrences. Fifty patients undergoing AF cryoballoon ablation were prospectively enrolled. Cardiac MRI was performed before and 30 days after the index ablation. Commercially available software and a specifically designed image processing workflow were used to quantify left atrium (LA) fibroses. Thirty-six patients were finally included in the analysis; twenty-eight were analyzed with the dedicated workflow. Acute electrical isolation was achieved in 98% of the treated pulmonary veins (PVs). After a median follow-up of 16 months, AF recurrences occurred in 12 patients (33%). In both analyses, no differences were found between the subgroups of patients with and without recurrence in the variation of either LA fibrosis or fibrosis at the ostium of the PV, before and after ablation. The ability to predict arrhythmic recurrences evaluated via the ROC curve of the variations in both LA fibrosis (AUC 0.566) and PV fibrosis (AUC 0.600) was low. Cardiac MRI holds the potential to provide clinically significant information on LA disease and AF progression; however, LA fibrosis cannot be easily identified, either by currently available commercial programs or custom tools.

[Cardiac contractility modulation therapy: molecular mechanisms and rationale for clinical application in heart failure with systolic and diastolic dysfunction]. / Terapia di modulazione della contrattilità cardiaca: basi molecolari e razionale per l'impiego in modelli di insufficienza cardiaca sistolica e diastolica.

This review illustrates the pathophysiological aspects and available scientific evidence on molecular mechanisms about cardiac contractility modulation (CCM) therapy. The main advances in understanding the effect of this electrical therapy at cellular level in the heart are critically discussed in light of the data from clinical trials supporting the use of CCM therapy in patients with heart failure across a wide range of left ventricular ejection fraction values. This electrical therapy triggers a physiological cellular response leading to an improvement of cardiac performance and reverse ventricular remodeling, with no increase in oxygen consumption. The present review deals with the new potential applications of CCM for patients with chronic heart failure and paves the way for the development of a longitudinal Italian registry of patients implanted with this cardiac device.

Catheter ablation for treatment of bradycardia-tachycardia syndrome: is it time to consider it the therapy of choice? A systematic review and meta-analysis.

BACKGROUND: Atrial fibrillation catheter ablation (AFCA) should be considered as a strategy to avoid pacemaker (PM) implantation for patients with bradycardia-tachycardia syndrome (BTS), but lack of evidence is remarkable. METHODS: Our aim was to conduct a random-effects model meta-analysis on safety and efficacy data from controlled trials and observational studies. We compared atrial fibrillation (AF) recurrence, AF progression, procedural complication, additional procedure, cardiovascular death, cardiovascular hospitalization, heart failure and stroke in patients undergoing AFCA vs. PM implantation. RESULTS: PubMed/MEDLINE, Cochrane Database and Google Scholar were screened, and four retrospective studies were selected. A total of 776 patients (371 in the AFCA group, 405 in the PM group) were included. After a median follow-up of 67.5 months, lower AF recurrence [odds ratio (OR) 0.06, confidence interval (CI) 0.02-0.18, I2 = 82.42%, P < 0.001], AF progression (OR 0.12, CI 0.06-0.26, I2 = 0%, P < 0.001), heart failure (OR 0.12, CI 0.04-0.34, I2 = 0%, P < 0.001), and stroke (OR 0.30, CI 0.15-0.61, I2 = 0%, P = 0.001) were observed in the AFCA group. No differences were observed in cardiovascular death and hospitalization (OR 0.48, CI 0.10-2.28, I2 = 0%, P = 0.358 and OR 0.43, CI 0.14-1.29, I2 = 87.52%, P = 0.134, respectively). Higher need for additional procedures in the AFCA group was highlighted (OR 3.65, CI 1.51-8.84, I2 = 53.75%, P < 0.001). PM implantation was avoided in 91% of BTS patients undergoing AFCA. CONCLUSIONS: AFCA in BTS patients seems to be more effective than PM implantation in reducing AF recurrence and PM implantation may be waived in most BTS patients treated by AFCA. Need for additional procedures in AFCA patients is balanced by long-term benefit in clinical end points.

Incidence and Clinical Relevance of COVID-19 in a Population of Young Competitive and Elite Football Players: A Retrospective Observational Study.

BACKGROUND: The COVID-19 pandemic dramatically changed lifestyle worldwide, including sport. A comprehensive evaluation of the prevalence of cardiac involvement in COVID-19 is essential to finalize a safe protocol for resuming elite sport. The aim of this study is to evaluate incidence of cardiac involvement and COVID-19 impact on athletic performance. MATERIALS AND METHODS: This retrospective observational study analysed the data collected from consecutive competitive athletes who performed medical-sports examinations at the J Medical Center from March 2020 to March 2021. All athletes periodically performed a molecular test using a nasopharyngeal swab to detect COVID-19 infection. Positive athletes performed laboratory (cardiac troponin T-cTnT) and instrumental (echocardiography, stress test, Holter ECG) investigations following recovery to identify any cardiac involvement. Cardiac magnetic resonance imaging (MRI) was performed in case of abnormal findings at first-level evaluation. RESULTS: Among 238 athletes (median age 20 years), 77 contracted COVID-19, mainly males (79%) with a median age of 16 years. Fifty-one athletes (66%) presented mild symptoms, and none required hospitalization. Evaluation for resuming sport was performed after a median of 30 days from the first positive test. Abnormal findings were obtained in 13 cases (5 athletes [6%] with elevated cTnT values; 13 athletes [17%] with arrhythmias on Holter ECG and/or during stress test; 2 athletes [3%] anomalies at echocardiography). Cardiac MRI discovered abnormalities in 9 cases, but none of these was clearly related to COVID-19 and none fulfilled acute myocarditis criteria. No negative impact on athletic performance was observed, and none of the athletes developed persistent COVID-related symptoms. CONCLUSIONS: Our registry confirms the predominantly self-limiting illness in young athlete population. The incidence of clear COVID-19-related structural myocardial injury was very low, but transient exertional ventricular arrhythmias or pericardial effusion was observed without significant impact on athletic performance. Implemented screening for return to activity is likely reasonable only in moderate-to-severe symptomatic athletes.

Ante-mortem characterization of sudden deaths as first-manifestation in Italy.

PURPOSE: There is a relative paucity of data on ante-mortem clinical characteristics of young (age 1 to 35 years) sudden death (SD) victims. The aim of the study was to characterize ante-mortem characteristics of SD victims, in a selected national cohort identified by a web search. METHODS: A dataset of all SD (January 2010 and December 2015) was built from national forensic data and medical records, integrated with Google search model. Families were contacted to obtain consent for interviews. Data were obtained on ante-mortem symptoms. ECG characteristics and autopsy data were available. RESULTS: Out of 301 SD cases collected, medical and family history was available in 132 (43.9%). Twenty-eight (21.1%) had a positive family history for SD. SD occurred during sport/effort in 76 (57.6%). One hundred twelve (85%) SD cases had no prior reported symptoms. Autopsy data were available in 100/132 (75.8%) cases: an extra cardiac cause was identified in 20 (20%). Among the 61 cases with a cardiac diagnosis, 21 (34%) had hypertrophic cardiomyopathy. Among the 19 (19%) victims without structural abnormalities, molecular autopsy identified pathogenic variants for channelopathies in 9 cases. Ten (10%) victims had no identifiable cause. CONCLUSIONS: Most SD were due to cardiac causes and occurred in previously asymptomatic patients. SD events mainly occurred during strenuous activity. In a minority of cases, no cause was identified. The web-based selection criteria, and incomplete data retrieval, need to be carefully taken into account for data interpretation and reproducibility.

Check the Need-Prevalence and Outcome after Transvenous Cardiac Implantable Electric Device Extraction without Reimplantation.

BACKGROUND: after transvenous lead extraction (TLE) of cardiac implantable electric devices (CIEDs), some patients may not benefit from device reimplantation. This study sought to analyse predictors and long-term outcome of patients after TLE with vs. without reimplantation in a high-volume centre. METHODS: all patients undergoing TLE at our centre between January 2010 and November 2015 were included into this analysis. RESULTS: a total of 223 patients (median age 70 years, 22.0% female) were included into the study. Cardiac resynchronization therapy-defibrillator (CRT-D) was the most common device (40.4%) followed by pacemaker (PM) (31.4%), implantable cardioverter-defibrillator (ICD) (26.9%), and cardiac resynchronization therapy-PM (CRT-P) (1.4%). TLE was performed due to infection (55.6%), malfunction (35.9%), system upgrade (6.7%) or other causes (1.8%). In 14.8%, no reimplantation was performed after TLE. At a median follow-up of 41 months, no preventable arrhythmia-related events were documented in the no-reimplantation group, but 11.8% received a new CIED after 17-84 months. While there was no difference in short-term survival, five-year survival was significantly lower in the no-reimplantation group (78.3% vs. 94.7%, p = 0.014). CONCLUSIONS: in patients undergoing TLE, a re-evaluation of the indication for reimplantation is safe and effective. Reimplantation was not related to preventable arrhythmia events, but all-cause survival was lower.

"Never Trust to General Impressions, My Boy, but Concentrate Yourself upon Details": An Unusual and Challenging Presentation of Pheochromocytoma.

We present the case of a 45-year-old woman admitted to our unit with acute heart failure and cardiogenic shock, requiring an intra-aortic balloon pump insertion and inotropes and vasopressors infusion. Despite such treatment, the patient developed multi organ failure and intravascular disseminated coagulation with haemolysis. The initial diagnosis of acute myocarditis was subsequently denied by the finding of bilateral adrenal masses by MRI scan, and urine and plasma metanephrines measurements confirmed a pheochromocytoma (PCC). Genetic analysis revealed a mutation in the neurofibromatosis type 1 (NF1) gene, and an accurate physical examination drew attention to small cafè-au-lait spots, usually associated with this syndrome. PCC diagnosis should be promptly considered in patients presenting with unexplained acute heart failure and cardiogenic shock of unknown origin, considering its life-threatening complications and the good prognosis after radical surgery.

Feasibility and safety of left atrial appendage closure in a patient with previous foramen ovale occlusion: a case report.

BACKGROUND: Left atrial appendage (LAA) closure is an alternative to chronic oral anticoagulation for stroke prevention in patients with atrial fibrillation (AF) at high bleeding risk. Patients with a previous percutaneous closure of a patent foramen ovale (PFO) present an increased risk for developing AF during their life, and the presence of an atrial septal device renders future percutaneous left atrial access more challenging. Very few cases of LAA occlusion in patients with a preexisting PFO closure device have been previously reported. CASE SUMMARY: A 74-years old woman was admitted to our hospital for symptomatic severe anaemia during direct oral anticoagulant treatment. Her past medical history reported an ischaemic stroke at the age of 55, at that time a PFO was diagnosed and a STARFlex™ PFO occluder (NMT Medical, Boston, MA, USA) was implanted. During the current hospitalization, the patient underwent a colonoscopy that showed colonic angiodysplasias unsuitable for endoscopic treatment and LAA closure was indicated for stroke prevention. After a multimodality pre-procedural planning that included a transoesophageal echocardiogram, a cardiac computed tomography scan and a three-dimensional cardiac model printing, the procedure was planned and the LAA successfully occluded. DISCUSSION: LAA closure can be performed safely and effectively in patients carrying a previously implanted PFO occlusion device. In complex settings, a pre-procedural multimodality imaging is critical for improving the procedural safety and success rate. We describe the first case of percutaneous LAA closure in a patient with a prior PFO occlusion with the implantation of a STARflex™ septal occlusion device.

Cardiac contractility modulation in left ventricular systolic dysfunction: one-year experience in a pilot study and design of a prospective registry.

BACKGROUND: Cardiac contractility modulation (CCM) is a treatment option for patients suffering symptomatic chronic heart failure (CHF) with reduced left ventricular ejection fraction (LVEF) who are not eligible for cardiac resynchronization. Data on mid-term follow-up are limited to small observational studies. The aim of this study was to assess the impact of CCM on quality of life, symptoms, exercise tolerance and left ventricular function in patients with CHF and moderate-to-severe left ventricular systolic dysfunction. METHODS: Patients suffering CHF with LVEF <45% and NYHA class >II despite optimal medical therapy, underwent CCM implantation. Enrolled patients underwent baseline and 3, 6 and 12-months evaluation with ECG, echocardiogram, clinical assessment, 6-minute walking test and Minnesota Living with Heart Failure Questionnaire (MLWHFQ). RESULTS: Ten patients underwent CCM implantation. All patients were actively treated with the optimal pharmacological therapy as tolerated and had at least one hospitalization for worsening heart failure during the previous year. After a mean follow-up of 15 months, 9 patients were alive, while one patient died for worsening heart failure precipitated by pneumonia. Among the remaining 9 patients, LVEF improved non-significantly from 29.4±8% to 32.2±10% (P=0.092), 6-minute walking test distance improved from 179±73 m to 304±99 m (P<0.001), NYHA class reduced from 3.0±0.4 to 1.6±0.5 (P=0.003) and MLWHFQ score improved from 59.6±49 to 34.2±32 (P=0.037). Only 2 patients have been hospitalized during the 12 months. Overall, a net clinical benefit was detected in 6 out of 9 patients. CONCLUSIONS: CCM could be effective in improving quality of life, symptoms and exercise tolerance, and reduces hospitalizations in patients with symptomatic CHF on top of optimal medical and electrical therapy. A prospective registry has been designed to identify the subsets of patients gaining more benefit, and to assess the long-term effect of CCM on those clinical endpoints.

Ablation of Accessory Pathways with Uncommon Electrophysiologic Properties.

In rare cases, atrioventricular reentrant arrhythmias are sustained by accessory pathways with peculiar electrophysiologic features that may be related to their specific anatomy. Most of these bundles show decremental nodelike conduction properties and sustain peculiar forms of arrhythmias that require careful differential diagnosis. On the other hand, some pathways do not actively sustain any reentrant circuit and should nevertheless be promptly recognized to avoid unnecessary ablation attempts. Although rare, these variants of accessory pathway should be known to warrant a safe and effective catheter ablation procedure.

Late atrial arrhythmias after lung transplantation: a meta-analysis.

BACKGROUND: Atrial arrhythmias are common following noncardiac thoracic surgery. In particular, early postoperative atrial arrhythmias after lung transplantation are very frequent, especially atrial fibrillation (AFib). Late atrial arrhythmia occurrence following lung transplantation, instead, has been less commonly reported. METHODS: The aim of the present systematic review and meta-analysis is to analyse the incidence rate of late atrial arrhythmia and AFib in lung transplantation patients, with a special focus on double lung transplant (DLT), also to assess potential predictors of AFib occurrence. After bibliographic search (PUBMED/Medline and Embase databases), a random-effect model meta-analysis was performed: seven studies were finally included, including 2068 lung transplantation patients. RESULTS: The pooled incidence rate of late atrial arrhythmia was 4.3%/year [95% confidence interval (CI) 2.8-6.1%/year, I = 69%], whereas late AFib incidence rate was 1.5%/year (95% CI 0.7-2.6%/year, I = 87%). In patients undergoing DLT, the pooled incidence rate of late atrial arrhythmia was 4.1%/year (95% CI 2.5-6.0%/year, I = 67%), while the AFib incidence rate was 0.9%/year (95% CI 0.1-2.4%/year, I = 92%). A longer follow-up duration significantly related to the reduced incidence rate of AFib (P = 0.02). History of AFib (hazard ratio 11.2, 95% CI 5.9-21.3) and early postoperative AFib (hazard ratio 10.3, 95% CI 5.9-18.0) emerged, instead, as relevant predictors of AFib occurrence. CONCLUSION: Late atrial arrhythmia occurrence is not infrequent in lung transplantation patients; however, late Afib incidence was rare and showed a time-dependent decrease, particularly in DLT patients, suggesting that a transmural pulmonary veins isolation, the mainstay of transcatheter ablation, is effective in decreasing the likelihood of experiencing AFib.

Long-term atrial arrhythmias incidence after heart transplantation.

OBJECTIVES: Atrial arrhythmias after heart transplantation have rarely been investigated. The aim of this study is to assess incidence, type and predictors of atrial arrhythmias during a long-term follow-up in a large population of heart-transplanted patients. METHODS: Consecutive patients undergone to heart transplantation at our Centre from 1990 to 2017 were enrolled. All documented atrial arrhythmias were systematically reviewed during a long-term follow-up after heart transplantation. Atrial fibrillation (AF), atrial flutter and tachycardias were defined according to current guidelines. RESULTS: Overall, 364 patients were included and followed for 120 ± 70 months. During the follow-up period 108 (29.7%) patients died and 3 (0.8%) underwent re-transplantation. Sinus rhythm was present in 355 (97.5%) patients. Nine patients had persistent atrial arrhythmias: 8 (2.2%) presented atypical flutter and one (0.3%) patient AF. Paroxysmal sustained arrhythmias were detected in 42 (11.5%) patients, always atrial flutters. At univariate analysis several echocardiographic (left ventricular end-diastolic diameter, TEI index, mitral and tricuspid regurgitation grade) hemodynamic (systolic and diastolic pulmonary pressure, capillary wedge pressure) and clinical (dyslipidaemia, weight, pacemaker implantation) parameters related to higher incidence of atrial arrhythmias. CONCLUSION: Persistent atrial arrhythmias, and most of all AF, are rare among heart transplantation carriers, despite substantial comorbidities resulting in significant mortality. It can be speculated that the lesion set provided by the surgical technique, a complete and transmural electrical isolation of the posterior left atrium wall, represents an effective lesion set to prevent persistent AF.

Sex-specific efficacy and safety of cryoballoon versus radiofrequency ablation for atrial fibrillation: An individual patient data meta-analysis.

BACKGROUND: Atrial fibrillation (AF) is a growing health burden, and pulmonary vein isolation (PVI) using cryoballoon (CB) or radiofrequency (RF) represents an attractive therapeutic option. Sex-specific differences in the epidemiology, pathophysiology, and clinical presentation of AF and PVI are recognized. OBJECTIVE: We aimed at comparing the efficacy, safety, and procedural characteristics of CB and RF in women and men undergoing a first PVI procedure. METHODS: We searched for randomized controlled trials and prospective observational studies comparing CB and RF ablation with at least 1 year of follow-up. After merging individual patient data from 18 data sets, we investigated the sex-specific (procedure failure defined as recurrence of atrial arrhythmia, reablation, and reinitiation of antiarrhythmic medication), safety (periprocedural complications), and procedural characteristics of CB vs RF using Kaplan-Meier and multilevel models. RESULTS: From the 18 studies, 4840 men and 1979 women were analyzed. An analysis stratified by sex correcting for several covariates showed a better efficacy of CB in men (hazard ratio for recurrence 0.88; 95% confidence interval 0.78-0.98, P = .02) but not in women (hazard ratio 0.98; 95% confidence interval 0.83-1.16; P = .82). For women and men, the energy source had no influence on the occurrence of at least 1 complication. For both sexes, the procedure time was significantly shorter with CB (-22.5 minutes for women and -27.1 minutes for men). CONCLUSION: CB is associated with less long-term failures in men. A better understanding of AF-causal sex-specific mechanisms and refinements in CB technologies could lead to higher success rates in women.

Impact of atrial fibrillation catheter ablation on mortality, stroke, and heart failure hospitalizations: A meta-analysis.

BACKGROUND: The impact of atrial fibrillation catheter ablation (AFCA) on hard clinical endpoints remains controversial. OBJECTIVE: Our aim was to conduct a random-effect model meta-analysis on efficacy data from high-quality large matched database/registry studies and randomized clinical trials. We compared long-term all-cause mortality, stroke, and hospitalization for heart failure in patients undergoing AFCA vs patients treated with medical therapy alone (rhythm and/or rate control medications) in a general AF population. METHODS AND RESULTS: PubMed/MEDLINE and Embase databases were screened and a total of nine studies were selected (one randomized clinical trial-CABANA-and eight large matched population studies). A total of 241 372 patients (27 711 in the ablation group, 213 661 in the nonablation group) were included. After a median follow-up of 3.5 years, AFCA decreased the risk of mortality (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.54-0.72; I2 = 54%; number needed to treat [NNT] = 28), stroke (HR, 0.63; 95% CI, 0.56-0.70; I2 = 23%; NNT = 59) and hospitalization for heart failure (HR, 0.64; 95% CI, 0.51-0.80; I2 = 28%; NNT = 33) compared with AF patients treated with medical therapy alone. CONCLUSION: Based on the currently available efficacy and effectiveness evidence, AFCA significantly reduces the risk of death, stroke, and hospitalization compared with medical therapy alone.

Thermodynamic properties of atrial fibrillation cryoablation: a model-based approach to improve knowledge on energy delivery.

The objective of this study is to describe a suitable model of atrial fibrillation cryoablation thermodynamic properties. Three different thermal loads were applied to a cylindrical copper element simulating the cryoprobe, thermally coupled with a Peltier stack producing the freezing effect, and in contact with a bovine liver sample. Thermal events occurring inside the samples were measured using mirror image technique. Heat subtracted flux during ice formation and minimum temperature measured at probe-tissue interface were, respectively, 1.33 W cm-2 and -27.8°C for Sample#0, 1.88 W cm-2 and -35.6°C for Sample#1 and 1.82 W cm-2 and 1.44 W cm-2 before and after the ice trigger, respectively, and -29.3°C for Sample#2. Ice trigger temperature was around -8.5°C for Sample#0 and Sample#2, and -10.4°C for Sample#1. In all the investigated samples, ice front penetration was proportional to the square root of time and its velocity depended on the heat flux subtracted. The fraction of the useful energy spent for ice formation was less than 60% for Sample#0, and about 80% for Sample#1 and for Sample#2, before the reduction of the removed heat flux. Freezing time exceeding a cut-off, according to the heat subtracted flux, does not improve the procedure effectiveness and is detrimental to the surrounding tissues.

Subclinical and Asymptomatic Atrial Fibrillation: Current Evidence and Unsolved Questions in Clinical Practice.

Atrial Fibrillation (AF) may be diagnosed due to symptoms, or it may be found as an incidental electrocardiogram (ECG) finding, or by implanted devices recordings in asymptomatic patients. While anticoagulation, according to individual risk profile, has proven definitely beneficial in terms of prognosis, rhythm control strategies only demonstrated consistent benefits in terms of quality of life. In fact, evidence collected by observational data showed significant benefits in terms of mortality, stroke incidence, and prevention of cognitive impairment for patients referred to AF catheter ablation compared to those medically treated, however randomized trials failed to confirm such results. The aims of this review are to summarize current evidence regarding the treatment specifically of subclinical and asymptomatic AF, to discuss potential benefits of rhythm control therapy, and to highlight unclear areas.