Heart Size Difference Drives Sex-Specific Response to Cardiac Resynchronization Therapy: A Post Hoc Analysis of the MORE-MPP CRT Trial.

BACKGROUND: Studies have reported that female sex predicts superior cardiac resynchronization therapy (CRT) response. One theory is that this association is related to smaller female heart size, thus increased relative dyssynchrony at a given QRS duration (QRSd). Our objective was to investigate the mechanisms of sex-specific CRT response relating to heart size, relative dyssynchrony, cardiomyopathy type, QRS morphology, and other patient characteristics. METHODS AND RESULTS: This is a post hoc analysis of the MORE-CRT MPP (More Response on Cardiac Resynchronization Therapy with Multipoint Pacing)  trial (n=3739, 28% women), with a subgroup analysis of patients with nonischemic cardiomyopathy and left bundle-branch block (n=1308, 41% women) to control for confounding characteristics. A multivariable analysis examined predictors of response to 6 months of conventional CRT, including sex and relative dyssynchrony, measured by QRSd/left ventricular end-diastolic volume (LVEDV). Women had a higher CRT response rate than men (70.1% versus 56.8%, P<0.0001). In subgroup analysis, regression analysis of the nonischemic cardiomyopathy left bundle-branch block subgroup identified QRSd/LVEDV, but not sex, as a modifier of CRT response (P<0.0039). QRSd/LVEDV was significantly higher in women (0.919) versus men (0.708, P<0.001). CRT response was 78% for female patients with QRSd/LVEDV greater than the median value, compared with 68% with QRSd/LVEDV less than the median value (P=0.012). The association between CRT response and QRSd/LVEDV was strongest at QRSd <150 ms. CONCLUSIONS: In the nonischemic cardiomyopathy left bundle-branch block population, increased relative dyssynchrony in women, who have smaller heart sizes than their male counterparts, is a driver of sex-specific CRT response, particularly at QRSd <150 ms. Women may benefit from CRT at a QRSd <130 ms, opening the debate on whether sex-specific QRSd cutoffs or QRS/LVEDV measurement should be incorporated into clinical guidelines.

Risk Profiles and Treatment Patterns in Atrial Fibrillation Patients with Chronic Kidney Disease Receiving or not Receiving Anticoagulation Therapy.

Background Patients with atrial fibrillation (AF) and chronic kidney disease (CKD) are at high risk for both thromboembolism and bleeding events. The latter induces a potential reason for withholding oral anticoagulation (OAC) despite an indication for prophylaxis of thromboembolic events. Methods AF patients with CKD (estimated glomerular filtration [eGFR] rate between 15 and 49 mL/min per 1.73 m 2 ) were included in a prospective international registry in Europe between 2016 and 2020, that is, XARENO (factor XA inhibition in renal patients with nonvalvular atrial fibrillation observational registry). The study enrolled adult patients treated at the discretion of physicians with rivaroxaban, vitamin K antagonists (VKA), or without OAC (w/oOAC). Here, we report a prespecified explorative baseline comparison between patients receiving OAC or no OAC within XARENO. Results In total, 1,544 patients (mean age: 78.2 years, mean eGFR: 36.2 mL/min) were studied (rivaroxaban n = 764, VKA n = 691, w/oOAC n = 89). Patients in the w/oOAC group were older and had a similar stroke (mean CHA 2 DS 2 -VASc score 4.0) but higher bleeding risk (mean modified Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly score 2.5 vs. 1.8) compared with the OAC groups. The distribution of comorbidities including hypertension, diabetes, and heart failure was similar. Treatment with antiplatelet drugs was fivefold more frequent in the w/oOAC group. Conclusion Only 5.8% of the overall population of AF patients with advanced CKD received no OAC. These patients were older and had a higher bleeding risk, which might explain this decision, but which contrasts with the more frequent use of antiplatelet drugs in this vulnerable group of patients.

Heart size disparity drives sex-specific response to cardiac resynchronization therapy: a post-hoc analysis of the MORE-MPP CRT trial.

Background: Studies have reported that female sex predicts superior cardiac resynchronization therapy (CRT) response. One theory is that this association is related to smaller female heart size, thus increased "relative dyssynchrony" at given QRS durations (QRSd). Objective: To investigate the mechanisms of sex-specific CRT response relating to heart size, relative dyssynchrony, cardiomyopathy type, QRS morphology, and other patient characteristics. Methods: A post-hoc analysis of the MORE-CRT MPP trial (n=3739, 28% female), with a sub-group analysis of patients with non-ischaemic cardiomyopathy (NICM) and left bundle branch block (LBBB) (n=1308, 41% female) to control for confounding characteristics. A multivariable analysis examined predictors of response to 6 months of conventional CRT, including sex and relative dyssynchrony, measured by QRSd/LVEDV (left ventricular end-diastolic volume). Results: Females had a higher CRT response rate than males (70.1% vs. 56.8%, p<0.0001). Subgroup analysis: Regression analysis of the NICM LBBB subgroup identified QRSd/LVEDV, but not sex, as a modifier of CRT response (p<0.0039). QRSd/LVEDV was significantly higher in females (0.919) versus males (0.708, p<0.001). CRT response was 78% for female patients with QRSd/LVEDV>median value, compared to 68% < median value (p=0.012). Association between CRT response and QRSd/LVEDV was strongest at QRSd<150ms. Conclusions: In the NICM LBBB population, increased relative dyssynchrony in females, who have smaller heart sizes than their male counterparts, is a driver of sex-specific CRT response, particularly at QRSd <150ms. Females may benefit from CRT at a QRSd <130ms, opening the debate on whether sex-specific QRSd cut-offs or QRS/LVEDV measurement should be incorporated into clinical guidelines.

Outcomes of patients with atrial fibrillation on oral anticoagulation with and without heart failure: the ETNA-AF-Europe registry.

AIMS: Heart failure (HF) is a risk factor for major adverse events in atrial fibrillation (AF). Whether this risk persists on non-vitamin K antagonist oral anticoagulants (NOACs) and varies according to left ventricular ejection fraction (LVEF) is debated. METHODS AND RESULTS: We investigated the relation of HF in the ETNA-AF-Europe registry, a prospective, multicentre, observational study with an overall 4-year follow-up of edoxaban-treated AF patients. We report 2-year follow-up for ischaemic stroke/transient ischaemic attack (TIA)/systemic embolic events (SEE), major bleeding, and mortality. Of the 13 133 patients, 1854 (14.1%) had HF. Left ventricular ejection fraction was available for 82.4% of HF patients and was <40% in 671 (43.9%) and ≥40% in 857 (56.1%). Patients with HF were older, more often men, and had more comorbidities. Annualized event rates (AnERs) of any stroke/SEE were 0.86%/year and 0.67%/year in patients with and without HF. Compared with patients without HF, those with HF also had higher AnERs for major bleeding (1.73%/year vs. 0.86%/year) and all-cause death (8.30%/year vs. 3.17%/year). Multivariate Cox proportional models confirmed HF as a significant predictor of major bleeding [hazard ratio (HR) 1.65, 95% confidence interval (CI): 1.20-2.26] and all-cause death [HF with LVEF <40% (HR 2.42, 95% CI: 1.95-3.00) and HF with LVEF ≥40% (HR 1.80, 95% CI: 1.45-2.23)] but not of ischaemic stroke/TIA/SEE. CONCLUSION: Anticoagulated patients with HF at baseline featured higher rates of major bleeding and all-cause death, requiring optimized management and novel preventive strategies. NOAC treatment was similarly effective in reducing risk of ischaemic events in patients with or without concomitant HF.

Monitoring of mitral- and tricuspid valve interventions with CardioMEMS: Insights beyond imaging.

BACKGROUND: Mitral- and tricuspid regurgitation are associated with significant morbidity and mortality and are increasingly treated interventionally. CardioMEMS is a transcutaneously implanted pressure sensor placed in the pulmonary artery that allows invasive measurement of pulmonary artery pressure and cardiac output. METHODS: This proof-of-concept study aimed to observe hemodynamic changes as determined by CardioMEMS after transcatheter atrioventricular valve interventions, assess the additional value of CardioMEMS on top of echocardiography, and investigate a potential effect of CardioMEMS on outcome. Patients treated with transcatheter mitral- or tricuspid valve interventions (mitral: TMVR, tricuspid: TTVR) or bicaval valve implantation (bi-CAVI) were recruited. All patients were followed for 12 months. RESULTS: Thirty-six patients were included (4 with CardioMEMS, 32 controls). Patients with CardioMEMS were monitored prior to intervention and 3-12 months thereafter (one received TMVR, one bi-CAVI, one both TMVR and TTVR, and one isolated TTVR). CardioMEMS group: In both patients with TMVR and in the patient with bi-CAVI, mean pulmonary artery pressures decreased (all p < .001) and cardiac output increased significantly (both TMVR p < .001 and bi-CAVI p = .006) while functional parameters, echocardiography, and NT-proBNP were difficult to interpret, unreliable, or both. Changes after TTVR remained inconclusive. CONCLUSION: Invasive monitoring using CardioMEMS provides important information after mitral- and tricuspid valve interventions. Such data pave the way for a deeper understanding of the prerequisites for optimal patient selection and management for catheter-based interventions.

Ertugliflozin to reduce arrhythmic burden in ICD/CRT patients (ERASe-trial) - A phase III study.

Sodium glucose cotransporter 2 (SGLT2) have proven profound positive effects in heart failure with reduced ejection fraction (HFrEF). These effects are independent from the presence of diabetes. Metabolic effects, antiinflammatory, and antifibrotic properties are discussed as underlying mechanisms. Despite a strong correlation of ventricular arrhythmias with HFrEF, the impact of ertugliflozin on the ventricular arrhythmic burden has not been investigated, yet. Therefore, the Ertugliflozin to Reduce Arrhythmic burden in ICD ± CRT patientS (ERASe) trial was designed to investigate the efficacy and safety of ertugliflozin in patients with reduced and midrange ejection fraction (EF) with or without diabetes. METHODS: Within a multicentre, national, randomized, double-blind, placebo-controlled, phase 3b trial we aim to enrol a total of 402 patients across Austria. Patients with reduced or midrange EF and ICD ± CRT therapy >3 months and previous ventricular tachycardia (at least 10 documented VT episodes within the last 12 months) are randomized in a 1:1 ratio to ertugliflozin (5 mg once daily orally administered) or matching placebo. The primary endpoint of the ERASe trial is to investigate the impact of ertugliflozin on total burden of ventricular arrhythmias. Further objectives will include number of therapeutic interventions of implanted devices, atrial fibrillation and heart failure biomarkers. CONCLUSION: The ERASe trial will be the first trial to test ertugliflozin in heart failure patients with nonpreserved ejection fraction and ongoing ICD ± CRT therapy regardless of their diabetic status. The ERASe trial may therefore extend the concept of SGLT2 inhibition to improve cardiac remodelling, including reduced arrhythmic burden. Trial registration Identifier EudraCT Nr. 2020-002581-14 / ClinicalTrials.gov Identifier: NCT04600921.

Twiddler's syndrome after implantation of baroreflex activation therapy: a case report.

BACKGROUND: Twiddler's syndrome is a rare complication after implantation of cardiac pacemakers or cardioverter-defibrillators that usually occurs within the first year after the procedure. However, it has not yet been described following implantation of baroreflex activation therapy (BAT). CASE SUMMARY: A 61-year-old female patient was referred to the cardiology outpatient clinic due to uncontrolled arterial hypertension despite maximal doses of several established drugs. Therefore, right-sided BAT implantation was successfully performed in February 2017 with good clinical response. Because of sustained neck pain at the site of stimulator, surgical revision was performed in November 2019 including a switch of the lead to the contralateral position. Approximately 1 month later, Twiddler's syndrome was identified on the basis of recurrent pain at the generator site necessitating pocket-revision, however, the lead was only untwisted but not replaced. A few weeks afterwards, unfortunately, lead revision was indispensable due to lead fracture. DISCUSSION: This case presents the uncommon phenomenon of Twiddler's syndrome after BAT implantation. In addition, the commonly twisted lead should always be replaced as well during surgical pocket-revision in order to ensure proper long-term function.

Pacemaker lead-associated tricuspid regurgitation in patients with or without pre-existing right ventricular dilatation.

BACKGROUND: Transcatheter tricuspid valve intervention became an option for pacemaker lead-associated tricuspid regurgitation. This study investigated the progression of tricuspid regurgitation (TR) in patients with or without pre-existing right ventricular dilatation (RVD) undergoing pacemaker implantation. METHODS: Patients were included if they had implantation of transtricuspid pacemaker lead and completed echocardiography before and after implantation. The cohort was divided in patients with and without RVD (cut-off basal RV diameter ≥ 42 mm). TR was graded in none/mild, moderate, and severe. Worsening of one grade was defined as progression. Survival analyses were plotted for 10 years. RESULTS: In total, 990 patients were analyzed (24.5% with RVD). Progression of TR occurred in 46.1% of patients with RVD and in 25.6% of patients without RVD (P < 0.001). Predictors for TR progression were RV dilatation (OR 2.04; 95% CI 1.27-3.29; P = 0.003), pre-existing TR (OR 4.30; 95% CI 2.51-7.38; P < 0.001), female sex (OR 1.68; 95% CI 1.16-2.43; P = 0.006), single RV lead (OR 1.67; 95% CI 1.09-2.56; P = 0.018), mitral regurgitation (OR 2.08; 95% CI 1.42-3.05; P < 0.001), and enlarged left atrium (OR 1.98; 95% CI 1.07-3.67; P = 0.03). Survival-predictors were pacemaker lead-associated TR (HR 1.38; 95% CI 1.04-1.84; P = 0.028), mitral regurgitation (HR 1.34; 95% CI 1.02-1.77; P = 0.034), heart failure (HR 1.75; 95% CI 1.31-2.33; P < 0.001), kidney disease (HR 1.62; 95% CI 1.25-2.11; P < 0.001), and age ≥ 80 years (HR 2.84; 95% CI 2.17-3.71; P < 0.001). CONCLUSIONS: Patients with RVD receiving pacemaker suffered from increased TR progression, leading to decreased survival.

Recommendations on the utilization of telemedicine in cardiology.

The enormous progress made in recent years in the field of information and communication technology and also in sensor and computer technology has affected numerous fields of medicine and is capable of inducing even radical changes in diagnostic and therapeutic processes. This is particularly true for cardiology, where, for example, telemetric monitoring of cardiac and circulatory functions has been in use for many years. Nevertheless, broad application of newer telemedical processes has not yet been achieved to the extent one would expect from the encouraging results of numerous clinical studies in this field and the state of the art of the underlying technology. In the present paper, the Working Group on Rhythmology of the Austrian Cardiological Society aims to provoke a critical discussion of the digital change in cardiology and to make recommendations for the implementation of those telemedical processes that have been shown to exert positive effects on a wide variety of medical and economic parameters. The greatest benefit of telecardiological applications is certainly to be found in the long-term care of patients with chronic cardiovascular diseases. Accordingly, follow-up care of patients with cardiological rhythm implants, management of chronic heart failure and secondary prevention following an acute cardiac event during rehabilitation are currently the most important fields of application. Telemedicine is intended to enable high-quality and cost-efficient care for an increasing number of patients, whose care poses one of the greatest challenges to our healthcare system. Not least of all, telemedicine should make a decisive contribution to improving the quality of life of this segment of the population by favorably influencing mortality, morbidity and hospitalization as well as the patient's contribution to treatment.

Sex Differences and Long-Term Outcome in Patients With Pacemakers.

Introduction: Evidence of sex-related differences in patients with pacemakers regarding comorbidities is insufficiently investigated. The aim of this study was to determine the relationship of cardiovascular comorbidities and sex category with properties of pacemaker implantation, pacemaker follow-up, and long-term survival. Methods: This retrospective, single-center cohort study consisted of 6,362 pacemaker-patients (39.7% female) enrolled between May 2000 and April 2015. Functional pacemaker parameters were registered at regular pacemaker controls. Survival status and cause of death were analyzed in relation to comorbidities, implanted pacing devices, and echocardiography. Survival analyses were plotted for a 10-year follow-up. Results: Patients with hypertension or hyperlipidemia had higher rates of implantations due to sick sinus syndrome (28.6 vs. 25.5% without hypertension, P < 0.001; 30.7 vs. 25.7% without hyperlipidemia, P < 0.001), while endocarditis was associated with higher rates of implantations due to AV block (46.7 vs. 33.4%, P < 0.001). Patients with valvular heart disease had higher rates of pacemaker implantation due to bradycardic atrial fibrillation (24.9 vs. 21.0% without valvular heart disease, P < 0.001). Ventricular pacing threshold increased in both sexes during the follow-up and was higher in women in the final follow-up (0.94 vs. 0.91 V in men, P = 0.002). During the 10-years follow-up, 6.1% of women and 8.6% of men underwent lead replacement (P = 0.054). Device and lead replacement rates were increased if the comorbidities coronary artery disease, heart failure, hypertension, hyperlipidemia, valvular heart disease, previous stroke/TIA, atrial arrhythmias, chronic kidney disease, or endocarditis were present. Diabetes and previous CABG increase the rates of device replacement, but not the rate of lead replacement. Severe tricuspid regurgitation after implantation of pacemaker was present in more men than women (14.4 vs. 6.1%, P < 0.001). In a multivariate COX regression, the following variables were associated with independent decrease of 10-year survival: hypertension (HR 1.34, 95% CI 1.09-1.64), chronic kidney disease (HR 1.83, 95% CI 1.53-2.19), tricuspid regurgitation after pacemaker implantation (HR 1.48, 95% CI 1.26-1.74). Survival was independently increased in female sex (HR 0.83, 95% CI 0.70-0.99) and hyperlipidemia (HR 0.81, 95% CI 0.67-0.97). Conclusions: Cardiovascular comorbidities influenced significantly pacemaker implantations and long-term outcome. Trial Registration: ClinicalTrials.gov Unique identifier: NCT03388281.

Patients with Heart Failure and Preserved Ejection Fraction Are at Risk of Gastrointestinal Bleeding.

AIMS: Two thirds of patients with heart failure and preserved ejection fraction (HFpEF) have an indication for oral anticoagulation (OAC) to prevent thromboembolic events. However, evidence regarding the safety of OAC in HFpEF is limited. Therefore, our aim was to describe bleeding events and to find predictors of bleeding in a large HFpEF cohort. METHODS AND RESULTS: We recorded bleeding events in a prospective HFpEF cohort. Out of 328 patients (median age 71 years (interquartile range (IQR) 67-77)), 64.6% (n = 212) were treated with OAC. Of those, 65.1% (n = 138) received vitamin-K-antagonists (VKA) and 34.9% (n = 72) non-vitamin K oral anticoagulants (NOACs). During a median follow-up time of 42 (IQR 17-63) months, a total of 54 bleeding events occurred. Patients on OAC experienced more bleeding events (n = 49 (23.1%) versus n = 5 (4.3%), p < 0.001). Major drivers of events were gastrointestinal (GI) bleeding (n = 18 (36.7%)]. HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly) score (hazard ratios (HR) of 2.15 (95% confidence interval (CI) 1.65-2.79, p < 0.001)) was the strongest independent predictor for overall bleeding. In the subgroup of GI bleeding, mean right atrial pressure (mRAP: HR of 1.13 (95% CI 1.03-1.25, p = 0.013)) and HAS-BLED score (HR of 1.74 (95% CI 1.15-2.64, p = 0.009)] remained significantly associatiated with bleeding events after adjustment. mRAP provided additional prognostic value beyond the HAS-BLED score with an improvement from 0.63 to 0.71 (95% CI 0.58-0.84, p for comparison 0.032), by C-statistic. This additional prognostic value was confirmed by significant improvements in net reclassification index (61.3%, p = 0.019) and integrated discrimination improvement (3.4%, p = 0.015). CONCLUSION: OAC-treated HFpEF patients are at high risk of GI bleeding. High mRAP as an indicator of advanced stage of disease was predictive for GI bleeding events and provided additional risk stratification information beyond that obtained by HAS-BLED score.

Papillary Muscle Dyssynchrony-Mediated Functional Mitral Regurgitation: Mechanistic Insights and Modulation by Cardiac Resynchronization.

OBJECTIVES: This study sought to define interpapillary muscle dyssynchrony as a major contributing factor in functional mitral regurgitation (FMR) and prove the reversibility of FMR by interpapillary muscle resynchronization. BACKGROUND: Mechanistic features of FMR include papillary muscle displacement due to left ventricular remodeling. Intraventricular conduction delay might further augment this condition by introducing interpapillary muscle dyssynchrony. METHODS: We enrolled 269 chronic heart failure with reduced ejection fraction patients with conduction delay and comprehensively assessed dyssynchrony by complementary echocardiographic techniques covering the entire spectrum of dyssynchrony. RESULTS: Patients with severe FMR had markedly increased interpapillary longitudinal dyssynchrony (160 ms [interquartile range (IQR): 120 to 200 ms]) compared with those with moderate (70 ms [IQR: 40 to 110 ms]), no, or mild FMR (60 ms [IQR: 30 to 100 ms]; p < 0.001). Increased interpapillary muscle dyssynchrony was correlated with regurgitant volume (r = 0.50; p < 0.001) and vena contracta width (r = 0.49; p < 0.001). Restoration of longitudinal papillary muscle synchronicity by cardiac resynchronization therapy was correlated with FMR regression, as reflected by the reduction in regurgitant volume (r = 0.46; p < 0.001) and vena contracta width (r = 0.58; p < 0.001). Conversely, the improvement of FMR was associated with improved interpapillary radial (p = 0.006) and longitudinal (p < 0.001) dyssynchrony. The improvement of dyssynchrony-mediated FMR signified a better prognosis compared with no improvement in FMR during the 8-year follow-up period even after comprehensive adjustment by a bootstrap-selected confounder model (adjusted hazard ratio: 0.41; 95% confidence interval: 0.18 to 0.91; p = 0.028). The results remained virtually unchanged after adjustment for left bundle branch block. CONCLUSIONS: Intraventricular dyssynchrony introduces unequal contraction by papillary muscle bearing walls, which has an adverse effect on FMR. Cardiac resynchronization therapy can effectively restore interpapillary balance and thus create a less tented leaflet configuration, resulting in a clinically meaningful reduction of FMR. The restoration of papillary muscle synchronicity in dyssynchrony-mediated FMR translates into a significantly better prognosis.

[S1 guideline - Austrian consensus for anticoagulation in the context of atrial fibrillation ablation]. / S1 Leitlinie ­ Österreichischer Konsensus zur Antikoagulation im Rahmen der Vorhofflimmerablation.

In summary, uninterrupted oral antikoagulation can be recommended, with different recommendation classes and levels of evidence, for both, VKA and NOAC therapy, in the framework of PVI. Even with low CHA2DS2 VASc scores, OAK is indicated 3-4 weeks before and 8 weeks after the procedure. Periinterventional bridging with heparins should be avoided due to increased bleeding events.The present Consensus provides recommendations on the current state of knowledge and has been prepared exclusively by members of the Rhythmology Working Group of the Austrian Cardiological Society who have great practical experience in catheter ablation and peri-interventional OAK in patients with atrial fibrillation. Publication of new randomized and controlled studies on the subject are expected in the coming months, so that there will certainly be changes in the recommendations. The Rhythmology Working Group of the Austrian Cardiological Society will strive to keep this S1 guideline regularly up to date. We hope that this consensus is used to increase the safety for patients undergoing PVI and to provide physicians with a homogeneous approach in Austria.

Radiofrequency catheter ablation can be performed with high success rates and very low complication rates in children and adolescents.

AIM: Radiofrequency catheter ablation is a standard treatment for tachyarrhythmia in children. Recently, several centres using cryoenergy for ablation have reported high success and low complication rates, but an increased risk of recurrence of arrhythmia. The aim of this study was to report success, complications and recurrence rates for radiofrequency catheter ablation in children under current conditions. METHODS: A retrospective cohort study of 333 consecutive children undergoing radiofrequency catheter ablation over the last two decades. RESULTS: Radiofrequency catheter ablation was performed successfully in 96.7% of patients, but was significantly less successful in patients with a right anterior or right anterolateral accessory pathway (81.8%). Overall mortality was 0%; there was only one (0.3%) major complication, a pericardial haemorrhage, and only 2.8% of the patients developed minor vascular complications at the puncture site. None of the patients developed a persistent atrioventricular block. Over a median observation time of 4.3 years (0.1; 17.8), recurrence of arrhythmia occurred in 9.3% of all patients, but 50% of children with right lateral accessory pathways. CONCLUSION: Radiofrequency catheter ablation can be performed with high success and very low complication rates in children. Recurrence rates are substantially lower than those reported for cryoablation in the literature.

Combined circular multielectrode catheter and point-by-point ablation is superior to point-by-point ablation alone in eliminating atrial fibrillation.

BACKGROUND: Besides conventional point-by-point ablation, novel multielectrode catheters emerge for ablation of atrial fibrillation (AF). We sought to evaluate the clinical utility of a pulmonary vein (PV) isolation approach combining the advantages of both technologies. METHODS: The study included 240 consecutive AF patients (60±11 years, 68% males, 62% paroxysmal). In the combined ablation group (n=120), PV isolation was performed with a circular multielectrode catheter (PVAC, Medtronic Ablation Frontiers) and completed by conventional point-by-point ablation (NaviStar ThermoCool Catheter, Lasso/CARTO technology, Biosense Webster). In the point-by-point ablation group (n=120), PV isolation was performed with point-by-point ablation alone. RESULTS: Complete 1-year ablation success (freedom from any atrial arrhythmia off antiarrhythmic drugs) was more frequently observed in the combined ablation group (58.0% versus 43.3%, hazard ratio 1.72, 95% confidence interval 1.19-2.48, p=0.004). Also clinical success (≥90% reduction of arrhythmia burden on/off antiarrhythmic drugs) was significantly associated with the combined ablation approach (p=0.001). These associations remained significant after multivariable adjustment (both p≤0.005) and were not dependent on the type of AF. The rate of major adverse events (3.3% versus 2.5%) and the procedure time did not differ between groups. The fluoroscopy time, however, was significantly shorter in the combined ablation group (p<0.001) reflecting the reduced need for radiation during multielectrode catheter ablation. CONCLUSIONS: A combined PV isolation approach based on multielectrode catheter ablation and complementary point-by-point ablation is superior to point-by-point ablation alone and reveals to be safe. A potential explanation for these findings is the improved durability of ablation lesion after the combined ablation approach.

Prognostic value of induction of atrial fibrillation before and after pulmonary vein isolation.

BACKGROUND: Apart from pulmonary vein isolation, catheter ablation of atrial fibrillation (AF) lacks reliable electrophysiological endpoints. The present study investigated the prognostic value of changes in AF inducibility due to ablation. METHODS: Between 10/2006 and 10/2009 121 patients referred for catheter ablation of symptomatic, drug refractory paroxysmal AF were included. Sinus rhythm immediately before ablation was a prerequisite for study entry. Two respective attempts to induce AF (>1min) by decremental coronary sinus stimulation before and after ablation were performed. RESULTS: A total of 121 patients aged 59.5±10.4years undergoing pulmonary vein isolation due to paroxysmal AF were included. The median follow-up duration was 12.1months [quartiles: 6.5-20.3months]. In 36 (30%) patients AF was inducible before, but not after ablation. Forty-nine (41%) patients were neither inducible before nor after the procedure, whereas 25 patients (21%) displayed unchanged inducibility. In 11 patients (9%) AF was inducible only after ablation. Patients with inducibility solely after the ablation had the highest risk of AF recurrence (HR 6.71 [95%-CI 2.76-16.30], p=0.0005) compared to patients without inducibility before and after the procedure. CONCLUSION: The results of attempted AF induction before and after ablation have significance with respect to ablation outcome. Both patient groups with either unchanged inducibility or facilitated induction after ablation had the highest recurrence rates of AF.

Markers of oxidative stress after ablation of atrial fibrillation are associated with inflammation, delivered radiofrequency energy and early recurrence of atrial fibrillation.

BACKGROUND: The role of oxidative stress after radiofrequency ablation of atrial fibrillation (AF) has not yet been well characterized. We sought to evaluate the time course of biomarkers of oxidative stress and inflammation after AF ablation and their association with clinical variables. METHODS: Thirty consecutive patients (57.9 ± 1.7 years, 63% males) with paroxysmal AF underwent pulmonary vein isolation and ablation of complex fractionated atrial electrograms. Biomarkers were determined in blood samples before ablation and 6 h, 1, 2, 7, 30, 90 and 180 days post-ablation. RESULTS: The pro-oxidant enzyme myeloperoxidase and oxidized low-density lipoprotein reflecting oxidant damage of lipoproteins increased 2.9 ± 0.2-fold and 1.2 ± 0.1-fold, respectively, and were significantly up-regulated until day 2 post-ablation. The anti-oxidant enzyme copper/zinc superoxide dismutase did not change significantly. Inflammatory markers significantly increased (high-sensitivity C-reactive protein (hs-CRP): 41 ± 8-fold; interleukin-6: 4.4 ± 0.7-fold) for 7 and 2 days, respectively. The increase of myeloperoxidase and hs-CRP was interrelated and both predicted early recurrence of AF within the first post-ablation week (both p < 0.05). The increase of both markers was associated with the amount of delivered radiofrequency energy (p < 0.05). The up-regulation of hs-CRP correlated with troponin T (p = 0.008), while myeloperoxidase and troponin T were borderline associated (p = 0.054). However, the oxidative and inflammatory responses did not predict long-term ablation outcome (p > 0.05). CONCLUSIONS: Markers of oxidative stress showed a significant up-regulation during the first 2 days after AF ablation. Their up-regulation was linked to inflammation, delivered radiofrequency energy, and early recurrence of AF, but did not predict long-term ablation outcome.

Time course of markers of tissue repair after ablation of atrial fibrillation and their relation to left atrial structural changes and clinical ablation outcome.

BACKGROUND: Radiofrequency ablation of atrial fibrillation (AF) creates left atrial (LA) tissue damage with a subsequent healing process. We sought to prospectively assess the time course of biomarkers of tissue repair after ablation and to evaluate their association with clinical variables. METHODS: 30 consecutive patients (57.9 ± 1.7 yrs, 63% males) with paroxysmal AF underwent a CARTO-guided LA circumferential ablation, Lasso-guided segmental pulmonary vein isolation and ablation of complex fractionated atrial electrograms. Matrix metalloproteinase-9 (MMP-9) and transforming growth factor-ß1 (TGF-ß1), both key regulators of tissue repair, and the aminoterminal propeptide of type III procollagen (PIIINP), reflecting collagen synthesis, were determined in blood samples before and 6h, 1, 2, 7, 30, 90 and 180 days post-ablation. RESULTS: All markers showed a significant ablation-induced up-regulation (MMP-9: 1.8 ± 0.1-fold, TGF-ß1: 2.4 ± 0.4-fold, PIIINP: 1.3 ± 0.1-fold). MMP-9 was significantly up-regulated until day 90, TGF-ß1 only on day 2. PIIINP increased from day 2 to 7. The area under the curve (AUC) of MMP-9 and TGF-ß1 correlated with the ablation-induced reduction of LA volume (both p<0.05). The AUC of MMP-9 was additionally associated with the amount of radiofrequency energy delivered during ablation (p < 0.05). At 12 months of follow-up 57% of patients were free of AF off antiarrhythmic drugs. The AUC of PIIINP independently predicted recurrent AF (p < 0.05). CONCLUSIONS: Markers of healing showed a significant up-regulation after AF ablation detectable for up to 90 days. A more pronounced up-regulation of MMP-9 or TGF-ß1 is associated with a greater reduction of LA size. High PIIINP levels after ablation predict a poor ablation outcome.

Treatment of a recurrent atrial tachycardia by isolation of the right inferior pulmonary vein using a multi-electrode duty cycled ablation catheter.

We report on a 29-year-old man who underwent an ablation procedure for a focal atrial tachycardia. Three-dimensional mapping located the site of origin to the ostium of the right inferior pulmonary vein. By using a novel multi-electrode duty cycled ablation catheter, pulmonary vein isolation and elimination of tachycardia was achieved.