Left atrial total emptying fraction measured by cardiovascular magnetic resonance imaging predicts low-voltage areas detected during electroanatomical mapping.

AIMS: Low-voltage areas (LVAs) found during left atrial (LA) electroanatomical mapping are increasingly targeted by radiofrequency catheter ablation (RFCA) on top of pulmonary vein isolation to improve arrhythmia-free survival in patients with atrial fibrillation (AF). However, pre-procedural prediction of LVAs remains challenging. The purpose of the present study was to describe the association between parameters of LA function and dimensions, respectively, derived from pre-procedural cardiovascular magnetic resonance (CMR) imaging, and the presence of LVAs on LA voltage mapping. METHODS AND RESULTS: Patients who underwent first-time RFCA for paroxysmal or persistent AF and who were in stable sinus rhythm during pre-procedural CMR imaging were included in this study. Cardiovascular magnetic resonance-derived parameters of LA function and dimensions were calculated. Low-voltage areas were defined as areas with bipolar voltage amplitudes of ≤0.5 mV on electroanatomical mapping. In total, 259 consecutive patients were included in this analysis. Low-voltage areas were found in 25 of 259 patients (9.7%). Compared with those without LVAs, patients with LVAs were significantly older, were more likely to be female, had a higher CHA2DS2-VASc score, had larger LA volumes, and had a lower LA total emptying fraction (TEF). In multivariate analysis, only LA TEF [odds ratio (OR) 0.885, 95% confidence interval (CI) 0.846-0.926, P < 0.001] and the CHA2DS2-VASc score (OR 1.507, 95% CI 1.115-2.038, P = 0.008) remained independently associated with the presence of LVAs. CONCLUSION: Left atrial TEF and the CHA2DS2-VASc score were independently associated with the presence of LVAs found during LA electroanatomical mapping. These findings may help to improve pre-procedural prediction of pro-arrhythmogenic LVAs and to improve peri-procedural patient management.

Major incidental findings on routine cardiovascular magnetic resonance imaging prior to first-time catheter ablation of atrial fibrillation.

INTRODUCTION: Preprocedural cardiovascular magnetic resonance (CMR) or computed tomography (CT) imaging of the left atrium/pulmonary veins is usually employed to guide catheter ablation of atrial fibrillation (AFCA). Incidental findings (IFs) are common on cardiac imaging prior to AFCA. However, previous studies have mainly focused on extracardiac IFs detected on CT scan. We aimed to assess the prevalence of relevant cardiac and extracardiac IFs on routine preprocedural CMR in a large patient cohort scheduled for first-time AFCA and report its impact on clinical decision-making and management. METHODS AND RESULTS: We included 2000 consecutive patients (62 ± 10 years; 59% male) who underwent CMR prior to first-time AFCA between April 2015 and March 2019. Among these patients 172 (8.6%) had a total of 184 major IFs. Detection of major IFs resulted in cancellation of the scheduled AFCA procedure in 88 patients (4.4%). Forty-two patients (2.1%) have never been ablated, 46 (2.3%) underwent postponed AFCA after a median time of 83 (32-213) days. The remaining 84 patients (4.2%) underwent an individualized approach to AFCA. The most common major IFs were accessory or anomalous PVs in 76 (3.8%), extracardiac abnormalities suspicious of malignancy in 29 (1.5%), and positive stress perfusion imaging in 19 (7.2% of 261 tested) patients. In 19 patients (1.0%) preprocedural CMR provided the diagnosis of a previously unknown structural cardiac disease. CONCLUSIONS: Unexpected relevant findings on routine preprocedural CMR affected clinical decision-making and management in 8.6% of patients scheduled for first-time AFCA. However, whether preprocedural CMR imaging may improve overall clinical outcome needs to be addressed in future research.

Oesophageal Probe Evaluation in Radiofrequency Ablation of Atrial Fibrillation (OPERA): results from a prospective randomized trial.

AIMS: The aim of the study was to determine the incidence of oesophageal lesions after radiofrequency ablation (RFA) of atrial fibrillation (AF) with or without the use of oesophageal temperature probes. METHODS AND RESULTS: Two hundred patients were prospectively randomized into two groups: the OPERA+ group underwent RFA using oesophageal probes (SensiTherm™); the OPERA- group received RFA using fixed energy levels of 25 W at the posterior wall without an oesophageal probe. All patients underwent post-interventional endoscopy and Holter-electrocardiogram after 6 months. (Clinical.Trials.gov: NCT03246594). One hundred patients were randomized in OPERA+ and 100 patients in OPERA-. The drop-out rate was 10%. In total, 18/180 (10%) patients developed endoscopically diagnosed oesophageal lesions (EDEL). There was no difference between the groups with 10/90 (11%) EDEL in OPERA+ vs. 8/90 (9%) in OPERA- (P = 0.62). Despite the higher power delivered at the posterior wall in OPERA+ [28 ± 4 vs. 25 ± 2 W (P = 0.001)], the average EDEL size was equal [5.7 ± 2.6 vs. 4.5 ± 1.7 mm (P = 0.38)]. The peak temperature did not correlate with EDEL size. During follow-up, no patient died. Only one patient in OPERA- required a specific therapy for treatment of the lesion. Cumulative AF recurrence after 6 (3-13) months was 28/87 (32%) vs. 34/88 (39%), P = 0.541. CONCLUSION: This first randomized study demonstrates that intraoesophageal temperature monitoring using the SensiTherm™ probe does not affect the probability of developing EDEL. The peak temperature measured by the thermoprobe seems not to correlate with the incidence of EDEL. Empiric energy reduction at the posterior wall did not affect the efficacy of the procedure.

Atrial Fibrillation and Cognitive Impairment: New Insights and Future Directions.

INTRODUCTION: Atrial fibrillation (AF) has been recognised as the most prevalent sustained arrhythmia. Recently, a growing body of evidence has suggested that AF might be involved in the progression of cognitive impairment (CIM), potentially extending into types of dementia. Accordingly, the purpose of the present study was to summarise the findings of investigations examining association between AF and cognitive function as well as highlighting the possible causes of discrepancy between the findings and reviewing the probable mechanisms of CIM in patients affected with AF. METHODS: A systematic search in the literature was conducted in the databases of PubMed, Scopus, Cochrane Library, and Google Scholar with no language restrictions, using specified search terms to identify studies published between 1 January 1990 and 1 April 2018. Then, study designs, participant information, diagnostic approaches used for cognitive assessments, and incidence/prevalence rates of CIM and/or dementia were assessed. RESULTS: Out of the initial 2,364 articles retrieved, a total number of 40 studies were selected for data collection. Most studies had suggested a significant relationship between AF and CIM. In this regard, cerebral hypo-perfusion, altered cerebral blood flow, cerebral micro-bleeds, micro-emboli, vascular inflammation, cerebral small vessel diseases, vascular inflammation, and genetic factors were considered as the possible mechanisms of CIM in patients suffering from AF. It seemed that differences in study settings and designs, variations of diagnostic tools for CIM and AF, as well as underlying conditions such as age groups, concurrent chronic diseases, and therapeutic interventions for AF might be amongst probable factors justifying the diversity of findings across the selected articles. CONCLUSION: Although evidence is much more directed towards an association between AF and CIM, the role of AF in CIM needs to be confirmed in-depth via longer prospective and cohort studies at larger scales using accurate neuropsychological and cognitive function assessments. Moreover, the mechanisms involved in the relationship between AF and Alzheimer's disease (AD) require further studies. To conclude, the effect of different therapeutic strategies of AF on CIM should be investigated in more clinical trials.

Effect of remote ischemic preconditioning on electrophysiological parameters in nonvalvular paroxysmal atrial fibrillation: The RIPPAF Randomized Clinical Trial.

BACKGROUND: Atrial fibrillation (AF) remains the most relevant arrhythmia with a prevalence of 2%. The treatment options are either highly invasive and cost-intensive or limited by potential side effects or insufficient efficacy. However, no direct means of prevention that could reduce the burden of AF have been tested. OBJECTIVE: The purpose of this study was to determine whether remote ischemic preconditioning (RIPC) has an impact on inducibility and sustainability of AF. METHODS: A total of 146 patients with paroxysmal AF undergoing electrophysiology study were randomized to receive either RIPC, performed by short episodes of forearm ischemia, or sham intervention (clinicaltrials.gov identifier: NCT02779660). Effective refractory periods, conduction times, velocities, and conduction delays measured were analyzed by pacing from the coronary sinus (CS). End points of the study were the inducibility and sustainability of AF after prespecified rapid pacing sequences. RESULTS: RIPC significantly reduces the inducibility (odds ratio 0.35; 95% confidence interval 0.17-0.71; P = .003) and sustainability (odds ratio 0.36; 95% confidence interval 0.16-0.81; P = .01) of AF. Furthermore, it decreased dispersion of atrial refractory periods (16.0 ± 14.0 ms vs 22.7 ± 19.0 ms; P = .021) as well as atrial conduction delays (49.2 ± 19.6 ms vs 56.2 ± 22.5 ms; P = .049 for proximal CS and 42.4 ± 16.6 ms vs 49.8 ± 22.2 ms; P = .029 for distal CS). In the whole cohort, longer atrial conduction delay (57.6 ± 22.2 ms vs 50.0 ± 20.5 ms; P = .044) and slower conduction velocity (1.74 ± 0.3 mm/ms vs 1.93 ± 0.5 mm/ms; P = .006) were associated with inducibility of AF whereas a wider dispersion of effective refractory periods (25.9 ± 18.3 ms vs 15.7 ± 11.6 ms; P = .028) maintained AF episodes. CONCLUSION: RIPC reduces the inducibility and sustainability of AF, which is possibly mediated by changes in electrophysiological properties of the atria. It may be used as a simple noninvasive procedure to reduce AF burden.

Combined single-session cardiovascular magnetic resonance: stress perfusion and three-dimensional pulmonary vein angiography for stratification of atrial fibrillation patients with chest pain syndromes prior to catheter ablation.

AIMS: To determine the clinical utility of a combined single-session cardiovascular magnetic resonance (CMR) imaging protocol integrating adenosine stress perfusion and three-dimensional pulmonary vein angiography for stratification of atrial fibrillation (AF) patients referred for pulmonary vein isolation (PVI) and complaining about chest pain syndromes. METHODS AND RESULTS: The preprocedural CMR examination (adenosine stress perfusion, late gadolinium enhancement, and three-dimensional pulmonary vein angiography) was performed in 357 consecutive AF patients with chest pain syndromes referred for PVI. Stress perfusion results were used for stratification: ischaemia positive patients underwent invasive coronary angiography, ischaemia negative patients underwent PVI, and follow-up/outcome data were collected (combined primary endpoint of cardiac death/non-fatal myocardial infarction). The integrated CMR protocol had a high success rate (356/357, 99.7%), a short total examination duration (<30 min in all patients), and delivered high-quality three-dimensional pulmonary vein angiography in all patients undergoing PVI (324/324, 100%). Variants of pulmonary vein anatomy were identified in 33% of all patients (117/357). Stress positivity (28/356, 8%) had a high positive predictive value for identification of obstructive coronary artery disease (86%), while stress negativity carried a low short-term event rate following PVI (cumulative 1-year event-free survival rate, 99.6%). CONCLUSION: Combined single-session CMR as a routine diagnostic workup for AF patients with chest pain syndromes prior to PVI proved to represent a time-efficient and effective stratification tool.

Catheter ablation of atrial fibrillation with nonfluoroscopic catheter visualization-a prospective randomized comparison.

PURPOSE: The application of a novel platform for nonfluoroscopic catheter sensor tracking within pre-recorded x-ray loops in the context of catheter ablation of atrial fibrillation (AF) demonstrated significant potential for reduction of fluoroscopy. We sought to provide the first prospective randomized comparison of fluoroscopy needs, procedure times, and complications in AF catheter ablation with or without additional use of nonfluoroscopic catheter visualization (NFCV). METHODS: Patients with AF were randomized into two groups before scheduled radiofrequency ablation: (1) using established mapping systems and fluoroscopy as needed (CONV group) or (2) with additional NFCV (NFCV group). All procedures were performed in the same lab using the same ablation catheter tip technology and the same mapping and ablation strategies. Primary endpoints were radiation time and dose. Secondary endpoints were procedural parameters, complications, and long-term success. RESULTS: A total of 80 patients (48 male patients, mean age 60 years, 46 patients with paroxysmal AF) were randomized into the two groups. Clinical parameters between both groups were similar. NFCV use reduced mean fluoroscopy time (1.9 vs. 13.2 min, p < 0.001) and mean dose (510 vs. 1549 Gycm2, p < 0.001) significantly. Procedural parameters were similar in the two groups. One conservatively treated groin complication occurred (1.3%). CONCLUSIONS: Radiation exposure can be significantly reduced by using the novel NFCV technology in addition to standard AF ablation technologies without negative effects on procedure durations, success rates, or complication rates. With the use of the technology, abandonment of lead protection for EP staff is possible following transseptal puncture.

Catheter ablation of atrial fibrillation: current status, techniques, outcomes and challenges

Atrial fibrillation (AF) is the most common human arrhythmia. Interventional treatment with catheter ablation is an established technique that is increasingly applied and has become one of the main treatment modalities in patients with AF. Ablation results in significant improvement of symptoms and the quality of life. There is as yet no clear evidence of any impact of the procedure on hard clinical endpoints, except in patients with heart failure, who seem to benefit significantly from ablation. The cornerstone of the procedure is the achievement of pulmonary vein isolation. Radiofrequency energy is the main applied energy source, but cryoballoon ablation has emerged as a safe and effective alternative to radiofrequency ablation. Additional ablation strategies and novel technical features have been proposed but without unequivocal proof of clinical benefit. The most promising of these seems to be substrate mapping of the left atrium with substrate modification in areas with low voltage as an adjunct to pulmonary vein isolation. Complication rates remain considerable despite accumulated experience and can be partly reduced by application of preventive measures.

Safety profile of near-zero fluoroscopy atrial fibrillation ablation with non-fluoroscopic catheter visualization: experience from 1000 consecutive procedures.

Aims: Efforts to reduce radiation exposure during catheter ablation procedures have included the use of various technological measures. Significant results have been achieved to the point where near lead-free procedures in routine clinical practice has become a realistic goal. The integration of MediGuide technology [non-fluoroscopic catheter visualization technology (NFCV)] and three-dimensional electroanatomical mapping is one of the methods developed in response to radiation reduction initiatives. We aimed to evaluate the impact of this NFCV technology on atrial fibrillation (AF) catheter ablation in terms of reduction in procedural and radiation time as well as safety aspects. Methods and results: Between March 2012 and March 2017, a total of 1000 patients underwent AF ablation using NFCV. Patient and procedural data and complications within the first 3 months were entered into a prospective registry and analysed. We assessed procedure time, fluoroscopy time, and dose and complications. In a cohort of 1000 patients (62.9 ± 11 years; 72% men; left ventricular ejection fraction 57%; and left atrial diameter 43.2 mm), the median procedure time was 120 min, median fluoroscopy time was 0.90 min, and the median fluoroscopy dose of was 345.1 cGy · cm2. Stratification of the first (Group 1) and the last 250 (Group 2) cases showed significant improvement in the median procedure time (140-110 min) and reduction in the median fluoroscopy time (6-0.5 min) and the median dose (2263-151.9 cGy · cm2). The overall complication rate was 2.0%. Conclusion: The use of NFCV technology enables safe, consistent, and 'near lead-free' performance of AF ablation in routine clinical practice.

Individually tailored vs. standardized substrate modification during radiofrequency catheter ablation for atrial fibrillation: a randomized study.

Aims: This randomized single-centre study sought to compare the efficacy and safety of pulmonary vein isolation (PVI) plus voltage-guided ablation vs. PVI with or without linear ablation depending on the type of atrial fibrillation (AF). Methods and results: Overall, 124 ablation-naive patients with paroxysmal or persistent AF were randomized to PVI with (persistent AF) or without (paroxysmal AF) additional linear ablation (control group) vs. PVI plus ablation of low-voltage areas (LVAs) irrespective of AF type. Bipolar voltage mapping was performed during stable sinus rhythm. An LVA consisted of ≥ 3 adjacent mapping points that each had a peak-to-peak amplitude ≤0.5 mV. After a mean follow-up of 12 ± 3 months, significantly more patients in the LVA ablation group were free from atrial arrhythmia recurrence >30 s off antiarrhythmic drugs (AADs) after a single procedure (primary endpoint) compared with control group patients [40/59 (68%) vs. 25/59 (42%), log-rank P = 0.003]. Arrhythmia-free survival on or off AADs was found in 33/59 control group patients (56%) and in 41/59 LVA ablation group patients (70%) (adjusted log-rank P = 0.10). During the 7 day Holter monitoring period at 12 months, significantly more patients in the LVA ablation group were free from arrhythmia recurrence on or off AADs [45/50 (90%) vs. 33/46 (72%), P = 0.04]. No between-group differences were observed regarding procedure duration, fluoroscopy time, and major complications. Conclusion: In this single-centre study, individually tailored substrate modification guided by voltage mapping was associated with a significantly higher arrhythmia-free survival rate compared with a conventional approach applying linear ablation according to AF type.

Supraventricular arrhythmias in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy associate with long-term outcome after catheter ablation of ventricular tachycardias.

Aims: This study aimed to assess the impact of supraventricular tachycardia (SVT) on long-term results of radiofrequency catheter ablation therapy of ventricular tachycardia (VT) in a large cohort of patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Methods and results: Supraventricular tachycardia occurrence has been studied in patients from our ARVD/C registry (70 patients, 48 male, age 53.2 ± 14.0, 45 patients (64.3%) with previous VT ablation). SVT were diagnosed in 26 of 70 patients (37.1%). Atrial fibrillation (AF) was the most frequent atrial arrhythmia, diagnosed in 17 patients (24.3%). In univariate analysis advanced age, clinical symptoms of heart failure, enlarged right atrium, diagnosis of significant tricuspid regurgitation (TR), and inappropriate implantable cardioverters-defibrillators therapy were associated with SVT. In binary logistic regression analysis only heart failure: hazard ratio (HR) 10.89, 95% confidence interval (95% CI) 1.08-109.96 (P = 0.043) and significant TR: HR 4.79, 95% CI 1.35-16.33 (P = 0.015) remained associated with SVT. In patients with previous VT ablation Cox multiple regression survival analysis revealed older age (≥53 years): HR 4.63, 95% CI 1.51-14.24 (P = 0.008) and SVT: HR 3.01, 95% CI 1.15-7.89 (P = 0.025) as predictors for VT recurrence during the follow-up. Conclusion: SVT and older age are associated with the recurrence of VT after catheter ablation in patients with ARVD/C.

Predictors of ventricular arrhythmia after left ventricular assist device implantation: A large single-center observational study.

BACKGROUND: Ventricular arrhythmias (VAs) are common in patients after left ventricular assist device (LVAD) implantation. OBJECTIVE: The purpose of this study was to determine the predictors of VAs and their impact on mortality in LVAD patients. METHODS: A total of 98 consecutive patients with an implantable cardioverter-defibrillator (ICD) (86 [88%] male, mean age 57 ± 10 years), 57 [58%] with nonischemic dilated cardiomyopathy) who had received an LVAD between May 2011 and December 2013 at our institution were included in the study. RESULTS: Mean left ventricular ejection fraction and left ventricular end-diastolic diameter were 20% ± 8% and 73 ± 11 mm, respectively. Seventy-three patients (75%) had atrial fibrillation (AF). During the 12 months before LVAD implantation, 38 patients (39%) had experienced ≥1 episode of VAs (11.5 ± 20) requiring ICD therapies. The number of patients with VAs was comparable among all types of ICDs (P = .48). During the 12-month follow-up after LVAD implantation, 48 patients (49%) experienced ≥1 episode of VAs (30 ± 98) with appropriate ICD therapies. The prevalence of VAs was significantly higher among patients with pre-LVAD VAs compared to those without VAs during the year before LVAD implantation (66% vs 38%; P = .008). In a binary multiple logistic regression analysis, pre-LVAD VAs (hazard ratio 5.36, 95% confidence interval 2.0-14.3; P = .001) and AF (hazard ratio 3.1, 95% confidence interval 1.1-11.9; P = .024) predicted post-LVAD VAs. CONCLUSION: Pre-LVAD VAs and AF predict the occurrence of VAs after LVAD implantation. According to the latest data on the negative impact of post-LVAD VAs on all-cause mortality, further studies should clarify the reasonability of maintaining sinus rhythm in patients with AF and/or prophylactic catheter ablation of ventricular tachycardias before LVAD implantation.

Myocardial voltage ratio in arrhythmogenic right ventricular dysplasia/cardiomyopathy.

AIMS: This study aimed to analyze the influence of scar distribution between the endocardium and the epicardium in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). METHODS: Electroanatomical mapping data were derived from our ARVD/C registry. Myocardial voltage distribution between the endocardium and the epicardium was analyzed in 28 patients (18 men, 49.9 ± 13.0 years) with previous ventricular tachycardia (VT) ablation and complete right ventricular maps. RESULTS: During the follow-up period of 28 ± 22 months after ablation, 18 of 28 patients (64.3%) remained free from VT recurrence. In univariate analysis, five variables associated with VT recurrence, i. e., advanced age, right ventricular (RV) myocardial voltage ratio ≥0.58, inducibility of VT after ablation, and longer procedure and fluoroscopy time. In binary logistic regression analysis only RV myocardial voltage ratio ≥0.58 (hazard ratio 11.667, 95% confidence interval 1.487-91.543, p = 0.012) remained associated with an increased risk of VT recurrence. CONCLUSION: The myocardial voltage ratio (bipolar low voltage area/unipolar low voltage area) as a potential surrogate parameter for scar distribution between the endocardium and the epicardium is significantly associated with the outcome after VT ablation in ARVD/C.

Successful Repeat Catheter Ablation of Recurrent Longstanding Persistent Atrial Fibrillation With Rotor Elimination as the Procedural Endpoint: A Case Series.

BACKGROUND: There remains a lack of consensus regarding the ideal ablation strategy for atrial fibrillation (AF), particularly in patients with persistent or longstanding persistent AF. Given increasing evidence from clinical imaging studies that rotors sustain AF, rotor elimination may be a desirable procedural endpoint. However, there is no description to date of the clinical outcomes using rotor elimination during ablation as the procedural endpoint. Moreover, a series of studies question whether procedural AF termination is a desirable endpoint for ablation after many forms of AF ablation. METHODS AND RESULTS: We report a single-center experience of rotor elimination during AF ablation using Focal Impulse and Rotor Mapping (FIRM), describing 20 consecutive patients with case descriptions of 3 patients with recurrent longstanding persistent AF after prior ablation. In all cases, endocardial mapping using a 64-electrode basket catheter was performed to identify rotors, which were eliminated using radiofrequency catheter ablation. After it was verified that all identified rotors were eliminated, standard ablation consisting of PV isolation was performed. Notably, persistent AF terminated in only 1/20 (5%) patients. However, after a follow-up of 6 months, single-procedure freedom from AF was 80% (16/20 patients) with only 1 patient on antiarrhythmic drugs. All three patients in the highlighted series are AF free despite the lack of acute procedural AF termination. CONCLUSIONS: Patients with persistent AF including those with unsuccessful prior ablation can be treated successfully by rotor targeted ablation, using the elimination of all rotors rather than acute AF termination as the procedural endpoint.

Prospective, multicenter validation of a clinical risk score for left atrial arrhythmogenic substrate based on voltage analysis: DR-FLASH score.

BACKGROUND: Left atrial (LA) low-voltage areas (LVAs) are frequently observed in patients with atrial fibrillation (AF) and may predict AF recurrence after catheter ablation. OBJECTIVE: The aim of this study was to develop and validate a clinical tool to identify LVAs that are associated with AF recurrence after pulmonary vein isolation (PVI). METHODS: In a cohort of 238 patients, voltage maps were created during LA procedures. LVAs were defined as areas with electrogram amplitudes <0.5 mV. On the basis of regression analysis, predictors of LA substrate were identified. These parameters were used to establish a dedicated risk score (DR-FLASH score, based on diabetes mellitus, renal dysfunction, persistent form of AF, LA diameter >45 mm, age >65 years, female sex, and hypertension). This risk score was then prospectively validated in a multicenter cohort of 180 patients. The association of the score with long-term recurrence of atrial arrhythmias after circumferential PVI was tested in a retrospective cohort of 484 patients. RESULTS: The DR-FLASH score effectively identified LVA substrate (C statistic = 0.801, P < .001). In the prospective multicenter validation cohort, the predictive value of the DR-FLASH score was confirmed (C statistic = 0.767, P < .001). The probability for the presence of LA substrate increased by a factor of 2.2 (95% confidence interval [CI] 1.6-2.9, P < .001) with each point scored. Furthermore, the risk of AF recurrence after PVI increased by a factor of 1.3 (95% CI 1.1-1.5, P < .001) with every additional point and was almost 2 times higher in patients with a DR-FLASH score >3 (odds ratio 1.7, 95% CI 1.1-2.8, P = .026). CONCLUSION: The DR-FLASH score may be useful to identify patients who may require extensive substrate modification instead of PVI alone.

Non-fluoroscopic catheter tracking for fluoroscopy reduction in interventional electrophysiology.

A technological platform (MediGuide) has been recently introduced for non-fluoroscopic catheter tracking. In several studies, we have demonstrated that the application of this non-fluoroscopic catheter visualization system (NFCV) reduces fluoroscopy time and dose by 90-95% in a variety of electrophysiology (EP) procedures. This can be of relevance not only to the patients, but also to the nurses and physicians working in the EP lab. Furthermore, in a subset of indications such as supraventricular tachycardias, NFCV enables a fully non-fluoroscopic procedure and allows the lab staff to work without wearing lead aprons. With this protocol, we demonstrate that even complex procedures such as ablations of atrial fibrillation, that are typically associated with fluoroscopy times of >30 min in conventional settings, can safely be performed with a reduction of >90% in fluoroscopy exposure by the additional use of NFCV.

Tailored atrial substrate modification based on low-voltage areas in catheter ablation of atrial fibrillation.

BACKGROUND: Reduced electrogram amplitude has been shown to correlate with diseased myocardium. We describe a novel individualized approach for catheter ablation of atrial fibrillation (AF) based on low-voltage areas (LVAs) in the left atrium (LA). We sought to assess (1) the incidence of LVAs in patients undergoing AF catheter ablation, (2) the distribution of LVAs within the LA, and (3) the effect of an individualized ablation strategy on long-term rhythm outcomes. METHODS AND RESULTS: In 178 patients with paroxysmal or persistent AF, LA voltage maps were created during sinus rhythm after circumferential pulmonary vein isolation. Subsequent substrate modification was confined to the presence of LVA (<0.5 mV) and inducible regular atrial tachycardias. LVAs were identified in 35% and 10% of patients with persistent and paroxysmal AF, respectively. The LA roof and the anterior, septal, and posterior wall LA were most often affected. The 12-month atrial tachycardias/AF-free survival was 62% for patients without LVAs and 70% for patients with LVAs and tailored substrate modification (P=0.3). Success rate in a comparison group of 26 LVA patients without further substrate modification was 27%. CONCLUSIONS: LVAs can be found at preferred sites in 10% of patients with paroxysmal AF and in 35% of patients with persistent AF. This is the first clinical report describing a consistent voltage-based approach for substrate modification in addition to circumferential pulmonary vein isolation irrespective of AF type. Application of this limited individualized approach may have the potential to compensate for the impaired 12-month outcome of patients with endocardial structural defects.

Impact of metabolic syndrome on left atrial electroanatomical remodeling and outcomes after radiofrequency ablation of nonvalvular atrial fibrillation.

BACKGROUND: Recent studies reported worse outcomes after atrial fibrillation (AF) ablation in patients with metabolic syndrome (MetS). However, mechanisms of AF recurrence in MetS remain unclear. METHOD AND RESULTS: We performed pulmonary vein isolation and voltage mapping in 236 patients with AF (age 61±9.6 years; persistent AF 64%; MetS 54%). Left atrial (LA) low voltage areas were semiquantitatively estimated and presented as low voltage index. MetS was defined according to National Cholesterol Education Program Adult Treatment Panel III. Follow-up for AF recurrence ≤12 months was performed. LA low voltage areas were observed in 46% of patients with MetS versus 8.2% patients without MetS ; P<0.0001. MetS was an independent predictor of LA low voltage areas: odds ratio, 11.64; 95% confidence interval, 4.381-30.903; P<0.0001. Observed AF recurrence at 12 months was 42.7% in MetS versus 36.1% in the non-MetS group (P=0.303). The presence of LA low voltage areas was a predictor of 12-month AF recurrence: odds ratio, 2.99; 95% confidence interval, 1.36-6.56; P=0.006. Probability of 12-month AF recurrence increased with 84.5% for every unit of low voltage Index. CONCLUSIONS: MetS was not associated with worse outcomes after radiofrequency catheter ablation of AF, but LA low voltage areas were more frequently observed in patients with MetS. The presence and extent of LA low voltage areas may influence the long-term outcomes after catheter ablation.

Novel oral anticoagulants in a real-world cohort of patients undergoing catheter ablation of atrial fibrillation.

AIMS: Experiences with novel oral anticoagulants (NOACs) early after atrial fibrillation (AF) catheter ablation are limited and show controversial results. We aimed to assess the longer-term safety, efficacy, and acceptance of NOACs in a large real-world cohort of patients presenting for AF catheter ablation. METHODS AND RESULTS: From July 2010 until June 2012, 259 patients undergoing AF catheter ablation were prospectively included. Novel oral anticoagulants were given for at least 3 months post-ablation. Clinical outcome (stroke, thromboembolic events, major bleeding), adverse effects, and drug adherence were assessed at discharge and follow-up. On admission patients were presented with a variety of anticoagulants including 54 patients (21%) already on NOACs prior ablation. After ablation 38% of patients received dabigatran 110 mg, 56% 150 mg, and 6% received rivaroxaban 20 mg. There were four periprocedural thromboembolic and major bleeding complications (1.5%), all in patients without NOACs prior ablation (two on warfarin and two on heparin). During long-term follow-up [311 (199; 418) days] no stroke, systemic embolism, or major haemorrhage could be observed. Uneventful electrical cardioversions and reablation procedures were performed in 27 and 12 patients on dabigatran, respectively. Novel oral anticoagulants were prematurely stopped or switched to another anticoagulant due to side effects or at the preference of the treating general practitioner in 9 and 10 patients, respectively. CONCLUSION: In this prospective observational study, anticoagulation with NOACs following AF catheter ablation was safe and effective at long-term follow-up. Fast onset of action makes NOACs especially attractive in patients without effective anticoagulation on admission and in patients following periprocedural complications.