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.

Characterizing left ventricular mechanical and electrical activation in patients with normal and impaired systolic function using a non-fluoroscopic cardiovascular navigation system.

PURPOSE: Cardiac disease frequently has a degenerative effect on cardiac pump function and regional myocardial contraction. Therefore, an accurate assessment of regional wall motion is a measure of the extent and severity of the disease. We sought to further validate an intra-operative, sensor-based technology for measuring wall motion and strain by characterizing left ventricular (LV) mechanical and electrical activation patterns in patients with normal (NSF) and impaired systolic function (ISF). METHODS: NSF (n = 10; ejection fraction = 62.9 ± 6.1%) and ISF (n = 18; ejection fraction = 35.1 ± 13.6%) patients underwent simultaneous electrical and motion mapping of the LV endocardium using electroanatomical mapping and navigational systems (EnSite™ NavX™ and MediGuide™, Abbott). Motion trajectories, strain profiles, and activation times were calculated over the six standard LV walls. RESULTS: NSF patients had significantly greater motion and systolic strains across all LV walls than ISF patients. LV walls with low-voltage areas showed less motion and systolic strain than walls with normal voltage. LV electrical dyssynchrony was significantly smaller in NSF and ISF patients with narrow-QRS complexes than ISF patients with wide-QRS complexes, but mechanical dyssynchrony was larger in all ISF patients than NSF patients. The latest mechanical activation was most often the lateral/posterior walls in NSF and wide-QRS ISF patients but varied in narrow-QRS ISF patients. CONCLUSIONS: This intra-operative technique can be used to characterize LV wall motion and strain in patients with impaired systolic function. This technique may be utilized clinically to provide individually tailored LV lead positioning at the region of latest mechanical activation for patients undergoing cardiac resynchronization therapy. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov . Unique identifier: NCT01629160.

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.

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.

Mapping-guided characterization of mechanical and electrical activation patterns in patients with normal systolic function using a sensor-based tracking technology.

AIMS: In times of evolving cardiac resynchronization therapy, intra-procedural characterization of left ventricular (LV) mechanical activation patterns is desired but technically challenging with currently available technologies. In patients with normal systolic function, we evaluated the feasibility of characterizing LV wall motion using a novel sensor-based, real-time tracking technology. METHODS AND RESULTS: Ten patients underwent simultaneous motion and electrical mapping of the LV endocardium during sinus rhythm using electroanatomical mapping and navigational systems (EnSite™ NavX™ and MediGuide™, SJM). Epicardial motion data were also collected simultaneously at corresponding locations from accessible coronary sinus branches. Displacements at each mapping point and times of electrical and mechanical activation were combined over each of the six standard LV wall segments. Mechanical activation timing was compared with that from electrical activation and preoperative 2D speckle tracking echocardiography (echo). MediGuide-based displacement data were further analysed to estimate LV chamber volumes that were compared with echo and magnetic resonance imaging (MRI). The lateral and septal walls exhibited the largest (12.5 [11.6-15.0] mm) and smallest (10.2 [9.0-11.3] mm) displacement, respectively. Radial displacement was significantly larger endocardially than epicardially (endo: 6.7 [5.0-9.1] mm; epi: 3.8 [2.4-5.6] mm), while longitudinal displacement was significantly larger epicardially (endo: 8.0 [5.0-10.6] mm; epi: 10.3 [7.4-13.8] mm). Most often, the anteroseptal/anterior and lateral walls showed the earliest and latest mechanical activations, respectively. 9/10 patients had concordant or adjacent wall segments of latest mechanical and electrical activation, and 6/10 patients had concordant or adjacent wall segments of latest mechanical activation as measured by MediGuide and echo. MediGuide's LV chamber volumes were significantly correlated with MRI (R2= 0.73, P < 0.01) and echo (R2= 0.75, P < 0.001). CONCLUSION: The feasibility of mapping-guided intra-procedural characterization of LV wall motion was established. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov; Unique identifier: CT01629160.

Asymmetrical left atrial remodelling in atrial fibrillation: relation with diastolic dysfunction and long-term ablation outcomes.

AIMS: The association between anatomical left atrial (LA) remodelling and ventricular diastolic dysfunction (DD) in atrial fibrillation (AF) patients is not well studied. We aimed to examine the effect of DD on anatomic LA remodelling and their relation with ablation outcomes. METHODS AND RESULTS: In 104 patients (58 ± 10 years, 69% male) referred for AF ablation, LA volume (LAV) was determined by computed tomography. A cutting plane, between the pulmonary vein (PV) ostia and the appendage and parallel to the posterior wall, divided LAV into anterior- (LA-A) and posterior-LA parts. The ratio of LA-A and LAV was defined as the LA asymmetry index (ASI). According to the current guidelines, the presence of DD was evaluated by echocardiography. Regression analysis was used to identify predictors of asymmetry changes and long-term success. Univariate linear regression revealed that ASI is associated with LAV, the presence of DD, and mitral regurgitation. Asymmetry index was higher in patients with DD (n = 35, 62 ± 5 vs. 59 ± 6%, P = 0.013) or mitral regurgitation (n = 67, 61 ± 6 vs. 58 ± 5%, P = 0.025). Multiple linear regression analysis showed that DD (B = 2.6, ß = 0.207, 95% confidence interval, CI: 0.167-5.011, P = 0.036) and LAV (B = 0.037, ß = 0.211, 95% CI: 0.003-0.071, P = 0.033) were the only factors independently associated with ASI (adjusted r2 = 0.92, F = 6.2, P = 0.003). Regression analysis showed that AF recurrence (33% after 24 months) is associated with asymmetric LA changes, while DD is not. CONCLUSIONS: Left atrial symmetry changes are associated with DD and dilatation. Since DD could cause LA remodelling, appropriate early treatment should be considered for AF patients with DD, before geometrical changes occur.

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.

Differences in predictors of implantable cardioverter-defibrillator therapies in patients with ischaemic and non-ischaemic cardiomyopathies.

AIMS: Implantable cardioverter-defibrillators (ICDs) have been shown to reduce mortality in patients with both ischaemic and non-ischaemic cardiomyopathy by terminating life-threatening arrhythmias. However, such arrhythmic events are unequally distributed among different patient subgroups. We aimed to evaluate predictors of appropriate ICD therapies as a step towards risk stratification in a real-world cohort. METHODS AND RESULTS: The prevalence and predictors of appropriate ICD therapies were analysed in 330 consecutive patients (mean age 65 ± 11, 81% male) with implanted ICDs due to ischaemic (n = 204) or dilated (n = 126) cardiomyopathy. During a mean follow-up of 19 ± 9 months, 1545 appropriate ICD therapies (antitachycardia pacing and shocks) were detected in 94 patients (29%). In multivariate analysis applied on the whole cohort, the presence of atrial fibrillation [AF: odds ratio (OR) = 1.906, confidence interval (CI) = 1.143-3.177, P = 0.013] and secondary prevention indication (OR = 1.963, CI = 1.123-3.432, P = 0.018) was associated with ICD therapy. The presence of cardiac resynchronization therapy (CRT) had a protective value (OR = 0.563, CI = 0.327-0.968, P = 0.038). Moreover, the predictors were different depending on the aetiology of the cardiomyopathy: in the ischaemic group, only secondary prevention indication (OR = 2.0, CI = 1.029-3.891, P = 0.041) and the presence of a biventricular system (OR = 0.359, CI = 0.163-0.794, P = 0.011) remained significant, while in the non-ischaemic group, an association with AF was observed (OR = 4.281, CI = 1.632-11.231, P = 0.003). CONCLUSION: The aetiology of cardiomyopathy should be taken into consideration for the therapy of ICD patients. The protective role of CRT devices should be pointed out in ischaemic cardiomyopathy (ICM) and a more rigorous antiarrhythmic treatment should be considered for ICM patients with secondary prevention or for dilated cardiomyopathy patients with AF.

Electrical storm in patients with implantable cardioverter-defibrillator in the era of catheter ablation: Implications for better rhythm control.

BACKGROUND: The modern era of cardiology has changed the population of implantable cardioverter-defibrillator (ICD) recipients. Identifying predictors of electrical storm (ES) in contemporary ICD patients could improve risk stratification, therapeutic strategies, and mortality. OBJECTIVE: The purpose of this study was to address these points in a real-world setting. METHODS: In 330 consecutive patients (65 ± 11 years, 81% male, left ventricular ejection fraction 29% ± 9%) with ICD implanted because of ischemic (n, 204) or nonischemic dilated cardiomyopathy (n, 126), we analyzed the prevalence, predictors, and outcome of ES (≥3 separate VT/VF episodes within 24 hours) therapy. RESULTS: During a median of 21 months (range 17-36 months), 23 patients (7%) had ES. Secondary prevention (61% vs 24%, P <.01), single-chamber devices (57% vs 38%, P = .02), and prior appropriate (96% vs 24%, P < .001) and inappropriate (30% vs 9%, P = .004) therapies were more prevalent in these patients. In ES patients, first appropriate therapy occurred more often in the first year after implantation than in the rest of the cohort (85% vs 45%, P = .008), and mortality was significantly higher (22% vs 2%, P < .001). Multivariate Cox regression analysis showed that secondary prevention (hazard ratio [HR] 2.83, 95% confidence interval [CI] 1.21-6.61, P = .016) and prior appropriate (HR 88.99, 95% CI 11.73-675, P < .001) and inappropriate (HR 2.83, 95% CI 1.14-7.0, P = .04) therapies were independent predictors of ES. CONCLUSION: ES is not uncommon in ICD recipients. A secondary prevention indication and the occurrence of both appropriate and inappropriate ICD therapies increase the risk for ES. Prompt initiation of aggressive treatment, especially catheter ablation, should be considered for these patients.

Cardiogenic Stroke Despite Low CHA2 DS2 -VASc Score: Assessing Stroke risk by Left Atrial Appendage Anatomy (ASK LAA).

INTRODUCTION: In patients with atrial fibrillation (AF), LAA morphology has been suggested to modify thromboembolic event (TE) risk. We tested the hypothesis that TE in low-risk patients is associated with LAA characteristics. METHODS: Of 2,069 patients who underwent AF ablation, 25 (1.2%) had a prior TE and a low CHA2 DS2 -VASc score (≤1). Those patients were matched for the CHA2 DS2 -VASc criteria with 75 event-free patients and CT data were compared. LAA measurements, morphology (Cactus, Chicken-Wing, Windsock, Cauliflower), and takeoff of the superior and inferior edge in relation (higher or lower) to the respective takeoff of the adjacent pulmonary vein (PV) were determined. LAA flow in relation to heart rate was also compared. RESULTS: Univariate analysis showed that TE patients had a higher incidence of superior LAA takeoff (i.e., higher than the left superior PV; 28% vs. 4%, P = 0.002) and a higher incidence of hyperlipidemia (40% vs. 17%, P = 0.028), while LAA morphologies, inferior takeoff, and other LAA characteristics were similar between groups. Logistic regression revealed that a superior LAA takeoff (OR: 9.1, 95% CI: 2.1-38.6, P = 0.003) was the only independent predictor of TE. There was a negative correlation between heart rate and LAA flow (r = -0.2 cm/s pro bpm, P = 0.048), that was even more pronounced for the superior LAA takeoff (r = -0.67 cm/s pro bpm, P = 0.035). CONCLUSION: A higher LAA takeoff is associated with a tachycardia-mediated thrombogenic flow and an increased thromboembolic risk. These findings may have implications for anticoagulation management of AF patients with low CHA2 DS2 -VASc scores and higher LAA takeoff.

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.

Comparison of left atrial dimensions in CT and echocardiography as predictors of long-term success after catheter ablation of atrial fibrillation.

PURPOSE: Left atrium (LA) size is a common predictor of ablation outcomes in atrial fibrillation (AF), but different LA diameters have not been adequately studied yet. We aimed to find the best predictor of ablation outcomes using single-linear LA dimensions by computed tomography (CT) or echocardiography. METHODS: Patients (n = 103, 72 males, 59 ± 9 years) undergoing AF ablation were analyzed. LA diameter (LA-D) was measured by transthoracic echocardiography (parasternal long axis). After 3D reconstruction of CT data (EnSite Verismo, SJM, MN), maximal LA dimensions were measured on a coronal plane (superior-inferior, SI, and transversal, TV) and a sagittal plane (anterior-posterior, AP). Volume (LAV) was rendered after LA appendage and pulmonary vein exclusion. RESULTS: Patients with persistent AF (n = 40) had significantly larger LA size than those with paroxysmal AF (n = 63). After 26 ± 14 months, 31 (30 %) patients had AF recurrence. Univariate Cox regression analysis revealed that LA-D, LA-SI, LA-TV, LAV, and LAV-index (LAV/body surface area) were associated with AF recurrence. Multivariate Cox regression analysis revealed that LAV was the strongest independent predictor of AF recurrence (HR = 1.011 per ml, 95 % CI 1.003-1.020, p = 0.002). LA-TV had the best correlation with LAV (r = 0.69, p < 0.01) and was the strongest single-linear predictor (HR = 1.07 per mm, 95 % CI 1.022-1.121, p = 0.004). Independent of LA-D, an LA-TV>74.5 mm predicted AF recurrence similarly to LAV>126 ml. CONCLUSIONS: LA dilatation, especially on the coronal plane, is associated with reduced long-term success after catheter ablation. LA-TV is the best linear predictor of AF recurrence, stronger than the commonly used LA-D.

Procedural Outcomes and Survival After Catheter Ablation of Ventricular Tachycardia in Relation to Electroanatomical Substrate in Patients With Nonischemic-Dilated Cardiomyopathy: The Role of Unipolar Voltage Mapping.

INTRODUCTION: In patients with ischemic cardiomyopathy the size of bipolar low-voltage areas (LVA) in electroanatomical maps (EAM) was associated with poorer outcomes after catheter ablation (CA) of ventricular tachycardia (VT). However, the effect of LVA size on the survival after VT ablation in patients with nonischemic dilated cardiomyopathy (NIDCM) has not been studied. METHODS AND RESULTS: In 55 patients with NIDCM (48 male, age 61 ± 16 years, ejection fraction 32 ± 13%) an EAM to delineate the bipolar and unipolar LVAs was performed in 52 (94.5%) patients endocardially, in 24 (43.6%) patients epicardially, and in 21 (38.2%) patients on both surfaces. Additionally, activation mapping of the VT was possible in 22 (40%) patients. CA with lines transecting the scar and targeting late potentials was performed in all patients. Complete VT noninducibility at the end was achieved in 40 (72.7%) patients. During the median follow-up of 22 (interquartile range IQR 6, 34) months, VT recurrences were observed in 30 (54.5%) and cardiac death in 14 (25.5%) patients. The ROC analysis revealed that the size of endocardial unipolar LVA (<8.3 mV) was associated with cardiac death (AUC 0.89, 95% CI 0.79-0.98, P <0.0001). UVA = 145 cm2 discriminates for cardiac death with 83% sensitivity and 78% specificity. Endocardial UVA > 145 cm2 was a predictor for cardiac death (adjusted HR = 6.9; P = 0.014) and UVA ≥ 54% (of total endocardial LV surface) for VT recurrence (adjusted HR = 3.5; P = 0.016). CONCLUSION: The size of endocardial unipolar LVA (<8.3 mV) was a strong and independent predictor for cardiac mortality and VT recurrence in patients with NIDCM.

Differentiating the origin of outflow tract ventricular arrhythmia using a simple, novel approach.

BACKGROUND: Numerous electrocardiographic (ECG) criteria have been proposed to identify localization of outflow tract ventricular arrhythmias (OT-VAs); however, in some cases, it is difficult to accurately localize the origin of OT-VA using the surface ECG. OBJECTIVE: The purpose of this study was to assess a simple criterion for localization of OT-VAs during electrophysiology study. METHODS: We measured the interval from the onset of the earliest QRS complex of premature ventricular contractions (PVCs) to the distal right ventricular apical signal (the QRS-RVA interval) in 66 patients (31 men aged 53.3 ± 14.0 years; right ventricular outflow tract [RVOT] origin in 37) referred for ablation of symptomatic outflow tract PVCs. We prospectively validated this criterion in 39 patients (22 men aged 52 ± 15 years; RVOT origin in 19). RESULTS: Compared with patients with RVOT PVCs, the QRS-RVA interval was significantly longer in patients with left ventricular outflow tract (LVOT) PVCs (70 ± 14 vs 33.4±10 ms, P < .001). Receiver operating characteristic analysis showed that a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 100%, 94.6%, 93.5%, and 100%, respectively, for prediction of an LVOT origin. The same analysis in the validation cohort showed sensitivity, specificity, and positive and negative predictive values of 94.7%, 95%, 95%, and 94.7%, respectively. When these data were combined, a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 98%, 94.6%, 94.1%, and 98.1%, respectively, for prediction of an LVOT origin. CONCLUSION: A QRS-RVA interval ≥49 ms suggests an LVOT origin. The QRS-RVA interval is a simple and accurate criterion for differentiating the origin of outflow tract arrhythmia during electrophysiology study; however, the accuracy of this criterion in identifying OT-VA from the right coronary cusp is limited.

Catheter ablation of ventricular tachycardia and mortality in patients with nonischemic dilated cardiomyopathy: can noninducibility after ablation be a predictor for reduced mortality?

BACKGROUND: Data on outcomes after catheter ablation of ventricular tachycardia (VT) in patients with nonischemic dilated cardiomyopathy (NIDCM) are insufficient. We aimed to investigate the effects of successful catheter ablation of VT on cardiac mortality in patients with NIDCM. METHODS AND RESULTS: One hundred two patients with NIDCM (86 men; mean age, 58.8±15.2 years; mean ejection fraction, 33.3±11.9%) underwent VT ablation. After catheter ablation, a programmed ventricular stimulation to test for success was performed. Complete VT noninducibility was achieved in 62 (61%) patients and partial success or failure in 32 (31%) patients. During 2 years of follow-up, VT recurrence was observed in 33 patients (53%) without inducible VTs and in 24 patients (75%) with inducible VT inducible (P=0.041). VT inducibility was associated with higher VT recurrence (adjusted hazard ratio, 1.84; 95% confidence interval, 1.08-3.13; P=0.025). The primary end point of all-cause mortality was reached in 9 patients (15%) with noninducible VTs versus 11 patients (34%) with inducible sustained VTs (P=0.026). VT inducibility was associated with all-cause mortality (adjusted hazard ratio, 2.73; 95% confidence interval, 1.003-7.43; P=0.049). CONCLUSIONS: In patients with NIDCM and recurrent sustained VTs, a complete ablation of all inducible VTs may be achieved in 60% of the cases. The complete noninducibility may be a preferable end point of ablation because it was associated with better long-term success. Importantly, if possible to achieve through ablation, a complete VT noninducibility was associated with reduction of the likelihood for all-cause mortality in patients with NIDCM.

The APPLE score: a novel and simple score for the prediction of rhythm outcomes after catheter ablation of atrial fibrillation.

BACKGROUND: Recurrent atrial fibrillation (AF) occurs in up to 50 % of patients within 1 year after catheter ablation, and a clinical risk score to predict recurrence remains a critical unmet need. The aim of this study was to (1) develop a simple score for the prediction of rhythm outcome following catheter ablation; (2) compare it with the CHADS2 and CHA2DS2-VASc scores, and (3) validate it in an external cohort. METHODS: Rhythm outcome between 3 and 12 months after AF catheter ablation were documented. The APPLE score [one point for age >65 years, persistent AF, impaired eGFR (<60 ml/min/1.73 m(2)), LA diameter ≥43 mm, EF < 50 %] was associated with AF recurrence and was validated in an external cohort in 261 patients with comparable ablation and follow-up. RESULTS: In 1145 patients (60 ± 10 years, 65 % male, 62 % paroxysmal AF) the APPLE score showed better prediction of AF recurrences (AUC 0.634, 95 % CI 0.600-0.668, p < 0.001) than CHADS2 (AUC 0.538) and CHA2DS2-VASc (AUC 0.542). Compared to patients with an APPLE score of 0, the odds ratio for AF recurrences was 1.73, 2.79 and 4.70 for APPLE scores 1, 2, or ≥3, respectively (all p < 0.05). In the external validation cohort, the APPLE score showed similar results (AUC 0.624, 95 % CI 0.562-0.687, p < 0.001). CONCLUSIONS: The novel APPLE score is superior to the CHADS2 and CHA2DS2-VASc scores for prediction of rhythm outcome after catheter ablation. It holds promise as a useful tool to identify patients with low, intermediate, and high risk for AF recurrence.