Predictors of high-degree conduction disturbances and pacemaker implantation after transcatheter aortic valve replacement: Prognostic role of the electrophysiological study.

BACKGROUND: Predictors of high-degree atrioventricular block (HAVB) after transcatheter aortic valve replacement (TAVR) are recognized, but the electrophysiological study's (EPS) role is still a subject to debate. The objective of our study was to determine factors associated with PPM implantation including the potential role of EPS before and/or after TAVR. METHODS AND RESULTS: Seventy four consecutive patients (pts) were included and 21 pts (28.4%) received a PPM during the immediate postoperative follow-ups (until Day 5): HAVB in 15 pts (71.4%), prophylactic implantation due to a documented increased HV interval ≥ 95-100 ms plus LBBB in 2 pts (9.5%), a high-degree HV block evidenced at the EPS plus LBBB in 3 pts (14.3%) and one additional patient was implanted for AV-block in presence of AFib (4.8%). In the multivariate model 1 including parameters before TAVR, both prosthesis diameter and PR lengthening remained significantly associated with PPM as well RBBB. In the multivariate model 2 including parameters after TAVR, only HV remained significantly associated with the risk of PPM (OR = 1.15 (1.05-1.26), p = .004). When all the significant variables in models 1 and 2 were analyzed together in model 3, only HV after TAVR remained significantly associated with an increased risk of PPM. CONCLUSIONS: In this prospective observational study, it was revealed that a Day 4-5 EPS is likely to more precisely stratify the risk of PPM implantation regarding its ability to discover asymptomatic severe infra-hisian conduction disturbances particularly in presence of LBBB. Multivariate analysis confirmed the prognostic value of HV alteration.

Does a patent foramen ovale matter when using a remote-controlled magnetic system for pulmonary vein isolation?

BACKGROUND: Pulmonary vein isolation (PVI) takes longer when using a patent foramen ovale (PFO) compared with a transseptal puncture in paroxysmal atrial fibrillation (AF) with manual catheter ablation. To our knowledge, no data exist concerning the impact of a PFO on AF ablation procedure variables when using a remote magnetic navigation (RMN) system. AIM: To assess the impact of a PFO when using an RMN system in patients requiring AF ablation. METHODS: Between December 2011 and December 2012, catheter ablation was performed remotely using the CARTO(®) 3 system in 167 consecutive patients who underwent PVI for symptomatic drug-refractory AF. The radiofrequency generator was set to a fixed power ≤ 35 W. The primary endpoint was wide-area circumferential PVI confirmed by spiral catheter recording during ablation for all patients and including additional lesion lines (left atrial roof) or complex fractionated atrial electrograms for persistent AF. Secondary endpoints included procedural data. RESULTS: Mean age 58±10 years; 18% women; 107 (64%) patients with symptomatic paroxysmal AF; 60 (36%) with persistent AF; CHA2DS2-VASc score 1.2 ± 1. The PFO presence was evidenced in 49/167 (29.3%) patients during the procedure but in only 26/167 (16%) by transoesophageal echocardiography. Median procedure time 2.5 ± 1 hours; median total X-ray exposure time 14 ± 7 minutes; transseptal puncture and catheter positioning time 7.5 ± 5 minutes; left atrium electroanatomical reconstruction time 3 ± 2.3 minutes; catheter ablation time 3 ± 3 minutes. No procedure time or X-ray exposure differences were observed between patients with or without a PFO during magnetic navigation catheter ablation. X-ray exposure time was significantly reduced using a PFO compared with double transseptal puncture access. CONCLUSIONS: A PFO does not affect magnetic navigation during AF ablation; procedure times and X-ray exposure were similar. Septal catheter probing is mandatory to limit X-ray exposure and prevent potential complications.

Remote-controlled magnetic pulmonary vein isolation using a new three-dimensional non-fluoroscopic navigation system: a single-centre prospective study.

BACKGROUND: Catheter ablation of atrial fibrillation (AF) focuses on pulmonary vein isolation (PVI), but the procedure is associated with significant X-ray exposure. Few data exist concerning the combination of remote magnetic navigation (RMN) and a new three-dimensional non-fluoroscopic navigation system (Carto(®) 3), which facilitates precise catheter navigation and limits X-ray exposure. AIMS: To assess the efficacy and extent of fluoroscopic exposure associated with the combination of RMN and the Carto 3 system in patients requiring AF ablation. METHODS: Between January and September 2011, catheter ablation was performed remotely using the Carto 3 system in 81 consecutive patients who underwent PVI for symptomatic drug-refractory AF. The radiofrequency generator was set to a fixed power ≤ 35W. The primary endpoint was wide-area circumferential PVI confirmed by spiral catheter recording during ablation and including additional lesion lines (left atrial roof and coronary sinus defragmentation) or complex fractionated atrial electrograms for persistent AF. Secondary endpoints included procedural data, complications and freedom from atrial tachycardia (AT)/AF. RESULTS: Mean age was 60 ± 9 years; 20% were women; 73% had symptomatic paroxysmal AF; 27% had persistent AF. The CHA2DS2-VASc score was 1.2 ± 1. Median procedure time was 3.5 ± 1 hours; median total X-ray exposure time was 13 ± 7 minutes; transseptal puncture and catheter positioning took 8 ± 4 minutes, left atrium electroanatomical reconstruction 1 ± 4 minutes and catheter ablation 3.5 ± 5minutes. Recurrences were AT (n=3; 3.7%), paroxysmal AF (n=8; 9.9%) and persistent AF (n=4; 4.9%); redo ablation was performed in these 15 (19%) patients. After a median follow-up of 15 ± 6 months and a single procedure, 71% of patients were free of symptoms; 84% remained asymptomatic after two procedures. CONCLUSIONS: RMN with irrigated catheters combined with the Carto 3 system can be effectively performed in patients requiring AF ablation with minimal use of fluoroscopy, but larger randomized studies are warranted.

Clinical impact of the implantable loop recorder in patients with isolated syncope, bundle branch block and negative workup: a randomized multicentre prospective study.

BACKGROUND: Few studies have compared conventional testing with prolonged monitoring using an implantable loop recorder (ILR) following the first syncope episode in patients with bundle branch block (BBB) and negative workup. OBJECTIVES: To compare two syncope evaluation strategies-primary use of an ILR (Group 1) versus conventional testing (Group 2)-and to estimate the prevalence of significant arrhythmias in the ILR patient subset. METHODS: From January 2005 to December 2010, 78 patients admitted after one syncope episode were randomized to ILR (n=41) or conventional follow-up (n=37). Mean follow-up was 27 ± 12 months. RESULTS: Mean age was 76 ± 8 years and 30 patients were women (38.5%); 18 presented cardiomyopathy (23%) and 12 had a history of atrial fibrillation (15.4%). Mean left ventricular ejection fraction was 56.5 ± 11% and mean His-to-ventricle interval was 55 ± 6ms based on negative electrophysiological study (EPS). Electrocardiogram abnormalities involved: 34 left bundle branch blocks (BBBs); 11 right BBBs; and 33 bifascicular blocks. Overall, 21 patients (27%) developed significant arrhythmic events: ventricular tachycardia (n=1; 1.3%); sudden death (n=2; 2.6%); third-degree atrioventricular (AV) block (n=14; 18%); sick sinus syndrome (n=4; 5.1%). In 19 (24.4%) patients, relevant arrhythmias were detected, with a significant difference between the ILR group (n=15/41; 36.6%) and the conventional follow-up group (n=4/37; 10.8%) (P=0.02). Eighteen patients were implanted with pacemakers; one received an implantable defibrillator. No predictors of AV block were identified in the ILR group. CONCLUSIONS: In this randomized prospective study, the ILR strategy proved largely superior to conventional follow-up in detecting recurrent events, with a potential impact on therapeutic management. This observation highlights the usefulness of early monitoring in patients with BBB and negative EPS even after the first syncope episode but an empiric pacemaker strategy remains to be validated in this selected population.

Radiofrequency catheter selection based on cavotricuspid angiography compared with a control group with an externally cooled-tip catheter: a randomized pilot study.

BACKGROUND: Radiofrequency ablation (RFA) of cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) can be performed using either externally cooled-tip RFA catheters or large-tip (8 mm) catheters. However, experimental and clinical studies suggest that the efficacy of both catheters may vary with CTI anatomy and catheters orientation. OBJECTIVES: The aim of this prospective study was to evaluate: a RFA catheter selection based on CTI angiography compared with a control group with an externally cooled-tip catheter together with the risk of an expensive crossover catheter in both groups. METHOD: Over a period of 16 months, 119 patients were included and randomized. RESULTS: When comparing the angiographic group (n = 56) and the externally cooled-tip RFA catheter group (n = 63), the duration of application time with a median of 7 min (interquartile range 4.5-11) versus a median of 10 min (interquartile range 6-20; P = 0.008) and the duration of X-ray exposure with a median of 7 min (interquartile range 4-10) versus a median of 10 min (interquartile range 5-15; P = 0.025) were significantly lower in the angiographic group versus externally cooled-tip catheter group. Furthermore, the number of catheters crossover was significantly higher in the angiographic group versus externally cooled-tip catheter group I (27% vs 7%; P = 0.007). CONCLUSIONS: This study shows that a strategy with a catheter selection based on a CTI angiographic evaluation is superior to an empirical use of an externally cooled-tip catheter during CTI RFA. Thus, angiographic isthmus evaluation predicts the effectiveness of a RFA catheter and the risk of an expensive catheter crossover.

Long-term efficacy and safety of radiofrequency ablation in elderly patients with atrioventricular nodal re-entrant tachycardia.

AIMS: The purpose of this study was to evaluate the efficacy, risks, safety, and follow-up of radiofrequency (RF) catheter ablation of atrioventricular nodal re-entrant tachycardia (AVRNT) in patients (pts) > or = 75 years old (n=42) (GpI) compared with pts younger than 75 years (n=234) (GpII). METHODS AND RESULTS: The study population consisted of 276 consecutive pts (39.5% men/60.5% women), from 15 to 98-year-old (average 56+/-17 years) with AVRNT referred for RF ablation (RFA) from October 1997 to January 2004. Combined anatomical and electrogram approaches were used to guide RFA. The cumulative risk of AVRNT recurrence was analysed by the Kaplan-Meier method and log-rank test. The average follow-up was 34+/-18 months. GpI (80+/-4 years) differed significantly from GpII (51+/-14 years) regarding: heart rate tachycardia (160+/-20 vs. 180+/-30 bpm; P=0.0001), the slow pathway antegrade refractory period (370+/-70 vs. 340+/-60 ms; P=0.01), the fast pathway antegrade refractory period (360+/-60 vs. 330+/-60 ms; P=0.003), retrograde refractory period (360+/-60 vs. 330+/-60 ms; P=0.0007), left ventricular ejection fraction (60+/-12 vs. 65+/-7%; P=0.0009), and ischaemic ECG signs during tachycardia (76.2% vs. 61%; P=0.09). RFA was successfully obtained in 275/276 (99.6%), 42/42 in GpI (100%), and 233/234 (99.6%) in GpII. Five complications occurred (1.8%): major complications in two pts (0.7%) and minor complications in three pts (1.1%). Major complications were deep venous thrombosis with pulmonary embolus (n=1) and pericardial effusion (n=1), minor complications were groin haematoma (n=3). One complication was observed in GpI (groin haematoma) (2.4%) and four in GpII (deep venous thrombosis with pulmonary embolus in one, groin haematoma in two, and pericardial effusion in one) (1.7%). The number of recurrences was not statistically different between the two groups (0 vs. 3.4%; P=0.5) with a respective average follow-up of 28+/-18 and 35+/-18 months, respectively. CONCLUSION: Catheter ablation of AVRNT in elderly and very elderly pts appears to be a reasonable approach regarding feasibility and effectiveness without increasing the risk of AV block.

Clinical predictors of cardiac events in patients with isolated syncope and negative electrophysiologic study.

BACKGROUND: Patients with syncope or near syncope of unknown etiology represent a great challenge to cardiologists. An initial symptomatic episode triggers a series of diagnostic analysis which remain unsatisfactory when negative. More invasive tools such as electrophysiologic testing yield only partial answers to risk stratification while the complementary implantable holter diagnostics are not usually considered until a recurrent episode is documented. OBJECTIVE: This study targets predictors of significant cardiac rhythmic events in patients with a reported episode of syncope or near syncope presenting with negative diagnostics and electrophysiologic study results (EPS). A significant cardiac rhythmic event was defined as a combined end-point of (1) symptomatic AV block; (2) symptomatic conduction abnormalities requiring pacemaker therapy; (3) symptomatic sustained ventricular arrhythmia; and (4) sudden death. METHODS: All patients undergoing EPS after a first episode of syncope or presyncope between January 1997 and December 2001 were included for analysis. The study population consisted of 329 pts (42.6% women), 21 to 96 years old (mean 70+/-15 years) referred for an EP study for syncope or near syncope. RESULTS: Of the 329 patients who underwent EPS, 305 (92.7%) had follow-up data. The population, mean age 70 (+/- 15 years) and composed of 42% women, presented with hypertension (51.5%), diabetes mellitus (14.4%), hypercholesterolemia (30%), tobacco use (35%), a familial history of coronary heart disease (22%), history of stroke (4%), history of MI (12%), history of atrial fibrillation (10%), structural heart disease (17.4%), left ventricular ejection fraction 61 (+/- 11%) and ECG abnormalities (37%). These anomalies included right (RBBB) or left (LBBB) bundle branch blocks, left anterior fascicular block (LAFB), left posterior fascicular block (LPFB), bifascicular block (RBBB+LAFB) and traces of myocardial infarction. The mean follow-up was 31+/-20 months with 5% of patients recording significant cardiac rhythmic events (15/305): AV block requiring pacemaker therapy in 7 patients, sinus dysfunction in 4, sudden death in 3 and ventricular tachycardia in 1. Univariate analysis reveals structural heart disease, ECG abnormalities and LVEF associated with the risk of significant cardiac rhythmic events defined by the combined end-point. Multivariate analysis using a Cox model found that the only independent predictor of events was an ECG abnormality. The long-term risk of significant event in the subset with ECG abnormalities is of 10.6% (12/113). If unexplained syncope recurrence was included in the combined end-point, ECG abnormality and LVEF were both determinants with a 13.3% (15/113) risk of a arrhythmic events analysis in the subset of patients presenting with ECG abnormalities and Cox model found ECG abnormality as the only independent predictor of event. CONCLUSIONS: This study demonstrated that an ECG abnormality is the only predictive variable associated with a significant arrhythmic event in patients with a lone episode of syncope or near syncope and a negative EPS.

Safety and efficacy of radiofrequency ablation of common atrial flutter in elderly patients: a single center prospective study.

Little data is available concerning the invasive treatment of atrial flutter (AFL) in elderly patients. The purpose of this prospective study was to evaluate the risks, safety, and follow-up of radiofrequency (RF) catheter ablation of common AFL in patients >75 years old (n = 61) (Group I) compared to patients younger than 75 years (n = 187) (Group II). The study population consisted of 248 patients (81% men/19% women), 21 to 96 years old (mean 66.3 +/- 12 years) with AFL, referred for RF from June 1999 to June 2001. RF endpoint was the assessment of the bidirectional block. The cumulative risk of atrial fibrillation (AF) was analyzed by the Kaplan-Meier method and log-rank test. The mean follow-up was 12.4 +/- 9 months. No complication occurred. Group I (80.1 +/- 4.5 years) did not differ significantly from Group II (61 +/- 11 years) regarding: AF history before ablation (34.4% vs 39.8%), structural heart disease (54% vs 42%), LVEF (57%+/- 12% vs 58%+/- 12%), left atrial size (43.8 +/- 7 vs 42.5 +/- 7), cava-tricuspid isthmus dimension (40 +/- 10 vs 39 +/- 4 mm), bidirectional block (100% vs 96.2%), RF application (12.5 +/- 10 vs 13.5 +/- 12 minutes), AFL recurrence (3.3% vs 5.3%), antiarrhythmic agents at hospital discharge (34.4% vs 38.9%), mean follow-up (12 +/- 9 vs 13 +/- 9 months) and AF occurrence (29.5% vs 20.3%; P = 0.2). Of these, the incidence of AF in patients without prior history (n = 150) was 7 (18%) of 39 for Group I and 11 (10%) of 111 for Group II (P = 0.1) after follow-up. Catheter ablation of AFL in very elderly patients appears to be a reasonable approach regarding feasibility, effectiveness, and low procedural risk.