Insight into contact force local impedance technology for predicting effective pulmonary vein isolation.

Background: Highly localized impedance (LI) measurements during atrial fibrillation (AF) ablation have the potential to act as a reliable predictor of the durability of the lesions created. Objective: We aimed to collect data on the procedural parameters affecting LI-guided ablation in a large multicenter registry. Methods: A total of 212 consecutive patients enrolled in the CHARISMA registry and undergoing their first pulmonary vein (PV) isolation for paroxysmal and persistent AF were included. Results: In all, 13,891 radiofrequency (RF) applications of ≥3 s duration were assessed. The first-pass PV isolation rate was 93.3%. A total of 80 PV gaps were detected. At successful ablation spots, baseline LI and absolute LI drop were larger than at PV gap spots (161.4 ± 19â€…Ω vs. 153.0 ± 13 Ω, p < 0.0001 for baseline LI; 22.1 ± 9â€…Ω vs. 14.4 ± 5 Ω, p < 0.0001 for LI drop). On the basis of Receiver operating characteristic curve analysis, the ideal LI drop, which predicted successful ablation, was >21â€…Ω at anterior sites and >18â€…Ω at posterior sites. There was a non-linear association between the magnitude of LI drop and contact-force (CF) (r = 0.14, 95% CI: 0.13-0.16, p < 0.0001) whereas both CF and LI drop were inversely related with delivery time (DT) (-0.22, -0.23 to -0.20, p < 0.0001 for CF; -0.27, -0.29 to -0.26, p < 0.0001 for LI drop). Conclusion: An LI drop >21â€…Ω at anterior sites and >18â€…Ω at posterior sites predicts successful ablation. A higher CF was associated with an increased likelihood of ideal LI drop. The combination of good CF and adequate LI drop allows a significant reduction in RF DT. Clinical trial registration: http://clinicaltrials.gov/, identifier: NCT03793998.

Device-Related Thrombosis After Percutaneous Left Atrial Appendage Occlusion for Atrial Fibrillation.

BACKGROUND: Transcatheter left atrial appendage (LAA) occlusion is an alternative strategy for stroke prevention in patients with atrial fibrillation (AF). OBJECTIVES: This study sought to determine the incidence, predictors, and prognosis of thrombus formation on devices in patients with AF who were treated with LAA closure. METHODS: The study retrospectively analyzed data from patients treated with 2 LAA closure devices seen in 8 centers in France from February 2012 to January 2017. RESULTS: A total of 469 consecutive patients with AF underwent LAA closure (272 Watchman devices [Atritech, Boston Scientific, Natick, Massachusetts] and 197 Amplatzer devices [St. Jude Medical, Minneapolis, Minnesota]). Mean follow-up was 13 ± 13 months, during which 339 (72.3%) patients underwent LAA imaging at least once. There were 98 major adverse events (26 thrombi on devices, 19 ischemic strokes, 2 transient ischemic attacks, 18 major hemorrhages, 33 deaths) recorded in 89 patients. The incidence of device-related thrombus in patients with LAA imaging was 7.2% per year. Older age (hazard ratio [HR]: 1.07 per 1-year increase; 95% confidence interval [CI]: 1.01 to 1.14; p = 0.02) and history of stroke (HR: 3.68; 95% CI: 1.17 to 11.62; p = 0.03) were predictors of thrombus formation on the devices, whereas dual antiplatelet therapy (HR: 0.10; 95% CI: 0.01 to 0.76; p = 0.03) and oral anticoagulation at discharge (HR: 0.26; 95% CI: 0.09 to 0.77; p = 0.02) were protective factors. Thrombus on the device (HR: 4.39; 95% CI: 1.05 to 18.43; p = 0.04) and vascular disease (HR: 5.03; 95% CI: 1.39 to 18.23; p = 0.01) were independent predictors of ischemic strokes and transient ischemic attacks during follow-up. CONCLUSIONS: Thrombus formation on the device is not uncommon in patients with AF who are treated by LAA closure. Such events are strongly associated with a higher risk of ischemic stroke during follow-up. (REgistry on Real-Life EXperience With Left Atrial Appendage Occlusion [RELEXAO]; NCT03279406).

A 5-year clinical follow-up after duty-cycled phased RF ablation of paroxysmal atrial fibrillation.

PURPOSE: Catheter radiofrequency ablation (RFA) is an effective treatment for symptomatic paroxysmal atrial fibrillation (AF). It has been demonstrated that the multielectrode pulmonary vein ablation catheter (PVAC) has favourable outcomes at 6-12 months post-ablation, but there are only few studies with a long-term follow-up. METHODS: We retrospectively reviewed 77 consecutive PVAC procedures in our centre, from November 2007 to December 2012. RFA was attempted in patients with symptomatic paroxysmal AF (mean age 58.7 ± 9.8 years, 50 men (64.9 %). The ablation strategy consisted of circumferential pulmonary vein isolation (CPVI) with the PVAC system. A questionnaire was used over the follow-up period to assess the efficacy of AF ablation. Success was defined as freedom from AF/atrial flutter or atrial arrhythmia for a period ranging from 3 to 12 months or more. RESULTS: Seventy-seven patients were included with paroxysmal AF. The mean duration of the procedure was 99.6 ± 26 min and fluoroscopy time 19.4 ± 6.8 min. Time of RFA was 22.4 ± 5.8 min. Acute complication rate was 10.4 % (the most frequent was vascular injury for 6 patients 7.8 %, 1 patient presented sepsis (1.3 %), 1 patient presented transient ischemic stroke). After a single procedure at a mean FU of 55 ± 11 months, 54/77 (70.1 %) patients were free of symptomatic AF. CONCLUSIONS: These long-term results suggest that PVAC is an efficient system for CPVI of symptomatic paroxysmal AF.

A randomized study of defibrillator lead implantations in the right ventricular mid-septum versus the apex: the SEPTAL study.

INTRODUCTION: The study was designed to evaluate the feasibility and performance of right ventricular (RV) mid-septal versus apical implantable defibrillator (ICD) lead placement. METHODS AND RESULTS: SEPTAL is a randomized, noninferiority trial, which randomly assigned patients to implantation of ICD leads in the RV mid-septum versus apex, with a primary objective of comparing the implant success rate of implant at each site, based on strict electrical predefined criteria. We also compared the (1) pacing lead characteristics, (2) rates of appropriate and inappropriate ICD therapies, and (3) all-cause mortality between the 2 sites at 1 year. The trial enrolled 215 patients (mean age = 59.7 ± 12.4 years, mean LVEF = 34.0 ± 14.2%, 84.2% men), of whom 148 (68.8%) presented with ischemic heart disease. The ICD indication was primary prevention in 117 patients (54.4%). The lead was successfully implanted in 96/107 patients (89.7%) assigned to the RV mid-septum, and in 99/108 (91.7%) assigned to the apex (ns). The 1-year rate of lead-related adverse events was similar in both groups. A total of 8 first inappropriate ICD therapies (7.9%) were delivered in the RV mid-septal group, versus 8 (7.8%) in the apical group (ns), while first appropriate therapies were delivered to 22 (21.4%) and 24 patients (23.8%), respectively (ns). All-cause mortality was 7.9% in the RV mid-septal versus 2.9% in the RV apical group (ns). CONCLUSION: This study confirmed the technical feasibility and noninferior performance of ICD leads implanted in the RV mid-septum versus the apex.

Relationship between New York Heart Association class change and ventricular tachyarrhythmia occurrence in patients treated with cardiac resynchronization plus defibrillator.

AIMS: In patients with advanced heart failure (HF) and prolonged QRS interval, cardiac resynchronization therapy (CRT) reduces symptoms and risk of death. The added benefit of an implantable cardioverter defibrillator (ICD) remains questionable in some patients. METHODS AND RESULTS: In 332 HF patients treated with CRT-D (CRT with ICD) [65 +/- 10 years, 86% men, 23% New York Heart Association (NYHA) class II, 65% class III, and 11% class IV, 70% primary prevention, 55% ischaemic cardiomyopathy, left ventricular ejection fraction 25 +/- 7.5%, and QRS width 167 +/- 32 ms], we evaluated the relationship between functional status change, death at 6-month follow-up (FU), and the occurrence of ventricular tachyarrhythmia/ventricular fibrillation (VT/VF). A total of 68 patients (20.5%) experienced 1266 spontaneous episodes of VT/VF during FU. There was no difference in baseline characteristics between patients with or without VT/VF, except for ICD indication (primary or secondary prevention). Improvement in NYHA class was significantly associated with a decreased occurrence of VT/VF (P = 0.004). Sixteen patients who died had significantly more often VT/VF than the survivors (50 vs. 19%, P = 0.007). CONCLUSION: Within the initial 6-month post-CRT therapy, 20% of patients received an appropriate ICD therapy. Patients improving on NYHA class (responders to CRT) have less VT/VF episodes than non-responders. Discriminant criteria for CRT response are awaited to optimize the choice of the device (CRT alone, defibrillator alone, or CRT-D).

Abnormalities of ventricular repolarization in mitral valve prolapse.

OBJECTIVES: Mitral valve prolapse (MVP) is associated with arrhythmias and sudden death. Some studies suggest that abnormalities of the autonomic nervous system (ANS) may contribute to these arrhythmias. In a family investigation with genetic analysis of patients carrying a MVP, we performed a Holter study to define the autonomic profile of MVP. METHODS AND RESULTS: A 24-hour digitized 3-lead Holter ECG was recorded in 30 patients with MVP and in two control groups, a group of 30 healthy relatives and a group of 31 healthy volunteers. We studied especially heart rate variability (HRV) and QT dynamicity. The slope of the relationship between ventricular repolarization and heart rate was studied separately during day and night. There was no difference in HRV (SDNN, rMSSD) among the three groups. On the contrary, QT interval duration was increased in patients with MVP as compared to healthy relatives (QT end: 409+/-52 ms vs 372+/-23 ms, P<0.05; QT apex: 319+/-42 ms vs 286+/-23 ms, P<0.01) and to healthy volunteers (QT end: 409+/-52 ms vs 376+/-25 ms, P=0.004; QT apex: 319+/-42 ms vs 289+/-23 ms, P<0.01). Nocturnal ventricular repolarization rate dependence was increased in MVP as compared to healthy relatives (0.16+/-0.06 vs 0.13+/-0.04, P<0.05) and to healthy volunteers (0.16+/-0.06 vs 0.11+/-0.06, P<0.001) whereas the 24-hour and diurnal QT-R-R slope was not disturbed. CONCLUSION: In MVP, QT is increased and the circadian modulation of QT end/RR slope is disturbed with an increased nocturnal rate dependence. These abnormalities of ventricular repolarization might explain the risk of arrhythmic events in MVP.

Determinants of mortality in patients undergoing cardiac resynchronization therapy: baseline clinical, echocardiographic, and angioscintigraphic evaluation prior to resynchronization.

BACKGROUND: In dilated cardiomyopathy (DCM) patients (pts) with cardiac resynchronization therapy (CRT) for ventricular dyssynchrony, long-term predictors of mortality and morbidity remain poorly investigated. METHOD AND RESULTS: We reviewed data of 102 pts, 68 +/- 10 years, NYHA Class II-IV (14 Class II, 67 Class III, 21 Class IV), who benefited from CRT (69 CRT, 33 CRT-ICD). Fifty-two patients had an ischemic DCM, 36 a previously implanted conventional PM/ICD, 29 a permanent atrial fibrillation, and 19 needed dobutamine in the month preceding implant. QRS duration was 187 +/- 35 ms, left ventricular end-diastolic diameter 72 +/- 10 mm, mitral regurgitation severity 1.9 +/- 0.8, echographic aorto-pulmonary electromechanical delay 61.5 +/- 25 ms and septo-lateral left intraventricular delay 86 +/- 56 ms, pulmonary artery pressure (PAP) 43 +/- 11 mmHg, angioscintigraphic left ventricular ejection fraction (EF) 20 +/- 9%, and right ventricular EF 30.5 +/- 14%. Over a mean follow-up of 23 +/- 20 months, 26 pts died (18 heart failures (HFs), 1 arrhythmic storm, 7 noncardiac deaths). Positive univariate predictors of death from any cause were NYHA Class IV (P < 0.001), and need for dobutamine the month preceding CRT (P < 0.008), while use of beta-blocking agents (P < 0.08) and left ventricular EF (P < 0.09) were negative ones. NYHA Class IV was the only independent predictor at multivariate analysis (P < 0.01). Survival at 24 months was 85% in Class II, 80% in Class III, and 37% in Class IV (II vs III, P = ns; III vs IV, P < 0.001). When using a composite endpoint of death from any cause and unplanned rehospitalization for a major cardiovascular event, there were 48 events (14 HF deaths, 3 noncardiac deaths, 26 HF rehospitalizations, 2 paroxysmal atrial fibrillation, 2 sustained ventricular tachycardia, 1 nonfatal pulmonary embolism). Predictors of death from any cause/unplanned rehospitalization for a major cardiovascular event in the follow-up were NYHA Class IV (P < 0.001), need for dobutamine during the month preceding CRT (P < 0.002), and PAP (<0.02). NYHA Class IV was the only independent predictor at multivariate analysis (P < 0.05). Event-free proportion at 24 months was 70% in Class II, 64% in Class III, and 37% in Class IV (II vs III, P = ns; III vs IV, P < 0.01). When considering determinants of mortality only in NYHA Class IV patients, no variable was significantly correlated to mortality. Need for dobutamine during the last month preceding CRT did not add an adjunctive mortality risk. CONCLUSION: Baseline NYHA Class IV at implantation appears as the most important determinant of a poor clinical outcome in terms of both mortality and morbidity. No predictive criteria seem available for NYHA Class IV patients, in order to discriminate who will die after CRT and who will not. NYHA Class IV strongly influences the clinical outcome, suggesting that, in future studies planned on mortality and rehospitalization as major endpoints, baseline NYHA Class IV should be separately taken into account.

[Catheter cryoablation for the treatment of supraventricular arrhythmias]. / La cryoablation endocardiaque percutanée dans le traitement des arythmies supraventriculaires.

Catheter ablation is a radical treatment for various severe and drug-refractory arrhythmias. Radiofrequency is the reference energy for ablation, but has some limitations. Cryoenergy gradually freezes myocardial tissue, allowing the consequences to be predicted before inducing the lesion. Furthermore, the lesions are better-circumscribed and less thrombogenic than those induced by radiofrequency. Twenty-two patients (12 women) aged from 20 to 79 years with drug-refractory supraventricular arrhythmias underwent cryoablation. The ablation catheter was cooled by nitrous oxide expansion. The electrophysiological properties of the tissue are reversibly lost at a temperature of -30 degrees C, allowing cryomapping. When the appropriate target has been located, the temperature is reduced to -70 degrees C. The cryoablation is painless. The procedure was initially successful in all 12 patients with atrionodal reentrant tachycardias, usually after one or two applications. However, during the 8-month follow-up period, slower, transient tachycardia recurred in 3 patients. We observed no cases of atrioventricular (AV) block, a possible complication of radiofrequency. Cryoablation was successful and safe in two patients with an accessory pathway (Kent). In eight patients with atrial fibrillation and uncontrolled ventricular tachycardia, cryoablation was used with the aim of slowing nodal conduction. Initial success was obtained in 7 cases (3 modulations and 4 complete AV blocks) but only persisted in four cases, suggesting that more applications should be used or different sites targeted. The efficacy and safety of cryoablation make it an attractive option for the ablation of small substrates close to the nodo-Hisian tissue (atrionodal reentries and accessory pathways). New criteria must be developed to define long-term success of cryoablation of the AV node, which is successful in the acute setting.

Cost of care distribution in atrial fibrillation patients: the COCAF study.

BACKGROUND: Atrial fibrillation (AF) currently represents a major economic burden for society. Very few studies have been performed to evaluate the cost of care for AF patients. This study is a large prospective survey designed to analyze the different cost drivers in the treatment of these patients. This survey, named Cost of Care in Atrial Fibrillation (COCAF), evaluated the cost of care for patients with AF treated by cardiologists in general office practice. METHODS: A group of 671 patients was recruited by 82 cardiologists distributed in all regions of France. The mean age of the patients was 69 years, and 64% were male. The mean follow-up was 329 +/- 120 days. The costs of care were analyzed from the health care payer and the societal perspectives. RESULTS: During the follow-up period, 21 patients (3.13%) died and 210 (31.3%) patients were hospitalized. The number of hospitalizations and deaths was significantly higher in the group of persistent or permanent AF (PEAF) patients, as compared to paroxysmal AF (PAAF) patients. Hospitalizations were much more frequent in the PEAF group (127) than in the PAAF group (83, P <.05). Deaths were also much more frequent in the PEAF group (17) as compared to the PAAF group (4, P <.001). From the societal perspective, the first cost driver was hospitalizations (52%), followed by drugs (23%), consultations (9%), further investigations (8%), loss of work (6%), and paramedical procedures (2%). In multivariate analysis the following parameters were significantly associated with higher costs: heart failure (P <.04), coronary artery disease (P <.001), use of class III antiarrhythmic drugs (P <.002), hypertension (P <.002) and metabolic disease (P <.001). CONCLUSIONS: This prospective survey shows that hospitalizations represent the major cost driver in the treatment of AF patients. Outpatient care programs must be proposed to AF patients in order to avoid readmissions and to reduce the cost of treatment.

[Atrial fibrillation: rhythm or rate control?]. / Fibrillation atriale: réduire ou ralentir?

For many years it has been considered that it was necessary, whenever possible, to cardiovert atrial fibrillation and to maintain the sinus rhythm with antiarrhythmic drugs. There are many theoretical advantages to this maintenance of the sinus rhythm. Nevertheless the choice of the drugs used to maintain rhythm is often difficult and the therapeutical index of these drugs may be poor. It is necessary to avoid class I antiarrhythmic drugs in patients with congestive heart failure and coronary artery disease. In these cases, only sotalol and amiodarone can be used. The safety index of these drugs being low, plain rate control with persistence of atrial fibrillation has been proposed as a treatment alternative. Several drugs may be used: calcium inhibitors, beta-blockers, digitalis. It is always necessary to associate anticoagulation: of course if rate control is chosen, but also if rhythm control is obtained, owing to the possible risk of relapse. Several trials of comparison between these 2 strategies have been recently performed. Available results show no clear superiority of a strategy above the other but there is a tendency towards a lower mortality in the rate control group.