Sergio Richter

Efficacy and Safety of ICD Therapy in a Population of Elderly Patients Treated with Optimal Background Medication

Introduction: Implantable cardioverter-defibrillator (ICD) therapy has been shown to improve survival in patients with structural heart disease and at high risk for life threatening ventricular arrhythmias. Whether elderly patients benefit from device therapy in a similar way as younger patients is largely unknown.Methods: We retrospectively analyzed data from 375 consecutive ICD recipients with structural heart disease. Patients were divided into two groups, younger than 70 years at time of ICD implantation (group 1) or 70 years or older (group 2). Main outcome measures were time to death from any cause and time from first appropriate ICD therapy to death.Results: Group 1 and 2 patients were comparable with respect to clinical presentation and average follow-up duration. In the elderly patient group, 78% received an ICD for secondary prevention versus 63% in group 1 (p = 0.007). During a mean follow-up period of 26.5 ± 18.1 months, there was no significant difference in overall mortality among the two groups: 47 patients died, 34 (12.5%) of group 1 versus 13 (12.7%) of group 2. The average time to death was 28.4 ± 16.7 vs 30.4 ± 22.1 months after device implantation, respectively (p = ns). There was no difference in time from device implantation to first adequate ICD therapy and time from first appropriate ICD therapy to death among the two groups (p = ns). Device associated complications were comparable in both groups.Conclusions: Elderly ICD recipients had comparable survival rates and appropriate use of the ICD compared to younger individuals.

Arrhythmic death in implantable cardioverter defibrillator patients: A long-term study over a 10 year implantation period

AIMS Evaluation of cause-specific mortality in a large cohort of unselected implantable cardioverter defibrillator (ICD) recipients. METHODS AND RESULTS Causes of death of consecutive ICD recipients implanted over a 10 year period were analysed. Overall 822 patients (age 63 +/- 11 years, 80% male, EF 34 +/- 14%, secondary prevention 65%) were followed for 43 +/- 30 months during which time 225 patients died (annual mortality 7.6%). Causes of death were cardiac arrhythmic in 16%, cardiac non-arrhythmic in 39%, non-cardiac vascular in 4%, non-cardiovascular in 27%, and unknown in 13%. Advanced age [relative risk (RR) 1.23 per decades, 95% confidence interval (CI) 1.06-1.43], NYHA class >II (RR 2.27, 95% CI 1.51-3.41), renal failure (RR 1.57, 95% CI 1.15-2.14), use of amiodarone (RR 2.56, 95% CI 1.91-3.43), digitalis (RR 1.87, 95% CI 1.40-2.49), diuretics (RR 1.89, 95% CI 1.35-2.66) were independent predictors of all-cause mortality. Predictors for arrhythmic mortality were NYHA class >II (RR 12, 95% CI 3.69-37.5), spontaneous or inducible VT as indication for ICD therapy (RR 2.53, 95% CI 1.06-6.05), and use of amiodarone (RR 3.95, 95% CI 2.02-7.75). CONCLUSION In this unselected group of ICD recipients, at least 16% of patients died from arrhythmic causes. Risk factors associated with arrhythmic mortality were a history of spontaneous or inducible VT, higher NYHA class, and amiodarone use.

Treatment with novel oral anticoagulants in a real-world cohort of patients undergoing cardiac rhythm device implantations

AIMS The safety and efficacy of novel oral anticoagulants in patients with atrial fibrillation undergoing pacemaker or implantable cardioverter-defibrillator interventions have not been clearly defined. Therefore, we compared the incidence of bleeding and thrombo-embolic complications following cardiac rhythm device (CRD) implantations under dabigatran vs. rivaroxaban in a real-world cohort. METHODS AND RESULTS We analysed 176 consecutive procedures performed in 93 patients treated peri-interventionally with dabigatran and 83 patients with rivaroxaban, respectively. Post-operative bleeding complications and thrombo-embolic events occurring within 30 days were compared. There were no significant differences in baseline characteristics between patients in the dabigatran and the rivaroxaban group. Most of the patients in both the groups received dual chamber or cardiac resynchronization devices (71 vs. 78%) as opposed to single-chamber systems (29 vs. 22%). In the dabigatran group, two (2%) bleeding complications (two pocket haematomas) were observed in comparison with four (5%, three pocket haematomas and one pericardial effusion) in the rivaroxaban group (P = 0.330). Three complications in the rivaroxaban group necessitated surgical intervention as opposed to none in the dabigatran group (P = 0.064). One case of a transient ischaemic attack occurred in the dabigatran group (P = 0.343). CONCLUSION Bleeding and thrombo-embolic complications in patients treated with dabigatran or rivaroxban are rare. Further and larger studies are warranted to define the optimal anticoagulation management in patients with a need for oral anticoagulation and CRD interventions.

Nonfluoroscopic Catheter Visualization in Atrial Fibrillation Ablation Experience From 375 Consecutive Procedures

Background—A technological platform (MediGuide) has been recently introduced for nonfluoroscopic catheter tracking. No data on the safety of this technology are yet available in a large cohort of patients. Methods and Results—Data from a prospective ablation registry were analyzed. All patients undergoing atrial fibrillation ablation procedures supported by nonfluoroscopic catheter visualization technology were included. Patient characteristics and procedural data and complications within the first 3 months were recorded. Between May 2012 and February 2014, a total of 375 patients underwent atrial fibrillation ablation using nonfluoroscopic catheter visualization technology. The patients were predominantly men (68%); the majority were ablated for the first time (71%); left atrium was 43±6 mm; and left ventricular function was normal (59±9%). The median ablation procedure time was 135 (113–170) minutes, median fluoroscopy time 2.8 (1.5–4.4) minutes, and median radiation dose 789 (470–1466) cGy*cm2. Regression analysis demonstrated a significant decrease of fluoroscopy time, dose, and procedure time. To confirm the result and show overall changes, the initial 50 cases (group 1) to the last 50 cases (group 2) of the series were compared: fluoroscopy time decreased from 6.0 (4.1–10.3) minutes in group 1 to 1.1 (0.7–1.5) minutes in group 2 and radiation dose from 2363 (1413–3475) to 490 (230–654) cGy*cm2, respectively. Ten patients (2.7%) experienced complications: 5 cardiac tamponades (1.4%), 4 pseudoaneurysms (1.1%), and 1 stroke (0.3%). Conclusions—Atrial fibrillation ablation using the nonfluoroscopic catheter visualization technology is safe with a rate of complications of 2.7%. Procedure time (135 minutes) is not prolonged. A dramatic reduction in fluoroscopy time and dose was achieved.Background— A technological platform (MediGuide) has been recently introduced for nonfluoroscopic catheter tracking. No data on the safety of this technology are yet available in a large cohort of patients. Methods and Results— Data from a prospective ablation registry were analyzed. All patients undergoing atrial fibrillation ablation procedures supported by nonfluoroscopic catheter visualization technology were included. Patient characteristics and procedural data and complications within the first 3 months were recorded. Between May 2012 and February 2014, a total of 375 patients underwent atrial fibrillation ablation using nonfluoroscopic catheter visualization technology. The patients were predominantly men (68%); the majority were ablated for the first time (71%); left atrium was 43±6 mm; and left ventricular function was normal (59±9%). The median ablation procedure time was 135 (113–170) minutes, median fluoroscopy time 2.8 (1.5–4.4) minutes, and median radiation dose 789 (470–1466) cGy*cm2. Regression analysis demonstrated a significant decrease of fluoroscopy time, dose, and procedure time. To confirm the result and show overall changes, the initial 50 cases (group 1) to the last 50 cases (group 2) of the series were compared: fluoroscopy time decreased from 6.0 (4.1–10.3) minutes in group 1 to 1.1 (0.7–1.5) minutes in group 2 and radiation dose from 2363 (1413–3475) to 490 (230–654) cGy*cm2, respectively. Ten patients (2.7%) experienced complications: 5 cardiac tamponades (1.4%), 4 pseudoaneurysms (1.1%), and 1 stroke (0.3%). Conclusions— Atrial fibrillation ablation using the nonfluoroscopic catheter visualization technology is safe with a rate of complications of 2.7%. Procedure time (135 minutes) is not prolonged. A dramatic reduction in fluoroscopy time and dose was achieved.

Assessment of microvolt T-wave alternans in high-risk patients with the congenital long-QT syndrome

Background: Microvolt T‐wave alternans (MTWA) has been used for arrhythmogenic risk stratification in cardiac disease conditions associated with increased risk of sudden cardiac death. Macroscopic T‐wave alternans has been observed in patients with congenital long‐QT syndrome (LQTS). The role of MTWA testing in patients with LQTS has not been established.

Early cerebral thromboembolic complications after radiofrequency catheter ablation of atrial fibrillation: Incidence, characteristics, and risk factors

BACKGROUND Thromboembolic complications remain one of the most severe adverse events associated with catheter ablation of atrial fibrillation (AF), but data on such events are limited. OBJECTIVE The purpose of this study was to evaluate the incidence, characteristics, and risk factors of thromboembolic complications after AF ablation. METHODS Cerebral thromboembolic complications occurring within 1 month of 3360 consecutive AF radiofrequency catheter ablations were assessed. Stroke was defined as a neurologic deficit lasting more than 24 hours or with imaging study showing new infarction. Transient ischemic attack (TIA) was defined as a deficit lasting less than 24 hours and without documented infarction. RESULTS There were 17 peri-interventional cerebral thromboembolic events (0.5%). Nine cases (53%) were diagnosed as strokes and 8 (47%) as TIAs. Sixty percent of the events occurred within 48 hours after the ablation; the rest occurred within 1 week. In univariate analysis, peri-interventional thromboembolism was associated with peripheral vascular disease (P = .010), impaired left ventricular ejection fraction (P = .040), periprocedural bridging with heparin (P = .007), and previous stroke (P = .026). Multivariable analysis demonstrated that peripheral vascular disease (odds ratio [OR] 8.81, confidence interval [CI] 1.61-48.31, P = .012) and previous stroke (OR 6.13, CI 1.18-31.91, P = .031) were independent predictors. In a different model, the CHA2DS2-VASc score was associated with thromboembolism (OR 1.35, CI 1.00-1.80, P = .049). CONCLUSION Cerebral thromboembolic complications after AF radiofrequency catheter ablation are rare. They mostly occur within 48 hours after the procedure and remain without lasting neurologic deficits in the majority of cases. Such complications are associated with peripheral vascular disease, previous stroke, and the CHA2DS2-VASc score.

Impact of single atrial fibrillation catheter ablation on implantable cardioverter defibrillator therapies in patients with ischaemic and non-ischaemic cardiomyopathies

AIMS Atrial fibrillation (AF) is associated with frequent appropriate and inappropriate implantable cardioverter defibrillator (ICD) therapies. Catheter ablation of AF has been shown to reduce AF burden and improve left ventricular function in heart failure patients but the impact on ICD therapies has not yet been studied. The aim of this study was to test the hypothesis that AF ablation reduces ICD therapies in patients with cardiomyopathies. METHODS AND RESULTS In 73 consecutive patients (mean age 59 ± 10 years, 85% male) with previously implanted ICD due to ischaemic (n = 30) or dilated cardiomyopathy (n = 43) undergoing AF ablation, the prevalence and frequency of ICD therapies before and after AF ablation were compared. During the total follow-up of 3.3 ± 3 years prior to AF ablation, 5.1 ± 14.7 therapies per patient-year were delivered as opposed to 1.8 ± 10.9 in a period of 1.1 ± 0.9 years after ablation (P = 0.002). Prior to AF ablation, 39 patients (53%) received at least one ICD therapy when compared with 15 patients (21%) after ablation. Atrial fibrillation ablation was associated with freedom from any therapy regardless of appropriateness (odds ratio, OR, 0.366, CI 0.164-0.816, P = 0.014, adjusted for follow-up). Appropriate shocks significantly decreased from 0.3 ± 1.3 to 0.1 ± 0.5 per patient-year (P = 0.030). While heart failure medication and use of antiarrhythmic drugs were comparable during the entire follow-up, a statistically significant improvement of left ventricular ejection fraction (LVEF) from 36.9 ± 12.3% to 40.7 ± 6.7% (P = 0.008) was observed after AF ablation. CONCLUSIONS In patients with ischaemic or dilated cardiomyopathy, catheter ablation of AF is associated with the reduction of inappropriate and appropriate ICD therapies and improvement of LVEF.

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.

Diagnosis of Arrhythmias in Athletes Using Leadless, Ambulatory HR Monitors.

Exercise-related palpitations, vertigo, and syncope may be caused by benign etiologies but can also herald life-threatening arrhythmias. The precise diagnosis of these findings is therefore essential and potentially life saving but often is a challenge for sports physicians and cardiologists. Leadless, ambulatory HR monitors with chest strap transmitters have been designed to steer exercise intensity in athletes with a baseline sinus rhythm. However, they also can capture arrhythmias. Presented here are three cases of varying arrhythmias: atrial fibrillation, atrioventricular nodal reentrant tachycardia, and ectopic atrial tachycardia that demonstrate the utility of HR monitors designed for athletic purposes in facilitating the diagnosis of arrhythmias and guiding appropriate treatment.

The Brugada syndrome: facts and controversies.

The diagnosis of Brugada syndrome (BS) is based on a combination of clinical (malignant arrhythmias presenting as syncopal or sudden death episodes) and electrocardiographic (pathognomonic ST segment elevation morphology) features. Over the last 15 years, since its introduction as a distinct clinical entity, the BS has been extensively investigated worldwide. In this article an overview of recent developments concerning the genetic background, the diagnostic tools and the therapeutic alternatives will be presented. In the last years, the results of the first medium-term follow-up studies have also been published. Some of these studies present contradictory results, especially concerning the identification of useful sudden death predictors in asymptomatic patients. The review presented here will discuss this prognostic controversy and will offer possible explanations for the different results.ZusammenfassungDie Diagnose des Brugada-Syndroms (BS) ergibt sich aufgrund der Klinik (maligne Arrhythmien mit Synkopen oder plötzlicher Herztod) sowie aufgrund von EKG-Veränderungen (pathognomonische ST-Hebungen). Vor 15 Jahren wurde das BS als eigenständiges Syndrom entdeckt. Seither wird es weltweit intensiv erforscht. Dieser Artikel gibt einen Überblick über die Entdeckungen der letzten Jahre bezüglich des genetischen Hintergrunds sowie der diagnostischen und therapeutischen Möglichkeiten. In den letzten Jahren wurden die Ergebnisse der ersten mittelfristigen Nachsorgestudien veröffentlicht. Einige dieser Studien erbrachten widersprüchliche Ergebnisse, vor allem bezüglich der Identifikation von Risikofaktoren für den plötzlichen Herztod bei asymptomatischen Patienten. Diese Übersicht geht auf die prognostischen Widersprüche ein und gibt mögliche Erklärungen für die unterschiedlichen Ergebnisse.