Xavier Navarro

Dual-chamber defibrillators reduce clinically significant adverse events compared with single-chamber devices: results from the DATAS (Dual chamber and Atrial Tachyarrhythmias Adverse events Study) trial.

AIMS This randomized trial evaluated clinically significant adverse events (CSAEs), in patients implanted with dual-chamber (DC) vs. single-chamber (SC) implantable cardioverter defibrillator (ICD). DC-ICD had atrial tachyarrhythmia (AT) therapy capabilities. Strict programming recommendations were reinforced. METHODS AND RESULTS Patients with conventional SC-ICD indication were randomized to DC-ICD, SC-ICD, or a DC-ICD programmed as an SC-ICD (SC-simulated) and followed for 16 months. Patients in the DC and SC-simulated groups crossed over after 8 months. The primary endpoint was a composite of CSAE: all-cause mortality; invasive intervention; hospitalization (> 24 h) for cardiovascular causes; inappropriate shocks (two or more episodes); and sustained symptomatic AT lasting > 48 h. The outcome variable was a pre-specified score that corrected for clinical severity and follow-up duration. Three hundred and thirty-four patients were analysed (DC-ICD, n = 112; SC-ICD, n = 111; SC-simulated, n = 111). The mean left ventricular ejection fraction was 0.36 +/- 0.13, 69% were in functional class > or = II. CSAE occurred in 65 DC-ICD, 82 SC-ICD, and 84 SC-simulated patients. The outcome variable was 33% lower in the DC-ICD group (OR 0.31; 95% CI 0.14-0.67; P = 0.0028). Mortality was 4% in DC, 9% in SC, and 10% in SC-simulated. CONCLUSION In patients with a standard SC-ICD indication, DC-ICD was associated with less CSAE when compared with SC-ICD.

Preventing ventricular dysfunction in pacemaker patients without advanced heart failure: results from a multicentre international randomized trial (PREVENT-HF)

Previous experimental and clinical studies have consistently suggested that right ventricular (RV) apical pacing has important adverse effects. Ventricular pacing (VP), however, is required, and cannot be reduced in many patients with atrioventricular (AV) block. The PREVENT‐HF study was an international randomized trial that explored differences in left ventricular (LV) remodelling during RV apical vs. biventricular (BIV) pacing in patients with AV block.

The MOnitoring Resynchronization dEvices and CARdiac patiEnts (MORE-CARE) Randomized Controlled Trial: Phase 1 Results on Dynamics of Early Intervention With Remote Monitoring

Background Remote monitoring (RM) in patients with advanced heart failure and cardiac resynchronization therapy defibrillators (CRT-D) may reduce delays in clinical decisions by transmitting automatic alerts. However, this strategy has never been tested specifically in this patient population, with alerts for lung fluid overload, and in a European setting. Objective The main objective of Phase 1 (presented here) is to evaluate if RM strategy is able to reduce time from device-detected events to clinical decisions. Methods In this multicenter randomized controlled trial, patients with moderate to severe heart failure implanted with CRT-D devices were randomized to a Remote group (with remote follow-up and wireless automatic alerts) or to a Control group (with standard follow-up without alerts). The primary endpoint of Phase 1 was the delay between an alert event and clinical decisions related to the event in the first 154 enrolled patients followed for 1 year. Results The median delay from device-detected events to clinical decisions was considerably shorter in the Remote group compared to the Control group: 2 (25th-75th percentile, 1-4) days vs 29 (25th-75th percentile, 3-51) days respectively, P=.004. In-hospital visits were reduced in the Remote group (2.0 visits/patient/year vs 3.2 visits/patient/year in the Control group, 37.5% relative reduction, P<.001). Automatic alerts were successfully transmitted in 93% of events occurring outside the hospital in the Remote group. The annual rate of all-cause hospitalizations per patient did not differ between the two groups (P=.65). Conclusions RM in CRT-D patients with advanced heart failure allows physicians to promptly react to clinically relevant automatic alerts and significantly reduces the burden of in-hospital visits. Trial Registration Clinicaltrials.gov NCT00885677; http://clinicaltrials.gov/show/NCT00885677 (Archived by WebCite at http://www.webcitation.org/6IkcCJ7NF).

Diagnosis, management, and outcomes of patients with syncope and bundle branch block

Aims Although patients with syncope and bundle branch block (BBB) are at high risk of developing atrio-ventricular block, syncope may be due to other aetiologies. We performed a prospective, observational study of the clinical outcomes of patients with syncope and BBB following a systematic diagnostic approach. Methods and results Patients with ≥1 syncope in the last 6 months, with QRS duration ≥120 ms, were prospectively studied following a three-phase diagnostic strategy: Phase I, initial evaluation; Phase II, electrophysiological study (EPS); and Phase III, insertion of an implantable loop recorder (ILR). Overall, 323 patients (left ventricular ejection fraction 56 ± 12%) were studied. The aetiological diagnosis was established in 267 (82.7%) patients (102 at initial evaluation, 113 upon EPS, and 52 upon ILR) with the following aetiologies: bradyarrhythmia (202), carotid sinus syndrome (20), ventricular tachycardia (18), neurally mediated (9), orthostatic hypotension (4), drug-induced (3), secondary to cardiopulmonary disease (2), supraventricular tachycardia (1), bradycardia–tachycardia (1), and non-arrhythmic (7). A pacemaker was implanted in 220 (68.1%), an implantable cardioverter defibrillator in 19 (5.8%), and radiofrequency catheter ablation was performed in 3 patients. Twenty patients (6%) had died at an average follow-up of 19.2 ± 8.2 months. Conclusion In patients with syncope, BBB, and mean left ventricular ejection fraction of 56 ± 12%, a systematic diagnostic approach achieves a high rate of aetiological diagnosis and allows to select specific treatment.

Impact of anti-tachycardia pacing on atrial fibrillation burden when added on top of preventive pacing algorithms: results of the prevention or termination (POT) trial

AIMS The efficacy of preventive pacing algorithms (PPA) and anti-tachycardia pacing (ATP) in reducing atrial fibrillation (AF) burden remains controversial. The aim of this study was to assess whether ATP on top of PPA decreases AF burden. METHODS AND RESULTS A series of 199 consecutive patients, with conventional indications for pacing, and documented AF, received a DDDR (rate adaptive dual chamber pacemaker) pacemaker with ATP capabilities (AT 500 Medtronic). After 3 months of conventional DDDR pacing at 70 b.p.m., AF burden was analysed. If patients had >30 min/week of AF, they were randomized to PPA or to PPA+ATP for 3 months (period 1). They were then crossed to the alternative therapy (period 2) and followed three additional months with a 1-month wash out period in-between. A group of 85 patients were randomized. Mean age 68 +/- 8 years, 61% men. Both groups showed a significant decrease in AF burden at the end of period 1 (64 and 81%, respectively). CONCLUSIONS Atrial pacing with PPA decreases AF burden in patients with pacing indication. We did not observe a further decrease in AF burden or in the number of episodes when adding ATP on top of PPA.

The MOnitoring Resynchronization dEvices and CARdiac patiEnts (MORE-CARE) study: Rationale and design

BACKGROUND With the advent of remote monitoring, current models of implantable cardioverter defibrillators (ICDs) have the possibility of sending automatic alert messages that allow early diagnosis of events such as lung fluid overload, atrial fibrillation and device integrity issues. Timely treatment of these events has the potential to improve patient outcome, but this has not as yet been proven. METHODS The MORE-CARE study is a multicenter randomized controlled trial evaluating the efficacy of advanced device diagnostics and remote monitoring in improving the outcome of patients with biventricular ICDs. Up to 1720 patients with a standard indication for a biventricular ICD will be randomized to standard in-office follow-up, or to a remote monitoring strategy using the CareLink network and involving automatic alerts for lung fluid overload, atrial fibrillation, and device integrity issues. The first phase aims at evaluating the delay between an alert event, and clinical action to the event. The second phase of the study will evaluate whether the remote monitoring strategy results in a significant reduction of a combined end point of total mortality or cardiovascular and device-related hospitalization. The duration of the study will be event-driven due to its sequential design. CONCLUSION MORE-CARE will evaluate the efficacy of remote monitoring for improving patient outcome in patients implanted with a biventricular ICD.

Dual-chamber implantable cardioverter defibrillators reduce clinical adverse events related to atrial fibrillation when compared with single-chamber defibrillators: a subanalysis of the DATAS trial

AIMS The aim of the present analysis of the DATAS study was to compare the impact of dual- vs. single-chamber defibrillators on atrial fibrillation (AF) occurrence and AF-related clinical events in patients with Class I indication for implantable cardioverter defibrillators (ICDs) and no indication for dual-chamber pacing. METHODS AND RESULTS Three hundred and thirty-four patients were randomized, through a centralized assignment, to single-chamber ICDs, dual-chamber ICDs programmed as single-chamber ICDs, and dual ICDs with full diagnostics and AF prevention and therapy capabilities. The latter two groups in the first 8 months of the study, when the study design was that of a randomized parallel trial, were compared in the present analysis. The primary endpoint was composed by the following AF-related clinical events: permanent AF, AF-related hospitalizations, cardiac-embolic events, and inappropriate ICD shocks due to AF misclassification. Two hundred and twenty-three patients were available for this analysis, of whom 111 in the single-chamber-simulated group and 112 in the dual-chamber true group. Atrial fibrillation-related composite endpoint raw incidence was 9 of 111 (8.1%) in the single-chamber group vs. 1 of 112 (0.9%) in the dual-chamber group (P = 0.0098 by Fishers exact test). Single-chamber ICDs were associated with a significantly higher risk to develop the AF-related composite endpoint by Cox regression analysis (hazard ratio 8.25, 95% CI 1.03-65.96, P = 0.047) and by the Kaplan-Meier survival analysis (log-rank test, P = 0.047). CONCLUSION Dual-chamber ICDs compared with single-chamber ICDs reduced the incidence of an endpoint composed by permanent AF, AF-related hospitalizations, and ICD shocks deemed inappropriate due to AF misclassification.

Incidence, determinants, and prognostic implications of true pleomorphism of ventricular tachycardia in patients with implantable cardioverter-defribillators: a substudy of the DATAS trial

Background—The occurrence of monomorphic ventricular tachycardia (M-VT) with >1 QRS morphology during the same episode (pleomorphism [PL]) or in different episodes (multiple morphologies [MM]) has been described through ECG. Implantable cardioverter-defribillator (ICD) electrograms (EGs) provide the opportunity to analyze virtually all spontaneous M-VT episodes. We sought to study the incidence, determinants, and prognostic significance of PL and MM as assessed by ICD-EG in a prospective series of patients with ICDs. Methods and Results—Spontaneous episodes of M-VT were analyzed before ICD intervention. PL was defined as >1 ICD-EG morphology, each having ≥6 consecutive identical beats during the same VT episode, and MM as >1 ICD-EG morphology in different M-VT episodes in the same patient. We analyzed 1881 M-VT episodes from 315 patients followed for 17 months. PL and MM occurred in 6% and 19%, respectively, of the total population (16% and 62% of patients with M-VT). Recurrent M-VT as diagnosis for ICD indication predicted PL and MM. Patients with PL more frequently developed MM (85% versus 15%; P<0.001) compared to patients without PL. Total mortality (5%) was significantly higher in patients with PL (20%), in patients with MM (11.5%), and in women (12%). In multivariate analysis, only PL (odds ratio, 5.33; P=0.009) and female sex (odds ratio, 3.1; P=0.038) predicted mortality. Conclusions—In a prospective series of patients with ICDs, mostly indicated for secondary prevention, both PL and MM of VT, as judged by ICD-EG, were not uncommon and were strongly associated. Female sex and the development of PL VT were the only independent predictors of mortality.

Incidence, Determinants and Prognostic Implications of True Pleomorphism of Ventricular Tachycardia in ICD Patients: A Substudy of the DATAS Trial

Background—The occurrence of monomorphic ventricular tachycardia (M-VT) with >1 QRS morphology during the same episode (pleomorphism [PL]) or in different episodes (multiple morphologies [MM]) has been described through ECG. Implantable cardioverter-defribillator (ICD) electrograms (EGs) provide the opportunity to analyze virtually all spontaneous M-VT episodes. We sought to study the incidence, determinants, and prognostic significance of PL and MM as assessed by ICD-EG in a prospective series of patients with ICDs. Methods and Results—Spontaneous episodes of M-VT were analyzed before ICD intervention. PL was defined as >1 ICD-EG morphology, each having ≥6 consecutive identical beats during the same VT episode, and MM as >1 ICD-EG morphology in different M-VT episodes in the same patient. We analyzed 1881 M-VT episodes from 315 patients followed for 17 months. PL and MM occurred in 6% and 19%, respectively, of the total population (16% and 62% of patients with M-VT). Recurrent M-VT as diagnosis for ICD indication predicted PL and MM. Patients with PL more frequently developed MM (85% versus 15%; P<0.001) compared to patients without PL. Total mortality (5%) was significantly higher in patients with PL (20%), in patients with MM (11.5%), and in women (12%). In multivariate analysis, only PL (odds ratio, 5.33; P=0.009) and female sex (odds ratio, 3.1; P=0.038) predicted mortality. Conclusions—In a prospective series of patients with ICDs, mostly indicated for secondary prevention, both PL and MM of VT, as judged by ICD-EG, were not uncommon and were strongly associated. Female sex and the development of PL VT were the only independent predictors of mortality.

Improvement of quality of life by means of antitachy pacing: from PainFREE to the ADVANCE-D Trial.

Background: Implantable cardioverter‐defibrillators (ICD) can terminate ventricular tachyarrhythmias with shocks (painful) or antitachycardia pacing (painless). According to the results of the Pacing Fast VT Reduces Shock ThErapies Trials, antitachycardia pacing (ATP) can avoid painful shocks and also increase device longevity. The purpose of the ADVANCE‐D (Atp DeliVery for PAiNless ICD ThErapy) study is to determine the most appropriate ventricular tachycardia (VT) therapy, so as to optimize painless therapy for life‐threatening arrhythmias.