Ventricular arrhythmias in super-responders to cardiac resynchronization therapy.

INTRODUCTION AND OBJECTIVES: Cardiac resynchronization therapy is associated with improved quality of life and reduced morbidity and mortality in patients with severe ventricular dysfunction and wide QRS. However, its role in the reduction of ventricular arrhythmias is more controversial. METHODS: We compared the incidence of ventricular arrhythmias in patients who were undergoing cardiac resynchronization therapy with an implantable cardioverter-defibrillator in terms of the degree of echocardiographic response to resynchronization. Patients were classified in 3 subgroups;super-responders, responders, and nonresponders. RESULTS: We included 196 patients who were followed up for a median 30.1 months [interquartile range, 18.0-55.1 months]. We recorded the presence of ventricular arrhythmias in 37 patients (18.8%); 3 patients (5.9%) in the super-responder group had ventricular arrhythmias vs 14 (22.2%) among the responders and 20 (24.4%) in the group of nonresponders (P = .025). In multivariate analysis, the only independent predictors of the appearance of ventricular arrhythmias were secondary-prevention device implantation (odds ratio = 4.04; 95% confidence interval, 1.52-10.75; P=.005), absence of echocardiographic super-response (odds ratio=3.81; 95% confidence interval, 1.04-13.93; P=043), QRS >160 ms (odds ratio=2.39; 95% confidence interval, 1.00-1.35; P=.049) and treatment with amiodarone (odds ratio=2.47; 95% confidence interval, 1.03-5.91; P=.041). CONCLUSIONS: The patients classified as super-responders to cardiac resynchronization therapy had a significant reduction in incidence of ventricular arrhythmias by comparison with the other patients. Despite this, arrhythmic episodes do not completely disappear in this subgroup.

Effectiveness and safety of remote monitoring of patients with an implantable loop recorder.

INTRODUCTION AND OBJECTIVES: Implantable loop recorders have proven efficacy in the study of patients with syncope and palpitations. Remote monitoring of patients with pacemakers and implantable cardioverter-defibrillators has been shown to be safe and effective. The purpose of this study was to analyze the safety and effectiveness of remote monitoring in patients with an implantable loop recorder. METHODS: Retrospective observational study in which 109 patients with an implantable loop recorder were analyzed and 2 population groups were compared: 1 receiving conventional follow-up consisting of 3-monthly office visits (41 patients) and 1 with remote monitoring via monthly telephone transmissions and yearly visits (68 patients). The mean follow-up was 64 weeks (range, 0.57-164.57 weeks). The study analyzed diagnosis of a significant event, defined as any event that led to a therapeutic approach and explained the symptoms leading to the implant, as well as the mean time from implant to diagnosis and the specific treatment. RESULTS: A significant event was diagnosed in 82.6% of patients; of these, 54.4% had a normal electrocardiogram; 26.7%, asystole; 15.6%, tachycardia, and 3.3%, bradycardia. The mean time from implant to diagnosis was 260 days (range, 5-947 days) in conventional follow-up, compared with 56 days (range, 0-650 days) in patients with remote monitoring (P<.01), which led to targeted treatment in this group 187 days earlier, on average, with no secondary complications. CONCLUSIONS: Remote monitoring of patients with an implantable loop recorder can significantly shorten the time to diagnosis and targeted treatment, without adversely affecting patient safety.

Ventricular arrhythmias among implantable cardioverter-defibrillator recipients for primary prevention: impact of chronic total coronary occlusion (VACTO Primary Study).

BACKGROUND: An implantable cardioverter-defibrillator (ICD) is the therapy of choice for primary prevention in patients with ischemia who are at risk for sudden cardiac death (SCD). One third of patients with significant coronary disease have chronic total coronary occlusion (CTO), which is associated with long-term mortality in patients with previous myocardial infarction. However, the impact of CTO on the occurrence of ventricular arrhythmias and long-term mortality in ICD recipients remains unknown. METHODS AND RESULTS: All consecutive patients with coronary artery disease receiving ICD therapy for the prevention of SCD were included in the study. Among other characteristics, the existence of CTO was assessed. During follow-up, the occurrence of appropriate device delivery because of ventricular arrhythmias as well as mortality were noted. A total of 162 patients (mean age, 62±9 years; 93% men) with an ICD were included and followed for a median of 26 months (interquartile range, 12-42). At least 1 CTO was present in 71 (44%) patients. Appropriate device therapy was detected in 18% of the patients during the follow-up. The presence of CTO was associated with higher ventricular arrhythmia and mortality rates (log-rank test, <0.01). Multivariable analysis revealed that CTO was independently associated with appropriate ICD intervention (hazard ratio, 3.5; P=0.003). CONCLUSIONS: In patients with ischemic heart disease receiving ICDs for primary prevention of SCD, CTO is an independent predictor for the occurrence of ventricular arrhythmias and has an adverse impact on long-term mortality.

Long-term (5 years) effects of bosentan in patients with pulmonary arterial hypertension.

INTRODUCTION AND OBJECTIVES: Bosentan has proven efficacy in pulmonary hypertension in the short term. Little is known about its effects beyond 2 to 3 years. Our objective was to analyze the efficacy and safety of bosentan in the long term (5 years) in patients treated in our center. METHODS: This retrospective study sequentially analyzed clinical, functional, and laboratory parameters in a series of patients treated initially with bosentan as monotherapy from 2002 to 2009 in a single hospital. Treatment success was defined as survival without clinical worsening that required additional pulmonary vasodilators. RESULTS: We included 20 patients (70% women, mean age 46 ± 14 years, 65% congenital heart disease), with a median follow-up of 64 months. One patient required withdrawal of bosentan due to adverse effects. At 4 months, significant improvements were achieved in hemodynamic, clinical and functional parameters. Clinical and functional benefits persisted at 5-year follow-up. Overall 5-year survival after beginning bosentan therapy was 95% (84%-100%). Treatment success at 1, 2, 3, 4 and 5 years was 95% (84%-100%), 83% (65%-100%), 78% (58%-98%), 61% (38%-84%), and 41% (16%-66%), respectively. The group with better outcomes had NT-proBNP levels at 1 year <400 pg/mL (P=.013). CONCLUSIONS: In our series, treatment success with bosentan in monotherapy was maintained in 78% at 3-year follow-up and 41% at 5-year follow-up. The group with long-term success showed significantly lower NT-proBNP levels at 1-year follow-up. Survival at 5 years in our series was 95%.