Axel Brandes

Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure

BACKGROUND The benefit of an implantable cardioverter-defibrillator (ICD) in patients with symptomatic systolic heart failure caused by coronary artery disease has been well documented. However, the evidence for a benefit of prophylactic ICDs in patients with systolic heart failure that is not due to coronary artery disease has been based primarily on subgroup analyses. The management of heart failure has improved since the landmark ICD trials, and many patients now receive cardiac resynchronization therapy (CRT). METHODS In a randomized, controlled trial, 556 patients with symptomatic systolic heart failure (left ventricular ejection fraction, ≤35%) not caused by coronary artery disease were assigned to receive an ICD, and 560 patients were assigned to receive usual clinical care (control group). In both groups, 58% of the patients received CRT. The primary outcome of the trial was death from any cause. The secondary outcomes were sudden cardiac death and cardiovascular death. RESULTS After a median follow-up period of 67.6 months, the primary outcome had occurred in 120 patients (21.6%) in the ICD group and in 131 patients (23.4%) in the control group (hazard ratio, 0.87; 95% confidence interval [CI], 0.68 to 1.12; P=0.28). Sudden cardiac death occurred in 24 patients (4.3%) in the ICD group and in 46 patients (8.2%) in the control group (hazard ratio, 0.50; 95% CI, 0.31 to 0.82; P=0.005). Device infection occurred in 27 patients (4.9%) in the ICD group and in 20 patients (3.6%) in the control group (P=0.29). CONCLUSIONS In this trial, prophylactic ICD implantation in patients with symptomatic systolic heart failure not caused by coronary artery disease was not associated with a significantly lower long-term rate of death from any cause than was usual clinical care. (Funded by Medtronic and others; DANISH ClinicalTrials.gov number, NCT00542945 .).

Screening for Atrial Fibrillation A Report of the AF-SCREEN International Collaboration

Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed in September 2015 to promote discussion and research about AF screening as a strategy to reduce stroke and death and to provide advocacy for implementation of country-specific AF screening programs. During 2016, 60 expert members of AF-SCREEN, including physicians, nurses, allied health professionals, health economists, and patient advocates, were invited to prepare sections of a draft document. In August 2016, 51 members met in Rome to discuss the draft document and consider the key points arising from it using a Delphi process. These key points emphasize that screen-detected AF found at a single timepoint or by intermittent ECG recordings over 2 weeks is not a benign condition and, with additional stroke factors, carries sufficient risk of stroke to justify consideration of anticoagulation. With regard to the methods of mass screening, handheld ECG devices have the advantage of providing a verifiable ECG trace that guidelines require for AF diagnosis and would therefore be preferred as screening tools. Certain patient groups, such as those with recent embolic stroke of uncertain source (ESUS), require more intensive monitoring for AF. Settings for screening include various venues in both the community and the clinic, but they must be linked to a pathway for appropriate diagnosis and management for screening to be effective. It is recognized that health resources vary widely between countries and health systems, so the setting for AF screening should be both country- and health system-specific. Based on current knowledge, this white paper provides a strong case for AF screening now while recognizing that large randomized outcomes studies would be helpful to strengthen the evidence base.

Positive predictive value of device-detected atrial high-rate episodes at different rates and durations: An analysis from ASSERT

BACKGROUND Pacemakers can automatically identify and catalog atrial high-rate episodes (AHREs). While most AHREs represent true atrial tachyarrhythmia/atrial fibrillation (AT/AF), a review of stored electrograms suggests that a substantial proportion do not. As AHREs may lead to the initiation of oral anticoagulation, it is crucial to understand the relationship between AHREs and true AT/AF. OBJECTIVE To compare the positive predictive value of AHREs for electrogram-confirmed AT/AF for various atrial rates and episode durations. METHODS By using data from 2580 patients who participated in the ASymptomatic atrial fibrillation and Stroke Evaluation in pacemaker patients and the AF Reduction atrial pacing Trial, all AHREs >6 minutes and >190 beats/min with available electrograms were reviewed to determine whether they represented true AT/AF. The positive predictive value of these AHREs was assessed for episode durations of 6 minutes, 30 minutes, 6 hours, and 24 hours at atrial rates of 190 and 250 beats/min. RESULTS Of 5769 AHREs >6 minutes and >190 beats/min, 82.7% were true AT/AF and 17.3% were false positives (predominantly due to repetitive non-re-entrant ventriculoatrial synchrony). False positives dropped to 6.8%, 3.3%, and 1.8% when the threshold duration was increased to 30 minutes, 6 hours, and 24 hours, respectively. Increasing the threshold heart rate to 250 beats/min added little to the positive predictive value when longer threshold durations were used. CONCLUSIONS By using a cutoff of >6 minutes and >190 beats/min, the rate of false-positive AHREs is 17.3%, making physician review of electrograms essential. For AHREs lasting >6 hours, the rate of false positives is 3.3%, making physician review less crucial.

A proposal for interdisciplinary, nurse-coordinated atrial fibrillation expert programmes as a way to structure daily practice

Atrial fibrillation (AF) is a frequently occurring arrhythmia that is independently related to increased morbidity and mortality. In particular, AF is associated with complications such as ischaemic stroke, systemic thrombo-embolism, and heart failure, leading to increased hospitalizations.1 Atrial fibrillation, therefore, has a major impact on healthcare systems, which is likely to expand in an ageing population.1–3 Although AF can occur asymptomatically, two-thirds of the patients experience symptoms. The management of AF is, besides stroke prevention, predominantly focused on controlling symptoms and on improving quality of life (QOL).1,2,4 Symptom profile and burden can vary over time, both within and between patients. Consistent symptom assessment and follow-up are therefore important. Moreover, evidence-based guidelines facilitate clinicians in obtaining positive patient outcomes.1,2,5,6 Nonetheless, guideline adherence in practice is often poor,7 leading to suboptimal symptomatic control, reduced benefit from proven treatments on morbidity and mortality, and inappropriate healthcare resource use. Recognizing that symptom management and improving guideline adherence are important both for patients individually and for the impact on healthcare systems globally, it is mandatory to develop and implement more efficient ways to deal with AF.6,8,9 However, the best model for implementing AF care is still unclear. This article presents our viewpoint regarding optimized AF management by comprehensively addressing (i) the main goals to be achieved; (ii) the related requirements for AF management programmes to achieve those goals; (iii) our position that nurses should have an important coordinating role in such programmes; (iv) the implementation of such programme in practice; and (v) which outcomes should be targeted to evaluate effective deployment. Atrial fibrillation care should be organized to achieve clearly defined outcomes.10 As AF management is aimed at reducing symptoms and preventing …

Atrial sensing and AV synchrony in single lead VDD pacemakers: a prospective comparison to DDD devices with bipolar atrial leads.

Atrial Sensing and AV Synchrony in VDD and DDD Devices, Introduction: Single lead VDD pacing has offered an alternative to DDD systems in patients with isolated AV block. Up to now, however, the relative performance of these pacemaker systems was not systematically compared.

Circadian Profile of QT Interval and QT Interval Variability in 172 Healthy Volunteers

BONNEMEIER, H., et al.: Circadian Profile of QT Interval and QT Interval Variability in 172 Healthy Volunteers. The limited prognostic value of QT dispersion has been demonstrated in recent studies. However, longitudinal data on physiological variations of QT interval and the influence of aging and sex are few. This analysis included 172 healthy subjects (89 women, 83 men; mean age 38.7 ± 15 years). Beat‐to‐beat QT interval duration (QT, QTapex [QTa], Tend[Te]), variability (QTSD, QTaSD), and the mean R‐R interval were determined from 24‐hour ambulatory electrocardiograms after exclusion of artifacts and premature beats. All volunteers were fully active, awoke at approximately 7:00 am, and had 6–8 hours of sleep. QT and R‐R intervals revealed a characteristic day‐night‐pattern. Diurnal profiles of QT interval variability exhibited a significant increase in the morning hours (6–9 am; P < 0.01) and a consecutive decline to baseline levels. In female subjects the R‐R and Tend intervals were significantly lower at day‐ and nighttime. Aging was associated with an increase of QT interval mainly at daytime and a significant shift of the T wave apex towards the end of the T wave. The circadian profile of ventricular repolarization is strongly related to the mean R‐R interval, however, there are significant alterations mainly at daytime with normal aging. Furthermore, the diurnal course of the QT interval variability strongly suggests that it is related to cardiac sympathetic activity and to the reported diurnal pattern of malignant ventricular arrhythmias. (PACE 2003; 26[Pt. II]):377–382)

Development of sinus node disease in patients with AV block: implications for single lead VDD pacing

OBJECTIVE To investigate the incidence of sinus node disease after pacemaker implantation for exclusive atrioventricular (AV) block. DESIGN 441 patients were followed after VDD (n = 219) or DDD pacemaker (n = 222) implantation for AV block over a mean period of 37 months. Sinus node disease and atrial arrhythmias had been excluded by Holter monitoring and treadmill exercise preoperatively in 286 patients (group A). In 155 patients with complete AV block, a sinus rate above 70 beats/min was required for inclusion in the study (group B). Holter monitoring and treadmill exercise were performed two weeks, three months, and every six months after implantation. Sinus bradycardia below 40 beats/min, sinoatrial block, sinus arrest, or subnormal increase of heart rate during treadmill exercise were defined as sinus node dysfunction. RESULTS Cumulative incidence of sinus node disease was 0.65% per year without differences between groups. Clinical indicators of sinus node dysfunction were sinus bradycardia below 40 beats/min in six patients (1.4%), intermittent sinoatrial block in two (0.5%), and chronotropic incompetence in five patients (1.1%). Only one of these patients (0.2%) was symptomatic. Cumulative incidence of atrial fibrillation was 2.0% per year, independent of the method used for the assessment of sinus node function and of the implanted device. CONCLUSIONS In patients undergoing pacemaker implantation for isolated AV block, sinus node syndrome rarely occurs during follow up. Thus single lead VDD pacing can safely be performed in these patients.

Age and Outcomes of Primary Prevention Implantable Cardioverter-Defibrillators in Patients With Nonischemic Systolic Heart Failure

Background: The DANISH study (Danish Study to Assess the Efficacy of ICDs [Implantable Cardioverter Defibrillators] in Patients With Non-Ischemic Systolic Heart Failure on Mortality) did not demonstrate an overall effect on all-cause mortality with ICD implantation. However, the prespecified subgroup analysis suggested a possible age-dependent association between ICD implantation and mortality with survival benefit seen only in the youngest patients. The nature of this relationship between age and outcome of a primary prevention ICD in patients with nonischemic systolic heart failure warrants further investigation. Methods: All 1116 patients from the DANISH study were included in this prespecified subgroup analysis. We assessed the relationship between ICD implantation and mortality by age, and an optimal age cutoff was estimated nonparametrically with selection impact curves. Modes of death were divided into sudden cardiac death and nonsudden death and compared between patients younger and older than this age cutoff with the use of &khgr;2 analysis. Results: Median age of the study population was 63 years (range, 21–84 years). There was a linearly decreasing relationship between ICD and mortality with age (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.003–1.06; P=0.03). An optimal age cutoff for ICD implantation was present at ⩽70 years. There was an association between reduced all-cause mortality and ICD in patients ⩽70 years of age (HR, 0.70; 95% CI, 0.51–0.96; P=0.03) but not in patients >70 years of age (HR, 1.05; 95% CI, 0.68–1.62; P=0.84). For patients ⩽70 years old, the sudden cardiac death rate was 1.8 (95% CI, 1.3–2.5) and nonsudden death rate was 2.7 (95% CI, 2.1–3.5) events per 100 patient-years, whereas for patients >70 years old, the sudden cardiac death rate was 1.6 (95% CI, 0.8–3.2) and nonsudden death rate was 5.4 (95% CI, 3.7–7.8) events per 100 patient-years. This difference in modes of death between the 2 age groups was statistically significant (P=0.01). Conclusions: In patients with systolic heart failure not caused by ischemic heart disease, the association between the ICD and survival decreased linearly with increasing age. In this study population, an age cutoff for ICD implantation at ⩽70 years yielded the highest survival for the population as a whole. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00542945.

The EAST study: redefining the role of rhythmcontrol therapy in atrial fibrillation: EAST, the Early treatment of Atrial fibrillation for Stroke prevention Trial

Atrial fibrillation is not only a common condition and increasingly so in ageing populations, it is also a common cause of stroke, cardiovascular death, and cardiovascular hospitalizations. Even on optimal anticoagulation and rate control therapy, AF patients are at an unacceptable risk for cardiovascular death, in particular sudden death and death from heart failure. Furthermore, many patients with AF are hospitalized because of AF, illustrating the unmet needs in the current evidence-based management of AF.

Preadmission Oral Anticoagulant Treatment and Clinical Outcome Among Patients Hospitalized With Acute Stroke and Atrial Fibrillation A Nationwide Study

Background and Purpose— Preadmission oral anticoagulant treatment (OAT) has been linked with less severe stroke and a better outcome in patients with atrial fibrillation. However, the existing studies have methodological limitations and have, with one exception, not included hemorrhagic strokes. We performed a nationwide historic follow-up study using data from population-based healthcare registries to assess the effect of preadmission OAT on stroke outcomes further. Methods— We identified 11 356 patients with atrial fibrillation admitted to hospital with acute stroke (including ischemic stroke and intracerebral hemorrhage) between 2003 and 2009. Propensity score–matched analyses were used to compare stroke severity (Scandinavian Stroke Scale score) and mortality among 2175 patients with preadmission OAT and 2175 patients without preadmission OAT. Results— A total of 2492 (21.9%) patients received OAT at the time of their stroke. Preadmission OAT was associated with a lower risk of severe stroke (Scandinavian Stroke Scale score at time of admission, <30 point; propensity score–matched odds ratio, 0.74; 95% confidence interval, 0.63–0.86) and lower 30-day mortality rate (propensity score–matched adjusted odds ratio, 0.83; 95% confidence interval, 0.71–0.98). Conclusions— Only a minority of hospitalized patients with acute stroke with atrial fibrillation received OAT at the time of stroke. Preadmission OAT was associated with less severe stroke and lower 30-day mortality rate in a propensity score–matched analysis.