Radiofrequency Ablation as Initial Therapy in Paroxysmal Atrial Fibrillation

Background There are limited data comparing radiofrequency catheter ablation with antiarrhythmic drug therapy as first-line treatment in patients with paroxysmal atrial fibrillation. Methods We randomly assigned 294 patients with paroxysmal atrial fibrillation and no history of antiarrhythmic drug use to an initial treatment strategy of either radiofrequency catheter ablation (146 patients) or therapy with class IC or class III antiarrhythmic agents (148 patients). Follow-up included 7-day Holter-monitor recording at 3, 6, 12, 18, and 24 months. Primary end points were the cumulative and per-visit burden of atrial fibrillation (i.e., percentage of time in atrial fibrillation on Holter-monitor recordings). Analyses were performed on an intention-to-treat basis. Results There was no significant difference between the ablation and drug-therapy groups in the cumulative burden of atrial fibrillation (90th percentile of arrhythmia burden, 13% and 19%, respectively; P = 0.10) or the burden at 3, 6, 12, or 18 months. At 24 months, the burden of atrial fibrillation was significantly lower in the ablation group than in the drug-therapy group (90th percentile, 9% vs. 18%; P = 0.007), and more patients in the ablation group were free from any atrial fibrillation (85% vs. 71%, P = 0.004) and from symptomatic atrial fibrillation (93% vs. 84%, P = 0.01). One death in the ablation group was due to a procedure-related stroke; there were three cases of cardiac tamponade in the ablation group. In the drug-therapy group, 54 patients (36%) underwent supplementary ablation. Conclusions In comparing radiofrequency ablation with antiarrhythmic drug therapy as first-line treatment in patients with paroxysmal atrial fibrillation, we found no significant difference between the treatment groups in the cumulative burden of atrial fibrillation over a period of 2 years. (Funded by the Danish Heart Foundation and others; MANTRA-PAF ClinicalTrials.gov number, NCT00133211.

Osborn waves following out-of-hospital cardiac arrest:Effect of level of temperature management and risk of arrhythmia and death

Background: The Osborn or J-wave, an upright deflection of the J-point on the electrocardiogram (ECG), is often observed during severe hypothermia. A possible relation between Osborn waves (OW) and increased risk of ventricular arrhythmia has been reported. We sought to determine whether the level of targeted temperature management (TTM) following out-of-hospital cardiac arrest (OHCA) affects the prevalence of OW and to assess the associations between OW and risk of ventricular arrhythmia and death. Methods and results: The present study is part of the TTM-trial ECG-substudy (including OHCA-patients randomized to TTM at 33 °C vs. 36 °C from 24 of 36 sites). Serial 12-lead ECGs from 680 (94%) patients were analysed and stratified by OW at predefined time-points (0, 4, 28, 36, 72-h after admission). On admission, the overall prevalence of OW was 16%, increasing to 32% at target temperature, with higher prevalence in the 33 °C-group (40% vs. 23%, p < 0.0001). No difference in prevalence was found between the 33 °C- and 36 °C-groups on admission (18% vs. 14%, p =.11) or after rewarming (13% vs. 10%, p =.44). OW were not associated with increased risk of ventricular arrhythmia (Odds ratio = 0.78 (0.51–1.20), p =.26), but associated with significantly lower 180-day mortality as compared to no OW (38% vs. 52%, plog-rank = 0.001) in univariable analyses only. Conclusion: OW are frequent during TTM, particularly in patients treated with 33 °C. OW are not associated with increased risk of ventricular arrhythmia, and may be considered a benign physiological phenomenon, associated with lower mortality in univariable analyses

Organic selenium supplementation increased selenium concentrations in ewe and newborn lamb blood and in slaughter lamb meat compared to inorganic selenium supplementation

Background Selenium is part of the antioxidant defence system in animals and humans. The available selenium concentration in soil is low in many regions of the world. The purpose of this study was to evaluate the effect of organic versus inorganic selenium supplementation on selenium status of ewes, their lambs, and slaughter lambs. Methods Ewes on four organic farms were allocated five or six to 18 pens. The ewes were given either 20 mg/kg inorganic selenium as sodium selenite or organic selenium as selenized nonviable yeast supplementation for the two last months of pregnancy. Stipulated selenium concentrations in the rations were below 0.40 mg/kg dry matter. In addition 20 male lambs were given supplements from November until they were slaughtered in March. Silage, hay, concentrates, and individual ewe blood samples were taken before and after the mineral supplementation period, and blood samples were taken from the newborn lambs. Blood samples from ewes and lambs in the same pens were pooled. Muscle samples were taken from slaughter lambs in March. Selenium concentrations were determined by atomic absorption spectrometry with a hydride generator system. In the ANOVA model, selenium concentration was the continuous response variable, and selenium source and farm were the nominal effect variables. Two-sample t-test was used to compare selenium concentrations in muscle samples from the slaughtered lambs that received either organic or inorganic selenium supplements. Results In all ewe pens the whole blood selenium concentrations increased during the experimental period. In addition, ewe pens that received organic selenium had significantly higher whole blood selenium concentrations (mean 0.28 μg/g) than ewe pens that received inorganic selenium (mean 0.24 μg/g). Most prominent, however, was the difference in their lambs; whole blood mean selenium concentration in lambs from mothers that received organic selenium (mean 0.27 μg/g) was 30% higher than in lambs from mothers that received inorganic selenium (mean 0.21 μg/g). Slaughter lambs that received organic selenium had 50% higher meat selenium concentrations (mean 0.12 mg/kg wet weight) than lambs that received inorganic selenium (mean 0.08 mg/kg wet weight). Conclusion Organic selenium supplementation gave higher selenium concentration in ewe and newborn lamb blood and slaughter lamb meat than inorganic selenium supplementation

Effect of implantable cardioverter-defibrillators in patients with non-ischaemic systolic heart failure and concurrent coronary atherosclerosis

AIMS: Prophylactic implantable cardioverter‐defibrillators (ICD) reduce mortality in patients with ischaemic heart failure (HF), whereas the effect of ICD in patients with non‐ischaemic HF is less clear. We aimed to investigate the association between concomitant coronary atherosclerosis and mortality in patients with non‐ischaemic HF and the effect of ICD implantation in these patients. METHODS AND RESULTS: Patients were included from DANISH (Danish Study to Assess the Efficacy of Implantable Cardioverter Defibrillators in Patients with Non‐Ischaemic Systolic Heart Failure on Mortality), randomizing patients to ICD or control. Study inclusion criteria for HF were left ventricular ejection fraction ≤ 35% and increased levels (>200 pg/mL) of N‐terminal pro‐brain natriuretic peptide. Of the 1116 patients from DANISH, 838 (75%) patients had available data from coronary angiogram and were included in this subgroup analysis. We used Cox regression to assess the relationship between coronary atherosclerosis and mortality and the effect of ICD implantation. Of the included patients, 266 (32%) had coronary atherosclerosis. Of these, 216 (81%) had atherosclerosis without significant stenoses, and 50 (19%) had significant stenosis. Patients with atherosclerosis were significantly older {67 [interquartile range (IQR) 61–73] vs. 61 [IQR 54–68] years; P < 0.0001}, and more were men (77% vs. 70%; P = 0.03). During a median follow‐up of 64.3 months (IQR 47–82), 174 (21%) of the patients died. The effect of ICD on all‐cause mortality was not modified by coronary atherosclerosis [hazard ratio (HR) 0.94; 0.58–1.52; P = 0.79 vs. HR 0.82; 0.56–1.20; P = 0.30], P for interaction = 0.67. In univariable analysis, coronary atherosclerosis was a significant predictor of all‐cause mortality [HR, 1.41; 95% confidence interval (CI), 1.04–1.91; P = 0.03]. However, this association disappeared when adjusting for cardiovascular risk factors (age, gender, diabetes, hypertension, smoking, and estimated glomerular filtration rate) (HR 1.05, 0.76–1.45, P = 0.76). CONCLUSIONS: In patients with non‐ischaemic systolic heart failure, ICD implantation did not reduce all‐cause mortality in patients either with or without concomitant coronary atherosclerosis. The concomitant presence of coronary atherosclerosis was associated with increased mortality. However, this association was explained by other risk factors

Time‐dependent antiarrhythmic effects of flecainide on induced atrial fibrillation in horses

Background, Objective: Pharmacological treatment of atrial fibrillation (AF) in horses can be challenging because of low efficacy and adverse effects. Flecainide has been tested with variable efficacy. To test whether the efficacy of flecainide is dependent on AF duration. Animals and Methods: Nine Standardbred mares. Factorial study design. All horses were instrumented with a pacemaker and assigned to a control or an AF group. On day 0, all horses were in sinus rhythm and received 2 mg/kg flecainide IV. Atrial fibrillation subsequently was induced in the AF group by pacemaker stimulation. On days 3, 9, 27, and 55, flecainide was administered to all horses, regardless of heart rhythm. Results: Conclusions and Clinical ImportanceAll horses in AF cardioverted to sinus rhythm on days 3 and 9. On day 27, 5/6 horses cardioverted, whereas only 2/6 cardioverted on day 55. The time from the start of flecainide infusion to cardioversion (range, 3-185min, log transformed) showed linear correlation with the cumulative duration of AF (r(2)=.80, P<.0001). Flecainide induced abnormal QRS complexes in 4/6 AF horses and 1/3 controls. A positive correlation was found between heart rate before flecainide infusion and number of abnormal QRS complexes (0.14, P<.05). One horse suffered from cardiac arrest and died after flecainide infusion. Flecainide is effective for cardioversion of short-term induced AF, but the effect decreases with AF duration. Controlling heart rate may minimize adverse effects caused by flecainide, but the drug should be used with great caution

Comparison of Investigator-Reported and Centrally Adjudicated Heart Failure Outcomes in the EMPEROR-Reduced Trial.

BACKGROUND: There is limited published information on outcome adjudication in heart failure (HF). OBJECTIVES: The authors sought to compare investigator reports (IRs) to a Clinical Events Committee (CEC) and the impact of SCTI (Standardized Clinical Trial Initiative) criteria. METHODS: In the EMPEROR-Reduced trial, the authors compared IRs to the CEC for concordance; treatment effect on primary composite outcome events; and the components first event hospitalization primarily for HF or cardiovascular mortality (CVM), prognosis after hospitalization for heart failure (HHF), total HHFs, and trial duration with and without SCTI criteria. RESULTS: The CEC confirmed 76.3% of IR events for the primary outcome (CVM: 89.1%; HHF: 73.7%). The HR for treatment effect did not differ between adjudication methods for the primary outcome (IR: 0.75 [95% CI: 0.66-0.85]; CEC: 0.75 [95% CI: 0.65-0.86]), its components, or total HHFs. The prognosis after first HHF for all-cause mortality and CVM also did not differ between IR or CEC. Interestingly, IR primary HHF with different CEC primary cause had the highest subsequent fatal event rate. Full SCTI criteria were present in 90% of CEC HHFs-with a similar treatment effect to non-SCTI. The IR primary event reached the protocol target number (841) 3 months earlier than CEC (4 months with full SCTI criteria). CONCLUSIONS: Investigator adjudication is an alternative to a CEC with similar accuracy and faster event accumulation. The use of granular (SCTI) criteria did not improve trial performance. Finally, our data suggest that consideration be given to broadening the HHF definition to include "for or with" worsening disease. (Empagliflozin Outcome Trial in Patients With Chronic Heart Failure With Reduced Ejection Fraction [EMPEROR-Reduced]; NCT03057977)

Effect of Empagliflozin on the Clinical Stability of Patients With Heart Failure and a Reduced Ejection Fraction: The EMPEROR-Reduced Trial.

BACKGROUND: Empagliflozin reduces the risk of cardiovascular death or hospitalization for heart failure in patients with heart failure and a reduced ejection fraction, with or without diabetes, but additional data are needed about the effect of the drug on inpatient and outpatient events that reflect worsening heart failure. METHODS: We randomly assigned 3730 patients with class II to IV heart failure with an ejection fraction of ≤40% to double-blind treatment with placebo or empagliflozin (10 mg once daily), in addition to recommended treatments for heart failure, for a median of 16 months. We prospectively collected information on inpatient and outpatient events reflecting worsening heart failure and prespecified their analysis in individual and composite end points. RESULTS: Empagliflozin reduced the combined risk of death, hospitalization for heart failure or an emergent/urgent heart failure visit requiring intravenous treatment (415 versus 519 patients; empagliflozin versus placebo, respectively; hazard ratio [HR], 0.76; 95% CI, 0.67-0.87; P<0.0001). This benefit reached statistical significance at 12 days after randomization. Empagliflozin reduced the total number of heart failure hospitalizations that required intensive care (HR, 0.67; 95% CI, 0.50-0.90; P=0.008) and that required a vasopressor or positive inotropic drug or mechanical or surgical intervention (HR, 0.64; 95% CI, 0.47-0.87; P=0.005). As compared with placebo, fewer patients in the empagliflozin group reported intensification of diuretics (297 versus 414 [HR, 0.67; 95% CI, 0.56-0.78; P<0.0001]). Additionally, patients assigned to empagliflozin were 20% to 40% more likely to experience an improvement in New York Heart Association functional class and were 20% to 40% less likely to experience worsening of New York Heart Association functional class, with statistically significant effects that were apparent 28 days after randomization and maintained during long-term follow-up. The risk of any inpatient or outpatient worsening heart failure event in the placebo group was high (48.1 per 100 patient-years of follow-up), and it was reduced by empagliflozin (HR, 0.70; 95% CI, 0.63-0.78; P<0.0001). CONCLUSIONS: In patients with heart failure and a reduced ejection fraction, empagliflozin reduced the risk and total number of inpatient and outpatient worsening heart failure events, with benefits seen early after initiation of treatment and sustained for the duration of double-blind therapy. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03057977