Resuscitation Outcomes Consortium-Amiodarone, Lidocaine or Placebo Study (ROC-ALPS): Rationale and methodology behind an out-of-hospital cardiac arrest antiarrhythmic drug trial.

Background: Despite their wide use, whether antiarrhythmic drugs improve survival after out-of-hospital cardiac arrest (OHCA) is not known. The ROC-ALPS is evaluating the effectiveness of these drugs for OHCA due to shock-refractory ventricular fibrillation or pulseless ventricular tachycardia (VF/VT).

Methods: ALPS will randomize 3,000 adults across North America with nontraumatic OHCA, persistent or recurring VF/VT after ≥1 shock, and established vascular access to receive up to 450 mg amiodarone, 180 mg lidocaine, or placebo in the field using a double-blind protocol, along with standard resuscitation measures.

β-Blockers and atrial fibrillation: hypertension and other medical conditions influencing their use.

β-Blockers are among the most frequently used drugs in patients with atrial fibrillation. They are often used for ventricular rate control, acutely in emergency situations and chronically, in patients with persistent or permanent atrial fibrillation. They are also used, with less evidence of benefit, to prevent the first occurrence or recurrence of atrial fibrillation, particularly in patients with hypertension.

Cost-effectiveness of apixaban vs. current standard of care for stroke prevention in patients with atrial fibrillation.

Aims: Warfarin, a vitamin K antagonist (VKA), has been the standard of care for stroke prevention in patients with atrial fibrillation (AF). Aspirin is recommended for low-risk patients and those unsuitable for warfarin. Apixaban is an oral anticoagulant that has demonstrated better efficacy than warfarin and aspirin in the ARISTOTLE and AVERROES studies, respectively, and causes less bleeding than warfarin.

Cost-effectiveness of apixaban versus other new oral anticoagulants for stroke prevention in atrial fibrillation.

Background: Apixaban (5 mg BID), dabigatran (available as 150 mg and 110 mg BID in Europe), and rivaroxaban (20 mg once daily) are 3 novel oral anticoagulants (NOACs) currently approved for stroke prevention in patients with atrial fibrillation (AF).

Objective: The objective of this study was to evaluate the cost-effectiveness of apixaban against other NOACs from the perspective of the United Kingdom National Health Services.

Methods: A Markov model was developed to evaluate the pharmacoeconomic impact of apixaban versus other NOACs over a lifetime.

The 2013 Canadian Cardiovascular Society Heart Failure Management Guidelines Update: focus on rehabilitation and exercise and surgical coronary revascularization.

The 2013 Canadian Cardiovascular Society Heart Failure Management Guidelines Update provides focused discussions on the management recommendations on 2 topics: (1) exercise and rehabilitation; and (2) surgical coronary revascularization in patients with heart failure. First, all patients with stable New York Heart Association class I-III symptoms should be considered for enrollment in a tailored exercise training program, to improve exercise tolerance and quality of life. Second, selected patients with suitable coronary anatomy should be considered for bypass graft surgery.

Lack of difference in T wave variability between patients at risk of sudden cardiac death and healthy subjects.

Background: T wave variability (Tvar) is a proposed method to predict sudden cardiac death (SCD). The purpose of this trial was to evaluate the reproducibility of Tvar measurements over time and demonstrate a difference in Tvar between patient populations at risk for ventricular arrhythmias and healthy subjects.

Methods: Sixty subjects were enrolled in into 3 groups: healthy subjects (Population I), patients at high risk of SCD (Population II), and patients with a recent ventricular tachyarrhythmia event (Population III).

Dantrolene improves survival after ventricular fibrillation by mitigating impaired calcium handling in animal models.

Background: Resistant ventricular fibrillation, refibrillation. and diminished myocardial contractility are important factors leading to poor survival after cardiac arrest. We hypothesized that dantrolene improves survival after ventricular fibrillation (VF) by rectifying the calcium dysregulation caused by VF.

Probability of a shockable presenting rhythm as a function of EMS response time.

Introduction: Survival from cardiac arrest is associated with having a shockable presenting rhythm (VF/pulseless VT) upon EMS arrival. A concern is that several studies have reported a decline in the incidence of VF/PVT over the past few decades. One plausible explanation is that contemporary cardiovascular therapies, such as increased use of statin and beta blocker drugs, may shorten the duration of VF/PVT after arrest.

Prevention of thromboembolism in the patient with acute coronary syndrome and atrial fibrillation: the clinical dilemma of triple therapy.

Purpose Of Review: Atrial fibrillation in patients with acute coronary syndrome (ACS) is associated with a high thromboembolic event rate. Combined oral anticoagulant (OAC) and antiplatelet therapy (APT) are often used to reduce thromboembolic risk, recurrent coronary ischemic events, and stent thrombosis, despite the high bleeding risk. This review is timely with the recent introduction of novel OACs (NOACs), more potent antiplatelet agents, and second-generation coronary stents with a lower risk of late stent thrombosis, and considers strategies and new opportunities to reduce both thrombotic events and bleeding.

Characteristics and evidence-based management of stable coronary artery disease patients in Canada compared with the rest of the world: insights from the CLARIFY registry.

Background: Previous Canadian high vascular risk registries have demonstrated suboptimal goal-directed reductions in cardiovascular risk factors and underutilization of guideline-recommended therapies in part because of physician underestimation of cardiovascular risk.

Methods: The Prospective Observational Longitudinal Registry of Patients With Stable Coronary Artery Disease (CLARIFY) registry enrolled 33,438 stable coronary artery disease patients in 45 countries. In Canada, supplemental information was obtained specifying reasons that patients were not taking guideline-recommended medications.

Blind source separation in characterizing ECG pre-shock waveforms during Ventricular Fibrillation.

Ventricular Fibrillation (VF) is a cardiac arrhythmia for which the only available treatment option is defibrillation by electrical shock. Existing literature indicates that VF could be the manifestation of different sources controlling the heart with different degrees of organization. In this work we test the hypothesis that the pre-shock waveforms of successful and unsuccessful shock outcomes could be related to the number of independent sources present in these waveforms.

Antiarrhythmic drugs in atrial fibrillation: do they have a future?

Atrial fibrillation (AF) is a common arrhythmia associated with significant morbidity and mortality. There has been much debate about the relative merits of rate vs rhythm control strategies, and studies to date have failed to show advantage with a rhythm-control strategy using antiarrhythmic drugs (AADs). This is likely because of the inadequacies of our current AADs and the limitations of study designs.

Interpreting changes in quality of life in atrial fibrillation: how much change is meaningful?

Background: The Atrial Fibrillation Effect on QualiTy of Life (AFEQT) questionnaire is a novel quality of life (QOL) measure previously shown to be valid, reliable, and sensitive to clinical change in patients with atrial fibrillation (AF). The clinical relevance of a given change in the score is not known. The most useful "anchor" for a measure of meaningful change in QOL is patient-reported magnitude of change.

A population-based description of atrial fibrillation in the emergency department, 2002 to 2010.

Study Objective: We aimed to describe the demographics, care, and outcomes of patients with atrial fibrillation in the emergency department (ED), as well as temporal changes over time.

Methods: In this retrospective cohort study, we used a province-wide database to identify all adult patients who were treated in a nonpediatric ED in the province of Ontario with a primary diagnosis of atrial fibrillation, April 2002 to March 2010. We determined the frequency and rate of ED visits and assessed patient demographics, ED care, and outcomes, both overall and by year.

Survival after implantable cardioverter-defibrillator implantation in the elderly.

Background: The benefit of implantable cardioverter-defibrillators (ICDs) among elderly patients is controversial and may be attenuated by nonarrhythmic death. We examined the impact of age on device-delivered therapies and outcomes after primary or secondary prevention ICD.

Methods And Results: In a prospective, inclusive registry of 5399 ICD recipients in Ontario, Canada (February 2007 to September 2010), device-delivered therapies and complications were determined at routine clinic visits.

Evaluating early repeat emergency department use in patients with atrial fibrillation: a population-based analysis.

Background: Emergency department (ED) use by patients with atrial fibrillation is high and will accelerate with the aging of the population. In patients with atrial fibrillation who are discharged from the ED, we aimed to describe their subsequent outpatient care, return ED visits, and management strategies associated with early return.

Methods: We conducted a retrospective cohort analysis of patients 65 years or older with a primary ED diagnosis of atrial fibrillation who were discharged home from an ED in the province of Ontario, Canada, between April 2007 and March 2010.

Randomized cluster crossover trials for reliable, efficient, comparative effectiveness testing: design of the Prevention of Arrhythmia Device Infection Trial (PADIT).

Randomized clinical trials are a major advance in clinical research methodology. However, there are myriad important questions about the effectiveness of treatments used in daily practice that are not informed by the results of randomized trials. This is in part because of important limitations inherent in the methodology of randomized efficacy trials which are performed with tight control of inclusion, exclusion, treatment, and follow-up.

Mexiletine as an adjunctive therapy to amiodarone reduces the frequency of ventricular tachyarrhythmia events in patients with an implantable defibrillator.

The most effective pharmacological management of frequent ventricular tachyarrhythmia events in patients with an implantable defibrillator who failed or did not tolerate amiodarone is unknown. The aim of this retrospective cohort study was to assess the efficacy and tolerability of mexiletine in such patients. The patients served as self-controls.

Quantitative assessment of brain microvascular and tissue oxygenation during cardiac arrest and resuscitation in pigs.

Cardiac arrest is associated with a very high rate of mortality, in part due to inadequate tissue perfusion during attempts at resuscitation. Parameters such as mean arterial pressure and end-tidal carbon dioxide may not accurately reflect adequacy of tissue perfusion during cardiac resuscitation. We hypothesised that quantitative measurements of tissue oxygen tension would more accurately reflect adequacy of tissue perfusion during experimental cardiac arrest.

Dronedarone and Captisol-enabled amiodarone in an experimental cardiac arrest.

Objective: To compare the energy required for defibrillation and postshock outcomes after the administration of dronedarone, amiodarone, and placebo in a porcine model of cardiac arrest.

Methods: Forty-two pigs were randomized to amiodarone, dronedarone, or control treatments. After induction of ventricular fibrillation, compressions and ventilations were performed for 3 minutes and treatment was administered over 30 seconds.

Factors associated with 90-day death after emergency department discharge for atrial fibrillation.

Study Objective: More than 10% of patients treated in the emergency department (ED) for atrial fibrillation die within a year of the visit. We sought to describe the post-ED care of an older population of atrial fibrillation patients who were discharged home from the ED and to assess patient characteristics and processes of care associated with risk of death within 90 days of discharge.

Methods: This retrospective cohort analysis included patients aged 65 years or older with a primary ED diagnosis of atrial fibrillation who were treated at all nonpediatric EDs in the province of Ontario, Canada, between April 2007 and March 2010.