Atrial fibrillation burden and atrial fibrillation type: Clinical significance and impact on the risk of stroke and decision making for long-term anticoagulation

Physician decision making in anticoagulating atrial fibrillation: a prospective survey of a physician notification system for atrial fibrillation detected on cardiac implantable electronic devices of patients at increased risk of stroke

OBJECTIVES

The objectives of this study were to evaluate the effectiveness of a physician notification system for atrial fibrillation (AF) detected on cardiac devices, and to assess predictors of anticoagulation in patients with device-detected AF.

METHODS

In 2013, a physician notification system for AF detected on a patient's CIED [including pacemakers, implantable cardioverter defibrillators (ICD) or cardiac resynchronization therapy (CRT) devices] was implemented, with a recommendation to consider oral anticoagulation in high-risk patients. We prospectively investigated the effectiveness of this system, and evaluated both patient and physician predictors of anticoagulation, as well as factors influencing physician decision making in prescribing anticoagulation. Both uni- and multivariable analysis as well as descriptive statistics were used in the analysis.

RESULTS

We identified 177 patients with device-detected AF, 126 with a CHADS2 ⩾2. Only 41% were prescribed anticoagulation at any point within 12 months. On multivariable analysis, stroke risk as predicted by CHADS2 was not a predictor of anticoagulation. ASA use predicted a lower rate of anticoagulation (OR 0.39, 95% CI 0.16-0.97, p = 0.04); physicians in practice for <20 years were more likely to prescribe anticoagulation (OR 3.39, 95% CI 1.28-8.93, p = 0.01); and physicians who believed both cardiologist and family doctor should be involved in managing anticoagulation were more likely to prescribe anticoagulation (OR 3.28, 95% CI 1.02-10.5, p = 0.05).

CONCLUSIONS

Patients on aspirin were less likely to be anticoagulated. Physicians in practice for <20 years and who believed that both the general practitioner and cardiologist should be involved in managing anticoagulants were more likely to prescribe anticoagulation.

l-Carnitine and heart disease

Cardiovascular disease (CVD) is a key cause of deaths worldwide, comprising 15-17% of healthcare expenditure in developed countries. Current records estimate an annual global average of 30 million cardiac dysfunction cases, with a predicted escalation by two-three folds for the next 20-30years. Although β-blockers and angiotensin-converting-enzymes are commonly prescribed to control CVD risk, hepatotoxicity and hematological changes are frequent adverse events associated with these drugs. Search for alternatives identified endogenous cofactor l-carnitine, which is capable of promoting mitochondrial β-oxidation towards a balanced cardiac energy metabolism. l-Carnitine facilitates transport of long-chain fatty acids into the mitochondrial matrix, triggering cardioprotective effects through reduced oxidative stress, inflammation and necrosis of cardiac myocytes. Additionally, l-carnitine regulates calcium influx, endothelial integrity, intracellular enzyme release and membrane phospholipid content for sustained cellular homeostasis. Carnitine depletion, characterized by reduced expression of "organic cation transporter-2" gene, is a metabolic and autosomal recessive disorder that also frequently associates with CVD. Hence, exogenous carnitine administration through dietary and intravenous routes serves as a suitable protective strategy against ventricular dysfunction, ischemia-reperfusion injury, cardiac arrhythmia and toxic myocardial injury that prominently mark CVD. Additionally, carnitine reduces hypertension, hyperlipidemia, diabetic ketoacidosis, hyperglycemia, insulin-dependent diabetes mellitus, insulin resistance, obesity, etc. that enhance cardiovascular pathology. These favorable effects of l-carnitine have been evident in infants, juvenile, young, adult and aged patients of sudden and chronic heart failure as well. This review describes the mechanism of action, metabolism and pharmacokinetics of l-carnitine. It specifically emphasizes upon the beneficial role of l-carnitine in cardiomyopathy.

Optimum Risk Assessment for Stroke in Atrial Fibrillation: Should We Hold the Status Quo or Consider Magnitude Synergism and Left Atrial Appendage Anatomy?

Thromboembolic stroke and systemic embolism are generally agreed to be the major morbidity/mortality concerns for patients with AF. However, the risk of thromboembolism is not the same for all AF patients. Both AF and comorbidities must interact synergistically to create the risk for thromboembolism. But, is the synergism dichotomous - AF present or absent, comorbid disorder present or absent - or does synergism have magnitude, depending on the number and severity of the associated disorders and the amount of time one is in AF? This review discusses the current risk-score contributors and options for assessing risk of thromboembolism in AF patients, and what their combined roles might be. Also covered is the consideration of left atrial appendage anatomy in this context.

Atrial fibrillation prevention: an appraisal of current evidence

Atrial fibrillation (AF), which is the most diagnosed arrhythmia, is becoming a significant issue for health policy-makers. In particular, more and more attention is being devoted to AF prevention. Indeed, several studies recently published point out how targeted interventions could be useful in reducing the risk of AF occurrence (or recurrence). In this review, we briefly summarised the role of the major risk factors associated with the incidence of AF, as well as the effectiveness of interventions aimed at controlling these risk factors. Several general risk factors, such as alcohol consumption, physical activity, smoking habit, as well as specific cardiovascular risk factors as diabetes mellitus, hypertension and obesity have a relevant impact in determining the occurrence of AF, along with a strong clinical evidence of a dose-effect response mechanism for most of the factors examined. Specific interventions aimed at controlling risk factors have been showed to clearly reduce the risk of AF in several cohorts. Even more importantly, integrated programmes aimed at controlling for multiple risk factors would be more efficient in terms of reducing risk of AF, in particular whena stricter control is observed. AF prevention requires a series of initiatives focused on the many risk factors that we reviewed, as well as a more integrated approach, which should involve many stakeholders at different levels. In this light and also considering the constantly changing epidemiology, AF prevention may constitute a future 'win-win' strategy for all the stakeholders.

Pharmacological and Non-pharmacological Treatments for Stroke Prevention in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is associated with significant risk of stroke and other thromboembolic events, which can be effectively prevented using oral anticoagulation (OAC) with either vitamin K antagonists (VKAs) or non-VKA oral anticoagulants (NOACs) dabigatran, rivaroxaban, apixaban, or edoxaban. Until recently, VKAs were the only available means for OAC treatment. NOACs had similar efficacy and were safer than or as safe as warfarin with respect to reduced rates of hemorrhagic stroke or other intracranial bleeding in the respective pivotal randomized clinical trials (RCTs) of stroke prevention in non-valvular AF patients. Increasing “real-world” evidence on NOACs broadly confirms the results of the RCTs. However, individual patient characteristics including renal function, age, or prior bleeding should be taken into account when choosing the OAC with best risk–benefit profile. In patients ineligible for OACs, surgical or interventional stroke prevention strategies should be considered. In patients undergoing cardiac surgery for other reasons, the left atrial appendage excision, ligation, or amputation may be the best option. Importantly, residual stumps or insufficient ligation may result in even higher stroke risk than without intervention. Percutaneous left atrial appendage occlusion, although requiring minimally invasive access, failed to demonstrate reduced ischemic stroke events compared to warfarin. In this review article, we summarize current treatment options and discuss the strengths and major limitations of the therapies for stroke risk reduction in patients with AF.

Controversies in postoperative atrial fibrillation after noncardiothoracic surgery: clinical and research implications

Post operative atrial fibrillation after non-cardiothoracic surgery is an increasingly common problem. There is little high quality data to guide clinicians in risk prediction as well as short term and long term management. There appears to be a significant risk of recurrent atrial fibrillation and stroke but effective screening strategies have not been tested. In this commentary, we delineate various controversies in the management of post operative atrial fibrillation and briefly review the available evidence. Prospective studies in this clinically important area of cardiology should be encouraged.