Influence of age on the prescription of vitamin K antagonists in outpatients with permanent atrial fibrillation in France

PURPOSE

The aim of the study was to describe the current rate and determinants of the prescription of antithrombotics in outpatients with permanent atrial fibrillation, with a pre-specified emphasis on the influence of age on the prescription of vitamin K antagonists.

METHODS

This was a prospective observational survey in France among 5893 consecutive outpatients with documented permanent atrial fibrillation being seen by 770 physicians from August to December 2002. We recruited physicians from two random lists of general practitioners and cardiologists, respectively, stratified according to their administrative region, from the list of all French private general practitioners and cardiologists.

RESULTS

The mean age of patients was 75.8 years. Mean duration since diagnosis of atrial fibrillation was 5.0 years; 31.7% of patients had valvular heart disease and 60.3% hypertension. An antithrombotic was prescribed to 95.5% of patients at the time of consultation. The percentage of patients treated with vitamin K antagonists was 76.4%; it decreased from 86.0% in patients aged 60-70 years to 63.5% in patients aged 80 years or above. On multivariate analysis, high age was a significant predictor (p = 0.001) for the non-prescription of vitamin K antagonists. In patients above 70 years currently receiving an antithrombotic, the probability of prescription of vitamin K antagonists decreased on average by 9.6% per year.

CONCLUSIONS

Vitamin K antagonists are administered to most outpatients with permanent atrial fibrillation at high thromboembolic risk seen by French physicians in private practice. However, their use decreases with age.

A comparative study of the efficacy and safety of procainamide versus propafenone versus amiodarone for the conversion of recent-onset atrial fibrillation

The appropriate treatment for the restoration of sinus rhythm in patients with atrial fibrillation (AF) of recent onset is still the subject of controversy. In this prospective, randomized, single-blind, placebo-controlled clinical study, we investigated the effectiveness and safety of procainamide, propafenone, and amiodarone, administered intravenously, for the conversion of recent-onset AF. We enrolled 362 consecutive patients (183 men; age 34 to 86 years; mean 65+/-10) with AF duration of no >48 hours. Of these patients, 89 were given procainamide, 91 propafenone, 92 amiodarone, and 90 placebo. Treatment was considered successful if conversion to sinus rhythm was achieved within the 24-hour study period. Baseline clinical characteristics were similar in the 4 groups. The treatment was successful in 61 of the 89 patients who received procainamide (68.53%; median time 3 hours), 73 of the 91 patients who received propafenone (80.21%; median time 1 hour), 82 of the 92 patients who received amiodarone (89.13%; median time 9 hours), and 55 of the 90 patients who received placebo (61.11%; median time 17 hours; p<0.05 for all medicated groups vs placebo; p<0.05 for amiodarone and propafenone vs procainamide). In conclusion, all 3 medications, when administered intravenously, are effective in the restoration of sinus rhythm in recent-onset AF. Amiodarone and propafenone are more effective whereas procainamide and propafenone are faster.

Meta-analysis of magnesium therapy for the acute management of rapid atrial fibrillation

The profile of electrophysiologic effects of magnesium on the heart suggests that magnesium might be effective in the treatment of atrial fibrillation (AF) in terms of rhythm and rate control. We aimed to investigate the efficacy of magnesium administration in the acute treatment of rapid AF. Randomized controlled trials comparing intravenous magnesium versus placebo or antiarrhythmic agents for the acute management of rapid AF were included. Nine electronic databases were searched for relevant trials from the earliest possible dates through June 2005, as were abstract books from 8 cardiovascular meetings held in the past 10 years. We analyzed all outcomes using a fixed-effect model because of the low number of trials in each comparison. The results were expressed as relative risks (RRs) or odds ratios (ORs) for dichotomous outcomes and weighted mean differences for continuous outcomes, along with their 95% confidence intervals (CIs). Data were pooled for 4 trials (n=303) and 8 trials (n=476), respectively, for rate control (<100 beats/min) and rhythm control. Magnesium was effective in achieving rate control (OR 1.96, 95% CI 1.24 to 3.08) or rhythm control (OR, 1.60, 95% CI 1.07 to 2.39). An overall response was achieved in 86% and 56% of patients in the magnesium and control groups, respectively (OR 4.61 95% CI 2.67 to 7.96). Time to response (in hours) was significantly shorter in the magnesium group (weighted mean difference, -6.98; 95% CI -9.27 to -4.68). The risk of having a major adverse effect in the magnesium group was similar to that in the placebo group (RR 0.85, 95% CI 0.44 to 1.61). In conclusion, the present meta-analysis of published data suggests that intravenous magnesium administration is an effective and safe strategy for the acute management of rapid AF.

Calmodulin kinase II inhibition prevents arrhythmic activity induced by alpha and beta adrenergic agonists in rabbit pulmonary veins

The autonomic nervous system and calcium regulation play important roles in the pathophysiology of atrial fibrillation. Calmodulin regulates the calcium homeostasis and may mediate the proarrhythmic effects of autonomic nervous agents. The purpose of this study was to compare the effects of beta- and alpha-adrenoceptor agonists on the pulmonary vein electrical activity and evaluate whether calmodulin kinase II inhibitors may change the effects of the adrenoceptor agonists on the pulmonary vein arrhythmogenesis. Conventional microelectrodes were used to record the action potentials in isolated rabbit pulmonary vein tissue specimens before and after the administration of isoproterenol, phenylephrine and KN-93 (a calmodulin kinase II inhibitor). In the tissue preparation, isoproterenol (0, 0.1, 3 microM) increased the beating rates (1.5+/-0.2, 1.6+/-0.2, 2.3+/-0.3 Hz, n=10, P<0.001) with the genesis of early afterdepolarizations (EADs, 0%, 40%, 50%, P<0.05) and increased the amplitude of the delayed afterdepolarizations (DADs, 0.6+/-0.3, 1.7+/-0.4, 3.9+/-1.0 mV, P<0.05). Phenylephrine (0, 1, 10 microM) also increased the beating rates (1.4+/-0.2, 1.6+/-0.2, 1.9+/-0.2 Hz, n=12, P<0.001), incidence of EADs (0%, 8%, 50%, P<0.05) and amplitude of the DADs (0.4+/-0.2, 1.2+/-0.4, 2.6+/-0.8 mV, P<0.05). KN-93 did not change the pulmonary vein beating rates or action potential duration. However, in the presence of KN-93 (1 microM), isoproterenol (3 microM) and phenylephrine (10 microM) did not induce any EADs or DADs in the pulmonary veins. In conclusion, calmodulin kinase II inhibition may prevent adrenergic induced pulmonary vein arrhythmogenesis.

Antiarrhythmic drug therapy after radiofrequency catheter ablation in patients with atrial fibrillation

OBJECTIVES

The use of antiarrhythmic drugs after ablation is a controversial issue when evaluating the efficacy of atrial fibrillation (AF) ablation. This study compares in a prospective and randomized fashion the impact of an antiarrhythmic drug in preventing AF recurrence after AF ablation.

METHODS

From February 2004 to May 2005, 107 consecutive patients (mean age 57 +/- 10 years, 69 men), with paroxysmal (60%) or persistent (40%) drug refractory AF, were randomly assigned to ablation alone (Group A, 53 patients) or combined with the best antiarrhythmic therapy, preferably amiodarone (Group B, 54 patients). All patients underwent cavo-tricuspid and left inferior pulmonary vein (PV)-mitral isthmus ablation plus circumferential PV ablation, using a guided electro-anatomical approach. Standard electrocardiograms (ECG), and ambulatory and transtelephonic ECG monitoring were used to assess AF recurrences. Recurrences during the first month after ablation were excluded from this analysis.

RESULTS

At 12 months of follow-up, no significant difference was observed in the rates of AF recurrences between Group A (18/53 patients, 34%) and Group B (16/54 patients, 30%). The percentage of patients with >/= 1 asymptomatic AF episode was higher in Group B than in Group A (10/16 patients, 63%, vs 5/18 patients, 28%, P = 0.04).

CONCLUSIONS

Continuing antiarrhythmic drug therapy in patients who undergo catheter ablation for AF did not lower the rate of AF recurrences. Antiarrhythmic drugs increased the proportion of patients with asymptomatic AF episodes.

Small or large isolation areas around the pulmonary veins for the treatment of atrial fibrillation? Results from a prospective randomized study

BACKGROUND

Pulmonary vein (PV) isolation is a promising new treatment for atrial fibrillation (AF). We hypothesized that isolation of large areas around both ipsilateral PVs with verification of conduction block is more effective than the isolation of each individual PV.

METHODS AND RESULTS

A total of 110 patients, 67 with paroxysmal AF and 43 with persistent AF, were randomly assigned to undergo either isolation of each individual PV or isolation of large areas around both ipsilateral PVs. The isolation of each individual PV was an electrophysiologically guided, ostial segmental ablation with a 64-pole basket catheter or a 20-pole circular mapping catheter (group I). Isolation of large areas was performed around the 2 ipsilateral veins with a nonfluoroscopic navigation system and a circular 20-pole mapping catheter for verification of conduction block (group II). In both groups, an irrigated-tip ablation catheter (25 to 35 W) was used to achieve complete isolation. Procedure and ablation times were longer in group II, whereas fluoroscopic time was significantly shorter (P < or = 0.001). After a follow-up period of 15+/-4 months, 27 patients in group I (49%) and 37 patients in group II (67%) remained free of symptoms of AF and had no AF or atrial flutter during repetitive Holter monitoring without antiarrhythmic drug treatment after a single procedure (P < or = 0.05).

CONCLUSIONS

The rate of success was significantly higher and fluoroscopy times were significantly lower in the group with large isolation areas around both ipsilateral PVs than in those who underwent individual PV isolation.

Influence of decision aids on patient preferences for anticoagulant therapy: a randomized trial

BACKGROUND

Decision aids have been shown to be useful in selected situations to assist patients in making treatment decisions. Important features such as the format of decision aids and their graphic presentation of data on benefits and harms of treatment options have not been well studied.

METHODS

In a randomized trial with a 3 x 2 factorial design, we investigated the effects of decision aid format (decision board, decision booklet with audiotape, or interactive computer program) and graphic presentation of data (pie graph or pictogram) on patients' comprehension and choices of 3 treatments for anticoagulation, identified initially as "treatment A" (warfarin), "treatment B" (acetylsalicylic acid) and "treatment C" (no treatment). Patients aged 65 years or older without known atrial fibrillation and not currently taking warfarin were included. The effect of blinding to the treatment name was tested in a before-after comparison. The primary outcome was change in comprehension score, as assessed by the Atrial Fibrillation Information Questionnaire. Secondary outcomes were treatment choice, level of satisfaction with the decision aid, and decisional conflict.

RESULTS

Of 102 eligible patients, 98 completed the study. Comprehension scores (maximum score 10) increased by an absolute mean of 3.1 (p < 0.01) after exposure to the decision aid regardless of the format or graphic presentation. Overall, 96% of the participants felt that the decision aid helped them make their treatment choice. Unblinding of the treatment name resulted in 36% of the participants changing their initial choice (p < 0.001).

INTERPRETATION

The decision aid led to significant improvement in patients' knowledge regardless of the format or graphic representation of data. Revealing the name of the treatment options led to significant shifts in declared treatment preferences.

National underuse of anti-thrombotic therapy in chronic atrial fibrillation identified from digoxin prescribing

AIMS

To examine if appropriate antithrombotic therapy in atrial fibrillation is implemented nationally.

METHODS

Using prescriptions for digoxin as a surrogate for atrial fibrillation, we identified its coprescription with antithrombotic therapy, aspirin or warfarin in a national prescribing database in 27 571 patients over 45 years old.

RESULTS

Proportionately significantly more men were on warfarin, and use in those >75 years old was three times less than in those <65 years. Reluctance to use antithrombotics was confirmed in a postal survey.

CONCLUSION

Data suggest a missed opportunity to prevent stroke with women and those >75 years old least likely to receive warfarin.

Medical management of atrial fibrillation

Atrial fibrillation (AF) is the most common sustained tachyarrhythmia encountered in clinical practice. The management of AF remains associated with many challenges that make its treatment a vexing problem. However, in recent years extraordinary progress has been made in the understanding and management of AF. In general, antiarrhythmic drugs for rhythm control have been disappointing. We have a better understanding of pharmacologic cardioversion and this has led to newer strategies, such as intermittent therapy. Several studies have been completed comparing pharmacologic rhythm control with pharmacologic heart rate control. There is also an emerging body of evidence concerning the value of adjunctive drug use for rhythm control using drugs that would not usually be considered to be antiarrhythmic. Finally, antithrombotic therapy is an increasingly important part of the medical management of AF. This article summarizes the results of many of the recent publications and their clinical implications concerning management of this common rhythm disorder.

Atrial fibrillation in the elderly

Atrial fibrillation is increasingly prevalent among older adults. It causes approximately 24% of strokes in patients aged 80 to 89 years. The management of atrial fibrillation is directed at preventing thromboembolism and controlling the heart rate and rhythm. Stroke prevention is most effectively accomplished through administering anticoagulants such as warfarin, although older patients have higher hemorrhagic risk. Cognitive dysfunction, functional impairments, and increased fall risk further complicate warfarin management in elderly patients. The use of risk stratification schemes can help guide the anticoagulation decision, although the benefits of warfarin generally outweigh the risks in most older patients with atrial fibrillation. Pharmacologic rate control has been shown to result in similar outcomes compared with pharmacologic restoration of sinus rhythm and should be the initial therapy for elderly patients. Anti-arrhythmic medications should be selected based on an individual patient's coexisting medical conditions. In symptomatic patients who fail pharmacologic therapy, invasive strategies such as AV nodal ablation may help improve quality of life and symptoms, although such strategies do not obviate the need for antithrombotic therapy.

Magnesium infusion and postoperative atrial fibrillation: a randomized clinical trial

BACKGROUND

Postoperative arrhythmias are among the most common complications of cardiac surgery. Total serum magnesium concentration will change after coronary bypass surgery but compensatory prophylactic administration of magnesium has remained a controversial issue. We studied whether prophylactic administration of magnesium could prevent post-coronary artery bypass grafting (CABG) arrhythmias and evaluated the effects of diabetes mellitus on prophylactic magnesium administration.

METHODS

In a clinical trial, 345 consecutive CABG candidates were randomly assigned to study (n = 166, 48.1%) and control groups. Patients in study group received supplemental magnesium infusion as following: 2 g [corrected] after induction of anesthesia until cardio-pulmonary bypass and then 8 g upon arrival in Intensive Care Unit (ICU) until 24 hr. Total serum magnesium concentration was measured at four designated time points: onset of induction, and 0, 24 and 48 hr after ICU admission. Cardiac arrhythmias were sought with a 12-lead electrocardiogram (ECG) from the end of surgery up till discharge.

RESULTS

Atrial Fibrillation (Af) occurred in 34 patients (9.9%). Total serum magnesium concentration was significantly higher in patients who received supplemental magnesium (P < 0.001) and significantly lower in Af patients (P= 0.02). Among non-diabetics, Af incidence was significantly lower in study group compared with control group.

CONCLUSIONS

The occurrence of atrial fibrillation correlates with serum magnesium level. Diabetes mellitus probably hampers prophylactic effect of supplemental magnesium in preventing the occurrence of Af.

[Left coronary artery embolism resulting from ineffective anticoagulation in a patient suffering from dilated cardiomyopathy as a possible cause of myocardial infarction--a case report]

We present a case of a 58-year-old male being treated for dilated cardiomyopathy and atrial fibrillation for more than ten years who was admitted to the intensive care unit with the diagnosis of acute ST-segment elevation myocardial infarction (STEMI). In course of further diagnostics the coronary artery embolism resulting from the unintentional anticoagulant drug (acenocumarol) dose reduction was established as the most probable cause of STEMI. Primary percutaneous coronary intervention was successfully performed and the patient was discharged home in good clinical condition.

Angiotensin converting enzyme inhibitor and angiotensin receptor blockade use in relation to outcomes in anticoagulated patients with atrial fibrillation

BACKGROUND

The renin-angiotensin-aldosterone-system (RAAS) plays an important role in atrial fibrillation (AF). Evidence shows that blocking the RAAS with angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) has a definite role in preventing new onset AF and in maintaining sinus rhythm in recurrent AF. Our aim was to determine if ACEI/ARB treatment was associated with clinical outcomes [stroke/systemic embolic events (SEE), mortality] in a controlled, anticoagulated AF population.

METHODS

An ancillary retrospective cross-sectional and longitudinal analysis of participants in the Stroke Prevention using an ORal Thrombin Inhibitor in AF (SPORTIF) III and V trials, in relation to use (or nonuse) of ACEI/ARBs.

RESULTS

Rates of stroke/SEEs, mortality or major bleeding were no different between users and nonusers in the whole cohort, or in relation to the presence/absence of hypertension, coronary artery disease and previous stroke/transient ischaemic attack, nor amongst those aged <75 years. Patients aged > or = 75 years taking ACEIs or ARBs had lower mortality (HR 0.71, 95% CI 0.52-0.95), but no significant influence on other end-points was noted. Diabetics and those with left ventricular dysfunction on ximelagatran had a higher odds ratio of abnormal liver enzyme levels. There was no apparent benefit of ACEIs or ARBs on other event rates.

CONCLUSIONS

This analysis from two large randomized trials of anticoagulation has not demonstrated a significant benefit of ACEI or ARB use amongst AF patients, except amongst elderly subjects.

Guideline-adherent antithrombotic treatment is associated with improved outcomes compared with undertreatment in high-risk patients with atrial fibrillation. The Euro Heart Survey on Atrial Fibrillation

BACKGROUND

The Euro Heart Survey showed that antithrombotic treatment in patients with atrial fibrillation (AF) was moderately tailored to the 2001 American College of Cardiology, American Heart Association, and European Society of Cardiology (ACC/AHA/ESC) guidelines for the management of AF. What consequences does guideline-deviant antithrombotic treatment have in daily practice?

METHODS

In the Euro Heart Survey on AF (2003-2004), an observational study on AF care in European cardiology practices, information was available on baseline stroke risk profile and antithrombotic drug treatment and on cardiovascular events during 1-year follow-up. Antithrombotic guideline adherence is assessed according to the 2001 ACC/AHA/ESC guidelines. Multivariable logistic regression was performed to assess the association of guideline deviance with adverse outcome.

RESULTS

The effect of antithrombotic guideline deviance was analyzed exclusively in 3634 high-risk patients with AF because these composed the majority (89%) and because few cardiovascular events occurred in low-risk patients. Among high-risk patients, antithrombotic treatment was in agreement with the guidelines in 61% of patients, whereas 28% were undertreated and 11% overtreated. Compared to guideline adherence, undertreatment was associated with a higher chance of thromboembolism (odds ratio [OR], 1.97; 95% CI, 1.29-3.01; P = .004) and the combined end point of cardiovascular death, thromboembolism, or major bleeding (OR, 1.54; 95% CI, 1.14-2.10; P = .024). This increased risk was nonsignificant for the end point of stroke alone (OR, 1.42; 95% CI, 0.82-2.46; P = .170). Overtreatment was nonsignificantly associated with a higher risk for major bleeding (OR, 1.52; 95% CI, 0.76-3.02; P = .405).

CONCLUSIONS

Antithrombotic undertreatment of high-risk patients with AF was associated with a worse cardiovascular prognosis during 1 year, whereas overtreatment was not associated with a higher chance for major bleeding.