-
The Cochrane Database of Systematic... Jan 2013Atrial fibrillation is a common post-operative complication of cardiac surgery and is associated with an increased risk of post-operative stroke, increased length of... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Atrial fibrillation is a common post-operative complication of cardiac surgery and is associated with an increased risk of post-operative stroke, increased length of intensive care unit and hospital stays, healthcare costs and mortality. Numerous trials have evaluated various pharmacological and non-pharmacological prophylactic interventions for their efficacy in preventing post-operative atrial fibrillation. We conducted an update to a 2004 Cochrane systematic review and meta-analysis of the literature to gain a better understanding of the effectiveness of these interventions.
OBJECTIVES
The primary objective was to assess the effects of pharmacological and non-pharmacological interventions for preventing post-operative atrial fibrillation or supraventricular tachycardia after cardiac surgery. Secondary objectives were to determine the effects on post-operative stroke or cerebrovascular accident, mortality, cardiovascular mortality, length of hospital stay and cost of treatment during the hospital stay.
SEARCH METHODS
We searched the Cochrane Central Register of ControlLed Trials (CENTRAL) (Issue 8, 2011), MEDLINE (from 1946 to July 2011), EMBASE (from 1974 to July 2011) and CINAHL (from 1981 to July 2011).
SELECTION CRITERIA
We selected randomized controlled trials (RCTs) that included adult patients undergoing cardiac surgery who were allocated to pharmacological or non-pharmacological interventions for the prevention of post-operative atrial fibrillation or supraventricular tachycardia, except digoxin, potassium (K(+)), or steroids.
DATA COLLECTION AND ANALYSIS
Two review authors independently abstracted study data and assessed trial quality.
MAIN RESULTS
One hundred and eighteen studies with 138 treatment groups and 17,364 participants were included in this review. Fifty-seven of these studies were included in the original version of this review while 61 were added, including 27 on interventions that were not considered in the original version. Interventions included amiodarone, beta-blockers, sotalol, magnesium, atrial pacing and posterior pericardiotomy. Each of the studied interventions significantly reduced the rate of post-operative atrial fibrillation after cardiac surgery compared with a control. Beta-blockers (odds ratio (OR) 0.33; 95% confidence interval) CI 0.26 to 0.43; I(2) = 55%) and sotalol (OR 0.34; 95% CI 0.26 to 0.43; I(2) = 3%) appear to have similar efficacy while magnesium's efficacy (OR 0.55; 95% CI 0.41 to 0.73; I(2) = 51%) may be slightly less. Amiodarone (OR 0.43; 95% CI 0.34 to 0.54; I(2) = 63%), atrial pacing (OR 0.47; 95% CI 0.36 to 0.61; I(2) = 50%) and posterior pericardiotomy (OR 0.35; 95% CI 0.18 to 0.67; I(2) = 66%) were all found to be effective. Prophylactic intervention decreased the hospital length of stay by approximately two-thirds of a day and decreased the cost of hospital treatment by roughly $1250 US. Intervention was also found to reduce the odds of post-operative stroke, though this reduction did not reach statistical significance (OR 0.69; 95% CI 0.47 to 1.01; I(2) = 0%). No significant effect on all-cause or cardiovascular mortality was demonstrated.
AUTHORS' CONCLUSIONS
Prophylaxis to prevent atrial fibrillation after cardiac surgery with any of the studied pharmacological or non-pharmacological interventions may be favored because of its reduction in the rate of atrial fibrillation, decrease in the length of stay and cost of hospital treatment and a possible decrease in the rate of stroke. However, this review is limited by the quality of the available data and heterogeneity between the included studies. Selection of appropriate interventions may depend on the individual patient situation and should take into consideration adverse effects and the cost associated with each approach.
Topics: Adrenergic beta-Antagonists; Adult; Amiodarone; Anti-Arrhythmia Agents; Atrial Fibrillation; Cardiac Pacing, Artificial; Cardiac Surgical Procedures; Humans; Magnesium Compounds; Pericardiectomy; Randomized Controlled Trials as Topic; Sotalol; Tachycardia, Supraventricular
PubMed: 23440790
DOI: 10.1002/14651858.CD003611.pub3 -
Journal of Neurology Mar 2013Essential tremor (ET) is one of the most common movement disorders of adults, characterized by postural and kinetic tremor. It often causes embarrassment and more rarely... (Review)
Review
Essential tremor (ET) is one of the most common movement disorders of adults, characterized by postural and kinetic tremor. It often causes embarrassment and more rarely serious disability, requiring treatment. To assess the current state of knowledge on ET therapy and produce recommendations based on the analysis of evidence the authors reviewed the literature regarding pharmacologic and surgical therapies, providing a quality assessment of the studies and the strength of recommendations for each treatment. A committee of experts selected clinical-based questions to guide the search. A systematic literature review was performed to identify all the studies conducted on patients with ET published until September 2010. Articles were classified according to GRADE evidence profile, a system for grading the quality of evidence and the strength of recommendation based on the quality of the studies. The quality of evidence was often rated as "low" or "very low" for the studies analyzed. Propranolol, long-acting propranolol, primidone, and topiramate are recommended as first-line therapy, with restrictions for their side effects. Arotinolol, sotalol, ICI 118.551 and LI 32.468 (experimental drugs), zonisamide, gabapentin, alprazolam, clozapine, and olanzapine are recommended as a second-line treatment. Botulinum toxin type A and thalamic deep-brain stimulation are recommended for refractory ET. The results highlight the need of well-designed direct comparison trials aimed at evaluating relative effectiveness and safety of the drugs currently used in clinical practice. Furthermore, additional controlled clinical trials are required to define other possible treatment strategies for ameliorating the management of ET.
Topics: Animals; Clinical Trials as Topic; Clozapine; Deep Brain Stimulation; Essential Tremor; Humans; Italy; Movement Disorders; Practice Guidelines as Topic; Propranolol; Treatment Outcome
PubMed: 22886006
DOI: 10.1007/s00415-012-6628-x -
The Cochrane Database of Systematic... May 2012Atrial fibrillation (AF) is the most frequent sustained arrhythmia. AF recurs frequently after restoration of normal sinus rhythm. Antiarrhythmic drugs have been widely... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Atrial fibrillation (AF) is the most frequent sustained arrhythmia. AF recurs frequently after restoration of normal sinus rhythm. Antiarrhythmic drugs have been widely used to prevent recurrence, but the effect of these drugs on mortality and other clinical outcomes is unclear.
OBJECTIVES
To determine, in patients who recovered sinus rhythm after AF, the effect of long-term treatment with antiarrhythmic drugs on death, stroke and embolism, adverse effects, pro-arrhythmia, and recurrence of AF.
SEARCH METHODS
We updated the searches of CENTRAL on The Cochrane Libary (Issue 1 of 4, 2010), MEDLINE (1950 to February 2010) and EMBASE (1966 to February 2010). The reference lists of retrieved articles, recent reviews and meta-analyses were checked.
SELECTION CRITERIA
Two independent reviewers selected randomised controlled trials comparing any antiarrhythmic with a control (no treatment, placebo or drugs for rate control) or with another antiarrhythmic, in adults who had AF and in whom sinus rhythm was restored. Post-operative AF was excluded.
DATA COLLECTION AND ANALYSIS
Two reviewers independently assessed quality and extracted data. Studies were pooled, if appropriate, using Peto odds ratio (OR). All results were calculated at one year of follow-up.
MAIN RESULTS
In this update, 11 new studies met inclusion criteria, making a total of 56 included studies, comprising 20,771 patients. Compared with controls, class IA drugs quinidine and disopyramide (OR 2.39, 95% confidence interval (95%CI) 1.03 to 5.59, number needed to harm (NNH) 109, 95%CI 34 to 4985) and sotalol (OR 2.47, 95%CI 1.2 to 5.05, NNH 166, 95%CI 61 to 1159) were associated with increased all-cause mortality. Other antiarrhythmics did not seem to modify mortality.Several class IA (disopyramide, quinidine), IC (flecainide, propafenone) and III (amiodarone, dofetilide, dronedarone, sotalol) drugs significantly reduced recurrence of AF (OR 0.19 to 0.70, number needed to treat (NNT) 3 to 16). Beta-blockers (metoprolol) also reduced significantly AF recurrence (OR 0.62, 95% CI 0.44 to 0.88, NNT 9).All analysed drugs increased withdrawals due to adverse affects and all but amiodarone, dronedarone and propafenone increased pro-arrhythmia. We could not analyse other outcomes because few original studies reported them.
AUTHORS' CONCLUSIONS
Several class IA, IC and III drugs, as well as class II (beta-blockers), are moderately effective in maintaining sinus rhythm after conversion of atrial fibrillation. However, they increase adverse events, including pro-arrhythmia, and some of them (disopyramide, quinidine and sotalol) may increase mortality. Possible benefits on clinically relevant outcomes (stroke, embolisms, heart failure) remain to be established.
Topics: Anti-Arrhythmia Agents; Atrial Fibrillation; Electric Countershock; Humans; Randomized Controlled Trials as Topic; Secondary Prevention
PubMed: 22592700
DOI: 10.1002/14651858.CD005049.pub3 -
International Journal of Cardiology May 2013To perform a systematic review/meta-analysis evaluating the efficacy and safety of anti-arrhythmic drugs (AADs) in the treatment of atrial fibrillation (AF). (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
To perform a systematic review/meta-analysis evaluating the efficacy and safety of anti-arrhythmic drugs (AADs) in the treatment of atrial fibrillation (AF).
METHODS
Database searches (accessed April 2009) were conducted to identify randomised controlled trials (RCTs). Comparators of interest included all AADs, rate/rhythm strategies or catheter ablation in comparison with AADs. Primary AADs of interest were restricted to Class IC (flecainide and propafenone) and Class III (amiodarone, dofetilide, dronedarone and sotalol). Data were analysed on an intention-to-treat basis and meta-analysis performed using the Peto odds ratio (OR)/fixed-effect model.
RESULTS
113 publications met inclusion criteria. Of these, 74 publications considered an AAD of primary interest. The odds of AF recurrence were generally significantly lower with all active treatments versus non-active control. Dronedarone was the only AAD to show a (non-significant) trend towards reducing the odds of mortality with a narrow CI (OR 0.85 [0.66, 1.09]). Withdrawals due to adverse events (AEs), incidence of serious adverse events (SAEs) and treatment discontinuation were increased following active treatment compared with control, with few significant differences reported between active treatments. Data for other morbidity outcomes such as cardiovascular mortality, hospitalizations or persistence/compliance and health-related quality of life (HRQoL) were limited and meta-analyses were not possible for these outcomes.
CONCLUSION
The current meta-analysis confirms the efficacy of AADs in preventing AF recurrence, although their use is associated with a greater incidence of AEs and treatment discontinuation. Further RCTs are required to establish the benefit of AADs in the management of both morbidity outcomes and HRQoL.
Topics: Anti-Arrhythmia Agents; Atrial Fibrillation; Humans; Randomized Controlled Trials as Topic; Secondary Prevention; Treatment Outcome
PubMed: 22469557
DOI: 10.1016/j.ijcard.2012.03.070 -
The American Journal of Medicine Sep 2011Supraventricular tachyarrhythmias including atrial fibrillation are common and troubling complications after cardiac surgery, and thus considerable interest in... (Comparative Study)
Comparative Study Meta-Analysis
OBJECTIVE
Supraventricular tachyarrhythmias including atrial fibrillation are common and troubling complications after cardiac surgery, and thus considerable interest in pharmacologic prophylaxis has developed. The aim of this study was to evaluate the efficacy of sotalol in the prevention of postoperative supraventricular tachyarrhythmias.
METHODS
Standard methods of meta-analysis were used. Randomized clinical trials published in English language were eligible for the meta-analysis.
RESULTS
A systematic review revealed 15 eligible publications that provided 20 comparisons of sotalol with a control group. The incidence and relative risk (RR) with 95% confidence interval (CI) of developing postoperative supraventricular tachyarrhythmias while taking sotalol were sotalol (n=489) versus placebo (n=499): 22.5% versus 41.5%, RR=0.55 (CI, 0.454-0.667, P<.001); sotalol (n=304) versus no treatment (n=311): 12% versus 39%, RR=0.329 (CI, 0.236-0.459, P<.001); sotalol (n=488) versus beta-blocker (n=555): 14% versus 23%, RR=0.644 (CI, 0.495-0.838, P<.001); sotalol (n=139) versus amiodarone (n=146): no significant differences in supraventricular tachyarrhythmia prevention; and sotalol (n=51) versus magnesium (n=54): no significant differences in supraventricular tachyarrhythmia prevention. Initiating sotalol orally or intravenously had no significant effect on efficacy. Initiating sotalol after surgery showed a trend toward less adverse events (before: RR=1.700 [CI, 0.903-3.200] and after: RR=0.767 [CI, 0.391-1.505]).
CONCLUSION
Sotalol is more effective in the prevention of supraventricular tachyarrhythmia than placebo or beta-blockers. Initiating sotalol before cardiac surgery has no advantage compared with initiating sotalol shortly after surgery. Starting sotalol intravenously after surgery may be a more reliable method than administering via a nasogastric tube or delaying treatment until the patient can take oral medication.
Topics: Anti-Arrhythmia Agents; Atrial Fibrillation; Double-Blind Method; Drug Therapy, Combination; Electrocardiography; Heart Diseases; Humans; Infusions, Intravenous; Magnesium; Postoperative Care; Postoperative Complications; Prospective Studies; Randomized Controlled Trials as Topic; Sotalol; Tachycardia, Supraventricular
PubMed: 21854895
DOI: 10.1016/j.amjmed.2011.04.025 -
BMJ Clinical Evidence Feb 2011Acute atrial fibrillation is rapid, irregular, and chaotic atrial activity of less than 48 hours' duration. Risk factors for acute atrial fibrillation include increasing... (Review)
Review
INTRODUCTION
Acute atrial fibrillation is rapid, irregular, and chaotic atrial activity of less than 48 hours' duration. Risk factors for acute atrial fibrillation include increasing age, cardiovascular disease, alcohol, diabetes, and lung disease. Acute atrial fibrillation increases the risk of stroke and heart failure. The condition resolves spontaneously within 24 to 48 hours in over 50% of people; however, many people will require interventions to control heart rate or restore sinus rhythm.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to prevent embolism, for conversion to sinus rhythm, and to control heart rate in people with recent-onset atrial fibrillation (within 7 days) who are haemodynamically stable? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 30 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review we present information relating to the effectiveness and safety of the following interventions: amiodarone, antithrombotic treatment before cardioversion, digoxin, diltiazem, direct current cardioversion, flecainide, propafenone, quinidine, sotalol, timolol, and verapamil.
Topics: Amiodarone; Anti-Arrhythmia Agents; Atrial Fibrillation; Humans; Propafenone; Sotalol
PubMed: 21718559
DOI: No ID Found -
Journal of Cardiothoracic Surgery Nov 2010Atrial Fibrillation (AF) is the most common arrhythmia occurring after cardiac surgery. Its incidence varies depending on type of surgery. Postoperative AF may cause... (Review)
Review
Atrial Fibrillation (AF) is the most common arrhythmia occurring after cardiac surgery. Its incidence varies depending on type of surgery. Postoperative AF may cause hemodynamic deterioration, predispose to stroke and increase mortality. Effective treatment for prophylaxis of postoperative AF is vital as reduces hospitalization and overall morbidity. Beta-blockers, have been proved to prevent effectively atrial fibrillation following cardiac surgery and should be routinely used if there are no contraindications. Sotalol may be more effective than standard b-blockers for the prevention of AF without causing an excess of side effects. Amiodarone is useful when beta-blocker therapy is not possible or as additional prophylaxis in high risk patients. Other agents such as magnesium, calcium channels blocker or non-antiarrhythmic drugs as glycose-insulin--potassium, non-steroidal anti-inflammatory drugs, corticosteroids, N-acetylcysteine and statins have been studied as alternative treatment for postoperative AF prophylaxis.
Topics: Anti-Arrhythmia Agents; Atrial Fibrillation; Cardiac Surgical Procedures; Chemoprevention; Humans; Premedication
PubMed: 21118555
DOI: 10.1186/1749-8090-5-121 -
Health Technology Assessment... Oct 2010This paper presents a summary of the evidence review group (ERG) report on the clinical effectiveness and cost-effectiveness of dronedarone for the treatment of atrial... (Review)
Review
This paper presents a summary of the evidence review group (ERG) report on the clinical effectiveness and cost-effectiveness of dronedarone for the treatment of atrial fibrillation (AF) or atrial flutter based upon a review of the manufacturer's submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal process. The population considered in the submission were adult clinically stable patients with a recent history of or current non-permanent AF. Comparators were the current available anti-arrhythmic drugs: class 1c agents (flecainide and propafenone), sotalol and amiodarone. Outcomes were AF recurrence, all-cause mortality, stroke, treatment discontinuations (due to any cause or due to adverse events) and serious adverse events. The main evidence came from four phase III randomised controlled trials, direct and indirect meta-analyses from a systematic review, and a synthesis of the direct and indirect evidence using a mixed-treatment comparison. Overall, the results from the different synthesis approaches showed that the odds of AF recurrence appeared statistically significantly lower with dronedarone and other anti-arrhythmic drugs than with non-active control, and that the odds of AF recurrence are statistically significantly higher for dronedarone than for amiodarone. However, the results for outcomes of all-cause mortality, stroke and treatment discontinuations and serious adverse events were all uncertain. A discrete event simulation model was used to evaluate dronedarone versus antiarrhythmic drugs and standard therapy alone. The incremental cost-effectiveness ratio of dronedarone was relatively robust and less than 20,000 pounds per quality-adjusted life-year. Exploratory work undertaken by the ERG identified that the main drivers of cost-effectiveness were the benefits assigned to dronedarone for all-cause mortality and stroke. Dronedarone is not cost-effective relative to its comparators when the only effect of treatment is a reduction in AF recurrences. In conclusion, uncertainties remain in the clinical effectiveness and cost-effectiveness of dronedarone. In particular, the clinical evidence for the major drivers of cost-effectiveness (all-cause mortality and stroke), and consequently the additional benefits attributed in the economic model to dronedarone compared to other anti-arrhythmic drugs are highly uncertain. The final guidance, issued by NICE on 25 August 2010, states that: Dronedarone is recommended as an option for the treatment of non-permanent atrial fibrillation only in people: whose atrial fibrillation is not controlled by first-line therapy (usually including beta-blockers), that is, as a second-line treatment option, and who have at least one of the following cardiovascular risk factors: - hypertension requiring drugs of at least two different classes, diabetes mellitus, previous transient ischaemic attack, stroke or systemic embolism, left atrial diameter of 50 mm or greater, left ventricular ejection fraction less than 40% (noting that the summary of product characteristics [SPC] does not recommend dronedarone for people with left ventricular ejection fraction less than 35% because of limited experience of using it in this group) or age 70 years or older, and who do not have unstable New York Heart Association (NYHA) class III or IV heart failure. Furthermore, 'People who do not meet the criteria above who are currently receiving dronedarone should have the option to continue treatment until they and their clinicians consider it appropriate to stop'.
Topics: Adult; Aged; Aged, 80 and over; Amiodarone; Anti-Arrhythmia Agents; Atrial Fibrillation; Atrial Flutter; Clinical Trials, Phase III as Topic; Cost-Benefit Analysis; Dronedarone; Humans; Middle Aged; Randomized Controlled Trials as Topic
PubMed: 21047492
DOI: 10.3310/hta14suppl2/08 -
Health Technology Assessment... Jun 2008To assess the clinical and cost-effectiveness of magnesium sulphate compared with sotalol, and to assess the clinical effectiveness of magnesium sulphate compared with... (Review)
Review
OBJECTIVES
To assess the clinical and cost-effectiveness of magnesium sulphate compared with sotalol, and to assess the clinical effectiveness of magnesium sulphate compared with placebo in the prevention of atrial fibrillation (AF) in patients who have had a coronary artery bypass graft (CABG).
DATA SOURCES
Major electronic databases were searched from December 2003 to May 2007.
REVIEW METHODS
Selected studies were assessed, subjected to data extraction using a standard template and quality assessment using published criteria. A simple short-term economic model was developed, informed by a systematic review of economic evaluations and populated with data from a review of costing/resource-use studies and other published studies. The cost-effectiveness of magnesium sulphate as prophylaxis was estimated for a set of base-case assumptions and the robustness of these results was assessed using deterministic and probabilistic sensitivity analysis.
RESULTS
Twenty-two papers met the inclusion criteria reporting 15 trials which all compared magnesium sulphate with placebo or control. They ranged in size from 15 to 176 patients randomised, and were conducted in Europe, the USA and Canada. The standard of reporting was generally poor, with details of key methodological attributes difficult to elucidate. No trials were identified that specifically aimed to compare magnesium sulphate with sotalol. Of 1070 patients in the pooled magnesium group, 230 (21%) developed postoperative AF, compared with 307 of 1031 (30%) patients in the placebo or (control) group. Meta-analysis using a fixed-effects model generated a pooled odds ratio (OR) that was significantly less than 1.0 [OR=0.65, 95% confidence interval (CI) 0.53 to 0.79, test for overall effect p<0.0001], but with statistically significant heterogeneity (I2=63.4%, p=0.0005). Two randomised controlled trials (RCTs) were notable as they had relatively lower ORs in favour of magnesium sulphate. When these were removed from the analyses the pooled OR remained statistically significant, but heterogeneity no longer remained significant. These two studies tended to impart a highly significant reduction in the odds of AF to whichever subgroup they were analysed in. When studies were ordered by total duration of prophylaxis, an apparent relationship between duration and odds of AF was evident, with decreasing odds of AF as duration of prophylaxis increased. This was confirmed by linear regression analysis (R2=0.743, p<0.001). When the data were grouped into three classes according to duration, a statistically significant intervention effect was only present for the longest duration (OR=0.12, 95% CI 0.06 to 0.23, p=0.00001). Statistically significant intervention effects were associated with the initiation of prophylaxis 12 hours or more before surgery (OR 0.26; 95% CI 0.16 to 0.44, test for overall effect p=0.00001, fixed-effects model) and less than 12 hours before surgery or during the surgery itself (OR=0.73, 95% CI 0.56 to 0.97, test for overall effect p = 0.03, fixed-effects model), but not when prophylaxis was initiated at the end of surgery or postsurgery (OR=0.85, 95% CI 0.59 to 1.22, p=0.37, fixed-effects model). When studies were ordered by total dose of intravenous magnesium sulphate (<25 g), the odds of AF were independent of the dose. A notable exception was that for a total dose of 9 g magnesium sulphate; here the odds of AF were significantly reduced relative to the control group, although this may be explained by the fact that these studies had excluded patients who were on antiarrhythmic drugs and so may have been at higher risk of AF. Sixty-three potentially relevant references about cost-effectiveness were identified, but no economic evaluations of intravenous magnesium alone as prophylaxis against AF following CABG, compared with sotalol as prophylaxis or no prophylaxis, were identified. Studies reporting resource use by patients with AF following CABG suggest that while AF significantly increased inpatient stays, by up to 2.3 days in the intensive care unit (ICU) and 3.4 days on the ward, differences in length of stay and costs between patients receiving prophylaxis and those not receiving prophylaxis were not statistically significant. In the base-case analysis, magnesium sulphate prophylaxis resulted in 0.081 fewer cases of AF at an incremental cost of 2.55 pounds sterling. The incremental cost-effectiveness ratio (ICER) was 32 pounds sterling per AF case avoided. The estimated difference in average length of stay between the prophylaxis and no-prophylaxis strategies was only 0.24 days, despite a large assumed difference of 3 days for patients experiencing AF in each group (1 extra day in the ICU and 2 extra days on the ward). In a deterministic sensitivity analysis the greatest variation in ICERs was observed for input parameters relating to the baseline risk of AF following CABG and the effectiveness of prophylaxis, cost of prophylaxis and the resource consequences of postoperative AF. The largest ICER (2092 pounds sterling) in the sensitivity analysis was associated with increasing the length of patients' preoperative stay. In the base case it was assumed that admission routines would be identical under both strategies. However, patients receiving prophylaxis by intravenous infusion may have longer preoperative stays. In a probabilistic analysis the majority of the simulations were associated with improved outcomes (in this case fewer cases of AF), but also higher costs. Prophylaxis was the dominant strategy (better outcome at lower cost) in about 41% of the simulations using the base-case assumptions. Under an alternative scenario where patients receiving prophylaxis are admitted for longer before their operation, to receive their initial infusion, the proportion of simulations where prophylaxis dominates fell to around 5%. The probability of being cost-effective was 99% at a willingness to pay (WTP) threshold of 2000 pounds sterling per AF case avoided and 100% at a WTP threshold of 5000 pounds sterling per AF case avoided under the base-case assumptions. Under the alternative scenario of longer preoperative stays the probability of being cost-effective at these two threshold values fell to 48% and 93%, respectively. It is unclear what the appropriate decision threshold should be, given that this model used intermediate rather than final outcomes.
CONCLUSIONS
No RCTs were identified that specifically aimed to compare intravenous magnesium with sotalol as prophylaxis for AF in patients undergoing CABG. Intravenous magnesium, compared with placebo or control, is effective in preventing postoperative AF, as confirmed by a statistically significant intervention effect based on pooled analysis of 15 RCTs. It was also found that AF was less likely to occur when a longer duration of prophylaxis was used, and the earlier that prophylaxis is started; however, this finding was associated with two RCTs that had more favourable results than the other trials. No clear relationship between dose and AF was observed, although a lower constant dose rate was associated with the lowest odds of AF. Further research should investigate the relationship between dose, dose rate, duration of prophylaxis, timing of initiation of therapy and patient characteristics, such as degree of risk for AF. This will provide stronger evidence for the optimum delivery of intravenous magnesium in patients undergoing CABG. In the base-case analysis in the economic model, magnesium sulphate prophylaxis reduced the number of postoperative AF cases at a modest increase in cost. The results of the economic analysis are highly sensitive to variation in certain key parameters. Prophylaxis is less likely to be a cost-effective option if it requires changes in admission routines that result in longer preoperative stays than would be the case without prophylaxis.
Topics: Anti-Arrhythmia Agents; Atrial Fibrillation; Coronary Artery Bypass; Cost-Benefit Analysis; Databases, Factual; Humans; Infusions, Intravenous; Magnesium Sulfate; Randomized Controlled Trials as Topic; Sotalol
PubMed: 18547499
DOI: 10.3310/hta12280 -
BMJ Clinical Evidence May 2008Risk factors for acute atrial fibrillation include increasing age, cardiovascular disease, alcohol, diabetes, and lung disease. Acute atrial fibrillation increases the... (Review)
Review
INTRODUCTION
Risk factors for acute atrial fibrillation include increasing age, cardiovascular disease, alcohol, diabetes, and lung disease. Acute atrial fibrillation increases the risk of stroke and heart failure. Acute atrial fibrillation resolves spontaneously within 24-48 hours in over 50% of people, however many people will require interventions to control heart rate or restore sinus rhythm.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions: to prevent embolism; for conversion to sinus rhythm; and to control heart rate in people with recent onset atrial fibrillation (within 7 days) who are haemodynamically stable? We searched: Medline, Embase, The Cochrane Library and other important databases up to October 2007 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 28 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review we present information relating to the effectiveness and safety of the following interventions: amiodarone, antithrombotic treatment before cardioversion, digoxin, diltiazem, direct current cardioversion, flecainide, propafenone, quinidine, sotalol, timolol, and verapamil.
Topics: Acute Disease; Amiodarone; Anti-Arrhythmia Agents; Atrial Fibrillation; Humans; Propafenone; Sotalol
PubMed: 19450312
DOI: No ID Found