Antiplatelet therapy for preventing stroke in patients with non-valvular atrial fibrillation and no previous history of stroke or transient ischemic attacks

Effect of aspirin on incidence, recurrence, and mortality in prostate cancer patients: integrating evidence from randomized controlled trials and real-world studies

PURPOSE

Aspirin has been suggested to reduce the risk of cancer. However, previous studies have been inconsistent regarding the relationship between aspirin use and the risk of occurrence of prostate cancer (PCa). The purpose of this study was to assess the effect of aspirin on clinical outcomes in patients with PCa in a meta-analysis and to explore the possible dose-response relationship.

METHODS

A systematic literature search was conducted in 10 electronic databases and 4 registries. The combined relative risks (RRs) were calculated using a random-effects model with 95% confidence interval (CIs) to assess the effect of aspirin on the risk of PCa. Relevant subgroup analyses and sensitivity analyses were performed.

RESULTS

The across studies results show that aspirin use associated with lower incidence of PCa (RR: 0.96, 95% CI: 0.95-0.98), and reduced mortality (RR: 0.88, 95% CI: 0.82-0.95). The results of the subgroup analysis indicated that both cohort and population studies in the Americas showed a reduction in PCa incidence and mortality with aspirin use. A linear correlation was observed between dosage/duration of aspirin use and its protective effect. Additionally, post-diagnosis aspirin use was associated with decreased risk of PCa mortality.

CONCLUSIONS

This meta-analysis revealed an independent correlation between the use of aspirin and reductions in both the incidence and mortality rates of PCa. However, randomized controlled trials did not find any association between aspirin use and PCa. Furthermore, the impact of aspirin on PCa occurrence was found to be dependent on both dosage and duration.

Does aspirin reduce the incidence, recurrence, and mortality of hepatocellular carcinoma? A GRADE-assessed systematic review and dose-response meta-analysis

PURPOSE

Aspirin has been suggested to reduce the risk of cancer. However, previous studies have been inconsistent regarding the relationship between aspirin use and the risk of occurrence of hepatocellular carcinoma (HCC). The purpose of this study was to assess the effect of aspirin on clinical outcomes in patients with HCC in a meta-analysis and to explore the possible dose-response relationship.

METHODS

A systematic literature search was conducted in 10 electronic databases and 4 registries. The combined hazard ratios (HRs) were calculated using a random-effects model with 95% confidence interval (CIs) to assess the effect of aspirin on the risk of HCC. Relevant subgroup analyses and sensitivity analyses were performed.

RESULTS

The results show that aspirin use correlated with lower incidence of HCC (HR: 0.75, 95% CI: 0.71-0.80), decreased risk of HCC recurrence (HR: 0.79, 95% CI: 0.65-0.96), and reduced mortality (HR: 0.72, 95% CI: 0.60-0.87). The results of the subgroup analysis showed that aspirin use was consistently associated with reduced incidence of HCC across different regions, study designs, and populations. A linear relationship was found for both dosage and duration of aspirin use. An increased of bleeding with aspirin use among patients was also observed (HR 1.10, 95% CI: 1.02-1.20).

CONCLUSIONS

This meta-analysis found that aspirin use was independently associated with a reduced risk of HCC incidence, recurrence, and death. Furthermore, aspirin use influenced HCC occurrence in a dose-dependent and duration-dependent manner. However, an increased risk of bleeding with aspirin use was noted.

WITHDRAWN: Pharmacological cardioversion for atrial fibrillation and flutter

BACKGROUND

Atrial fibrillation is the commonest cardiac dysrhythmia. It is associated with significant morbidity and mortality. There are two approaches to the management of atrial fibrillation: controlling the ventricular rate or converting to sinus rhythm in the expectation that this would abolish its adverse effects.

OBJECTIVES

To assess the effects of pharmacological cardioversion of atrial fibrillation in adults on the annual risk of stroke, peripheral embolism, and mortality.

SEARCH METHODS

We searched the Cochrane Controlled Trials Register (Issue 3, 2002), MEDLINE (2000 to 2002), EMBASE (1998 to 2002), CINAHL (1982 to 2002), Web of Science (1981 to 2002). We hand searched the following journals: Circulation (1997 to 2002), Heart (1997 to 2002), European Heart Journal (1997-2002), Journal of the American College of Cardiology (1997-2002) and selected abstracts published on the web site of the North American Society of Pacing and Electrophysiology (2001, 2002).

SELECTION CRITERIA

Randomised controlled trials or controlled clinical trials of pharmacological cardioversion versus rate control in adults (>18 years) with acute, paroxysmal or sustained atrial fibrillation or atrial flutter, of any duration and of any aetiology.

DATA COLLECTION AND ANALYSIS

One reviewer applied the inclusion criteria and extracted the data. Trial quality was assessed and the data were entered into RevMan.

MAIN RESULTS

We identified two completed studies AFFIRM (n=4060) and PIAF (n=252). We found no difference in mortality between rhythm control and rate control relative risk 1.14 (95% confidence interval 1.00 to 1.31).Both studies show significantly higher rates of hospitalisation and adverse events in the rhythm control group and no difference in quality of life between the two treatment groups.In AFFIRM there was a similar incidence of ischaemic stroke, bleeding and systemic embolism in the two groups. Certain malignant dysrhythmias were significantly more likely to occur in the rhythm control group. There were similar scores of cognitive assessment.In PIAF, cardioverted patients enjoyed an improved exercise tolerance but there was no overall benefit in terms of symptom control or quality of life.

AUTHORS' CONCLUSIONS

There is no evidence that pharmacological cardioversion of atrial fibrillation to sinus rhythm is superior to rate control. Rhythm control is associated with more adverse effects and increased hospitalisation. It does not reduce the risk of stroke. The conclusions cannot be generalised to all people with atrial fibrillation. Most of the patients included in these studies were relatively older (>60 years) with significant cardiovascular risk factors.

WITHDRAWN: Electrical cardioversion for atrial fibrillation and flutter

BACKGROUND

Atrial fibrillation increases stroke risk and adversely affects cardiovascular haemodynamics. Electrical cardioversion may, by restoring sinus rhythm, improve cardiovascular haemodynamics, reduce the risk of stroke, and obviate the need for long-term anticoagulation.

OBJECTIVES

To assess the effects of electrical cardioversion of atrial fibrillation or flutter on the risk of thromboembolic events, strokes and mortality (primary outcomes), the rate of cognitive decline, quality of life, the use of anticoagulants and the risk of re-hospitalisation (secondary outcomes) in adults (>18 years).

SEARCH METHODS

We searched the Cochrane CENTRAL Register of Controlled Trials (1967 to May 2004), MEDLINE (1966 to May 2004), Embase (1980 to May 2004), CINAHL (1982 to May 2004), proceedings of the American College of Cardiology (published in Journal of the American College of Cardiology 1983 to 2003), www.trialscentral.org, www.controlled-trials.com and reference lists of articles. We hand-searched the indexes of the Proceedings of the British Cardiac Society published in British Heart Journal (1980 to 1995) and in Heart (1995 to 2002); proceedings of the European Congress of Cardiology and meetings of the Joint Working Groups of the European Society of Cardiology (published in European Heart Journal 1983-2003); scientific sessions of the American Heart Association (published in Circulation 1990-2003). Personal contact was made with experts.

SELECTION CRITERIA

Randomised controlled trial or controlled clinical trials of electrical cardioversion plus 'usual care' versus 'usual care' only, where 'usual care' included any combination of anticoagulants, antiplatelet drugs and drugs for 'rate control'. We excluded trials which used pharmacological cardioversion as the first intervention, and trials of new onset atrial fibrillation after cardiac surgery. There were no language restrictions.

DATA COLLECTION AND ANALYSIS

For dichotomous data, odds ratios were calculated; and for continuous data, the weighted mean difference was calculated.

MAIN RESULTS

We found three completed trials of electrical cardioversion (rhythm control) versus rate control, recruiting a total of 927 participants (Hot Cafe; RACE; STAF) and one ongoing trial (J-RHYTHM). There was no difference in mortality between the two strategies (OR 0.83; CI 0.48 to 1.43). There was a trend towards more strokes in the rhythm control group (OR 1.9; 95% CI 0.99 to 3.64). At follow up, three domains of quality of life (physical functioning, physical role function and vitality) were significantly better in the rhythm control group (RACE 2002; STAF 2003).

AUTHORS' CONCLUSIONS

Electrical cardioversion (rhythm control) led to a non-significant increase in stroke risk but improved three domains of quality of life.

Antithrombotic therapy for atrial fibrillation: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

The risk of stroke varies considerably across different groups of patients with atrial fibrillation (AF). Antithrombotic prophylaxis for stroke is associated with an increased risk of bleeding. We provide recommendations for antithrombotic treatment based on net clinical benefit for patients with AF at varying levels of stroke risk and in a number of common clinical scenarios.

METHODS

We used the methods described in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines article of this supplement.

RESULTS

For patients with nonrheumatic AF, including those with paroxysmal AF, who are (1) at low risk of stroke (eg, CHADS(2) [congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke or transient ischemic attack] score of 0), we suggest no therapy rather than antithrombotic therapy, and for patients choosing antithrombotic therapy, we suggest aspirin rather than oral anticoagulation or combination therapy with aspirin and clopidogrel; (2) at intermediate risk of stroke (eg, CHADS(2) score of 1), we recommend oral anticoagulation rather than no therapy, and we suggest oral anticoagulation rather than aspirin or combination therapy with aspirin and clopidogrel; and (3) at high risk of stroke (eg, CHADS(2) score of ≥ 2), we recommend oral anticoagulation rather than no therapy, aspirin, or combination therapy with aspirin and clopidogrel. Where we recommend or suggest in favor of oral anticoagulation, we suggest dabigatran 150 mg bid rather than adjusted-dose vitamin K antagonist therapy.

CONCLUSIONS

Oral anticoagulation is the optimal choice of antithrombotic therapy for patients with AF at high risk of stroke (CHADS(2) score of ≥ 2). At lower levels of stroke risk, antithrombotic treatment decisions will require a more individualized approach.

Atrial fibrillation management: a prospective survey in ESC Member Countries

AIMS

To describe atrial fibrillation (AF) management in member countries of the European Society of Cardiology (ESC) and to verify cardiology practices against guidelines.

METHODS AND RESULTS

Among 182 hospitals in 35 countries, 5333 ambulant and hospitalized AF patients were enrolled, in 2003 and 2004. AF was primary or secondary diagnosis, and was confirmed on ECG in the preceding 12 months. Clinical type of AF was reported to be first detected in 978, paroxysmal in 1517, persistent in 1167, and permanent in 1547 patients. Concomitant diseases were present in 90% of all patients, causing risk factors for stroke to be also highly prevalent (86%). As many as 69% of patients were symptomatic at the time of the survey; among asymptomatic patients, 54% were previously experienced symptoms. Oral anticoagulation was prescribed in 67 and 49% of eligible and ineligible patients, respectively. A rhythm control strategy was applied in 67% of currently symptomatic patients and in 44% of patients who never experienced symptoms.

CONCLUSION

This survey provides a unique snapshot of current AF management in ESC member countries. Discordance between guidelines and practice was found regarding several issues on stroke prevention and antiarrhythmic therapy.

Anticoagulation for non-valvular atrial aibrillation - towards a new beginning with ximelagatran

OBJECTIVES: Ximelagatran is a novel oral direct thrombin inhibitor. It has favorable pharmacodynamic properties, with a broad therapeutic range without the need for anticoagulation monitoring. We aimed to discover whether ximelagatran offers a genuine future replacement to warfarin for patients in persistent atrial fibrillation (AF). MATERIALS AND METHODS: We provide an evidence-based review of the relative merits and disadvantages of warfarin and aspirin. We subsequently present an overview of the evidence for the utility of ximelagatran in the treatment of AF. RESULTS: Adjusted dose warfarin is recommended over aspirin for patients in AF at high risk of future stroke. Some of this benefit is partially offset by the higher bleeding risks associated with warfarin therapy. The SPORTIF III and V studies have shown that ximelagatran is not inferior to warfarin in the prevention of all strokes in patients with AF (both persistent and paroxysmal). This benefit was partially offset by the finding of a significant elevation of liver transaminases (>3 x normal) in 6% of patients. CONCLUSIONS: Current data would suggest that ximelagatran might represent a future alternative to warfarin. The lack of need for anticoagulant monitoring has been partially offset by a need for regular monitoring of liver function. Further data from randomized clinical trials is clearly needed.

Atrial fibrillation in a primary care practice: prevalence and management

BACKGROUND

Atrial fibrillation is a common serious cardiac arrhythmia. Knowing the prevalence of atrial fibrillation and documentation of medical management are important in the provision of primary care. This study sought to determine the prevalence of atrial fibrillation in a primary care population and to identify and quantify the treatments being used for stroke prevention in this group of patients.

METHODS

A prevalence study through chart audit was conducted in the family medicine practice at the Sunnybrook campus of the Sunnybrook and Women's College Health Sciences Centre. The main outcome measures were the prevalence of atrial fibrillation in our primary care practice and the use of warfarin for stroke prevention in this population.

RESULTS

261 patients in our practice have atrial fibrillation. The overall prevalence in our family practice unit is 3.9%. When considering patients aged 60 and over, the prevalence rises to 12.2%. 204 of our patients with atrial fibrillation (78.2%) are currently being treated with warfarin. Another 21 patients were previously treated and discontinued for a number of reasons. Of the 57 patients not currently treated with warfarin, 44 are treated with ASA, 2 with ticlopidine, and 11 are receiving no preventative treatment.

CONCLUSIONS

The prevalence of atrial fibrillation in our practice is higher than the range of prevalence reported in the general literature. However, our coverage with warfarin treatment exceeds previous reports in the literature.

Antithrombotic therapy to prevent stroke in patients with atrial fibrillation: a meta-analysis

PURPOSE

To characterize the efficacy and safety of anticoagulants and antiplatelet agents for prevention of stroke in patients with atrial fibrillation.

DATA SOURCES

Randomized trials identified by using the search strategy developed by the Cochrane Collaboration Stroke Review Group.

STUDY SELECTION

All published randomized trials testing antithrombotic agents to prevent stroke in patients with atrial fibrillation.

DATA EXTRACTION

Data on interventions, number of participants, duration of exposure and occurrence of all stroke (ischemic and hemorrhagic), major extracranial bleeding, and death were extracted independently by two investigators.

DATA SYNTHESIS

Sixteen trials included a total of 9874 participants (mean follow-up, 1.7 years). Adjusted-dose warfarin (six trials, 2900 participants) reduced stroke by 62% (95% CI, 48% to 72%); absolute risk reductions were 2.7% per year for primary prevention and 8.4% per year for secondary prevention. Major extracranial bleeding was increased by warfarin therapy (absolute risk increase, 0.3% per year). Aspirin (six trials, 3119 participants) reduced stroke by 22% (CI, 2% to 38%); absolute risk reductions were 1.5% per year for primary prevention and 2.5% per year for secondary prevention. Adjusted-dose warfarin (five trials, 2837 participants) was more efficacious than aspirin (relative risk reduction, 36% [CI, 14% to 52%]). Other randomized comparisons yielded inconclusive results.

CONCLUSIONS

Adjusted-dose warfarin and aspirin reduce stroke in patients with atrial fibrillation, and warfarin is substantially more efficacious than aspirin. The benefit of antithrombotic therapy was not offset by the occurrence of major hemorrhage among participants in randomized trials. Judicious use of antithrombotic therapy, tailored according to the inherent risk for stroke, importantly reduces stroke in patients with atrial fibrillation.