Bleeding in patients with atrial fibrillation treated with dabigatran, rivaroxaban or warfarin: A retrospective population-based cohort study

Gastrointestinal Bleeding on Oral Anticoagulation: What is Currently Known

Gastrointestinal bleeding (GIB) is the most common type of bleeding occurring in patients on oral anticoagulation. A meta-analysis of the landmark randomized controlled trials (RCTs) for patients with atrial fibrillation demonstrated that direct oral anticoagulants (DOACs) were associated with higher GIB rates compared to warfarin. However, significant heterogeneity existed between studies. While rivaroxaban, high-dose dabigatran, and high-dose edoxaban were associated with higher GIB rates than warfarin, GIB rates were similar between warfarin users and both apixaban and low-dose dabigatran users. Additionally, previous observational studies have yielded conflicting reports on whether GIB rates differ between warfarin and DOACs. Meta-analyses of observational studies demonstrated that warfarin is associated with lower rates of GIB compared to rivaroxaban, similar or lower rates compared to dabigatran, and higher rates compared to apixaban. Importantly, no RCT has compared individual DOACs directly and due to the different selection criteria of the initial RCTs, indirect comparisons between DOACs using these studies are unreliable. The best available information of comparisons between individual DOACs is therefore limited to observational studies. There is mounting evidence that suggests that rivaroxaban is associated with a higher risk of GIB compared to other DOACs. Finally, GIB induced by oral anticoagulation may have some positive aspects. Interestingly, there are studies that indicate oral anticoagulation facilitates colorectal cancer detection. Furthermore, results from RCTs and observational studies suggest that warfarin may even decrease the incidence of cancer.

Effectiveness and Safety of Dabigatran Compared to Vitamin K Antagonists in Non-Asian Patients with Atrial Fibrillation: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

Real-life data about the use of dabigatran in patients with non-valvular atrial fibrillation are warranted. The objective of this systematic review and meta-analysis was to assess the effectiveness and safety of dabigatran, globally and stratified by dose (110/150 mg twice daily), vs vitamin K antagonists in non-Asian patients with non-valvular atrial fibrillation from "real-world" studies.

METHODS

A systematic review was performed according to Cochrane methodological standards. The results were reported according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement) statement. The ROBINS-I tool was used to assess bias risk. MEDLINE and EMBASE, from inception up to May 2021, using appropriate controlled vocabulary and free search terms, were searched.  RESULTS: A total of 34 studies, corresponding to 37 articles involving 1,600,722 participants (1,154,283 exposed to vitamin K antagonists and 446,439 to dabigatran) were eligible for this review. Dabigatran 150 mg reduced the risk of ischemic stroke compared with vitamin K antagonists, with a 14% risk reduction (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.74-0.98). Globally, dabigatran reduced the risk of all-cause mortality compared with vitamin K antagonists (HR 0.76, 95% CI 0.69-0.84), with a greater effect observed with dabigatran 150 mg (HR 0.65, 95% CI 0.58-0.73). There was a trend towards a lower risk of myocardial infarction with dabigatran 150 mg (HR 0.86, 95% CI 0.71-1.04). Regarding the primary safety outcomes, dabigatran (either at a dose of 150 mg or 110 mg) reduced the risk of major bleeding compared with vitamin K antagonists (HR 0.77, 95% CI 0.70-0.83), as well as the risk of intracranial bleeding (HR 0.44, 95% CI 0.39-0.50) and fatal bleeding (HR 0.76, 95% CI 0.60-0.95), but with a slight increase in gastrointestinal bleeding risk (HR 1.16, 95% CI 1.08-1.26).

CONCLUSIONS

Dabigatran has a favorable impact on effectiveness and safety outcomes compared with vitamin K antagonists in real-world populations.

Non-vitamin K antagonist oral anticoagulants in Asian patients with atrial fibrillation: evidences from the real-world data

The role of non-vitamin K antagonist oral anticoagulants (NOACs) in stroke prevention remains unclear in Asian patients with atrial fibrillation (AF). Therefore, we performed a meta-analysis to compare the efficacy and safety outcomes of NOACs in Asian patients with AF from the real-world settings. The PubMed and Embase databases were systematically searched to identify eligible observational studies until June 2019. The odds ratios (OR) and 95% confidence intervals (CIs) were calculated and then pooled by a random-effects model. A total of 18 observational studies were included. Compared with warfarin, dabigatran (OR, 0.56, 95% CI 0.43-0.73), rivaroxaban (OR, 0.54, 95% CI 0.44-0.67), apixaban (OR, 0.41, 95% CI 0.35-0.48), and edoxaban (OR, 0.19, 95% CI 0.14- 0.25) reduced the risk of major bleeding, while dabigatran (OR, 0.78, 95% CI 0.71-0.85), rivaroxaban (OR, 0.74, 95% CI 0.68-0.82), and edoxaban (OR, 0.29, 95% CI 0.22-0.39) were associated with reduced risks of stroke or systemic embolism. In addition, dabigatran versus apixaban was associated with increased risks of ischemic stroke and gastrointestinal bleeding, while rivaroxaban versus apixaban was associated with elevated risks of stroke or systemic embolism, ischemic stroke, intracranial hemorrhage, and gastrointestinal bleeding. In Asian patients with AF, NOACs are non-inferior to warfarin for stroke prevention, and apixaban may be a better choice compared with dabigatran or rivaroxaban.

Comparative effectiveness and safety of direct acting oral anticoagulants in nonvalvular atrial fibrillation for stroke prevention: a systematic review and meta-analysis

PURPOSE

To systematically review available evidence of indirect comparisons from RCTs and direct comparisons from observational studies regarding the comparative effectiveness and safety of DOACs in patients with AF.

METHODS

Electronic databases including EMBASE, MEDLINE, and PUBMED were searched up to June 5th, 2020. Primary endpoints included effectiveness (stroke or systemic embolism [SE]) and safety (major bleeding) outcomes. Bucher methods and random-effects models were conducted for indirect and direct comparisons among DOACs, respectively. Ranking probability analyses and the number needed to treat for net effect (NNTnet) were applied.

RESULTS

A total of 36 studies, involving 7 RCTs (n = 60,292 patients) and 29 observational studies (n = 1,164,821 patients), were included for analyses. Regarding the risk of stroke/SE, no significant differences were found from indirect comparisons of RCTs among the DOACs. For major bleeding, apixaban tended to be safer than rivaroxaban and dabigatran based on both direct and indirect comparisons (all p < 0.05; evidence quality: very low to moderate). Ranking probability analysis showed that apixaban had a high probability of being the best treatment in decreased risk of stroke/SE and major bleeding (80.30% and 91.30%, respectively). Likewise, apixaban was found to have the highest net clinical benefit (0.02, 95% CI: 0.014-0.029) and smallest NNTnet (48, 95% CI: 35-74).

CONCLUSIONS

Apixaban appeared to have a favorable effectiveness-safety profile compared with the other DOACs in AF for stroke prevention, based on evidence from both direct and indirect comparisons. However, additional high-quality evidence is needed to support firm recommendations on clinical decision-making.

Cost-Effectiveness of Direct Non-Vitamin K Oral Anticoagulants Versus Vitamin K Antagonists for the Management of Patients with Non-Valvular Atrial Fibrillation Based on Available "Real-World" Evidence: The Italian National Health System Perspective

BACKGROUND AND OBJECTIVE

The increasing availability of real-world evidence (RWE) about safety and effectiveness of direct non-vitamin K oral anticoagulants (DOACs) for the management of atrial fibrillation (AF) offers the opportunity to better understand the clinical and economic implications of DOACs versus vitamin K antagonists (VKAs). The objective of this study was to compare the economic implications of DOACs and VKAs using data from real-world evidence in patients with AF.

METHODS

A Markov model simulating the lifetime course of patients diagnosed with non-valvular AF was used to evaluate the cost-effectiveness of DOACs (i.e., rivaroxaban, dabigatran and apixaban) versus VKAs from the Italian National Health System (INHS) perspective. The model was made up of data from the literature and a meta-analysis of RWE on the incidence of stroke/systemic embolism (SE), major bleeding (MB), intracranial haemorrhage (ICH) and all-cause mortality (ACM); direct costs included drug costs, costs for drug monitoring, and management of events from official national lists. One-way and probabilistic sensitivity analyses (PSA) were used to assess the robustness of the results.

RESULTS

Results from the meta-analysis showed that apixaban had a high probability of being the most effective for stroke/SE, MB and ACM. Despite their higher acquisition costs, the cost-effectiveness analysis showed all DOACs involved a saving when compared with VKAs, with per-patient savings ranging between €4647 (rivaroxaban) to €6086 (apixaban). Moreover, all DOACs indicated a gain both in quality-adjusted life-years and life-years. According to PSA, findings related to apixaban were consistent, while for dabigatran and rivaroxaban PSA revealed a higher degree of uncertainty.

CONCLUSIONS

The beneficial effect of DOACs on containing events showed in RWE had the potential to offset drug-related costs, thus improving the sustainability of treatment for non-valvular AF in daily clinical practice.

Oral Anticoagulant Adequacy in Non-Valvular Atrial Fibrillation in Primary Care: A Cross-Sectional Study Using Real-World Data (Fantas-TIC Study)

Background: Oral anticoagulants (OAs) are the treatment to prevent stroke in atrial fibrillation (AF). Anticoagulant treatment choice in non-valvular atrial fibrillation (NVAF) must be individualized, taking current guidelines into account. Adequacy of anticoagulant therapy under the current criteria for NVAF in real-world primary care is presented. Methods: Cross-sectional study, with real-world data from patients treated in primary care (PC). Data were obtained from the System for the Improvement of Research in Primary Care (SIDIAP) database, covering 60,978 NVAF-anticoagulated patients from 287 PC centers in 2018. Results: In total, 41,430 (68%) were treated with vitamin K antagonists (VKAs) and 19,548 (32%) NVAF with direct-acting oral anticoagulants (DOACs). Inadequate prescription was estimated to be 36.0% and 67.6%, respectively. Most DOAC inadequacy (77.3%) was due to it being prescribed as a first-line anticoagulant when there was no history of thromboembolic events or intracranial hemorrhage (ICH). A total of 22.1% had missing estimated glomerular filtration rate (eGFR) values. Common causes of inadequate VKA prescription were poor control of time in therapeutic range (TTR) (98.8%) and ICH (2.2%). Conclusions: Poor adequacy to current criteria was observed, being inadequacy higher in DOACs than in VKAs. TTR and GFR should be routinely calculated in electronic health records (EHR) to facilitate decision-making and patient safety.

Real-world safety and efficacy of direct oral anticoagulants in atrial fibrillation: a systematic review and meta-analysis of 605 771 patients

AIMS

To analyse the safety and efficacy of direct oral anticoagulants (DOACs) in real-world studies including atrial fibrillation (AF) patients.

METHODS AND RESULTS

Systematic review and meta-analysis of observational studies including AF patients on DOACs. Primary endpoints: any, major, gastrointestinal (GI), intracranial haemorrhage (ICH), and haemorrhagic stroke (HS). Secondary endpoints: ischaemic stroke (IS), systemic embolism (SE), myocardial infarction (MI), and all-cause of death. A set of pair-wise meta-analyses using a random effect model and a random effect network meta-analysis under a Bayesian framework were performed. Prospero registration number: CRD42019137111. We included 21 studies with 605 771 AF patients. Apixaban was associated with lower major and GI bleeding compared with Rivaroxaban [hazard ratio (HR) 2.0, 95% confidence interval (CI) 1.6-2.5] and Dabigatran (HR 1.6, 95% CI 1.3-2.1). The latter drug performed better than Rivaroxaban (HR 1.2, 95% CI 1.0-1.5). Dabigatran and Apixaban had a similar association with HS, but Apixaban performed better than Rivaroxaban (HR 1.8, 95% CI 1.1-3.0). Apixaban had a similar association with Rivaroxaban and Dabigatran for ICH, the latter drug performing better than Rivaroxaban (HR 1.3, 95% CI 1.0-1.7). Rankograms showed that Apixaban was likely to be the first-choice treatment in relation to any (65%) major (100%) and GI bleeding (100%) followed by Dabigatran (46%, 100%, 99%, respectively). Dabigatran and Apixaban had similar rank as first choice for ICH (44% and 55%) and HS (52% and 48%). DOACs showed similar association with IS/SE, MI, all-cause of death.

CONCLUSIONS

Analysis of real-world studies shows significant differences for safety among DOACs.

Bleeding Risk in Nonvalvular Atrial Fibrillation Patients Receiving Direct Oral Anticoagulants and Warfarin: A Systematic Review and Meta-Analysis of Observational Studies

Introduction  In randomized trials in atrial fibrillation (AF) patients on direct oral anticoagulants (DOACs) have a lower risk of bleeding compared with warfarin. However, data from randomized trials may not extrapolate to general population. We aimed to determine the risk of bleeding in patients on DOACs in observational studies. Materials and Methods  Observational studies from 1990 to January 2019 were included. A pooled effect hazard ratio (HR) was calculated with a random effects model using the generic inverse variance method. Subgroup analyses according to previous anticoagulants exposure, study type, funding source, and DOAC type (direct thrombin inhibitors vs. factor Xa inhibitors) were conducted. Results  A total of 35 studies comprising 2,356,201 patients were included. The average pooled HR for observational data was 0.78 (95% confidence interval [CI] 0.71, 0.85). There were no statistically significant differences in pooled HR by previous exposure to anticoagulants, DOAC type (direct thrombin vs. factor Xa inhibitors), study type, and funding source. Among patients receiving factor Xa inhibitors, patients on apixaban had a lower risk of bleeding compared with warfarin (HR 0.60, 95% CI 0.50, 0.71, p  < 0.001) in contrast to those on rivaroxaban (HR 0.98, 95% CI 0.91, 1.06, p  = 0.60). Conclusion  In observational studies, AF patients on DOACs experience less bleeding events compared with warfarin; however, apixaban and dabigatran, but not rivaroxaban, have a lower risk of bleeding than warfarin.

Efficacy and Safety of Non-Vitamin K Antagonist Oral Anticoagulants in Asians With Nonvalvular Atrial Fibrillation: A Network Meta-Analysis

There are few head-to-head trials directly comparing non-vitamin K antagonist oral anticoagulants (NOACs) against one other. A network meta-analysis (NMA) was performed to examine the indirect comparisons among NOACs in Asians with nonvalvular atrial fibrillation (NVAF). STATA 15.0 and ADDIS 1.16.8 softwares were used to perform the statistical analysis. Odds ratios with 95% credible intervals were applied to evaluate the end points. The probabilities of treatment rank were used to understand which interventions are more effective and safe, and the total rank probability was 1. In our NMA, the rank probabilities of apixaban in the case of stroke or systemic embolism, death from any cause, major bleeding, and intracranial hemorrhage (ICH) were 0.47, 0.49, 0.42, and 0.51, respectively. For cases of myocardial infarction, the rank probabilities of rivaroxaban were 0.40. This NMA indirectly compares the main efficacy and safety end points among NOACs in Asians with NVAF, and the rank probability analysis showed that apixaban likely performs best in cases of stroke or systemic embolism, death from any cause, and ICH; rivaroxaban may have the best performance for myocardial infarction.

Risk of Major Gastrointestinal Bleeding With New vs Conventional Oral Anticoagulants: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

There is controversy over whether use of non-vitamin K antagonist oral anticoagulants (NOACs) associates with increased risk of major gastrointestinal bleeding (GIB) compared with conventional therapies (such as vitamin K antagonists or anti-platelet agents). We performed a systematic review and meta-analysis of data from randomized controlled trials and high-quality real-world studies.

METHODS

We performed a systematic search of the MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov Website databases (through Oct 12, 2018) for randomized controlled trials and high-quality real-world studies that reported major GIB events in patients given NOACs or conventional therapy. Relative risks (RRs) for randomized controlled trials and adjusted hazard ratios (aHRs) for real-world studies were calculated separately using random-effects models.

RESULTS

We analyzed data from 43 randomized controlled trials (183,752 patients) and 41 real-world studies (1,879,428 patients). The pooled major rates of GIB for patients on NOACs (1.19%) vs conventional treatment (0.92%) did not differ significantly (RR from randomized controlled trials, 1.09; 95% CI, 0.91-1.31 and aHR from real-world studies, 1.02; 95% CI, 0.94-1.10; P_interaction=.52). Rivaroxaban, but not other NOACs, was associated with an increased risk for major GIB (RR from randomized controlled trials, 1.39; 95% CI, 1.17-1.65 and aHR from real-world studies, 1.14; 95% CI, 1.04-1.23; P_interaction = .06). Analyses of subgroups, such as patients with different indications, dosage, or follow-up time, did not significantly affect results. Meta-regression analysis failed to detect any potential confounding to impact the primacy outcome.

CONCLUSIONS

In a systematic review and meta-analysis of data from randomized controlled trials and real-world studies, we confirmed that there is no significant difference in risk of major GIB between patients receiving NOACs vs conventional treatment. Rivaroxaban users had a 39% increase in risk for major GIB.

Effectiveness and Safety of Off-Label Dose-Reduced Direct Oral Anticoagulants in Atrial Fibrillation

BACKGROUND

Direct oral anticoagulants (DOACs) reduce the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation but may result in serious bleeding complications. Off-label dose-reduced use of DOACs to mitigate bleeding is common in routine clinical practice although data about its consequences on patient outcomes are limited. Therefore, our objective was to evaluate the effectiveness and safety of off-label dose-reduced vs per-label standard-dose DOAC treatment.

METHODS

The study cohort included newly diagnosed patients with nonvalvular atrial fibrillation that had initiated DOAC therapy between 2011 and 2017 in Clalit Health Services (Tel Aviv, Israel). Effectiveness was defined as the composite outcome of all-cause mortality, stroke, or myocardial infarction. The safety outcome was defined as bleeding events requiring hospitalization. Patients were followed until March 30, 2018 or until occurrence of an outcome event. Hazard ratios (HR) were adjusted for 21 variables, including comorbidities, concomitant medications, and socioeconomic factors, using multivariate regression.

RESULTS

A total of 8425 patients met the study criteria; 5140 (61%) patients were treated with DOACs at per-label dosing and 3285 (39%) patients were treated with off-label dose-reduced DOAC. Off-label dose-reduced treatment was associated with a higher rate of the composite effectiveness outcome: adjusted HR 1.57 (95% confidence interval, 1.34-1.83; P < .001) and a higher rate of bleeding: adjusted HR 1.63 (95% confidence interval, 1.14-2.34; P = .008).

CONCLUSIONS

Almost 4 of 10 patients were treated with off-label dose-reduced DOAC, which was associated with reduced effectiveness without a safety benefit. Compliance with per-label dosage may significantly improve outcomes of this population.

Anticoagulation Therapy in Patients with Liver Cirrhosis is Associated With an Increased Risk of Variceal Hemorrhage

OBJECTIVE

The belief that cirrhotic patients are "auto-anticoagulated" often results in anticoagulation therapy being withheld in these patients. We aimed to understand patterns of use of anticoagulation and to determine the risk of bleeding complications in cirrhotic patients.

METHODS

We retrospectively analyzed 320 cirrhotic patients treated with anticoagulation therapy from July 15, 2014 to January 30, 2018. We performed bivariate and multivariate analyses to identify risk factors for clinically relevant bleeding. We conducted a separate analysis using propensity score matching to compare bleeding rates of a noncirrhotic cohort group on anticoagulation to anticoagulated patients with cirrhosis.

RESULTS

Nonalcoholic steatohepatitis (47%) was the most common cause of cirrhosis, and 49% were classified as Child-Pugh class B, a mean model for end-stage liver disease score of 14 and Charlson comorbidity index of 7. Anticoagulation was initiated for atrial fibrillation/atrial flutter in 56% of patients; warfarin was used in 57% of patients and concomitant use of antiplatelet therapy in 25%. Bleeding occurred in 18%, with upper gastrointestinal bleeding (53%) being the most common source. In the propensity-matched cohort, bleeding rates were higher in cirrhotics than in control patients who were matched for baseline characteristics. In multivariate analysis of the cirrhotic patients, the presence of esophageal varices was associated with higher odds of clinically relevant bleeding.

CONCLUSION

Anticoagulated cirrhotic patients who have esophageal varices are at an increased risk of bleeding. We recommend that patients with cirrhosis and esophageal varices who require anticoagulation have their varices managed carefully prior to initiation of anticoagulation.

Direct oral anticoagulation and mortality in moderate to high-risk atrial fibrillation

OBJECTIVE

Although direct oral anticoagulants (DOAC) are the recommended antithrombotic therapy for patients with non-valvular atrial fibrillation (NVAF), anticoagulation in patients with NVAF is still inadequate. The effect of withholding DOAC therapy on patient survival is unknown. Therefore, our objective was to compare all-cause mortality rates between DOAC-treated patients with NVAF and similar patients receiving no anticoagulation.

METHODS

We performed a retrospective cohort study analysing Clalit Health Services' extensive electronic database, regarding all newly diagnosed, anticoagulant-naïve patients with NVAF who were eligible for DOAC therapy from 1 January 2011 to 31 December 2016. Patients who received DOAC therapy were matched by propensity scoring to patients receiving no anticoagulation. The primary outcome was all-cause mortality. Final patient follow-up date was 15 May 2017.

RESULTS

18 901 eligible patients were identified. 8298 received treatment with a DOAC and 10 603 received no anticoagulation therapy. Of those, 5657 patients who received DOAC therapy were matched with 5657 patients who did not receive any anticoagulant. Death occurred in 715 patients in the DOAC-treated group (7.6% per year) and in 2075 patients in the non-anticoagulated patient group (11.1% per year). DOAC therapy was associated with significantly lower risk for all-cause mortality (HR=0.69, 95% CI 0.63 to 0.75, p<0.001). The benefit of DOAC therapy was demonstrated across all subgroups analysed.

CONCLUSIONS

In this cohort of newly diagnosed patients with NVAF, DOAC therapy was associated with a significantly lower risk of death compared with no oral anticoagulation. Our findings provide further evidence for the importance of providing DOAC anticoagulation in patients with NVAF.

Epidemiology of Intracranial Hemorrhage Associated with Oral Anticoagulants in Spain: Trends in Anticoagulation Complications Registry - The TAC 2 Study

Objective

Patients receiving treatment with oral anticoagulants (OACs) are at risk of intracranial hemorrhage (ICH). In this study, we describe the epidemiological and clinical characteristics of patients receiving OACs who experience ICH and compare those receiving vitamin K antagonists (ICH-VKAs) with those receiving direct OACs (ICH-DOACs).

Methods

We performed a national, multicenter, descriptive, observational, retrospective study of all adult patients receiving OACs who were admitted to the neurology department with ICH over a 1-year period. The study population was divided into 2 groups (ICH-VKAs and ICH-DOACs). Epidemiological, clinical, radiological, and therapy-related variables, as well as functional outcome, were compared at 3 months. A total of 366 cases were included (331 ICH-VKAs, 35 ICH- DOACs).

Results

The crude annual incidence of OAC-induced ICH was 3.8 (95% CI, 2.78-3.41) per 100,000 inhabitants/year. The mean (± SD) age was greater for ICH-DOACs (81.5 ± 8.3 vs. 77.7 ± 8.3 years; p = 0.012). The median (IQR) volume of the hemorrhage was lower for ICH-DOACs (11 [30.8] vs. 25 [50.7] mL; p = 0.03). The functional independence rate at 3 months (modified Rankin Scale, mRS < 3) was similar in both groups, although stroke-related mortality was greater in ICH-VKAs (40 vs. 72.7%; p = 0.02). The most frequently indicated poststroke antithrombotic therapy was DOACs (38.7%).

Conclusion

We found that the incidence of OAC-induced ICH was greater than in previous studies. Hemorrhage volume and mortality were lower in ICH-DOACs than in ICH-VKAs. After stroke, DOACs were the most frequently indicated antithrombotic treatment.

Direct Oral Anticoagulants Versus Vitamin K Antagonists in Real-life Patients With Atrial Fibrillation. A Systematic Review and Meta-analysis

INTRODUCTION AND OBJECTIVES

To assess the effectiveness of direct oral anticoagulants vs vitamin K antagonists in real-life patients with atrial fibrillation.

METHODS

A systematic review was performed according to Cochrane methodological standards. The results were reported according to the PRISMA statement. The ROBINS-I tool was used to assess risk of bias.

RESULTS

A total of 27 different studies publishing data in 30 publications were included. In the studies with a follow-up up to 1 year, apixaban (HR, 0.93; 95%CI, 0.71-1.20) and dabigatran (HR, 0.95; 95%CI, 0.80-1.13) did not significantly reduce the risk of ischemic stroke vs warfarin, whereas rivaroxaban significantly reduced this risk (HR, 0.83; 95%CI, 0.73-0.94). Apixaban (HR, 0.66; 95%CI, 0.55-0.80) and dabigatran (HR, 0.83; 95%CI, 0.70-0.97) significantly reduced the major bleeding risk vs warfarin, but not rivaroxaban (HR, 1.02; 95%CI, 0.95-1.10), although with a high statistical heterogeneity among studies. Apixaban (HR, 0.56; 95%CI, 0.42-0.73), dabigatran (HR, 0.45; 95%CI, 0.39-0.51), and rivaroxaban (HR, 0.66; 95%CI, 0.49-0.88) significantly reduced the risk of intracranial bleeding vs warfarin. Reduced doses of direct oral anticoagulants were associated with a slightly better safety profile, but with a marked reduction in stroke prevention effectiveness.

CONCLUSIONS

Data from this meta-analysis suggest that, vs warfarin, the stroke prevention effectiveness and bleeding risk of direct oral anticoagulants may differ in real-life patients with atrial fibrillation.

Bleeding-related admissions in patients with atrial fibrillation receiving antithrombotic therapy: results from the Tasmanian Atrial Fibrillation (TAF) study

PURPOSE

Limited data are available from the Australian setting regarding bleeding in patients with atrial fibrillation (AF) receiving antithrombotic therapy. We aimed to investigate the incidence of hospital admissions due to bleeding and factors associated with bleeding in patients with AF who received antithrombotic therapy.

METHODS

A retrospective cohort study was conducted involving all patients with AF admitted to the Royal Hobart Hospital, Tasmania, Australia, between January 2011 and July 2015. Bleeding rates were calculated per 100 patient-years (PY) of follow-up, and multivariable modelling was used to identify predictors of bleeding.

RESULTS

Of 2202 patients receiving antithrombotic therapy, 113 presented to the hospital with a major or minor bleeding event. These patients were older, had higher stroke and bleeding risk scores and were more often treated with warfarin and multiple antithrombotic therapies than patients who did not experience bleeding. The combined incidence of major and minor bleeding was significantly higher in warfarin- versus direct-acting oral anticoagulants (DOAC)- and antiplatelet-treated patients (4.1 vs 3.0 vs 1.2 per 100 PY, respectively; p = 0.002). Similarly, the rate of major bleeding was higher in patients who received warfarin than in the DOAC and antiplatelet cohorts (2.4 vs 0.4 vs 0.6 per 100 PY, respectively; p = 0.001). In multivariate analysis, increasing age, prior bleeding, warfarin and multiple antithrombotic therapies were independently associated with bleeding.

CONCLUSION

The overall rate of bleeding in this cohort was low relative to similar observational studies. The rate of major bleeding was higher in patients prescribed warfarin compared to DOACs, with a similar rate of major bleeding for DOACs and antiplatelet agents. Our findings suggest potential to strategies to reduce bleeding include using DOACs in preference to warfarin, and avoiding multiple antithrombotic therapies in patients with AF.

Pharmacological treatments of cardiovascular diseases: Evidence from real-life studies

The management of chronic cardiovascular diseases has evolved greatly in the last decades. Over the last thirty years, the management of acute coronary syndrome has improved, leading to an important lowering of the mortality in the acute phase of the event. Consequently, the optimal management of the secondary prevention of acute coronary syndrome has greatly evolved. Moreover, the increased number of pharmacological alternatives for patients affected by chronic heart failure and by non-valvular atrial fibrillation reserves a number of challenges for their correct management. Moreover, these diseases are without any reasonable doubt the largest contributor to global mortality in the present and will continue to be it in the future. The aim of this study was to provide the most updated information of the real-life drug use and their effectiveness. This review was performed to assess the potential knowledge gaps in the treatments of these diseases and to indicate potential perspective of pharmaco-epidemiological research in this area.