Bleeding complications associated with warfarin treatment in ischemic stroke patients with atrial fibrillation: a population-based cohort study

Associations of anaemia with bleeding and thrombotic complications in patients with atrial fibrillation treated with warfarin: a registry-based nested case-control study

OBJECTIVES

We studied association of laboratory testing beyond the international normalised ratio (INR) with bleeding and stroke/transient ischaemic attack (TIA) outcomes in patients with atrial fibrillation treated with warfarin.

DESIGN

This was a retrospective nested case-control study from the Finnish Warfarin in Atrial Fibrillation (FinWAF) registry (n=54 568), reporting the management and outcome in warfarin-anticoagulated patients. Associations of blood count test frequency and results were assessed together with risk of bleeding or stroke/TIA during 5-year follow-up.

SETTING

National FinWAF registry, with data from all six hospital districts. Follow-up period for complications was 1 January 2007-31 December 2011.

PARTICIPANTS

A total of 54 568 warfarin-anticoagulated patients.

RESULTS

The number of patients with bleeding was 4681 (9%) and stroke/TIA episodes, 4692 (9%). In patients with bleeds, lower haemoglobin (within 3 months) preceded the event compared with the controls (median 126 vs 135 g/L; IQR 111-141 g/L vs 123-147 g/L, p<0.001), while patients with stroke/TIA had only modestly lower INR (median 2.2 vs 2.3; 1.8-2.6 vs 2.1-2.7, p<0.001). When the last measured haemoglobin was below the reference value (130 g/L for men, 120 g/L for women), the OR for a bleeding complication was 2.9 and stroke/TIA, 1.5. If the haemoglobin level was below 100 g/L, the complication risk increased further by 10-fold. If haemoglobin values were repeatedly (more than five times) low during the preceding 3 months, future OR was for bleeds 2.3 and for stroke/TIA 2.4.

CONCLUSIONS

The deeper the anaemia, the higher the risk of bleeding and stroke/TIA. However, INR remained mainly at its target and only occasionally deviated, failing to detect the complication risk. Repeated low haemoglobin results, compatible with persistent anaemia, refer to suboptimal management and increased the complication risk in anticoagulated patients.

Comparison of HAS-BLED with other risk models for predicting the bleeding risk in anticoagulated patients with atrial fibrillation: A PRISMA-compliant article

BACKGROUND

The HAS-BLED, HEMORR2HAGES, ATRIA, and ORBIT scores are used to predict bleeding risk in anticoagulated patients with atrial fibrillation (AF). Recently, these scores have been validated in various studies. Therefore, we aimed to compare the occurrence of major bleeding across different risk categories between HAS-BLED and any of HEMORR2HAGES, ATRIA, or ORBIT scores.

METHODS

A systemic literature search of PubMed and Embase databases was conducted to screen the relevant studies. We calculated and pooled the odds ratios (ORs) and 95% confidence intervals (CIs) for a comparative analysis of the occurrence of major bleeding.

RESULTS

Nine studies fulfilled the inclusion criteria in this meta-analysis. Compared with HEMORR2HAGES, there were 87% and 39% reduced rates of major bleeding in the HAS-BLED "low-risk" and "moderate-risk" groups, respectively. Compared with ATRIA, there was an 89% decreased rate of major bleeding in the HAS-BLED "low-risk" group. Compared with ORBIT, there were 84% and 44% reduced rates of major bleeding in the HAS-BLED "low-risk" and "moderate-risk" groups, respectively. Patients with HAS-BLED scores ≥3 showed an approximately 3-fold greater risk of major bleeding compared with patients with scores <3 (OR=3.00, CI: 1.21-7.43).

CONCLUSIONS

Compared with any of HEMORR2HAGES, ATRIA, or ORBIT scores, the HAS-BLED score distributed more major bleeding events into the "low" or "moderate" risk categories.

Accuracy of HAS-BLED and other bleeding risk assessment tools in predicting major bleeding events in atrial fibrillation: A network meta-analysis

BACKGROUND

Preventing thrombosis is an important part of atrial fibrillation (AF) treatment. However, it may increase the risk of bleeding, and bleeding risk assessment tools' predictive value remains unclear. This network meta-analysis investigated the sensitivity and specificity of HAS-BLED, and other bleeding risk assessment tools, to predict major bleeding events in AF patients.

METHODS

The PubMed, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched using keywords, including "AF," "bleeding," and "HAS-BLED," for results published through 30 November 2018. The predictive sensitivity and specificity of each bleeding risk assessment tool was analyzed by network meta-analysis.

RESULTS

Our analysis included 18 studies, recruiting a total of 321 888 people. The bleeding risk assessment tools analyzed in this study included the ABC-bleeding score, ATRIA, European score, GARFIELD-AF, HAS-BLED, HEMORR2HAGES, ORBIT, Shireman, and mOBRI. A comprehensive analysis of sensitivity and specificity, based on an inconsistency model, showed that European score, ABC, and mOBRI have relatively high-sensitivity but low-specificity tools, whereas HAS-BLED and HEMORR2HAGES have balanced sensitivity and specificity. ORBIT, ATRIA, Shireman, and GARFIELD-AF had relatively high specificity but low sensitivity. A consistency model analysis showed similar results.

CONCLUSIONS

HAS-BLED is a balanced bleeding risk assessment tool in terms of sensitivity and specificity, whereas the European score, ABC, and mOBRI are high-sensitivity tools and ORBIT, ATRIA, Shireman, and GARFIELD-AF are high-specificity tools.

Frequency and outcomes of primary central sleep apnea in a population-based study

BACKGROUND

Primary central sleep apnea (PCSA) is believed to be rare and data regarding its prevalence and long-term outcomes are sparse. We used the Rochester Epidemiology Project (REP) resources to identify all Olmsted County, Minnesota, residents with an incident diagnosis of PCSA and their clinical outcomes.

METHODS

We searched the REP database for all residents with polysomnography (PSG)-confirmed diagnoses of central sleep apnea (CSA) between 2007 and 2015. From these, we reviewed the PSGs and medical records to find those who had PCSA based upon accepted diagnostic criteria. Data based on detailed review of the medical records, including all clinical notes and tests were recorded for analysis.

RESULTS

Of 650 patients identified with CSA, 25 (3.8%; 23 male) had PCSA, which was severe in most patients (n = 16, 64%). Of those, 23 (92%) patients were prescribed and 18/23 (78.2%) adherent to positive airway pressure therapy. Median duration of follow-up was 4.4 years (IQR:4.2). Four (16%) patients were subsequently diagnosed with cardiac arrhythmias, one (4%) with unstable angina, two (8%) with heart failure, five (20%) with mild cognitive impairment (MCI)/dementia and two (8%) with depression. Six (25%) patients died (median time to death = 5 years; IQR:4.8), three of whom had Lewy body dementia.

CONCLUSIONS

In this population-based study, PCSA was rare and when present, was severe in a majority of patients. The mortality rate was high. Most frequently observed disorders during follow-up were mild cognitive impairment (MCI)/dementia followed by cardiac arrhythmias; it is possible that these entities were present and not recognized prior to the diagnosis of PCSA.

Bleeding risk assessment for stroke patients on antithrombotic therapy

INTRODUCTION

After an ischemic cerebrovascular event the risk of new ischemic events is high, therefore antithrombotic therapy are indicated to prevent stroke recurrence.

DISCUSSION

Despite its clear benefit, these therapies increase the risk of bleeding. Therefore, it is essential to identify high hemorrhagic risk patients. There are different predictive models of hemorrhage, in particular of intracranial hemorrhage, associated with the use of antiaggregants in patients who have presented an ischemic stroke or TIA, such as the CCSC, intracranial scales -B2LEED3S score or S2TOP-BLEED. However, though main international guidelines recommend the use of scales, in particular, the HAS-BLED score, to assess the risk of bleeding in anticoagulated patients, there is no specific recommendation in the case of the use of antiplatelet drugs.

CONCLUSIONS

In this review we present the main models currently available for the prediction of bleeding of antithrombotic therapy in patients who have had a stroke or TIA.

Characteristics of patients with thromboembolic disorders on warfarin therapy in resource limited settings

Background

Warfarin is a drug with narrow therapeutic index used in the management of thromboembolic disorders. Several factors affect its plasma concentrations with a resultant risk of toxicity. We examined the database of patients on warfarin therapy in order to establish the factors that affect the stability of INR and correlated them to clinical outcomes in resource limited settings.

Methods

We analysed retrospective data of patients admitted to adult medical wards at Moi Teaching and Referral Hospital (MTRH) in 2015. Inclusion criteria were patients with thromboembolic and related disorders and on warfarin treatment. Derived data included demographics, indications for warfarin use, co-prescribed drugs, co-morbidities, INR measurements, duration of hospital stay and clinical outcomes. Descriptive statistics were used to summarize the data. Pearson’s correlation coefficient was used to assess relationships between duration of hospitalization and number of INR tests. Regression splines were used to capture INR trends during the follow up period. Data was analysed using R v. 3.3.1.

Results

A total of 310 patients had thromboembolic disorders, out of which 63 met the study criteria.

The median age was 48 years, while the mean number of INR measurements was once every four days. Majority of patients did not achieve stable INR values, with only two having consecutive INR values within therapeutic goal. Patients who died had high INR levels. The median duration of hospital stay was 9 days (IQR: 7.0, 16.5). There was a significant correlation between length of stay in hospital and the number of times that INR were measured (Corr = 0.667, p < 0.001). The two most common indications for warfarin were DVT (64.4%) and atrial fibrillation (24.7%). All the patients had one or more comorbid conditions except for 11 with DVT alone, with cardiovascular diseases and infections being the most frequent, and on concomitant medications, majority of which are known to interact with warfarin.

Conclusions

It was difficult to achieve stable INR under the prevailing conditions despite the frequent tests.

The potential factors that may have contributed to the fluctuations include drug-drug interactions, frequency of INR tests, comorbidities and the short duration of hospital stay.

Comparison of bleeding risk scores in patients with atrial fibrillation: insights from the RE-LY trial

BACKGROUND

Oral anticoagulation is the mainstay of stroke prevention in atrial fibrillation (AF), but must be balanced against the associated bleeding risk. Several risk scores have been proposed for prediction of bleeding events in patients with AF.

OBJECTIVES

To compare the performance of contemporary clinical bleeding risk scores in 18 113 patients with AF randomized to dabigatran 110 mg, 150 mg or warfarin in the RE-LY trial.

METHODS

HAS-BLED, ORBIT, ATRIA and HEMORR₂ HAGES bleeding risk scores were calculated based on clinical information at baseline. All major bleeding events were centrally adjudicated.

RESULTS

There were 1182 (6.5%) major bleeding events during a median follow-up of 2.0 years. For all the four schemes, high-risk subgroups had higher risk of major bleeding (all P < 0.001). The ORBIT score showed the best discrimination with c-indices of 0.66, 0.66 and 0.62, respectively, for major, life-threatening and intracranial bleeding, which were significantly better than for the HAS-BLED score (difference in c-indices: 0.050, 0.053 and 0.048, respectively, all P < 0.05). The ORBIT score also showed the best calibration compared with previous data. Significant treatment interactions between the bleeding scores and the risk of major bleeding with dabigatran 150 mg BD versus warfarin were found for the ORBIT (P = 0.0019), ATRIA (P < 0.001) and HEMORR₂ HAGES (P < 0.001) scores. HAS-BLED score showed a nonsignificant trend for interaction (P = 0.0607).

CONCLUSIONS

Amongst the current clinical bleeding risk scores, the ORBIT score demonstrated the best discrimination and calibration. All the scores demonstrated, to a variable extent, an interaction with bleeding risk associated with dabigatran or warfarin.

Validation of knowledge and adherence assessment tools among patients on warfarin therapy in a Saudi hospital anticoagulant clinic

Background Although it can result in serious complications due to its narrow therapeutic index, warfarin is widely used in the treatment and prevention of thromboembolic disorders. However, patients' adherence and knowledge are determinants of therapeutic success. Objective We sought to validate instruments to provide a reliable means of identifying gaps in patient understanding and nonadherence to inform targeted pharmacists' interventions to improve these measures. Methods A cross-sectional survey was conducted. Patients' knowledge about warfarin was rated using an Arabic-language tool. Medication adherence was assessed using the eight-item Morisky Medication Adherence Scale (MMAS-8). The international normalized ratio (INR) control was quantified by the Rosendaal Method. Setting At the Security Forces hospital anticoagulant clinic (ACC), Riyadh. Main outcome measure Validity of a Knowledge and adherence tool. Results Totally, 101 patients completed the questionnaires. Interestingly, the knowledge tool demonstrated good internal consistency (total Cronbach's alpha = 0.75) and significant concurrent validity with adherence levels. Fifty-two patients were classified as having unsatisfactory knowledge. Deficiency in knowledge was most obvious with respect to the consequences of missing a dose and when to seek immediate medical attention. The MMAS-8 had moderate reliability (Cronbach's alpha = 0.65); however, its concurrent validity with good INR control was not demonstrated. Conclusions This study revealed high prevalence of nonadherence and poor knowledge in the population visiting the ACC. Given that available knowledge and adherence tools seemed to have little validity in predicting clinical outcomes, structured tools should be designed, considering progression in clinical outcomes with future pharmacists' interventions.

The HAS-BLED Score Identifies Patients with Acute Venous Thromboembolism at High Risk of Major Bleeding Complications during the First Six Months of Anticoagulant Treatment

Objective

The HAS-BLED score enables a risk estimate of major bleeds in patients with atrial fibrillation on vitamin K-antagonists (VKA) treatment, but has not been validated for patients with venous thromboembolism (VTE). We analyzed whether the HAS-BLED score accurately identifies patients at high risk of major bleeds during VKA treatment for acute VTE.

Methods

Medical records of 537 patients with acute VTE (primary diagnosis pulmonary embolism in 223, deep vein thrombosis in 314) starting VKA treatment between 2006-2007 were searched for items on the HAS-BLED score and the occurrence of major bleeds during the first 180 days of follow-up. The hazard ratio (HR) for the occurrence of major bleeds comparing non-high with high-risk patients as defined by a HAS-BLED score ≥ 3 points was calculated using Cox-regression analysis.

Results

Major bleeds occurred in 11/537 patients (2.0%, 5.2/100 person years, 95% CI 2.8-9.2). Cumulative incidences of major bleeds were 1.3% (95% CI 0.1-2.5) in the non-high (HAS-BLED < 3) and 9.6% (95%CI 2.2-17.0) in the high-risk group (HAS-BLED ≥ 3), (p <0.0001 by Log-Rank test), with a HR of 8.7 (95% CI 2.7-28.4). Of the items in the HAS-BLED score, abnormal renal function (HR 10.8, 95% CI 1.9-61.7) and a history of bleeding events (HR 10.4, 95% CI 2.5-42.5) were independent predictors of major bleeds during follow-up.

Conclusion

Acute VTE patients with a HAS-BLED score ≥ 3 points are at increased risk of major bleeding. These results warrant for correction of the potentially reversible risk factors for major bleeding and careful International Normalized Ratio monitoring in acute VTE patients with a high HAS-BLED score.

Atrial Fibrillation and Stroke: A Neurologic Perspective

Atrial fibrillation (AF) is the most common supraventricular arrhythmia in the United States. The incidence and prevalence of AF are increasing as the population ages and associated risk factors become more prevalent. Stroke is the most severe complication of AF. Various risk stratification schemes to guide therapy and the associated risk of bleeding are described. AF is also associated with cognitive decline, which may be secondary to recurrent microemboli; microbleeds secondary to anticoagulation therapy, or progression of vascular risk factors associated with AF. Prolonged monitoring can be performed to detect AF in patients with cryptogenic stroke.