Effect of intensity of oral anticoagulation on stroke severity and mortality in atrial fibrillation

Predicting Thromboembolic and Bleeding Event Risk in Patients with Non-Valvular Atrial Fibrillation: A Systematic Review

BACKGROUND

 Atrial fibrillation (AF) is a common cardiac arrhythmia that increases the risk of stroke. Medical therapy for decreasing stroke risk involves anticoagulation, which may increase bleeding risk for certain patients. In determining the optimal therapy for stroke prevention for patients with AF, clinicians use tools with various clinical, imaging and patient characteristics to weigh stroke risk against therapy-associated bleeding risk.

AIM

 This article reviews published literature and summarizes available risk stratification tools for stroke and bleeding prediction in patients with AF.

METHODS

 We searched for English-language studies in PubMed, Embase and the Cochrane Database of Systematic Reviews published between 1 January 2000 and 14 February 2018. Two reviewers screened citations for studies that examined tools for predicting thromboembolic and bleeding risks in patients with AF. Data regarding study design, patient characteristics, interventions, outcomes, quality, and applicability were extracted.

RESULTS

 Sixty-one studies were relevant to predicting thromboembolic risk and 38 to predicting bleeding risk. Data suggest that CHADS₂, CHA₂DS₂-VASc and the age, biomarkers, and clinical history (ABC) risk scores have the best evidence for predicting thromboembolic risk (moderate strength of evidence for limited prediction ability of each score) and that HAS-BLED has the best evidence for predicting bleeding risk (moderate strength of evidence).

LIMITATIONS

 Studies were heterogeneous in methodology and populations of interest, setting, interventions and outcomes analysed.

CONCLUSION

 CHADS₂, CHA₂DS₂-VASc and ABC scores have the best prediction for stroke events, and HAS-BLED provides the best prediction for bleeding risk. Future studies should define the role of imaging tools and biomarkers in enhancing the accuracy of risk prediction tools.

PRIMARY FUNDING SOURCE

 Patient-Centered Outcomes Research Institute (PROSPERO #CRD42017069999).

Is von Willebrand factor associated with stroke and death at mid-term in patients with non-valvular atrial fibrillation?

BACKGROUND

Heart failure and atrial fibrillation share common mechanisms that may contribute to hypercoagulability and thrombotic risk. Elevated von Willebrand factor (vWF) concentration has been associated with increased risk of thromboembolism and cardiovascular events.

AIM

To investigate whether increased vWF plasma concentration predicts occurrence of a composite endpoint (all-cause death and stroke) in patients with non-valvular atrial fibrillation (NVAF).

METHODS

We prospectively studied 122 patients (mean age 70±14years; 46% men) hospitalized with NVAF, and followed over a median (interquartile range) of 5.4 (2.3-9.0)years. Cox proportional models were used to estimate the association of vWF concentration with time to stroke and death.

RESULTS

Forty-three patients (35%) had at least a stroke or died during the 5-year follow-up. Kaplan-Meier curves using vWF plasma concentration tertiles (≤191IU/dL;>191 to≤295IU/dL;>295IU/dL) showed that vWF plasma concentrations discriminated groups of patients with higher cardiovascular event rates (log-rank P=0.01). In the multivariable analysis, higher vWF concentrations (middle tertile hazard ratio [HR] 4.59, 95% confidence interval [CI] 1.55-13.50 [P=0.006]; upper tertile HR 4.10, 95% CI 1.43-11.75 [P=0.009]), age≥75years (HR 5.02, 95% CI 1.53-16.49; P=0.008), heart failure (HR 2.05, 1.01-4.19; P=0.048), C-reactive protein, log₂ per unit increase (HR 1.29, 95% CI 1.04-1.61; P=0.021), no warfarin at discharge (HR 4.96, 95% CI 2.02-12.20; P<0.0001) and no aspirin at discharge (HR 4.41, 95% CI 1.71-11.97; P=0.002) were independently associated with an increased risk of stroke and all-cause death, whereas female sex was a protective factor (HR 0.35, 0.16-0.78; P=0.01).

CONCLUSIONS

High vWF plasma concentrations may discriminate patients with NVAF at greater risk of stroke or all-cause death.

Atrial Fibrillation and Central Nervous Complications in Liver Transplanted Hereditary Transthyretin Amyloidosis Patients

Background

Central nervous system (CNS) complications are increasingly noted in liver transplanted (LTx) hereditary transthyretin amyloid (ATTRm) amyloidosis patients; this suggests that the increased survival allows for intracranial ATTRm formation from brain synthesized mutant TTR. However, atrial fibrillation (AF), a recognised risk factor for ischemic CNS complications, is also observed after LTx. The aim of the study was to investigate the occurrence of CNS complications and AF in LTx ATTRm amyloidosis patients.

Methods

The medical records of all LTx ATTRm amyloidosis patients in the county of Västerbotten, Sweden, were investigated for information on CNS complications, AF, anticoagulation (AC) therapy, hypertension, cardiac ischemic disease, hypertrophy, and neurological status.

Results

Sixty-three patients that had survived for 3 years or longer after LTx were included in the analysis. Twenty-five patients had developed 1 or more CNS complications at a median of 21 years after onset of disease. AF was noted in 21 patients (median time to diagnosis 24 years). Cerebrovascular events (CVE) developed in 17 (median time to event 21 years). CVEs occurred significantly more often in patients with AF (P < 0.002). AC therapy significantly reduced CVEs, including bleeding in patients with AF (P = 0.04). Multivariate analysis identified AF as the only remaining regressor with a significant impact on CVE (hazard ratio, 3.8; 95% confidence interval 1.1-9.5; P = 0.029).

Conclusions

AF is an important risk factor for CVE in LTx ATTRm amyloidosis patients, and AC therapy should be considered. However, the increased bleeding risk with AC therapy in patients with intracranial amyloidosis should be acknowledged.

The authors of this retrospective study investigated the occurrence of central nervous system complications, such as cerebrovascular events and their potential association with atrial fibrillation in liver transplanted ATTRm Val30Met amyloidosis patients.

Prior Direct Oral Anticoagulant Therapy is Related to Small Infarct Volume and No Major Artery Occlusion in Patients With Stroke and Non-Valvular Atrial Fibrillation

Background The aims of the present study were to investigate the relationships between prior direct oral anticoagulant ( DOAC ) therapy and infarct volume and the site of arterial occlusion in patients with acute ischemic stroke and non-valvular atrial fibrillation. Methods and Results From March 2011 through November 2016, consecutive patients with acute ischemic stroke in the middle cerebral artery territory and non-valvular atrial fibrillation were recruited. The infarct volume was assessed semi-automatically using initial diffusion-weighted imaging, and the arterial occlusion site was evaluated on magnetic resonance angiography. The effect of prior DOAC treatment on the site of arterial occlusion was assessed by multivariate ordinal logistic regression analysis. A total of 330 patients (149 women; median age 79 [quartiles 71-86] years; median National Institutes of Health Stroke Scale score 11 [4-21]) were enrolled. Of these, 239 were on no anticoagulant, 40 were undertreated with a vitamin K antagonist ( VKA ), 22 were sufficiently treated with VKA ( PT - INR ≥1.6), and 29 were on a DOAC before the acute ischemic stroke. The infarct volume on admission differed among the groups (median 14.5 [2.0-59.8] cm3 in patients with no anticoagulation, 24.8 [2.1-63.0] in undertreated VKA , 1.3 [0.3-13.5] in sufficient VKA , and 2.3 [0.5-21.0] in DOAC , P=0.001). Multivariate analysis showed that prior DOAC treatment was independently and negatively associated with more proximal artery occlusion (odds ratio [OR] 0.34, P=0.015), compared with no anticoagulant. Conclusions DOAC treatment before the event was associated with smaller infarct volume and decreased risk of greater proximal artery occlusion in acute ischemic stroke patients with non-valvular atrial fibrillation, compared with no anticoagulation.

Automatic Detection of Atrial Fibrillation Based on Continuous Wavelet Transform and 2D Convolutional Neural Networks

Atrial fibrillation (AF) is the most common cardiac arrhythmias causing morbidity and mortality. AF may appear as episodes of very short (i.e., proximal AF) or sustained duration (i.e., persistent AF), either form of which causes irregular ventricular excitations that affect the global function of the heart. It is an unmet challenge for early and automatic detection of AF, limiting efficient treatment strategies for AF. In this study, we developed a new method based on continuous wavelet transform and 2D convolutional neural networks (CNNs) to detect AF episodes. The proposed method analyzed the time-frequency features of the electrocardiogram (ECG), thus being different to conventional AF detecting methods that implement isolating atrial or ventricular activities. Then a 2D CNN was trained to improve AF detection performance. The MIT-BIH Atrial Fibrillation Database was used for evaluating the algorithm. The efficacy of the proposed method was compared with those of some existing methods, most of which implemented the same dataset. The newly developed algorithm using CNNs achieved 99.41, 98.91, 99.39, and 99.23% for the sensitivity, specificity, positive predictive value, and overall accuracy (ACC) respectively. As the proposed algorithm targets the time-frequency feature of ECG signals rather than isolated atrial or ventricular activity, it has the ability to detect AF episodes for using just five beats, suggesting practical applications in the future.

Low-dose Prothrombin Complex Concentrate for Warfarin-Associated Intracranial Hemorrhage with INR Less Than 2.0

BACKGROUND

Prothrombin complex concentrates (PCCs) have become the first-line therapy for warfarin reversal in the setting of central nervous system (CNS) hemorrhage. Randomized, controlled studies comparing agents for warfarin reversal excluded patients with international normalized ratio (INR) <2, yet INR values of 1.6-1.9 are also associated with poor outcomes.

METHODS

We retrospectively reviewed our use of a low-dose (15 units/kg) strategy of 4-factor PCC (4F-PCC) on warfarin reversal (INR 1.6-1.9) in the setting of both traumatic and spontaneous intracranial bleeding.

RESULTS

A total of 21/134 (15.7%) patients with either spontaneous or traumatic intracranial hemorrhage presented with an INR value of 1.6-1.9. Nine patients (43%) presented with traumatic bleeding and 12 (57%) with spontaneous bleeding. The median (IQR) presenting INR was 1.8 (1.7, 1.9) which decreased to 1.3 (1.2, 1.3) following the administration of low-dose 4F-PCC (median dose = 1062 units; 15.2 units/kg). A total of 19/20 (95%) patients achieved a goal INR value of ≤1.5 on the first check following dosing and 17/20 (85%) achieved an INR value ≤1.3. One patient did not have follow-up INR testing due to withdrawal of life support. No patient experienced hematoma expansion within 48 h of 4F-PCC, and there were no thromboembolic events within 72 h of administration.

CONCLUSIONS

The administration of low dose (15 units/kg) of 4F-PCC for urgent warfarin reversal in the setting of CNS hemorrhage was effective in correcting the INR in patients presenting with INR values of 1.6-1.9. Further assessment of low-dose PCC for urgent reversal of modest INR elevation is warranted.

Risks and Benefits of Direct Oral Anticoagulants across the Spectrum of GFR among Incident and Prevalent Patients with Atrial Fibrillation

BACKGROUND AND OBJECTIVES

All randomized trials of direct oral anticoagulants in atrial fibrillation excluded patients with severe kidney disease. The safety and effectiveness of direct oral anticoagulants across the range of eGFR in real-world settings is unknown. Our objective is to quantify the risk of bleeding and benefit of ischemic stroke prevention for direct oral anticoagulants compared with warfarin in patients with atrial fibrillation with and without CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We created a propensity score-matched cohort of 3206 patients with atrial fibrillation and direct oral anticoagulant use and 3206 patients with atrial fibrillation using warfarin from October of 2010 to February of 2017 in an electronic health record (Geisinger Health System). The risks of bleeding and ischemic stroke were compared between direct oral anticoagulant and warfarin users using Cox proportional hazards regression, stratified by eGFR (≥60 and <60 ml/min per 1.73 m2).

RESULTS

The mean (SD) age of the 6412 participants was 72 (12) years, 47% were women, and average eGFR was 69 (21) ml/min per 1.73 m2. There were 1181 bleeding events and 466 ischemic strokes over 7391 person-years of follow-up. Compared with warfarin use, the hazard ratios (HRs) (95% confidence interval [95% CI]) of bleeding associated with direct oral anticoagulant use were 1.01 (0.88 to 1.17) and 1.23 (1.02 to 1.48) for those with eGFR≥60 and eGFR<60 ml/min per 1.73 m2, respectively (P-interaction=0.10). There was no difference between direct oral anticoagulant and warfarin users in the risk of ischemic stroke: HRs (95% CI) of 0.94 (0.74 to 1.18) and 1.02 (0.76 to 1.37) for those with eGFR≥60 and eGFR<60 ml/min per 1.73 m2, respectively (P-interaction=0.70). Similar findings were observed with individual drugs.

CONCLUSIONS

In a large health care system, patients with eGFR<60 ml/min per 1.73 m2 who took direct oral anticoagulants for atrial fibrillation had slightly higher risk of bleeding compared with those on warfarin, but similar benefits from prevention of ischemic stroke.

Reversal Strategies for Newer Oral Anticoagulants

Nonvitamin K antagonist oral anticoagulants have advantages compared with warfarin, but both types of anticoagulants come with uncertainty about how best to manage life-threatening bleeding events, urgent surgeries, and invasive procedures. Nurse practitioners and physician assistants may need to manage such emergency situations in the critical care setting. Achieving hemostasis quickly is key, and efforts to do so have relied mainly on blood products. Targeted reversal agents are in clinical development and one, idarucizumab, which reverses dabigatran anticoagulation, has been approved. Current options for managing events and urgent procedures in anticoagulated patients are discussed in this article, with a focus on specific reversal agents.

Quality of Chronic Anticoagulation Control in Patients with Intracranial Haemorrhage due to Vitamin K Antagonists

Introduction

Patients treated with vitamin K antagonists (VKA) are at increased risk of intracranial haemorrhage (ICH). The purpose of our study was to determine the quality of previous anticoagulation control in patients with VKA-associated ICH.

Materials and Methods

We prospectively assessed every consecutive patient admitted to our stroke unit with VKA-associated ICH between 2013 and 2016. Demographic, clinical, and radiological variables, as well as consecutive international normalized ratios (INR) during 7 previous months, were extracted. Time in therapeutic range (TTR), time over range (TOR), time below range (TBR), and percentage of INR within range (PINRR) were calculated.

Results and Discussion

The study population comprised 53 patients. Mean age was 79 years; 42% were women. Forty-eight patients had atrial fibrillation (AF) and 5 mechanical prosthetic valves. Therapeutic or infratherapeutic INR on arrival was detected in 64.4% of patients (95% CI 2.7 to 3.2). TTR was 67.8% (95% CI: 60.2 to 75.6 %) and PINRR was 75% (95% CI: 49.9-100). TOR was 17.2% (95% CI: 10.4 to 23.9% ) and TBR was 17% (95% CI: 10.6 to 23.9%).

Conclusion

VKA-associated ICH happens usually in the context of good chronic anticoagulation control. Newer risk assessment methods are required.

Trends and Variation in Oral Anticoagulant Choice in Patients with Atrial Fibrillation, 2010-2017

OBJECTIVE

Since 2010, several non-vitamin K antagonist oral anticoagulants (NOACs) have been brought to the U.S. market, yet little is known regarding their evolving adoption for prophylaxis of atrial fibrillation (AF)-related stroke. We examined temporal trends in choice of oral anticoagulants (OACs) among incident OAC users with AF and its association with patient demographic and clinical characteristics.

METHODS

We conducted a serial cross-sectional analysis of medical and pharmacy claims for commercial and Medicare Advantage enrollees in a large, private, U.S. health plan. We identified 112,187 adults with nonvalvular AF starting OACs between October 2010 and March 2017. Multivariable logistic regression was used to examine the associations of patient characteristics with prescription of NOACs versus warfarin. Multinomial logistic regression was used to test the associations of patient characteristics with choice among NOACs.

RESULTS

The prescription of NOACs has increased dramatically since their introduction in October 2010. In the first quarter of 2017 (2017Q1), 7502 patients started OACs, of whom 78.9% used NOACs and 21.1% warfarin. For NOACs, 3.8% used dabigatran, 25.0% rivaroxaban, and 50.1% apixaban. In multivariable analyses, factors associated with choice of NOACs versus warfarin included younger age, lower stroke or bleeding risk, fewer comorbidities, higher education level or household net worth, and prescription by cardiologists (all p<0.001). There was no sex difference in likelihood of filling NOACs versus warfarin in 2010Q4-2012, but women had higher odds of starting NOACs (odds ratio = 1.19; 95% confidence interval = 1.14-1.25) in 2015-2017Q1. Among NOAC users, the odds of apixaban prescription increased with age, female sex, stroke or bleeding risk, and comorbidities (all p<0.05).

CONCLUSION

NOAC prescriptions have increased substantially among incident OAC users with nonvalvular AF, predominantly driven by increased prescription of apixaban. Warfarin and apixaban were generally preferred for elderly patients, patients with higher stroke or bleeding risk, and patients with more comorbidities.

Traumatic and spontaneous intracranial hemorrhage in atrial fibrillation patients on warfarin

Background

Intracranial hemorrhage is the most devastating complication in patients with atrial fibrillation (AF) receiving oral anticoagulation (OAC). It can be either spontaneous or caused by head trauma. We sought to address the prevalence, clinical characteristics, and prognosis of traumatic and spontaneous intracranial hemorrhages in AF patients on OAC.

Methods

Multicenter FibStroke registry of 5,629 patients identified 592 intracranial hemorrhages during warfarin treatment between 2003 and 2012.

Results

A large proportion (40%) of intracranial hemorrhages were traumatic. Of these, 64% were subdural hemorrhages (SDHs) and 20% intracerebral hemorrhages (ICHs). With respect to the spontaneous hemorrhages, 25% were SDHs and 67% ICHs. Patients with traumatic hemorrhage were older (81 vs 78 years, p = 0.01) and more often had congestive heart failure (30% vs 16%, p < 0.01) and anemia (7% vs 3%, p = 0.03) compared to patients with spontaneous hemorrhage. Admission international normalized ratio (INR) values (2.7 vs 2.7, p = 0.79), as well as CHA₂DS₂-VASc (median 4 vs 4, p = 0.08) and HAS-BLED (median 2 vs 2, p = 0.05) scores, were similar between the groups. The 30-day mortality after traumatic hemorrhage was significantly lower than after spontaneous hemorrhage (25% vs 36%, p < 0.01).

Conclusions

A significant proportion of intracranial hemorrhages in anticoagulated AF patients were traumatic. Traumatic hemorrhages were predominantly SDHs and less often fatal when compared to spontaneous hemorrhages, which were mainly ICHs. Admission INR values as well as CHA₂DS₂-VASc and HAS-BLED scores were similar in patients with spontaneous and traumatic intracranial hemorrhage.

Clinicaltrialsgov identifier

NCT02146040.

Factors associated with poor anticoagulation control with vitaminK antagonists among outpatients attended in Internal Medicine and Neurology. The ALADIN study

OBJECTIVE

To identify factors associated with poor anticoagulation control with vitaminK antagonists (VKA) among outpatients with nonvalvular atrial fibrillation (NVAF) attended in Neurology and Internal Medicine in Spain.

METHODS

Cross-sectional and multicenter study, from the ALADIN database, of outpatients with NVAF treated with VKA and attended in Internal Medicine and Neurology in Spain. Rates of anticoagulation control were determined with the direct and Rosendaal methods, considering data from the 6months before the inclusion.

RESULTS

Out of 1,337 patients included in the ALADIN study, 750 were taking VKA, and complete information about INR values in the last 6months was available in 383 patients. Mean scores of Charlson Index, CHADS₂, CHA₂DS₂-VASc and HAS-BLED were 1.94±1.54; 3.10±1.26; 4.63±1.54, and 2.20±0.90, respectively. 46.2% and 47.0% of patients had an adequate anticoagulation control according to the direct and Rosendaal methods, respectively. Inadequate anticoagulation control according to the direct method was associated with diabetes (OR: 2.511; 95%CI: 1.144-5.659), prior labile INR (OR: 35.371; 95%CI: 15.058-83.083) and the determination of >6INR controls in the last 6months (OR: 4.747; 95%CI: 2.094-10.759), and according to the Rosendaal method, with prior labile INR (P<.001) and HAS-BLED score (OR: 3.991; 95%CI: 2.520-6.319).

CONCLUSIONS

Despite the high thromboembolic risk, only a little more than a half of patients were well controlled. Factors associated with poor anticoagulation control were diabetes, labile INR, >6INR controls and HAS-BLED.

Stroke type and severity in patients with subclinical atrial fibrillation: An analysis from the Asymptomatic Atrial Fibrillation and Stroke Evaluation in Pacemaker Patients and the Atrial Fibrillation Reduction Atrial Pacing Trial (ASSERT)

BACKGROUND

The Asymptomatic Atrial Fibrillation and Stroke Evaluation in Pacemaker Patients and the Atrial Fibrillation Reduction Atrial Pacing Trial (ASSERT) demonstrated that subclinical atrial fibrillation (SCAF) was associated with a 2.5-fold increased risk of stroke. However, the absolute stroke rate was only 1.7% per year and fewer than 20% patients with stroke had SCAF in the preceding 30 days. This raises the possibility that SCAF is merely a risk marker for stroke rather than the cause. Systematic characterization of stroke subtypes among patients with SCAF would help clarify this issue.

METHODS

All ischemic strokes that occurred in the ASSERT trial were blindly adjudicated by stroke neurologists, classified as cortical versus subcortical, and subtyped using modified TOAST criteria. Stroke severity was measured using the modified Rankin Score.

RESULTS

Of the 44 participants who had an ischemic stroke, 14 had SCAF before stroke. Among patients with SCAF who had stroke, 57% of strokes (n = 8) were judged to be cardioembolic, 36% to be lacunar (n = 5), and 7% (n = 1) to be large artery disease. However, of 5 patients who had SCAF detected within 30 days before their index stroke, 4 patients had a cardioembolic stroke. The average duration of SCAF in these 4 patients was 6.0 ± 6.1 h/d. The modified Rankin score at 30 days was similar between patients with (2.7 ± 2.3) and without SCAF (2.3 ± 2.0; P = .68).

CONCLUSIONS

In patients with SCAF and stroke, SCAF seems probably causal in many cases; however, in more than 40%, it seems to be acting only as a risk marker.

Methodological challenges in assessment of current use of warfarin among patients with atrial fibrillation using dispensation data from administrative health care databases

PURPOSE

Algorithms to define current exposure to warfarin using administrative data may be imprecise. Study objectives were to characterize dispensation patterns, to measure gaps between expected and observed refill dates for warfarin and direct oral anticoagulants (DOACs).

METHODS

Retrospective cohort study using administrative health care databases of the Régie de l'assurance-maladie du Québec. We identified every dispensation of warfarin, dabigatran, rivaroxaban, or apixaban for patients with AF initiating oral anticoagulants between 2010 and 2015. For each dispensation, we extracted date and duration. Refill gaps were calculated as difference between expected and observed dates of successive dispensation. Refill gaps were summarized using descriptive statistics. To account for repeated observations nested within patients and to assess the components of variance of refill gaps, we used unconditional multilevel linear models.

RESULTS

We identified 61 516 new users. Majority were prescribed warfarin (60.3%), followed by rivaroxaban (16.4%), dabigatran (14.5%), apixaban (8.8%). Most frequent recorded duration of dispensation was 7 days, suggesting use of pharmacist-prepared weekly pillboxes. The average refill gap from multilevel model was higher for warfarin (9.28 days, 95%CI:8.97-9.59) compared with DOACs (apixaban 3.08 days, 95%CI: 2.96-3.20, dabigatran 3.70, 95%CI: 3.56-3.84, rivaroxaban 3.15, 95%CI: 3.03-3.27). The variance of refill gaps was greater among warfarin users than among DOAC users.

CONCLUSIONS

Greater refill gaps for warfarin may reflect inadequate capture of the period covered by the number of dispensed pills recorded in administrative data. A time-dependent definition of exposure using dispensation data would lead to greater misclassification of warfarin than DOACs use.

Time to therapeutic range (TtTR), anticoagulation control, and cardiovascular events in vitamin K antagonists-naive patients with atrial fibrillation

BACKGROUND

Vitamin K antagonists (VKAs) reduce cardiovascular events (CVEs) in atrial fibrillation (AF) when a time in therapeutic range (TiTR) >70% is achieved. Factors affecting the time to achieve the TR (TtTR) are unknown.

METHODS

Prospective observational study including 1,406 nonvalvular AF patients starting VKAs followed for a mean of 31.3months (3,690 patient/year); TiTR, TtTR, and SAMe-TT₂R₂ score were calculated, and CVEs were recorded.

RESULTS

Median TtTR was 8.0days (interquartile range 5.0-18.0). Patients with high TtTR (ie, >75th percentile) were more likely to be in AF than in sinus rhythm at entry (odds ratio [OR]: 1.423, P=.011). Median TiTR was 60.0%; low TiTR (below median) was associated with SAMe-TT₂R₂ score (OR: 1.175, P=.001), high TtTR (>75th percentile, OR: 1.357, P=.017), and number of international normalized ratio checks (OR: 0.998, P=.049). We recorded 113 CVEs (3.1%/y), with a higher rate seen in patients with TtTR >75th percentile compared to those below (log-rank test, P=.006). A multivariable Cox regression analysis showed that SAMe-TT₂R₂ score (hazard ratio [HR]: 1.331, P<.001), TtTR >75th percentile (HR: 1.505, P=.047), TiTR <70% (HR: 1.931, P=.004), number of international normalized ratio checks (HR: 0.988, P<.001), digoxin (HR: 1.855, P=.008), and proton-pump inhibitors (HR: 0.452, P<.001) were independently associated with CVEs.

CONCLUSIONS

High TtTR is associated with poorer long-term quality of VKAs therapy. Patients with TtTR >18days or with high SAMe-TT₂R₂ score should be considered for treatment with non-vitamin K oral anticoagulants.

Pleiotropic effects of the hemostatic system

Atherothrombosis is characterized by the inflammatory process of atherosclerosis combined with a hypercoagulable state leading to superimposed thrombus formation. In atherosclerotic plaques, cell signaling can occur via protease-activated receptors (PARs), four of which have been identified so far (PAR1-PAR4). Proteases that are able to activate PARs can be produced systemically, but also at the sites of lesions, and they include thrombin and activated factor X. After PAR activation, downstream signaling can lead to both proinflammatory effects and a hypercoagulable state. Which specific effect occurs depends on the type of protease and activated PAR, and the site of activation. Hypercoagulable effects are mainly exerted through PAR1 and PAR4, whereas proinflammatory responses are mostly seen after PAR1 and PAR2 activation. PAR signaling pathways contribute to atherothrombosis, suggesting that inhibition of these pathways possibly prevents cardiovascular events based on this pathophysiological mechanism. In this review, we highlight the pathways by which PAR activation leads to proinflammatory responses and a hypercoagulable state. Furthermore, we give an overview of potential pharmacological treatment targets that promote vascular protection.

How do anticoagulated atrial fibrillation patients who suffer ischemic stroke or spontaneous intracerebral hemorrhage differ?

BACKGROUND

Atrial fibrillation (AF) increases risk of ischemic stroke, and oral anticoagulation (OAC) increases risk of intracerebral hemorrhage (ICH). This study aimed to compare OAC-treated AF patients with an ischemic stroke/transient ischemic attack (TIA) or spontaneous ICH as their first lifetime cerebrovascular event, especially focusing on patients with therapeutic international normalized ratio (INR).

HYPOTHESIS

We assumed that in AF patients suffering ischemic stroke/TIA or ICH, patient characteristics could be different in patients with therapeutic INR than in patients with warfarin.

METHODS

FibStroke is a multicenter, retrospective registry collating details of AF patients with ischemic stroke/TIA or intracranial hemorrhage in 2003-2012. This substudy included AF patients on OAC with first lifetime ischemic stroke/TIA or spontaneous ICH.

RESULTS

A total of 1457 patients with 1290 ischemic strokes/TIAs and 167 ICHs were identified. Of these, 553 (42.9%) strokes/TIAs and 96 (57.5%) ICHs occurred in patients with INR within therapeutic range. During OAC with therapeutic INR, congestive heart failure (odds ratio [OR]: 2.33, 95% confidence interval [CI]: 1.18-4.58) and hypercholesterolemia (OR: 2.52, 95% CI: 1.51-4.19) were more common in patients with ischemic stroke/TIA, whereas a history of bleeding (OR: 0.30, 95% CI: 0.11-0.82) was less common when compared with patients with ICH. In the whole cohort, renal impairment (OR: 1.86, 95% CI: 1.23-2.80) and mechanical valve prosthesis (OR: 4.41, 95% CI: 1.32-14.7) were overrepresented in patients with stroke/TIA, whereas aspirin use (OR: 0.52, 95% CI: 0.30-0.91) and high INR (OR: 0.40, 95% CI: 0.33-0.48) were overrepresented in patients with ICH.

CONCLUSIONS

In anticoagulated AF patients with therapeutic INR and first lifetime cerebrovascular event, congestive heart failure and hypercholesterolemia were associated with ischemic stroke/TIA and history of bleeding with ICH.

The Role of Clinical Variables and VKORC1 Polymorphism in Efficacy and Stability of Acenocoumarol in Neurological Patients

Objective:

To analyze the clinical importance of VKORC1 polymorphism and its correlation with stability of oral anticoagulation.

Patients and Methods:

In a hospital-based study, the patients on oral anticoagulant (OAC) were included during 2013–2016. The patients received OAC for cardioembolic stroke, cerebral venous sinus thrombosis (CVST), and prevention of deep vein thrombosis (DVT). Demographic, clinical, and neurological findings were recorded. Stability of anticoagulation was determined by percentage of time international normalized ratio (INR) values were in therapeutic range. Time in therapeutic range (TTR) >65% was defined as stable and <65% was defined unstable. VKORC 1 polymorphism was studied by polymerase chain reaction and correlated with daily dose of OAC and stability of INR.

Results:

A total of 157 patients with a median age of 40 years were included in the study. Ninety-two patients received OAC for secondary stroke prevention, 62 for CVST, and 3 for DVT. Out of 2976 INR reports, 1458 (49%) were in the therapeutic range, 997 (33.1%) were below the therapeutic range, and 521 (17.5%) were above the therapeutic level. Stable INR was obtained in 75 (47.77%) patients which was improved by drug modification in 3 and dietary adjustment in 12 patients. VKORC1 polymorphism revealed GG genotype in 127 (80.9%), GA genotype in 22 (14%), and AA genotype in 8 (5.1%) patients. Therapeutic range of INR was seen in 49%, below therapeutic range was seen in 31.5%, and above in 17.5%.

Conclusion:

VKORC1 polymorphism was related to mean daily dose of OAC but not to the stability of INR.

Should atrial fibrillation patients with hypertension as an additional risk factor of the CHA2DS2-VASc score receive oral anticoagulation?

Hypertension has been found to be increased a risk of stroke in atrial fibrillation (AF). Both the European and U.S. guidelines advocate the use of the CHA₂DS₂-VASc (congestive heart failure, hypertension, age > 75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65-74 years, sex category) scheme for risk stratification. Although vitamin K antagonists is more effective than acetylsalicylic acid at preventing ischaemic stroke, its benefit is offs by an increased haemorrhage risk. The risk of ischemic stroke in patients with AF and a CHA₂DS₂-VASc score of 1 are considered to be low risk and may be not expected to benefit from anticoagulation therapy. Hypertension carries an increased risk of ischemic stroke, however, it is also a clear risk factor for hemorrhage in AF. Therefore, the optimal antithrombotic management is highlighted in patients with AF with only one risk factor especially hypertension.

Is there a role for pharmacokinetic/pharmacodynamic-guided dosing for novel oral anticoagulants?

The novel direct oral anticoagulants (NOACs) represent a major advance in oral anticoagulant therapy and are replacing vitamin K antagonists as the preferred options for many indications. Given in fixed doses without routine laboratory monitoring, they have been shown to be at least as effective in reducing thromboembolic stroke as dose-adjusted warfarin in phase 3 randomized trials and less likely to cause hemorrhagic stroke. Pharmacokinetic and/or pharmacodynamic subanalyses of the major NOAC trials in patients with atrial fibrillation have established relationships between clinical characteristics, and drug levels and/or pharmacodynamic responses with both efficacy and safety. Based on these analyses, pharmaceutical manufacturers and regulatory authorities have provided contraindications and dosing recommendations based on clinical characteristics that are associated with drug levels and/or pharmacodynamic responses, stroke reduction, and bleeding risk to optimize the risk-benefit profile of the NOACs in the real world. The current fixed-dosing strategy of NOACs has triggered discussions about the potential value of laboratory monitoring and dose adjustment in customizing drug exposure to further improve the safety and efficacy of the NOACs in patients with atrial fibrillation. As there is neither high-quality evidence nor consensus about the potential role of laboratory monitoring and dose adjustment for the NOACs, a Cardiac Research Safety Consortium "Think Tank" meeting was held at the American College of Cardiology Heart House in December 2015 to discussions these issues. This manuscript reports on the deliberations and the conclusions reached at that meeting.

Net clinical benefit of rivaroxaban compared with warfarin in atrial fibrillation: Results from ROCKET AF

AIMS

The aim of this study was to determine the net clinical benefit (NCB) of rivaroxaban compared with warfarin in patients with atrial fibrillation.

METHODS

This was a retrospective analysis of 14,236 patients included in ROCKET AF who received at least one dose of study drug. We analyzed NCB using four different methods: (1) composite of death, stroke, systemic embolism, myocardial infarction, and major bleeding; (2) method 1 with fatal or critical organ bleeding substituted for major bleeding; (3) difference between the rate of ischemic stroke or systemic embolism minus 1.5 times the difference between the rate of intracranial hemorrhage; and (4) weighted sum of differences between rates of death, ischemic stroke or systemic embolism, intracranial hemorrhage, and major bleeding.

RESULTS

Rivaroxaban was associated with a lower risk of the composite outcome of death, myocardial infarction, stroke, or systemic embolism (rate difference per 10,000 patient-years [RD]=-86.8 [95% CI -143.6 to -30.0]) and fatal or critical organ bleeding (-41.3 [-68 to -14.7]). However, rivaroxaban was associated with a higher risk of major bleeding other than fatal or critical organ bleeding (55.9 [14.7 to 97.2]). Method 1 showed no difference between treatments (-35.5 [-108.4 to 37.3]). Methods 2-4 favored treatment with rivaroxaban (2: -96.8 [-157.0 to -36.8]; 3: -65.2 [-112.3 to -17.8]; 4: -54.8 [-96.0 to -10.2]).

CONCLUSIONS

Rivaroxaban was associated with favorable NCB compared with warfarin. The NCB was attributable to lower rates of ischemic events and fatal or critical organ bleeding.

Development of a clinical prediction model for an international normalised ratio ≥ 4·5 in hospitalised patients using vitamin K antagonists

Vitamin K antagonists (VKAs) used for the prevention and treatment of thromboembolic disease, increase the risk of bleeding complications. We developed and validated a model to predict the risk of an international normalised ratio (INR) ≥ 4·5 during a hospital stay. Adult patients admitted to a tertiary hospital and treated with VKAs between 2006 and 2010 were analysed. Bleeding risk was operationalised as an INR value ≥4·5. Multivariable logistic regression analysis was used to assess the association between potential predictors and an INR ≥ 4·5 and validated in an independent cohort of patients from the same hospital between 2011 and 2014. We identified 8996 admissions of patients treated with VKAs, of which 1507 (17%) involved an INR ≥ 4·5. The final model included the following predictors: gender, age, concomitant medication and several biochemical parameters. Temporal validation showed a c statistic of 0·71. We developed and validated a clinical prediction model for an INR ≥ 4·5 in VKA-treated patients admitted to our hospital. The model includes factors that are collected during routine care and are extractable from electronic patient records, enabling easy use of this model to predict an increased bleeding risk in clinical practice.

Clinical manifestations and outcomes of severe warfarin overanticoagulation: from the EWA study

INTRODUCTION

Severe warfarin overanticoagulation is a risk factor for bleeding, but there is little information on its manifestations, prognosis and factors affecting the outcome. We describe the manifestations and clinical outcomes of severe warfarin overanticoagulation in a large group of patients with atrial fibrillation (AF).

MATERIAL AND METHODS

All international normalized ratio (INR) samples (n = 961,431) in the Turku University Hospital region between 2003 and 2015 were screened. A total of 412 AF patients with INR ≥9 were compared to 405 patients with stable warfarin anticoagulation for AF. Electronic patient records were manually reviewed to collect comprehensive data.

RESULTS

Of the 412 patients with INR ≥9, bleeding was the primary manifestation in 105 (25.5%). Non-bleeding symptoms were recorded in 165 (40.0%) patients and 142 (34.5%) had no symptoms. A total of 17 (16.2%) patients with a bleed and 67 (21.8%) without bleeding died within 30 days after the event. Intracranial haemorrhage strongly predicted death within 30 days. Other significant predictors were non-bleeding symptoms, active malignancies, recent bleed, history of myocardial infarction, older age, renal dysfunction and a recent treatment episode.

CONCLUSIONS

Bleeds are not the major determinant of the poor prognosis in severe overanticoagulation, as coincidental INR ≥9 findings also associate with high mortality. KEY MESSAGES Only a quarter of AF patients with INR ≥9 suffered a bleeding event and the clinical manifestation of INR ≥9 had a significant impact on patient outcome. The 30-day mortality rate in patients with INR ≥9 was high ranging from 9.2 to 32.7%. Several significant predictors of 30-day mortality after INR ≥9 were identified.

Level of agreement between laboratory and point-of-care prothrombin time in patients after stopping or continuation of acenocoumarol anticoagulation: A comparison of diagnostic accuracy

BACKGROUND

Procedures requiring optimisation of the coagulation status of patients using vitamin K antagonists are frequently postponed due to the late availability of laboratory international normalised ratio (INR) test results. A point-of-care (POC) alternative may facilitate early decision-making in peri-operative patients.

OBJECTIVES

To assess the level of agreement between the POC-INR and the laboratory INR in patients who continue or stop vitamin K antagonists to determine whether the POC test may be a good alternative to the laboratory INR.

DESIGN

Study of diagnostic accuracy.

SETTING

Single-centre study at Zaans Medical Centre, The Netherlands.

PATIENTS

Included patients were scheduled for cardioversion (these continued taking vitamin K antagonists), or a surgical procedure (these stopped taking vitamin K antagonists).

MAIN OUTCOME MEASURES

The level of agreement and clinical acceptability of the laboratory and POC-INR results, evaluated by Bland-Altman analysis and error grid analysis.

RESULTS

The surgical and cardioversion groups consisted of 47 and 46 patients, respectively. The bias in the INR in the surgical group was -0.12 ± 0.09 with limits of agreement of -0.29 to 0.05, whereas the cardioversion group showed a bias in the INR of -0.22 ± 0.36 with limits of agreement from -0.93 to 0.48. The percentage errors between methods in the surgical and cardioversion groups were 16 and 21%, respectively. Error grid analysis showed that the diagnostic accuracy of the POC prothrombin time is clinically acceptable as the difference did not lead to a different clinical decision in the surgical group with INR values less than 1.8.

CONCLUSION

The current study shows a good level of agreement and clinical accuracy between the laboratory and POC-INR in patients who stopped anticoagulation intake for surgery. However, in patients who continued their anticoagulation therapy, the agreement between the two methods was less accurate.

Early Outcome after Intracranial Hemorrhage Related to Non-Vitamin K Oral Anticoagulants

BACKGROUND

Intracranial hemorrhage (ICH) is a serious, life-threatening, but fortunately rare complication of non-vitamin K oral anticoagulant (NOAC) therapy. There are limited data on NOAC-related ICH prognosis.

METHODS

All consecutive patients admitted to a single center due to acute NOAC-related ICH from September 2012 until the beginning of 2017 were included. Risk factors, type of NOAC, and location of ICH were evaluated. Risk for ischemic and bleeding events and clinical status upon admission and at discharge were evaluated using standard scales.

RESULTS

Thirty-four patients aged 77.8 ± 8.3 years with NOAC-related ICH were included. The main predisposing risk factors were age and arterial hypertension. The median CHA2DS2-VASc score was 3.4 and the median HAS-BLED score was 1.8. Eighteen patients were treated with rivaroxaban, 11 with dabigatran, and 5 with apixaban. Ten patients (29%) had a favorable outcome with a modified Rankin Scale score ≤2 and 13 patients (38%) died. The location of the ICH was mainly intraparenchymal and subdural.

CONCLUSIONS

Our retrospective single-center study shows that the mortality rate with NOAC-related ICH is <40%, which makes it comparable to that with vitamin K antagonist-related ICH.

Anticoagulation therapy in atrial fibrillation after intracranial hemorrhage

BACKGROUND

The effect of oral anticoagulation therapy (OAT) in patients with atrial fibrillation (AF) with a history of intracranial hemorrhage (ICH) is poorly defined.

OBJECTIVE

The purpose of this study was to evaluate the efficacy and safety of OAT in patients with AF with an ICH history.

METHODS

We retrospectively compared the composite end point, including thromboembolic and major bleeding events, between patients with AF with a history of ICH who were (OAT group, n = 254) and those who were not (no-OAT group, n = 174) taking OAT.

RESULTS

During a mean follow-up of 39.5 ± 31.9 months, 5.5 and 3.1 major bleeding events/100 patient-years were observed in the OAT and no-OAT groups, respectively (P = .024). Recurrent ICH was observed only in patient with OAT. Thromboembolic events occurred in 2.4 and 8.3 events/100 patient-years in OAT and no-OAT groups, respectively (P < .001). There was no significant differences in composite end points between OAT and no-OAT groups (11.5 events/100 patient-years vs 7.9 events/100 patient-years; P = .154). Patients with OAT who achieved a time-in-therapeutic range of ≥60% of the international normalized ratio of 2.0-3.0 demonstrated a better cumulative survival free of the composite end point (P < .001) than did patients without OAT. Early (<2 weeks) OAT after an index ICH did not improve composite end points because of the increased incidence of major bleeding events. However, OAT at 2 weeks after an index ICH was associated with decreased clinical events including thromboembolic events and composite end point.

CONCLUSION

In patients with AF who require anticoagulation and have a history of ICH, maintaining optimal OAT with time-in-therapeutic range ≥ 60% and the initiation of OAT at least 2 weeks after an index ICH were associated with improved clinical outcomes.

Implementation of smart technology to improve medication adherence in patients with cardiovascular disease: is it effective?

INTRODUCTION

Medication adherence is of key importance in the treatment of cardiovascular disease. Studies consistently show that a substantial proportion of patients is non-adherent.

AREAS COVERED

For this review, telemedicine solutions that can potentially improve medication adherence in patients with cardiovascular disease were reviewed. A total of 475 PubMed papers were reviewed, of which 74 were assessed.

EXPERT COMMENTARY

Papers showed that evidence regarding telemedicine solutions is mostly conflictive. Simple SMS reminders might work for patients who do not take their medication because of forgetfulness. Educational interventions and coaching interventions, primarily delivered by telephone or via a web-based platform can be effective tools to enhance medication adherence. Finally, it should be noted that current developments in software engineering may dramatically change the way non-adherence is addressed in the nearby future.

Portuguese Observational Study of Ischaemic Stroke in Patients Medicated with Non-Vitamin K Antagonist Oral Anticoagulants

<b><i>Introduction:</i></b> Clinical trials and subsequent meta-analyses showed advantages of non-vitamin K antagonists oral anticoagulants (NOACs) over vitamin K antagonists (VKAs) in patients with non-valvular atrial fibrillation. The impact of preadmission anticoagulation in acute ischaemic stroke (AIS) has not been established. <b><i>Objective:</i></b> To compare functional outcome of patients with AIS with preadmission NOACs vs. VKAs. <b><i>Methods:</i></b> A retrospective analysis was conducted on consecutive AIS patients under oral anticoagulation (VKAs or NOACs) admitted in 4 Portuguese hospitals within a period of 30 months. Two primary outcomes were defined and compared between VKA and NOAC groups: symptomatic intracerebral hemorrhage transformation (sICH) and modified Rankin Scale (mRS) at 3 months. <b><i>Results:</i></b> Four hundred sixty-nine patients were included, of whom 332 (70.8%) were treated with VKA and 137 (29.2%) with NOAC. Patients’ median age was 78.0 and 234 (49.9%) were male. NOAC-treated patients had a higher median CHA₂DS₂-VASc score than those under VKA (5.0 vs. 4.0, <i>p</i> = 0.023). The two primary outcomes showed no statistical differences between the VKAs’ group and the NOACs’ group (sICH: 5.4 vs. 5.4% [<i>p</i> = 0.911]; mRS at 3 months: 3.0 vs. 3.0 [<i>p</i> = 0.646], respectively). <b><i>Conclusion:</i></b> Preadmission anticoagulation with NOACs in AIS has a functional impact similar to that of VKAs.

Association between satisfaction with and adherence to warfarin therapy on the control of international normalized ratio: A hospital-based study in Saudi Arabia

BACKGROUND

High satisfaction with, and adherence to, warfarin therapy are linked to better international normalized ratio (INR) control and good therapeutic outcomes.

OBJECTIVE

This study was conducted to identify the association between satisfaction with, and adherence to, warfarin therapy and the control of the INR within the target therapeutic range.

METHODS

A cross-sectional study was conducted from June 1 to August 31, 2016, at the Anticoagulation Clinic in the Cardiology Center at King Fahad Hospital, Qassim, Saudi Arabia. All adult patients included in the study were 18-years-old or older and were on warfarin therapy for 6 months or more. The data were collected through face-to-face interviews using a structured questionnaire.

RESULTS

A total of 298 patients were included. Of them, 194 patients (65.1%) were males and 152 (51.0%) were classified as satisfied with their warfarin therapy. Secondary educational level and above (P = .001) and being non-Saudi (P = .026) were identified as determinants of a high level of satisfaction. Ninety-five (31.8%) participants were classified as adherent to the therapy, and satisfaction with treatment was the only predictor of adherence (P = .009). One hundred thirty-six patients (45.6%) achieved their target INR range. Satisfaction (P = .038) and adherence (P = .023) were significantly associated with better INR control.

CONCLUSION

Substantial efforts are needed to improve patient satisfaction and adherence to treatment through different strategies in order to achieve the target therapeutic goal for warfarin treatment.

The cost-effectiveness and monetary benefits of dabigatran in the prevention of arterial thromboembolism for patients with non-valvular atrial fibrillation in the Netherlands

BACKGROUND

Atrial fibrillation (AF) causes a significant health and economic burden to the Dutch society. Dabigatran was proven to have at least similar efficacy and a similar or better safety profile when compared to vitamin K antagonists (VKAs) in preventing arterial thromboembolism in patients with AF.

OBJECTIVE

To evaluate the cost-effectiveness and monetary benefit of dabigatran vs VKAs in Dutch patients with non-valvular AF. Value-based pricing considerations and corresponding negotiations on dabigatran will be explicitly considered.

METHODS

The base case economic analysis was conducted from the societal perspective. Health effects and costs were analysed using a Markov model. The main model inputs were derived from the RE-LY trial and Dutch observational data. Univariate, probabilistic sensitivity, and various scenario analyses were performed.

RESULTS

Dabigatran was cost saving compared to VKAs. A total of 4,552 QALYs were gained, and €13,892,288 was saved in a cohort of 10,000 AF patients. The economic value of dabigatran was strongly related to the costs of VKA control that are averted. Notably, dabigatran was cost saving compared to VKAs if annual costs of VKA control exceeded €159 per person, or dabigatran costs were below €2.81 per day.

CONCLUSION

Dabigatran was cost saving compared to VKAs for the prevention of atrial thromboembolism in patients with non-valvular AF in the Netherlands. This result appeared robust in the sensitivity analysis. Furthermore, volume based reduction of the price in the Netherlands will further increase the monetary benefits of dabigatran.

Management of Stroke risk in atrial fibrillation patients with bleeding on Oral Anticoagulation Therapy-Role of Left Atrial Appendage Closure, Octreotide and more

Background

Bleeding complications especially gastrointestinal bleeding remains a major challenge associated with oral anticoagulation therapy (OAT) and often leads clinicians to withdraw oral anticoagulation therapy (OAT) . This exposes patients to risk of stroke and systemic thromboembolism (STE). Novel oral anticoagulants (NOACs) have proved no better when it comes to bleeding events and in fact studies have shown that overall NOACs are associated with higher incidence of gastrointestinal (GI) bleeding compared to warfarin .

Objectives

In this review, we describe the difficulties encountered in managing OAT in patients with bleeding and strategies to maneuver around these bleeding complications particularly gastrointestinal bleeding secondary to arteriovenous malformations (AVM) and other vascular abnormalities.

Findings

Left atrial appendage closure (LAAC) has emerged as a very elegant and promising tool for stroke prevention in non-valvular atrial fibrillation (AF) patients who are intolerant to OAT. But the need for OAT post procedure for a brief period is becoming a major hurdle for clinicians to pursue in this direction in patients with recurrent gastrointestinal bleeds. And in majority of cases, recurrent or refractory gastrointestinal bleeds are usually secondary to arteriovenous malformations/angiodysplasias (AVM/AD). We suggest that the problem has to be approached by decreasing or eliminating the acute bleeding risk and closing the LAA in the long term, to enable the patients to come off of OAT and minimize the risk of recurrent bleeding.

Bleeding with anticoagulant treatments

Anticoagulation with vitamin K antagonists (VKAs) is effective in the prevention and treatment of thrombotic complications in many clinical conditions, including atrial fibrillation (that represents today the most frequent indication for anticoagulant treatment), venous thromboembolism, acute coronary syndromes and after invasive cardiac procedures. Bleeding is the most important complication of VKAs and a major concern for both physicians and patients, limiting a more widespread prescription of the treatment. As a result, a non negligible proportion of all the subjects who would have a clear clinical indication for anticoagulation do not receive an effective treatment.

This review analyses the treatment- and person-associated risk factors for bleeding during VKAs. New oral anticoagulant drugs seems to overcome at least some of the limitations of VKAs. Potentially, they can allow a less demanding and more stable anticoagulant treatment, with less side-effects allowing that more patients can receive an appropriate anticoagulant treatment. Based on the so far available phase III clinical studies, it is possible to assume that these new drugs are associated with a risk of bleeding, that is probably related to the intensity of treatment.

Laboratory characteristics of ischemic stroke patients with atrial fibrillation on or off therapeutic warfarin

BACKGROUND

In patients with atrial fibrillation (AF), despite adequate anticoagulation, ischemic stroke (IS) is an uncommon yet concerning occurrence.

HYPOTHESIS

Specific laboratory parameters may affect the efficacy of warfarin despite therapeutic international normalized ratio (INR) in patient with AF who present with IS.

METHODS

We used the database from a multicenter clinical trial to identify AF patients who presented with IS. We trichotomized the cohort into patients with therapeutic INR on warfarin, subtherapeutic INR on warfarin, and on no anticoagulants. We then compared baseline laboratory characteristics and other baseline features among the groups.

RESULTS

Patients with therapeutic INR presented with higher serum creatinine (P = 0.01) and blood urea nitrogen (P = 0.02) and lower glomerular filtration rates (P = 0.001) compared with other groups. Other laboratory parameters were not different among the 3 groups. Patients with therapeutic INR also presented with milder stroke symptoms (P = 0.01). Medical history of the 3 groups was not different, except for history of valvular heart disease, which was more prevalent in patients with therapeutic INR (P = 0.004). In-hospital mortality rates and 90-day disability were not different among the 3 groups.

CONCLUSIONS

AF patients who presented with IS on therapeutic warfarin had higher average serum creatinine and blood urea nitrogen, and lower glomerular filtration rates, compared with others. Impaired renal function may be a factor contributing to occurrence of IS in AF patients despite adequate anticoagulation. Larger, targeted studies are needed to confirm these findings.

Evaluation of anticoagulation status for atrial fibrillation on early ischaemic stroke outcomes: a registry-based, prospective cohort study of acute stroke care in Surrey, UK

OBJECTIVE

The relationship of anticoagulation therapies with stroke severity and outcomes have been well documented in the literature. However, none of the previous research has reported the relationship of atrial fibrillation (AF)/anticoagulation therapies with urinary tract infection (UTI), pneumonia and length of stay in hyperacute stroke units (HASUs). The present study aimed to evaluate AF and anticoagulation status in relation to early outcomes in 1387 men (median age=75 years, IQR=65-83) and 1371 women (median age=83 years, IQR=74-89) admitted with acute ischaemic stroke to HASUs in Surrey between 2014 and 2016.

METHODS

We conducted this registry-based, prospective cohort study using data from the Sentinel Stroke National Audit Programme. Association between AF anticoagulation status with severe stroke on arrival (National Institutes of Health Stroke Scale score ≥16), prolonged HASU stay (>3 weeks), UTI and pneumonia within 7 days of admission, severe disability on discharge (modified Rankin Scale score=4 and 5) and inpatient mortality was assessed by logistic regression, adjusted for age, sex, hypertension, congestive heart failure, diabetes and previous stroke.

RESULTS

Compared with patients with stroke who are free from AF, those with AF without anticoagulation had an increased adjusted risk of having more severe stroke: 5.8% versus 14.0%, OR=2.4 (95% CI 1.6 to 3.6, P<0.001), prolonged HASU stay: 21.5% versus 32.0%, OR=1.4 (1.0-2.0, P=0.027), pneumonia: 8.2% versus 19.1%, OR=2.1 (1.4-2.9, P<0.001), more severe disability: 24.2% versus 40.4%, OR=1.6 (1.2-2.1, P=0.004) and mortality: 9.3% versus 21.7%, OR=1.9 (1.4-2.8, P<0.001), and AF patients with anticoagulation also had greater risk for having UTI: 8.6% versus 12.3%, OR=1.9 (1.2-3.0, P=0.004), pneumonia: 8.2% versus 11.5%, OR=1.6 (1.1-2.4, P=0.025) and mortality: 9.7% versus 21.7%, OR=1.9 (1.4-2.8, P<0.001). The median HASU stay for stroke patients with AF without anticoagulation was 10.6 days (IQR=2.8-26.4) compared with 5.8 days (IQR=2.3-17.5) for those free from AF (P<0.001).

CONCLUSIONS

Patients with AF, particularly those without anticoagulation, are at increased risk of severe stroke, associated with prolonged HASU stay and increased risk of early infection, disability and mortality.