Oral anticoagulants in patients with atrial fibrillation at low stroke risk: a multicentre observational study.

AIMS: There is currently no consensus on whether atrial fibrillation (AF) patients at low risk for stroke (one non-sex-related CHA2DS2-VASc point) should be treated with an oral anticoagulant. METHODS AND RESULTS: We conducted a multi-country cohort study in Sweden, Denmark, Norway, and Scotland. In total, 59 076 patients diagnosed with AF at low stroke risk were included. We assessed the rates of stroke or major bleeding during treatment with a non-vitamin K antagonist oral anticoagulant (NOAC), a vitamin K antagonist (VKA), or no treatment, using inverse probability of treatment weighted (IPTW) Cox regression. In untreated patients, the rate for ischaemic stroke was 0.70 per 100 person-years and the rate for a bleed was also 0.70 per 100 person-years. Comparing NOAC with no treatment, the stroke rate was lower [hazard ratio (HR) 0.72; 95% confidence interval (CI) 0.56-0.94], and the rate for intracranial haemorrhage (ICH) was not increased (HR 0.84; 95% CI 0.54-1.30). Comparing VKA with no treatment, the rate for stroke tended to be lower (HR 0.81; 95% CI 0.59-1.09), and the rate for ICH tended to be higher during VKA treatment (HR 1.37; 95% CI 0.88-2.14). Comparing NOAC with VKA treatment, the rate for stroke was similar (HR 0.92; 95% CI 0.70-1.22), but the rate for ICH was lower during NOAC treatment (HR 0.63; 95% CI 0.42-0.94). CONCLUSION: These observational data suggest that NOAC treatment may be associated with a positive net clinical benefit compared with no treatment or VKA treatment in patients at low stroke risk, a question that can be tested through a randomized controlled trial.

Early Risk of Stroke in Patients Undergoing Acute Versus Elective Cardioversion for Atrial Fibrillation.

Background Electrical cardioversion (ECV) is routinely used to restore sinus rhythm in patients with symptomatic atrial fibrillation. The European guidelines have been updated in recent years. Current information on differences in the risk for stroke after acute versus elective ECV is lacking. Methods And Results All patients with a first-time acute or elective ECV in the Stockholm regional health care data warehouse from 2011 to 2018 were included. Cox regression analyses were performed evaluating ischemic or unspecified stroke within 30 days after ECV with adjustments for the CHA2DS2-VASc score, medical treatment, and year of inclusion. The study included 9139 patients, 3094 after acute and 6045 after elective ECV. The mean age was 65.9±11.3 years, 69.5% were men, and the mean CHA2DS2-VASc score was 2.4±1.7. Before the intervention, 49.6% of patients with an acute ECV and 96.4% of those with an elective ECV had claimed an oral anticoagulant prescription. Ischemic or unspecified stroke occurred in 26 (0.28%) patients within 30 days. The unadjusted risk was higher after acute compared with elective ECV (hazard ratio [HR], 2.29; 95% CI, 1.06-4.96), whereas there was no difference after multivariable adjustments (adjusted HR, 0.99; 95% CI, 0.36-2.72). Both non-vitamin K oral anticoagulants (adjusted HR, 0.28; 95% CI, 0.08-0.98) and warfarin (adjusted HR, 0.17; 95% CI, 0.05-0.53) were associated with a lower risk for stroke compared with no anticoagulation. Conclusions Acute ECV was associated with a higher unadjusted risk for stroke than elective ECV, but the risk was similar after adjustment for anticoagulant treatment. This study indicates the importance of anticoagulation before ECV according to recent European guidelines.

Persistence and adherence to non-vitamin K antagonist oral anticoagulant treatment in patients with atrial fibrillation across five Western European countries.

AIMS: To assess persistence and adherence to non-vitamin K antagonist oral anticoagulant (NOAC) treatment in patients with atrial fibrillation (AF) in five Western European healthcare settings. METHODS AND RESULTS: We conducted a multi-country observational cohort study, including 559 445 AF patients initiating NOAC therapy from Stockholm (Sweden), Denmark, Scotland, Norway, and Germany between 2011 and 2018. Patients were followed from their first prescription until they switched to a vitamin K antagonist, emigrated, died, or the end of follow-up. We measured persistence and adherence over time and defined adequate adherence as medication possession rate ≥90% among persistent patients only. RESULTS: Overall, persistence declined to 82% after 1 year and to 63% after 5 years. When including restarters of NOAC treatment, 85% of the patients were treated with NOACs after 5 years. The proportion of patients with adequate adherence remained above 80% throughout follow-up. Persistence and adherence were similar between countries and was higher in patients starting treatment in later years. Both first year persistence and adherence were lower with dabigatran (persistence: 77%, adherence: 65%) compared with apixaban (86% and 75%) and rivaroxaban (83% and 75%) and were statistically lower after adjusting for patient characteristics. Adherence and persistence with dabigatran remained lower throughout follow-up. CONCLUSION: Persistence and adherence were high among NOAC users in five Western European healthcare settings and increased in later years. Dabigatran use was associated with slightly lower persistence and adherence compared with apixaban and rivaroxaban.

Greedy caliper propensity score matching can yield variable estimates of the treatment-outcome association-A simulation study.

PURPOSE: Greedy caliper propensity score (PS) matching is dependent on randomness, which can ultimately affect causal estimates. We sought to investigate the variation introduced by this randomness. METHODS: Based on a literature search to define the simulation parameters, we simulated 36 cohorts of different sizes, treatment prevalence, outcome prevalence, treatment-outcome-association. We performed 1:1 caliper and nearest neighbor (NN) caliper PS-matching and repeated this 1000 times in the same cohort, before calculating the treatment-outcome association. RESULTS: Repeating caliper and NN caliper matching in the same cohort yielded large variations in effect estimates, in all 36 scenarios, with both types of matching. The largest variation was found in smaller cohorts, where the odds ratio (OR) ranged from 0.53 to 10.00 (IQR of ORs: 1.11-1.67). The 95% confidence interval was not consistently overlapping a neutral association after repeating the matching with both algorithms. We confirmed these findings in a noninterventional example study. CONCLUSION: Caliper PS-matching can yield highly variable estimates of the treatment-outcome association if the analysis is repeated.

Association of preceding antithrombotic therapy in atrial fibrillation patients with ischaemic stroke, intracranial haemorrhage, or gastrointestinal bleed and mortality.

AIMS: To analyse 90-day mortality in atrial fibrillation (AF) patients after a stroke or a severe bleed and assess associations with the type of antithrombotic treatment at the event. METHODS AND RESULTS: From the Stockholm Healthcare database, we selected 6017 patients with a known history of AF who were diagnosed with ischaemic stroke, 3006 with intracranial haemorrhage, and 4291 with a severe gastrointestinal bleed (GIB). The 90-day mortality rates were 25.1% after ischaemic stroke, 31.6% after intracranial haemorrhage, and 16.2% after severe GIB. We used Cox regression and propensity score-matched analyses to test the association between antithrombotic treatment at the event and 90-day mortality. After intracranial haemorrhage, there was a significantly higher mortality rate in warfarin compared to non-vitamin K oral anticoagulant (NOAC)-treated patients [adjusted hazard ratio (aHR) 1.36, 95% confidence interval (CI) 1.04-1.78]. After an ischaemic stroke and a severe GIB, patients receiving antiplatelets or no antithrombotic treatment had significantly higher mortality rates compared to patients on NOACs, but there was no difference comparing warfarin to NOACs (aHR 0.84, CI 0.63-1.12 after ischaemic stroke, aHR 0.91, CI 0.66-1.25 after severe GIB). Propensity score-matched analysis yielded similar results. CONCLUSION: Mortality rates were high in AF patients suffering from an ischaemic stroke, an intracranial haemorrhage, or a severe GIB. NOAC treatment was associated with a lower 90-day mortality after intracranial haemorrhage than warfarin.

Long-term persistence and adherence with non-vitamin K oral anticoagulants in patients with atrial fibrillation and their associations with stroke risk.

AIMS: Studies on adherence and persistence with non-vitamin K oral anticoagulant (NOAC) treatment have relied on data from the early years of NOAC availability. We aimed to study long-term adherence and persistence with NOACs and their association with stroke risk. METHODS AND RESULTS: From the Stockholm Healthcare database, we included 21 028 atrial fibrillation patients claiming a first NOAC prescription from July 2011 until October 2018, with more than 1000 patients having more than 5 years of follow-up (median: 2.0, interquartile range: 1.0-3.2). Persistence rates, defined as continuing to claim NOAC prescriptions within a 90-day gap, decreased to 70% at the end of follow-up. However, 85% of the patients were treated at the end of the study due to reinitiations. Adherence, calculated as medication possession rate (MPR) in 3 and 6-month intervals among persistent users, remained stable at 90%, with 75% of patients having an MPR >95% throughout the study period. Using a case-control design, we calculated associations of persistence and adherence with stroke risk, adjusting for potential confounders. The outcome was a composite of ischaemic or unspecified stroke and transient ischaemic attack. Non-persistence and poor adherence were both associated with increased stroke risk [non-persistence adjusted odds ratio (aOR): 2.05; 95% confidence interval (CI): 1.49-2.82, 1% reduction MPR aOR: 1.03; CI: 1.01-1.05]. There was no association between non-persistence or poor adherence and the falsification endpoints; fractions and respiratory infections, indicating no 'healthy-adherer' effect. CONCLUSION: Persistence rates decreased slowly over time, but persistent patients had high adherence rates. Both non-persistence and poor adherence were associated with an increased stroke risk.

Patterns of multimorbidity and pharmacotherapy: a total population cross-sectional study.

BACKGROUND: Treatment of multimorbid patients can be improved. Development of patient-centred care of high-quality requires context-bound understanding of the multimorbid population's patterns of demographics, co-morbidities and medication use. OBJECTIVE: The aim of this study was to identify patterns of multimorbidity in the total population of Region Stockholm, Sweden, by exploring demographics, claimed prescription drugs, risk of mortality and non-random association of conditions. METHODS: In this cross-sectional descriptive population-based cohort study, we extracted data from the Swedish VAL database (N = 2 323 667) including all consultations in primary and specialized outpatient care, all inpatient care and all prescriptions claimed during 2017. We report number of chronic conditions and claimed prescription drugs, physical and mental co-morbidity, and 1-year mortality. We stratified the analyses by sex. We examined non-random associations between diseases using cluster analysis. RESULTS: In total, 21.6% had multimorbidity (two or more chronic conditions) and 24.1% had polypharmacy (more than five claimed prescription drugs). Number of claimed drugs, co-occurrence of mental and physical conditions, and 1-year mortality increased as multimorbidity increased. We identified seven multimorbidity clusters with clinically distinct characteristics. The smallest cluster (7% of individuals) had prominent cardiovascular disease, the highest 1-year mortality rate, high levels of multimorbidity and polypharmacy, and was much older. The largest cluster (27% of individuals) was younger and heterogenous, with primarily mental health problems. CONCLUSIONS: Individuals with chronic conditions often show clinical complexity with both concordant and discordant conditions and polypharmacy. This study indicates that clinical guidelines addressing clustering of conditions may be one strategy for managing complexity.

Concomitant Anticoagulant and Antidepressant Therapy in Atrial Fibrillation Patients and Risk of Stroke and Bleeding.

We aimed to quantify the effects of antidepressant (AD) use in oral anticoagulant (OAC)-treated patients with atrial fibrillation (AF). Using the Stockholm Healthcare database, we analyzed AF patients initiated with an OAC. Outcomes were severe bleeds and strokes and were analyzed using Cox models. We included 17,210 patients claiming warfarin and 13,385 claiming a non-vitamin K OAC. The number of patients that claimed an AD during follow-up was 4,303. Concomitant OAC and AD use was associated with increased rates of severe bleeds (4.7 vs. 2.7 per 100 person-years) compared with OAC treatment alone (adjusted hazard ratio (aHR) 1.42, confidence interval (CI): 1.12-1.80), but not significantly associated with increased stroke rates (3.5 vs. 2.1 per 100 person-years, aHR 1.23, CI: 0.93-1.62). No significant differences in risks were observed between different OAC classes or different AD classes. In conclusion, concomitant use of an OAC and an AD is associated with an increased bleeding risk.

Venous thromboembolism 2011-2018 in Stockholm: a demographic study.

Venous thromboembolism (VTE) is an important cause of morbidity and mortality in Western countries. The incidence rate of VTE is estimated at 1-2 cases per 1000 annually. This study was a population-based cohort study of previously treatment naïve patients with a first occurrence of venous thromboembolism (VTE), using data from the administrative health data register of the Stockholm Region 2011-2018. Data on anticoagulant treatment was taken from the Swedish Prescribed Drug Register. We also analyzed all VTE events between 2011 and 2018. Altogether 14,849 naïve incident VTE cases were identified. In 2011 the majority of patients with a first episode of VTE were prescribed warfarin versus non-vitamin K antagonist oral anticoagulants (NOACs), 1144 versus 5. In contrast in 2018, the majority of patients were treated with NOACs, 1049 versus 59 treated with warfarin. Treatment with low molecular weight heparin only decreased from 814 to 683 patients. The frequency of all VTE events in the population increased over time from 1.88/1000 to 1.93/1000 (p = 0.072), and PE diagnoses increased from 0.69/1000 to 0.76/1000 (p = 0.003). In conclusion, during 2011-2018 there has been a shift of prescription of warfarin to a clear predominance of NOACs in the treatment of VTE in the Stockholm Region, in line with current recommendations. In the clinical situation, treatment has been simplified as monitoring of warfarin has decreased substantially. PE events increased during the time period in the population even if the increase was rather modest, while all VTE events did not increase significantly.

[Improved stroke prevention in atrial fibrillation: the Stockholm experience of the introduction of NOACs]. / Förbättrad strokeprevention vid förmaksflimmer med NOAK - Erfarenheter från Stockholms Län.

The introduction of NOACs has put a focus on stroke prevention in atrial fibrillation (AF). The number of patients in Stockholm diagnosed with non-valvular AF increased from 41 008 in 2011 to 51 266 in 2017 and their treatment has been markedly improved. Between 2011 and 2017 total oral anticoagulant treatment increased from 51.6% (warfarin) to 77.3% (31% warfarin, 46.3% NOACs) and aspirin decreased from 31.6% to 7.2%. Treatment was especially improved among patients with CHA2DS2-VASc scores ≥2 and elderly high risk patients. We found an excellent persistence with OAC treatment (88% at 1 year and 83% at 2 years). A comparative effectiveness study showed that NOACs were at least as effective and safe as warfarin even among patients ≥80 years or with previous serious bleeds. After a gradual introduction of NOACs with many educational activities apixaban is now the first-line choice for stroke prevention in AF in Stockholm. Swedish guideline goals are fulfilled and outcomes are improved.

Improved Stroke Prevention in Atrial Fibrillation After the Introduction of Non-Vitamin K Antagonist Oral Anticoagulants.

Background and Purpose- The purpose of this study was to investigate the impact of improved antithrombotic treatment in atrial fibrillation after the introduction of non-vitamin K antagonist oral anticoagulants on the incidence of stroke and bleeding in a real-life total population, including both primary and secondary care. Methods- All resident and alive patients with a recorded diagnosis for atrial fibrillation during the preceding 5 years in the Stockholm County Healthcare database (Vårdanalysdatabasen) were followed for clinical outcomes during 2012 (n=41 008) and 2017 (n=49 510). Results- Pharmacy claims for oral anticoagulants increased from 51.6% to 73.8% (78.7% among those with CHA2DS2-VASc ≥2). Non-vitamin K antagonist oral anticoagulant claims increased from 0.4% to 34.4%. Ischemic stroke incidence rates decreased from 2.01 per 100 person-years in 2012 to 1.17 in 2017 (incidence rate ratio, 0.58; 95% CI, 0.52-0.65). The largest increases in oral anticoagulants use and decreases in ischemic strokes were seen in patients aged ≥80 years who had the highest risk of stroke and bleeding. The incidence rates for major bleeding (2.59) remained unchanged (incidence rate ratio, 1.00; 95% CI, 0.92-1.09) even in those with a high bleeding risk. Poisson regression showed that 10% of the absolute ischemic stroke reduction was associated with increased oral anticoagulants treatment, whereas 27% was related to a generally decreased risk for all stroke. Conclusions- Increased oral anticoagulants use contributed to a marked reduction of ischemic strokes without increasing bleeding rates between 2012 and 2017. The largest stroke reduction was seen in elderly patients with the highest risks for stroke and bleeding. These findings strongly support the adoption of current guideline recommendations for stroke prevention in atrial fibrillation in both primary and secondary care.

Stroke and bleeding with non-vitamin K antagonist oral anticoagulant or warfarin treatment in patients with non-valvular atrial fibrillation: a population-based cohort study.

Aims: Oral anticoagulants (OACs) effectively reduce the risk of stroke in atrial fibrillation (AF). Three non-vitamin K antagonist OACs (NOACs) are introduced in regular care based on promising results compared with warfarin in randomized trials. This study compares outcomes with NOAC vs. warfarin treatment in OAC naïve AF patients in routine care, including primary care, in a large region with decentralized anticoagulant treatment. Methods and results: Population-based cohort study. Individuals with non-valvular AF who initiated treatment with NOAC (n = 9279) or warfarin (n = 12 919) from 2012 to 2015 were identified in the Stockholm administrative health data register (population 2.2 million). Adjusted Cox regression analyses were performed to evaluate TIA/ischaemic or unspecified stroke/death, and severe bleeds (co-primary endpoints); and secondarily for components of the composites. NOAC patients were younger (72.9 vs. 74.1 years) and had lower CHA2DS2VASc scores (3.42 vs. 3.68) than warfarin patients. NOAC vs. warfarin treatment was associated with similar risks for TIA/ischaemic or unspecified stroke/death [hazard ratio (HR) 0.94; 0.85-1.05] and severe bleeds (HR 1.02; 0.88-1.19); lower risks of intracranial bleeds (HR 0.72; 0.53-0.97) or haemorrhagic stroke (HR 0.56; 0.34-0.93), but a higher risk for gastrointestinal bleeds (HR 1.28; 1.04-1.59). The advantages with NOAC treatment were most pronounced with standard dose in patients below 80 years, and with dose reduction in patients aged 80 and above. Conclusion: This population-based cohort study of routine care indicates similar or better effectiveness and safety with NOAC compared with warfarin treatment. NOACs were associated with fewer intracranial bleeds, but more gastrointestinal bleeds.

Sex and Gender Differences in Thromboprophylactic Treatment of Patients With Atrial Fibrillation After the Introduction of Non-Vitamin K Oral Anticoagulants.

To examine sex differences in thromboprophylaxis in patients with atrial fibrillation before and after the introduction of non-vitamin K oral anticoagulants, we performed a cross-sectional registry study based on anonymized individual-level patient data of all individuals with a diagnosis of nonvalvular atrial fibrillation (International Classification of Diseases, Tenth Revision code I48) in the region of Stockholm, Sweden (2.2 million inhabitants), in 2011 and 2015, respectively. Thromboprophylaxis improved considerably during the period. During 2007 to 2011, 23,198 men and 18,504 women had an atrial fibrillation diagnosis. In 2011, more men than women (53% men vs 48% women) received oral anticoagulants (almost exclusively warfarin) and more women received aspirin only (35% women vs 30% men), whereas there was no sex difference for no thromboprophylaxis (17%). During 2011 to 2015, 27,237 men and 20,461 women had a diagnosis of atrial fibrillation. Compared with the earlier time period, a higher proportion used oral anticoagulants (71% women vs 70% men), but fewer women ≥80 years received anticoagulants (67% women vs 72% men), more women received aspirin (15% women vs 13% men), and fewer women had no thromboprophylaxis (15% women vs 17% men). Patients with co-morbidities potentially complicating oral anticoagulant use used more oral anticoagulant in 2015 compared with 2011. The sex differences observed in 2011 with fewer women using oral anticoagulants had disappeared in 2015 except in women 80 years and older and in patients with complicated co-morbidity.

Factors associated with antithrombotic treatment decisions for stroke prevention in atrial fibrillation in the Stockholm region after the introduction of NOACs.

PURPOSE: The purpose of this study was to investigate the influence of patient characteristics such as age and stroke and bleeding risks on decisions for antithrombotic treatment in patients with atrial fibrillation (AF). METHODS: This was a retrospective, population-based study including AF patients initiated with either warfarin, dabigatran, rivaroxaban, apixaban, or low-dose aspirin (ASA) between March 2015 and February 2016. Multivariate models were used to calculate adjusted odds ratios (aOR) for factors associated with treatment decisions. RESULTS: A total of 6765 newly initiated patients were included, most with apixaban (46.4%) and least with ASA (6.7%). There were more comorbidities in patients initiated with ASA or warfarin compared to the cohort average. Patients with high stroke risks had higher chances of receiving ASA (CHA2DS2-VASc ≥5 vs 0; aOR 2.01; 95% confidence interval (CI) 1.12-3.33). Among patients receiving oral anticoagulants, patients with high bleeding risks more often received warfarin (ATRIA score 5-10 vs 0-3; aOR 1.40; CI 1.20-1.64). Among NOACs, apixaban was preferred for patients with higher stroke risks (aOR 1.78; CI 1.31-2.41), high bleeding risks (aOR 1.54; CI 1.26-1.88) and high age (age group ≥85 vs 0-65; aOR 1.84; CI 1.44-2.35). Conversely, dabigatran treatment was associated with lower ages and lower risks. CONCLUSIONS: High stroke and bleeding risks favored choices of warfarin or ASA. Among patients receiving NOACs, apixaban was favored for elderly and high-risk patients whereas dabigatran was used in lower risk patients. The inadvertent use of ASA, especially among those with high stroke risks, should be further discouraged.

Effects of policy interventions on the introduction of novel oral anticoagulants in Stockholm: an interrupted time series analysis.

AIMS: The aim of the present study was to assess the effect of policy interventions - i.e. reimbursement decisions, guidelines and regional recommendations - on the prescribing of oral anticoagulant treatment in patients with atrial fibrillation (AF). METHODS: Interrupted time series analyses were carried out using monthly data on all patients with a recorded diagnosis of AF newly initiated (switchers and anticoagulant-naïve patients alike) on warfarin, dabigatran, rivaroxaban or apixaban in the Stockholm region from April 2011 until February 2016. RESULTS: A total of 34 165 initiations in 27 942 patients were included. The publication of the European Guidelines was associated with an increase in novel oral anticoagulant (NOAC) initiations of 12.5% [95% confidence interval (CI) 7.3, 17.7] after 5 months. The choice between the different NOACs was mainly associated with changes in the regional recommendations, with apixaban initiations increasing by 19.5% (95% CI 16.3, 22.7) 5 months after the drug was recommended as a first-line alternative to warfarin. Dabigatran received a second-line recommendation but initiations decreased by -9.5% (95% CI -12.6, -6.4), and initiations of rivaroxaban, which had no specific recommendation, decreased by -9.2% (95% CI -12.7, -5.7). A steady decrease in warfarin and increase in NOAC initiations was seen throughout the study period and from November 2015, AF patients were more likely to receive apixaban than any other anticoagulant, while less than 20% of the initiations were with warfarin. CONCLUSIONS: After reimbursement and inclusion in the European guidelines, the NOACs started gaining in popularity, while changes in regional recommendations were associated with the biggest change in prescribers' choice between the different NOACs.

Comparison of treatment persistence with different oral anticoagulants in patients with atrial fibrillation.

PURPOSE: Oral anticoagugulants (OACs) effectively reduce the risk for ischemic stroke in patients with atrial fibrillation (AF), but undertreatment and poor persistence with treatment are important problems. NOACs now provide alternatives to warfarin. This study compares the persistence with presently available antithrombotic treatments in AF patients with a CHA2DS2VASc score ≥2. METHODS: All first claims of either warfarin (n = 9969), dabigatran (n = 2701), rivaroxaban (n = 2074), apixaban (n = 1352), or aspirin (n = 4540) from April 2011 until December 2014, in individuals with non-valvular AF and CHA2DS2VASc scores of 2-9, were identified in the administrative health data register (VAL) of the Stockholm region (2.1 million inhabitants). Prescription claims were analyzed with and without multivariate analysis in relation to age, sex, prescriber category, prior OAC treatment, number of drugs, and death. RESULTS: The overall persistence with any OAC was 88.2% (CI 87.5-88.9) at 1 year and 82.9% (CI 81.8-83.9) at 2 years. After 1 year, the crude persistence was 85.0% (CI 84.2-85.9) with warfarin, 85.9% (CI 81.8-90.1) with apixaban, 74.4% (CI 72.3-76.5) with dabigatran, and 77.4% (CI 74.6-80.2) with rivaroxaban. Multivariate analysis confirmed significantly higher persistence with warfarin and apixaban than with dabigatran or rivaroxaban. The adherence (proportion of days covered >80%) was above 90% for all NOACs; significantly higher with rivaroxaban compared to dabigatran (p < 0.001), but not compared to apixaban (p = 0.14). CONCLUSIONS: After 2 years, the persistence with any anticoagulant treatment was high in patients with non-valvular AF. Our results indicate better persistence with warfarin and apixaban than with dabigatran or rivaroxaban in regular care.

[More with atrial fibrillation, anticoagulants since the coming of NOAK ]. / Fler med förmaksflimmer får antikoagulantia sedan NOAK kom.

Since the introduction of NOAC (non-vitamin K antagonist oral anticoagulants) in 2011 as thromboprophylactic treatment for patients with atrial fibrillation, AF, the number of patients with a diagnosis of atrial fibrillation has increased markedly in our health care registers. The proportion of patients treated with warfarin or NOAC has increased from 47 % to 58 % in 2013. The use of acetylsalicylic acid in patients is decreasing rapidly in patients with AF. NOAC are mostly prescribed by specialists and are mainly used in younger patients with lower CHA2DS2-VASc scores and lower risk for renal insufficiency and bleeding.

Risks for stroke and bleeding with warfarin or aspirin treatment in patients with atrial fibrillation at different CHA(2)DS(2)VASc scores: experience from the Stockholm region.

PURPOSE: This study evaluated the benefits of and possible contraindications to warfarin treatment in patients with atrial fibrillation (AF) prior to the introduction of new oral anticoagulants using health registry data from inpatient care, specialist ambulatory care, and primary care. METHODS: This is a cohort study including all patients in the region of Stockholm, Sweden (2.1 million inhabitants) with a diagnosis of non-valvular AF (n = 41 810) recorded during 2005-2009. The risks of suffering ischemic stroke, bleeding, or death with warfarin, aspirin, or no antithrombotic treatment during 2010 were related to CHA2DS2VASc scores, age, and complicating co-morbidities. RESULTS: One-year risks for ischemic stroke were 1.0-1.2 % with aspirin, 0-0.3 % with warfarin, and 0.1-0.2 % without treatment at CHA2DS2VASc scores 0-1. Among the aspirin-treated patients with CHA2DS2VASc scores ≥2, half had possible contraindications and high risks for ischemic stroke (5.2 %), bleeding (5.0 %), and death (19.3 %). The other half of the patients with no identified contraindications had a high risk for ischemic stroke (4.0 %) but a low bleeding risk (1.8 %) and a moderate mortality rate (8.4 %). CONCLUSIONS: The present observations confirm earlier findings of undertreatment with warfarin and half of the high-risk patients treated with aspirin were obvious candidates for anticoagulant treatment. However, the other half of the patients had complicating co-morbidities, high bleeding risk, and poor prognosis. This and possible overtreatment of low-risk patients should be taken into account when considering more aggressive use of anticoagulant treatment.

Risk scoring and thromboprophylactic treatment of patients with atrial fibrillation with and without access to primary healthcare data: experience from the Stockholm health care system.

BACKGROUND: Earlier validation studies of risk scoring by CHA2DS2VASc for assessments of appropriateness of warfarin treatment in patients with atrial fibrillation have been performed solely with diagnoses recorded in hospital based care, even though many patients to a large extent are managed in primary care. METHODS: Cross-sectional registry study of all 43 353 patients with a diagnosis of non-valvular atrial fibrillation recorded in inpatient care, specialist ambulatory care or primary care in the Stockholm County during 2006-2010. RESULTS: The mean CHA2DS2VASc score was 3.82 (4.67 for women and 3.14 for men). 64% of the entire cohort of patients with atrial fibrillation had the diagnosis in primary care (12% only there). The mean CHA2DS2VASc score of patients with a diagnosis only in inpatient care or specialist ambulatory care increased from 3.63 to 3.83 when comorbidities registered in primary care were added. In 2010 warfarin prescriptions were claimed by 47.2%, and ASA by 41.6% of the entire cohort. 34% of patients with CHA2DS2VASc=1 and 20% with CHA2DS2VASc=0 had warfarin treatment. ASA was more frequently used instead of warfarin among women and elderly patients. CONCLUSIONS: Registry CHA2DS2VASc scores were underestimated without co-morbidity data from primary care. Many individuals with scores 0 and 1 were treated with warfarin, despite poor documentation of clinical benefit. In contrast, warfarin appears to be underused and ASA overused among high risk atrial fibrillation patients. Lack of diagnoses from primary care underestimated CHA2DS2VASc scores and may thereby have overestimated treatment benefits in low-risk patients in earlier studies.