Tomas Forslund

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.

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.

Usage, Risk, and Benefit of Weight-Loss Drugs in Primary Care

Purpose. To investigate the use of the weight-loss drugs rimonabant, sibutramine, and orlistat in primary care and to characterize the patients receiving the drugs. Methods. In this retrospective, descriptive study, 300 randomly selected patients having started weight-loss drug treatment at 15 primary care centres were investigated using the patients medical records and their complete drug purchase data. Results. Even though 48% of the patients specifically demanded drug treatment, 77% continued treatment less than one year. 28% of rimonabant patients and 32% of sibutramine patients had a history of depression or antidepressant treatment. 41% of sibutramine patients had a history of hypertension and/or cardiovascular disease. 36% had no documented weight after treatment initiation. Conclusions. These results suggest that weight-loss drug treatment was often initiated upon patient request but was of limited clinical benefit as it was managed in a large portion of Swedish primary carecenters.

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

PurposeThe 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).MethodsThis 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.ResultsA 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.ConclusionsHigh 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.

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.