ClinicalTrends in Atrial Fibrillation and Prescription of Oral Anticoagulants and Embolic Strokes in Germany
Introduction
Apart from atherosclerosis, arterial embolism is the main cause of cerebral infarction. Atrial fibrillation (AF) has been recognized to be most relevant pathology associated with embolic stroke (ES) and there has been much effort taken to prevent embolic stroke by implementing a consequent anticoagulation strategy in the case of AF in the recent years [1,2]. Furthermore it is known that a stroke in patients with AF is more severe and the outcome significant worse than in patients with sinus rhythm [3]. Oral anticoagulation (OAC) with direct new oral anticoagulants (DOAC) or Vitamin-K antagonists (VKA) is recommended by guidelines for patients with AF and a moderate to high risk of stroke [[4], [5], [6]]. Despite these recommendations ES is still of increasing relevance in different health systems. Data from a Canadian urgent transient ischemic attack clinic in Ontario reported that the proportion of ES increased from 26% to 56% during the period of 2002 to 2012 (p < 0.05) [7].
An increasing number of patients with AF and an underuse of OAC are discussed as main reasons for the increasing figure of ES. Analysis of the Framingham cohort over 50 years reported an increase of the age-adjusted prevalence of AF per 1000 person-years (from 12.6 in 1958–1967 to 25.7 in 1998–2007 in men, p = 0.0007; from 8.1 in 1958–1967 to 11.8 in 1998–2007 in women, p = 0.009) [8]. Accepting an indication for OAC in cases with a CHADS2- or CHA2DS2-VASC-score >1 a German study based on a claims-based data set from two statutory health insurance funds for the years 2007–2010 reported that 38.88% and 39.20% respectively, of observed patient-days were not covered by anticoagulants [9]. An analysis of the administrative health data registry of the Stockholm region reported better adherence to warfarin and apixaban than to dabigatran or rivaroxaban in regular care [10]. A growing rate of total OAC prescriptions is expected to continue because DOAC are given preference over warfarin in guidelines on stroke prevention in patients with atrial fibrillation, because of growing physician experience, and emergence of potential new indications [11].
The aim of this study was to compare nationwide trends in frequency of AF, prescription rates of OAC and incidence of ES in Germany from 2005 to 2014.
Section snippets
Methods
Hospitals in Germany annually transfer their individual hospitalization data, including one primary diagnosis, up to 89 secondary diagnoses coded by ICD-10 (International Classification of Diseases, 10th edition), and up to 100 medical procedures according to a national classification of operations and procedures to the Institute for the Hospital Renumeration System (InEK). After a plausibility control, the InEK forwards anonymized data to the Federal Bureau of Statistics. Principles of the
Statistical methods
For AF we considered any case with the principal and the additional diagnosis of I48 in the years 2005 to 2014. For strokes we considered only cases with the principal diagnosis I63 including the subtypes as coded by the last digit. Based on the data provided by WIDO, we analyzed the prescription time trend of all OAC in Germany from 2005 to 2014. As we compare hospitalization rates of AF and ES considering the whole German population with prescription rates of OAC outside the hospitals
Atrial fibrillation
The total number of cases with the principal or additional diagnosis AF increased continuously from 1.25 Million in 2005 to 2.19 Million in 2014 (+75.8, p < 0.001) (Table 1, Fig. 1). Most of these diagnoses were coded as additional diagnosis. The rate of those with the principal diagnosis AF that can be assumed to be hospitalized for AF treatment primarily increased from 180,000 in 2005 to 289,000 in 2014 (+60.6 p < 0.001).
Stroke
The total number of strokes increased from 185,014 in 2005 to 244,761 in
Discussion
The present data show an increase in prescription of OAC beginning in the years 2011 and 2012 that is not accompanied by a reduction of cases hospitalized with ES.
Exact incidence and prevalence data of AF in Germany are not available. Based on the population-based Gutenberg Health Study prevalence of AF, weighted for age and sex distribution of the general population, was 2.5%. AF was found to be more common in older persons, with a more pronounced increase in men: whereas its prevalence was
Strength and limitations
A major strength of this study is the large data set which includes virtually all German hospitals and the observation period of 10 years. This allows a unique view at the current clinical practice. Moreover, to the best of our knowledge, there is currently no other publication addressing this topic from a population based viewpoint in Germany.
There are a few limitations to this study. This observational study is based on retrospective hospital data. As we used routine hospitalization data, we
Conclusions
Our ecologic nationwide analysis of drug treatment rates for OAC in outpatients and hospitalization rates for ES revealed a disproportional increase in prescription of OAC beginning in the year 2010 that is not accompanied by a reduction of cases hospitalized with ES.
Acknowledgement
We thank Referat VIII A 1 from the Federal Statistical Office for extracting and providing the data from the DRG-Statistik.
Sources of funding
None.
Declaration of interest
None.
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Cited by (6)
Mortality in atrial fibrillation. Is it changing?
2021, Trends in Cardiovascular MedicineCitation Excerpt :A similar analysis of newly diagnosed AF patients in the US Medicare population between 1992 and 2010 reported increases in warfarin use from 29% to 63% in men, 31% to 59% in women, 27% to 61% in whites, 19% to 52% in blacks, and 19% to 49% in patients of other race [25]. Similar increases in oral anticoagulation use have been reported in other regions, including Quebec (period 1998–2006) [26], Norway (period 2010-2015) [27], and Germany (period 2005–2014) [28]. The impact on mortality trends of increased rates of oral anticoagulation in general and the growing use of direct oral anticoagulants, however, has not been quantified.
Trends in oral anticoagulant use in patients with atrial fibrillation in Belgium from 2013 to 2019: A nationwide cohort study
2023, British Journal of Clinical PharmacologyThe investigation of health outcomes in the German National Cohort: the most relevant endpoints and their assessment
2020, Bundesgesundheitsblatt - Gesundheitsforschung - GesundheitsschutzUptake in antithrombotic treatment and its association with stroke incidence in atrial fibrillation: insights from a large German claims database
2019, Clinical Research in Cardiology
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Contributed equally.