[Atrial fibrillation: are we faced with an epidemic? ]

Real-world data in primary care: validation of diagnosis of atrial fibrillation in primary care electronic medical records and estimated prevalence among consulting patients'

BACKGROUND

Primary care electronic medical records contain clinical-administrative information on a high percentage of the population. Before this information can be used for epidemiological purposes, its quality must be verified. This study aims to validate diagnoses of atrial fibrillation (AF) recorded in primary care electronic medical records and to estimate the prevalence of AF in the population attending primary care consultations.

METHODS

We performed a cross-sectional validation study of all diagnoses of AF recorded in primary care electronic medical records in Madrid (Spain). We also performed simple random sampling of diagnoses of AF (ICPC-2 code K78) registered by 55 physicians and random age- and sex-matched sampling of the records that included a diagnosis of AF. Electrocardiograms, echocardiograms, and hospital discharge or cardiology clinic reports were matched. Sensitivity, specificity, positive and negative predictive values (PPV and NPV), and overall agreement were calculated using the kappa statistic (κ). The prevalence of AF in the community of Madrid was estimated considering the sensitivity and specificity obtained in the validation. All calculations were performed overall and by sex and age groups.

RESULTS

The degree of agreement was very high (κ = 0.952), with a sensitivity of 97.84%, specificity of 97.39%, PPV of 97.37%, and NPV of 97.85%. The prevalence of AF in the population aged over 18 years was 2.41% (95%CI 2.39-2.42% [2.25% in women and 2.58% in men]). This increased progressively with age, reaching 16.95% in those over 80 years of age (15.5% in women and 19.44% in men).

CONCLUSIONS

The validation results obtained enable diagnosis of AF recorded in primary care to be used as a tool for epidemiological studies. A high prevalence of AF was found, especially in older patients.

[The management of atrial fibrillation and characteristics of its current care in outpatients. AFABE observational study]

AIM

To provide insights into the characteristics and management of outpatients when their atrial fibrillation (AF) was first detected: diagnosis, treatment and follow-up in the context of the public health system.

DESIGN

AFABE is an observational, multicentre descriptive study with retrospective data collection relating to the practice patterns, management and initial strategies of treatment of patients with diagnosed AF in the context of primary care, emergency and cardiologists of the public health system.

SETTING

Primary and Specialist care. Baix Ebre region. Tarragona. Spain.

SUBJECTS

A representative sample of 182 subjects > 60-year-old with AF who have been randomized, recruited among the registered patients with AF in 22 primary care centres in the area of the study.

MESUREMENTS

Demographic data, comorbidities (AF), CHA2DS2-VASc and HAS_BLED scores, and practice patterns results between Primary Care and referral services.

RESULTS

A total of 182 patients were included (mean age 78.5 SD:7.3 years; 50% women). Most patients (68.3% 95%CI; 60.3-76.3) had the first contact in Primary Care, of which 56.3% (95%CI; 45.2-66.0) were sent to Hospital Emergency Department where 72.7% (95%CI: 63.5-79.0) of the oral anticoagulation and 58.4% (95%CI: 49.4-66.9) of antiarrhytmic treatments were started. More than half (55.9%:95%CI; 47.2-64.7, of patients with permanent AF were followed-up by the Cardiology department.

CONCLUSIONS

Most patients with newly diagnosed AF made a first contact with Primary Care, but around half were sent to Hospital Emergency departments, where they were treated with an antiarrhythmic and/or oral anticoagulation.

Prevalence of undiagnosed atrial fibrillation and of that not being treated with anticoagulant drugs: the AFABE study

INTRODUCTION AND OBJECTIVES

Atrial fibrillation constitutes a serious public health problem because it can lead to complications. Thus, the management of this arrhythmia must include not only its treatment, but antithrombotic therapy as well. The main goal is to determine the proportion of cases of undiagnosed atrial fibrillation and the proportion of patients not being treated with oral anticoagulants.

METHODS

A multicenter, population-based, retrospective, cross-sectional, observational study. In all, 1043 participants over 60 years of age were randomly selected to undergo an electrocardiogram in a prearranged appointment. Demographic data, CHA2DS2-VASc and HAS-BLED scores, international normalized ratio results, and reasons for not receiving oral anticoagulant therapy were recorded.

RESULTS

The overall prevalence of atrial fibrillation was 10.9% (95% confidence interval, 9.1%-12.8%), 20.1% of which had not been diagnosed previously. In the group with known atrial fibrillation, 23.5% of those with CHA2DS2-VASc≥2 were not receiving oral anticoagulant therapy, and 47.9% had a HAS-BLED score≥3. The odds ratio for not being treated with oral anticoagulation was 2.04 (95% confidence interval, 1.11-3.77) for women, 1.10 (95% confidence interval, 1.05-1.15) for more advanced age at diagnosis, and 8.61 (95% confidence interval 2.38-31.0) for a CHA2DS2-VASc score<2. Cognitive impairment (15.2%) was the main reason for not receiving oral anticoagulant therapy.

CONCLUSIONS

The prevalence of previously undiagnosed atrial fibrillation in individuals over 60 years of age is 20.1%, and 23.5% of those who have been diagnosed receive no treatment with oral anticoagulants.

Gender differences related to the presence of atrial fibrillation in older hypertensive patients

AIM: To determine whether there are gender differences in the epidemiological profile of atrial fibrillation (AF) and to characterise the clinical, biochemical, and therapeutic factors associated with AF.

METHODS: Each investigator (primary care physicians or physicians based in hospital units for hypertension treatment) recruited the first 3 patients with an age of ≥ 65 years and a clinical diagnosis of hypertension (ambulatory blood pressure monitoring and an electrocardiogram, were performed) on the first working day of the week for 5 wk and identified those individuals with atrial fibrillation. A binary logistic regression was performed, including all of the variables that were significant in the univariate analysis, to establish the variables that were associated with the presence of arrhythmia.

RESULTS: A total of 1028 patients were included in the study, with a mean age of 72.8 ± 5.8 years. Of these patients, 47.3% were male, 9% were smokers, 27.6% were diabetics, 48.3% had dyslipidaemia, 10.9% had angina, and 6.5% had experienced a myocardial infarction. Regarding gender differences, the men exhibited a larger waist circumference, a lower body mass index, less obesity, and a more extensive history of diabetes, smoking, ischaemic heart disease, kidney failure, peripheral arterial disease and carotid disease than the women. There were no differences, however, in the prevalence of AF between the men and the women (11.5% vs 9.2%, respectively; P = no significant). Regarding treatment, the women received antiplatelet agents and diuretics less frequently, but there were no other differences in the use of antihypertensive and antithrombotic therapies. In the multivariate analysis, AF in the total study population was associated with age, alcohol consumption, the presence of heart disease, and decreased glomerular filtration. In the women, AF was associated with all of the factors included in the overall analysis, as well as the presence of left ventricle hypertrophy. In contrast, in the men, the only risk factors associated with AF were age, the presence of heart disease and alcohol consumption.

CONCLUSION: In patients with hypertension over 65 years of age, there are relevant gender differences in the factors associated with AF.

Features and costs of patients admitted for cardiac arrhythmias in Spain

AIM

Cardiac rhythm alterations are a frequent cause of hospital admission. However, we do not know their characteristics and economic costs. We have analyzed the epidemiology and cost of hospitalizations due to cardiac arrhythmias in the National Health System.

METHODS

The characteristics and costs were reviewed in patients admitted with a principal diagnosis of cardiac arrhythmia (1997-2010;diagnosis related groups [DRG] -138 and 139 of the National Health System minimum data base set). Atrial fibrillation/flutter accounted for 65% of these DRGs. The secondary diagnoses prevalent in such DRGs were also reviewed.

RESULTS

Hospitalizations due to cardiac arrhythmias were approximately 26.000 per year and close to 1.6% for mortality. In 2010 there were 26.421 hospitalizations with an estimated cost of 65 million Euros. Frequent comorbidities were recorded, such as hypertension (43%), heart failure (12%) or diabetes mellitus (20%). A total of 43% were admitted to cardiology and 36% to internal medicine.

CONCLUSIONS

During the period 1997-2010, there was a significant annual number of hospitalizations for cardiac arrhythmias (mainly atrial fibrillation), with measurable costs, in Spain. More than one third were attended by internists.

Prevalence of atrial fibrillation and use of antithrombotics in hypertensive patients aged >or=65 years. The FAPRES trial

INTRODUCTION AND OBJECTIVES

Age and arterial hypertension are two of the main factors associated with atrial fibrillation and an increased risk of embolism. The objective of this study was to determine the prevalence of atrial fibrillation and the extent of antithrombotic use in hypertensive patients aged >or=65 years in the Spanish region of Valencia.

METHODS

Each study investigator enrolled the first three hypertensive patients aged >or=65 years who came for a consultation on the first day of each week for 5 weeks. Each patient's risk factors, history of cardiovascular disease, CHADS2 score and medical treatment were noted and an ECG was recorded. Data were analyzed centrally. A patient was regarded as having atrial fibrillation if it was observable on the ECG or reported in medical records.

RESULTS

The study included 1,028 hypertensive patients with a mean age of 72.8 years. Overall, 10.3% had atrial fibrillation: in 6.7%, it was observable on the ECG while 3.6% were in sinus rhythm but had a history of the condition. Factors associated with atrial fibrillation were age, alcohol intake, structural heart disease and glomerular filtration rate. In total, 76.2% of patients with ECG evidence of atrial fibrillation and a CHADS2 score >1 were taking anticoagulants compared with 41.7% of those who had a history of the condition but were currently in sinus rhythm.

CONCLUSIONS

The prevalence of atrial fibrillation in our group of hypertensives was 10.3%; in 1.7%, it was previously undiagnosed. Antithrombotic use was high in patients with current atrial fibrillation, but lower in those who had experienced an episode previously.

Prevalence of atrial fibrillation and use of antithrombotics in hypertensive patients aged >or=65 years. The FAPRES trial

INTRODUCTION AND OBJECTIVES

Age and arterial hypertension are two of the main factors associated with atrial fibrillation and an increased risk of embolism. The objective of this study was to determine the prevalence of atrial fibrillation and the extent of antithrombotic use in hypertensive patients aged >or=65 years in the Spanish region of Valencia.

METHODS

Each study investigator enrolled the first three hypertensive patients aged >or=65 years who came for a consultation on the first day of each week for 5 weeks. Each patient's risk factors, history of cardiovascular disease, CHADS2 score and medical treatment were noted and an ECG was recorded. Data were analyzed centrally. A patient was regarded as having atrial fibrillation if it was observable on the ECG or reported in medical records.

RESULTS

The study included 1,028 hypertensive patients with a mean age of 72.8 years. Overall, 10.3% had atrial fibrillation: in 6.7%, it was observable on the ECG while 3.6% were in sinus rhythm but had a history of the condition. Factors associated with atrial fibrillation were age, alcohol intake, structural heart disease and glomerular filtration rate. In total, 76.2% of patients with ECG evidence of atrial fibrillation and a CHADS2 score >1 were taking anticoagulants compared with 41.7% of those who had a history of the condition but were currently in sinus rhythm.

CONCLUSIONS

The prevalence of atrial fibrillation in our group of hypertensives was 10.3%; in 1.7%, it was previously undiagnosed. Antithrombotic use was high in patients with current atrial fibrillation, but lower in those who had experienced an episode previously.