Estimating the prevalence of atrial fibrillation in a general population using validated electronic health data

The budget impact of implementing atrial fibrillation-screening in European countries

A budget impact analysis estimates the short-term difference between the cost of the current treatment strategy and a new treatment strategy, in this case to implement population screening for atrial fibrillation (AF). The aim of this study is to estimate the financial impact of implementing population-based AF-screening of 75-year-olds compared with the current setting of no screening from a healthcare payer perspective in eight European countries. The net budget impact of AF-screening was estimated in country-specific settings for Denmark, Germany, Ireland, Italy, Netherlands, Serbia, Spain, and Sweden. Country-specific parameters were used to allow for variations in healthcare systems and to reflect the healthcare sector in the country of interest. Similar results can be seen in all countries AF-screening incurs savings of stroke-related costs since AF treatment reduces the number of strokes. However, the increased number of detected AF and higher drug acquisition will increase the drug costs as well as the costs of physician- and control visits. The net budget impact per invited varied from €10 in Ireland to €122 in the Netherlands. The results showed the increased costs of implementing AF-screening were mainly driven by increased drug costs and screening costs. In conclusion, across Europe, though the initial cost of screening and more frequent use of oral anti-coagulants will increase the healthcare payers' costs, introducing population screening for AF will result in savings of stroke-related costs.

Temporal trends in lifetime risks of atrial fibrillation and its complications between 2000 and 2022: Danish, nationwide, population based cohort study

OBJECTIVES

To examine how the lifetime risks of atrial fibrillation and of complications after atrial fibrillation changed over time.

DESIGN

Danish, nationwide, population based cohort study.

SETTING

Population of Denmark from 1 January 2000 to 31 December 2022.

PARTICIPANTS

3.5 million individuals (51.7% women and 48.3% men) who did not have atrial fibrillation at 45 years of age or older were followed up until incident atrial fibrillation, migration, death, or end of follow-up, whichever came first. All 362 721 individuals with incident atrial fibrillation (46.4% women and 53.6% men), but with no prevalent complication, were further followed up until incident heart failure, stroke, or myocardial infarction.

MAIN OUTCOME MEASURES

Lifetime risk of atrial fibrillation and lifetime risks of complications after atrial fibrillation over two prespecified periods (2000-10 v 2011-22).

RESULTS

The lifetime risk of atrial fibrillation increased from 24.2% in 2000-10 to 30.9% in 2011-22 (difference 6.7% (95% confidence interval 6.5% to 6.8%)). After atrial fibrillation, the most frequent complication was heart failure with a lifetime risk of 42.9% in 2000-10 and 42.1% in 2011-22 (-0.8% (-3.8% to 2.2%)). Individuals with atrial fibrillation lost 14.4 years with no heart failure. The lifetime risks of stroke and of myocardial infarction after atrial fibrillation decreased slightly between the two periods, from 22.4% to 19.9% for stroke (-2.5% (-4.2% to -0.7%)) and from 13.7% to 9.8% for myocardial infarction (-3.9% (-5.3% to -2.4%). No evidence was reported of a differential decrease between men and women.

CONCLUSION

Lifetime risk of atrial fibrillation increased over two decades of follow-up. In individuals with atrial fibrillation, about two in five developed heart failure and one in five had a stroke over their remaining lifetime after atrial fibrillation diagnosis, with no or only small improvement over time. Stroke risks and heart failure prevention strategies are needed for people with atrial fibrillation.

Does a nurse-led interventional program improve clinical outcomes in patients with atrial fibrillation? A meta-analysis

BACKGROUND

Being the most common type of arrhythmia, atrial fibrillation (AF) is progressively increasing with an annual rate of 5 million new cases. Recent guidelines highlight the importance of using collaborative multidisciplinary teams in order to improve outcomes during management of patients with AF. A nurse-led program including a nurse-directed education, counselling and intervention has shown to improve patients' outcomes in candidates with AF. In this analysis, we aimed to systematically compare the clinical outcomes observed in patients with AF who were assigned to a nurse-led interventional program versus a usual care group.

METHODS

EMBASE, MEDLINE, Http://www.

CLINICALTRIALS

gov , Web of Science; Google Scholar and Cochrane databases were the data sources. The clinical outcomes were considered as the endpoints in this study. This is a meta-analysis, and the statistical analysis was conducted by the RevMan software (version 5.4). Risk ratios (RR) with 95% confidence intervals (CI) were used to represent the data after statistical analysis.

RESULTS

Six studies with a total number 2916 participants were included whereby 1434 participants were assigned to a nurse-led intervention and 1482 participants were assigned to the usual care group. Our results showed that participants with AF who were assigned to the nurse-led interventional group had a significantly lower risk of composite endpoints (RR: 0.82, 95% CI: 0.70-0.96; P = 0.01), heart failure (RR: 0.66, 95% CI: 0.47-0.92; P = 0.02), atrial fibrillation (RR: 0.77, 95% CI: 0.63-0.94; P = 0.01) and re-admission (RR: 0.78, 95% CI: 0.62-0.99; P = 0.04). However, the risks of all-cause mortality (RR: 0.86, 95% CI: 0.68-1.09; P = 0.21), cardiac death (RR: 0.67, 95% CI: 0.33-1.39; P = 0.28), myocardial infarction (RR: 0.70, 95% CI: 0.35-1.42; P = 0.33), stroke (RR: 0.75, 95% CI: 0.44-1.26; P = 0.28), all bleeding events (RR: 1.11, 95% CI: 0.81-1.53; P = 0.51) and major bleeding events (RR: 0.91, 95% CI: 0.56-1.49; P = 0.71) were not significantly different.

CONCLUSIONS

The nurse-led interventional program significantly improved composite endpoints including heart failure and the recurrence of AF, resulting in a significantly lower admission rate compared to the usual care group. However, nurse-led interventional program did not affect mortality, stroke, myocardial infarction and bleeding events. Based on our current results, a nurse-led interventional programs apparently could be beneficial in patients with AF. Future larger trials would be able to confirm this hypothesis.

Prevalence of atrial fibrillation and reasons for undertreatment with oral anticoagulants

OBJECTIVES

To investigate the prevalence of atrial fibrillation (AF), the proportion of AF patients not receiving oral anticoagulation (OAC) and reasons for abstaining from OAC treatment.

METHODS

A retrospective cross-sectional study of patients aged 18 years or older with an AF diagnosis on June 1st 2020 in Västernorrland County, Sweden. AF diagnosis was retrieved using the ICD10 code I.48, and medical records were reviewed for comorbidities and documented reasons to abstain OAC treatment.

RESULTS

Of 197 274 residents in Västernorrland County, 4.7% (9 304/197 274) had a documented AF diagnosis. Of these, 19% (1 768/9 304) had no OAC treatment, including 4.2% (393/9 304) with no indication, 2.5% (233/9 304) with a questionable and 2.5% (231/9 304) with a documented clear contraindication for OAC. In total 9.8% (911/9 304) were not treated with OAC despite indication and no reasonable documented contraindication, thus 90.8% (8 447/9 304) of all AF-patients were eligible for OAC treatment. Common reasons for abstaining treatment without reasonable contraindication were present sinus rhythm in 13.7% (125/911), perceived not an OAC candidate in 10.6% (97/911) and anemia in the past in 4.3% (39/911).

CONCLUSIONS

In the population of Västernorrland County, a very high AF prevalence of 4.7% was found, of which just over 90% would theoretically benefit from OAC treatment. This is higher than previously reported and stresses the importance of stroke prevention in this large patient group.

Incidence of clinical atrial fibrillation and related complications using a screening algorithm at a nationwide level

AIMS

In a recent position paper, the European Heart Rhythm Association (EHRA) proposed an algorithm for the screening and management of arrhythmias using digital devices. In patients with prior stroke, a systematic screening approach for atrial fibrillation (AF) should always be implemented, preferably immediately after the event. Patients with increasing age and with specific cardiovascular or non-cardiovascular comorbidities are also deemed to be at higher risk. From a large nationwide database, the aim was to analyse AF incidence rates derived from this new EHRA algorithm.

METHODS AND RESULTS

Using the French administrative hospital discharge database, all patients hospitalized in 2012 without a history of AF, and with at least a 5-year follow-up (FU) (or if they died earlier), were included. The yearly incidence of AF was calculated in each subgroup defined by the algorithm proposed by EHRA based on a history of previous stroke, increasing age, and eight comorbidities identified via International Classification of Diseases 10th Revision codes. Out of the 4526 104 patients included (mean age 58.9 ± 18.9 years, 64.5% women), 1% had a history of stroke. Among those with no history of stroke, 18% were aged 65-74 years and 21% were ≥75 years. During FU, 327 012 patients had an incidence of AF (yearly incidence 1.86% in the overall population). Implementation of the EHRA algorithm divided the population into six risk groups: patients with a history of stroke (group 1); patients > 75 years (group 2); patients aged 65-74 years with or without comorbidity (groups 3a and 3b); and patients < 65 years with or without comorbidity (groups 4a and 4b). The yearly incidences of AF were 4.58% per year (group 2), 6.21% per year (group 2), 3.50% per year (group 3a), 2.01% per year (group 3b), 1.23% per year (group 4a), and 0.35% per year (group 4b). In patients aged < 65 years, the annual incidence of AF increased progressively according to the number of comorbidities from 0.35% (no comorbidities) to 9.08% (eight comorbidities). For those aged 65-75 years, the same trend was observed, i.e. increasing from 2.01% (no comorbidities) to 11.47% (eight comorbidities).

CONCLUSION

These findings at a nationwide scale confirm the relevance of the subgroups in the EHRA algorithm for identifying a higher risk of AF incidence, showing that older patients (>75 years, regardless of comorbidities) have a higher incidence of AF than those with prior ischaemic stroke. Further studies are needed to evaluate the usefulness of algorithm-based risk stratification strategies for AF screening and the impact of screening on major cardiovascular event rates.

Leadless or Conventional Transvenous Ventricular Permanent Pacemakers: A Nationwide Matched Control Study

Background

Leadless ventricular permanent pacemakers (leadless VVI or LPM) were designed to reduce lead‐related complications of conventional VVI pacemakers (CPM). The aim of our study was to assess and compare real‐life clinical outcomes within the first 30 days and during a midterm follow‐up with the 2 techniques.

Methods and Results

This French longitudinal cohort study was based on the national hospitalization database. All adults (age ≥18 years) hospitalized in French hospitals from January 1, 2017 to September 1, 2020, who underwent a first LPM or CPM were included. The study included 40 828 patients with CPM and 1487 with LPM. After propensity score matching 1344 patients with CPM were matched 1:1 with patients treated with LPM. Patients with LPM had a lower rate of all‐cause and cardiovascular death within the 30 days after implantation. During subsequent follow‐up (mean: 8.6±10.5 months), risk of all‐cause death in the unmatched population was significantly higher in the LPM group than in the CPM group, whereas risk of cardiovascular death and of endocarditis was not significantly different. After matching on all baseline characteristics including comorbidities (mean follow‐up 6.2±8.7 months), all‐cause death, cardiovascular death, and infective endocarditis were not statistically different in the 2 groups.

Conclusions

Patients treated with leadless VVI pacemakers had better clinical outcomes in the first month compared with the patients treated with conventional VVI pacing. During a midterm follow‐up, risk of all‐cause death, cardiovascular death, and endocarditis in patients treated with leadless VVI pacemaker was not statistically different after propensity score matching.

Identification of undiagnosed atrial fibrillation using a machine learning risk prediction algorithm and diagnostic testing (PULsE-AI) in primary care: cost-effectiveness of a screening strategy evaluated in a randomized controlled trial in England

OBJECTIVE

The PULsE-AI trial sought to determine the effectiveness of a screening strategy that included a machine learning risk prediction algorithm in conjunction with diagnostic testing for identification of undiagnosed atrial fibrillation (AF) in primary care. This study aimed to evaluate the cost-effectiveness of implementing the screening strategy in a real-world setting.

METHODS

Data from the PULsE-AI trial - a prospective, randomized, controlled trial conducted across six general practices in England from June 2019 to February 2021 - were used to inform a cost-effectiveness analysis that included a hybrid screening decision tree and Markov AF disease progression model. Model outcomes were reported at both individual- and population-level (estimated UK population ≥30 years of age at high-risk of undiagnosed AF) and included number of patients screened, number of AF cases identified, mean total and incremental costs (screening, events, treatment), quality-adjusted-life-years (QALYs), and incremental cost-effectiveness ratio (ICER).

RESULTS

The screening strategy was estimated to result in 45,493 new diagnoses of AF across the high-risk population in the UK (3.3 million), and an estimated additional 14,004 lifetime diagnoses compared with routine care only. Per-patient costs for high-risk individuals who underwent the screening strategy were estimated at £1,985 (vs £1,888 for individuals receiving routine care only). At a population-level, the screening strategy was associated with a cost increase of approximately £322 million and an increase of 81,000 QALYs. The screening strategy demonstrated cost-effectiveness versus routine care only at an accepted ICER threshold of £20,000 per QALY-gained, with an ICER of £3,994/QALY.

CONCLUSIONS

Compared with routine care only, it is cost-effective to target individuals at high risk of undiagnosed AF, through an AF risk prediction algorithm, who should then undergo diagnostic testing. This AF risk prediction algorithm can reduce the number of patients needed to be screened to identify undiagnosed AF, thus alleviating primary care burden.

Patients' and clinicians' perceptions of oral anticoagulants in atrial fibrillation: a systematic narrative review and meta-analysis

Background

Atrial fibrillation (AF) increases the risk of developing a stroke by 20%. AF related strokes are associated with greater morbidity. Historically, warfarin was the anticoagulant of choice for stroke prevention in patients with AF but lately patients are being switched or started on direct oral anticoagulants (DOACs). DOACs are promoted as safer alternatives to warfarin and it is expected that they will be associated with fewer challenges both for patients and healthcare professionals. This systematic narrative review aimed to explore perspectives of patients and professionals on medicines optimisation of oral anticoagulation with vitamin K antagonists and DOACs in atrial fibrillation.

Methods

Prospero registration CRD42018091591. Systematic searches undertaken of research studies (qualitative and quantitative), published February 2018 to November 2020 from several databases (Web of Science, Scopus, Medline Via Ovid, CINHAL via Ebsco, and PubMED via NCBI) following PRISMA methodology. Data were organised using Covidence software. Two reviewers independently assessed the quality of the included studies and synthesized the findings (thematic analysis approach).

Results

Thirty-four studies were included. Studies were critically appraised using established critical appraisal tools (Qualsyst) and a risk of bias was assigned. Clinicians considered old age and the associated complexities such as co-morbidities and the increased potential for bleeding as potential barriers to optimising anticoagulation. Whereas patients’ health and medication beliefs influenced adherence. Notably, structured patient support was important in enhancing safety and effective anticoagulation. For both patients and clinicians, confidence and experience of safe anticoagulation was influenced by the presence of co-morbidities,  poor knowledge and understanding of AF and the purpose of anticoagulation.

Conclusion

Age, complex multimorbidity and polypharmacy influence prescribing, with DOACs being perceived to be safer than warfarin. This systematic narrative review suggests that interventions are needed to support patient self-management. There are residual anxieties associated with long term anticoagulation in the context of complexities.

Trial registration

Not applicable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01590-x.

Age-specific atrial fibrillation incidence, attributable risk factors and risk of stroke and mortality: results from the MORGAM Consortium

Background

The main aim was to examine age-specific risk factor associations with incident atrial fibrillation (AF) and their attributable fraction in a large European cohort. Additionally, we aimed to examine risk of stroke and mortality in relation to new-onset AF across age.

Methods

We used individual-level data (n=66 951, 49.1% men, age range 40–98 years at baseline) from five European cohorts of the MOnica Risk, Genetics, Archiving and Monograph Consortium. The participants were followed for incident AF for up to 10 years and the association with modifiable risk factors from the baseline examinations (body mass index (BMI), hypertension, diabetes, daily smoking, alcohol consumption and history of stroke and myocardial infarction (MI)) was examined. Additionally, the participants were followed up for incident stroke and all-cause mortality after new-onset AF.

Results

AF incidence increased from 0.9 per 1000 person-years at baseline age 40–49 years, to 17.7 at baseline age ≥70 years. Multivariable-adjusted Cox models showed that higher BMI, hypertension, high alcohol consumption and a history of stroke or MI were associated with increased risk of AF across age groups (p<0.05). Between 30% and 40% of the AF risk could be attributed to BMI, hypertension and a history of stroke or MI. New-onset AF was associated with a twofold increase in risk of stroke and death at ages≥70 years (p≤0.001).

Conclusion

In this large European cohort aged 40 years and above, risk of AF was largely attributed to BMI, high alcohol consumption and a history MI or stroke from middle age. Thus, preventive measures for AF should target risk factors such as obesity and hypertension from early age and continue throughout life.

Use of a Clinical Electrocardiographic Database to Enhance Atrial Fibrillation/Atrial Flutter Identification Algorithms Based on Administrative Data

Background

Administrative data have limited sensitivity for case finding of atrial fibrillation/atrial flutter (AF/AFL). Linkage with clinical repositories of interpreted ECGs may enhance diagnostic yield of AF/AFL.

Methods and Results

We retrieved 369 ECGs from the institutional Marquette Universal System for Electrocardiography (MUSE) repository as validation samples, with rhythm coded as AF (n=49), AFL (n=50), or other competing rhythm diagnoses (n=270). With blinded, duplicate review of ECGs as the reference comparison, we compared multiple MUSE coding definitions for identifying AF/AFL. We tested the agreement between MUSE diagnosis and reference comparison, and calculated the sensitivity and specificity. Using a data set linking clinical registries, administrative data, and the MUSE repository (n=11 662), we assessed the incremental diagnostic yield of AF/AFL by incorporating ECG data to administrative data‐based algorithms. The agreement between MUSE diagnosis and reference comparison depended on the coding definitions applied, with the Cohen κ ranging from 0.57 to 0.75. Sensitivity ranged from 60.6% to 79.1%, and specificity ranged from 93.2% to 98.0%. A coding definition with AF/AFL appearing in the first 3 ECG statements had the highest sensitivity (79.1%), with little loss of specificity (94.5%). Compared with the algorithms with only administrative data, incorporating ECG data increased the diagnostic yield of preexisting AF/AFL by 14.5% and incident AF/AFL by 7.5% to 16.1%.

Conclusions

Routine ECG interpretation using MUSE coding is highly specific and moderately sensitive for AF/AFL detection. Inclusion of MUSE ECG data in AF/AFL case identification algorithms can identify cases missed using administrative data‐based algorithms alone.

Hospital admissions for stroke and bleeding in Hounslow following a quality improvement initiative

OBJECTIVE

Atrial fibrillation (AF) is the most common arrhythmia. Undiagnosed and poorly managed AF increases risk of stroke. The Hounslow AF quality improvement (QI) initiative was associated with improved quality of care for patients with AF through increased detection of AF and appropriate anticoagulation. This study aimed to evaluate whether there has been a change in stroke and bleeding rates in the Hounslow population following the QI initiative.

METHODS

Using hospital admissions data from January 2011 to August 2018, interrupted time series analysis was performed to investigate the changes in standardised rates of admission with stroke and bleeding, following the start of the QI initiative in October 2014.

RESULTS

There was a 17% decrease in the rate of admission with stroke as primary diagnosis (incidence rate ratio (IRR) 0.83; 95% CI 0.712 to 0.963; p<0.014). There was an even larger yet not statistically significant decrease in admission with stroke as primary diagnosis and AF as secondary diagnosis (IRR 0.75; 95% CI 0.550 to 1.025; p<0.071). No significant changes were observed in bleeding admissions. For each outcome, an additional regression model including both the level change and an interaction term for slope change was created. In all cases, the slope change was small and not statistically significant.

CONCLUSION

Reduction in stroke admissions may be associated with the AF QI initiative. However, the immediate level change and non-significant slope change suggests a lack of effect of the intervention over time and that the decrease observed may be attributable to other events.

Atrial fibrillation prevalence, awareness and management in a nationwide survey of adults in China

OBJECTIVE

To determine AF prevalence and gaps in atrial fibrillation (AF) awareness and management in China.

METHODS

We conducted a community-based survey of 47 841 adults (age ≥45 years) in seven geographic regions of China between 2014 and 2016. Participants underwent a structured questionnaire, a standard 12-lead ECG, physical examination and blood sampling. AF prevalence, defined by either ECG detection or self-report, was estimated according to sampling weights, non-response and age and sex distribution of the population. We used multivariable logistic regression to estimate associations among sociodemographic, clinical and geographic factors with the AF prevalence, awareness and treatment.

RESULTS

The weighted AF prevalence was 1.8% (95% CI 1.7% to 1.9%), but varied from 0.9% to 2.4% across geographical regions and equates to being present in an estimated 7.9 (95% CI 7.4 to 8.4) million people in China. Among men and women, the AF prevalence increased from 0.8% and 0.6% in the age group 45-54 years to 5.4% and 4.9% in the age group ≥75 years, respectively. Proportions of people who were aware of having AF decreased overall from 65.3% in 45-54 year-olds to 53.9% in ≥75 year-olds and varied between sex (men 58.5%, women 68.8%) and residency status (urban 78.3%, rural 35.3%). Only 6.0% of patients with high-risk AF received anticoagulation therapy.

CONCLUSIONS

AF prevalence is higher than previously reported in China, with low awareness and large treatment gaps. Large-scale efforts are urgently needed to reduce AF adverse consequences.

Weight, height, weight change, and risk of incident atrial fibrillation in middle-aged men and women

BACKGROUND

Anthropometric factors are reported to be risk factors for atrial fibrillation (AF), but it is unclear whether weight change in mid-life is associated with AF. We aimed to study the possible associations of weight, height, and weight change with the risk of incident AF in men and women.

METHODS

Our study cohort included 108 417 persons (51% women) who participated in a population-based health examination in northern Sweden at 30, 40, 50, or 60 years of age. The health examination included weight and height measurement and collection of data regarding cardiovascular risk factors. Within this cohort, 40 275 participants underwent two health examinations with a 10-year interval. We identified cases with a first-ever diagnosis of AF through the Swedish National Patient Registry.

RESULTS

During a total follow-up of 1 469 820 person-years, 5154 participants developed incident AF. The mean age at inclusion was 46.3 years, and mean age at AF diagnosis was 66.6 years. After adjustment for potential confounders, height, weight, body mass index (BMI), and body surface area (BSA) were positively associated with risk of incident AF in both men and women. Among participants who underwent two health examinations 10 years apart, 1142 persons developed AF. The mean weight change from baseline was a gain of 4.8%. Weight gain or weight loss was not significantly associated with risk of incident AF.

CONCLUSIONS

Height, weight, BMI, and BSA showed positive associations with risk of incident AF in both men and women. Midlife weight change was not significantly associated with AF risk.

Prevalence and incidence rates of atrial fibrillation in Norway 2004-2014

Objective

To study time trends in incidence of atrial fibrillation (AF) in the entire Norwegian population from 2004 to 2014, by age and sex, and to estimate the prevalence of AF at the end of the study period.

Methods

A national cohort of patients with AF (≥18 years) was identified from inpatient admissions with AF and deaths with AF as underlying cause (1994–2014), and AF outpatient visits (2008–2014) in the Cardiovascular Disease in Norway (CVDNOR) project. AF admissions or out-of-hospital death from AF, with no AF admission the previous 10 years defined incident AF. Age-standardised incidence rates (IR) and incidence rate ratios (IRR) were calculated. All AF cases identified through inpatient admissions and outpatient visits and alive as of 31 December 2014 defined AF prevalence.

Results

We identified 175 979 incident AF cases (30% primary diagnosis, 69% secondary diagnosis, 0.6% out-of-hospital deaths). AF IRs (95% confidence intervals) per 100 000 person years were stable from 2004 (433 (426–440)) to 2014 (440 (433–447)). IRs were stable or declining across strata of sex and age with the exception of an average yearly increase of 2.4% in 18–44 year-olds: IRR 1.024 (1.014–1.034). In 2014, the prevalence of AF in the adult population was 3.4%.

Conclusions

We found overall stable IRs of AF for the adult Norwegian population from 2004 to 2014. The prevalence of AF was 3.4% at the end of 2014, which is higher than reported in previous studies. Signs of an increasing incidence of early-onset AF (<45 years) are worrying and need further investigation.

Outcome of Cardiac Monitor During Sleep Study for Screening of Subclinical Atrial Fibrillation

Background

There is growing evidence of a strong association between obstructive sleep apnea (OSA) and cardiovascular co-morbidities including atrial fibrillation (AF). We wanted to assess the usefulness of the overnight cardiac monitoring to screen for AF during the sleep study in patients newly diagnosed with OSA, in order to establish the usefulness of overnight active screening for subclinical AF during the sleep study in these patients.

Methods

A retrospective study in patients with new diagnosis of OSA carried out between January 2014 and December 2019 in the sleep clinic at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. All patients newly diagnosed with OSA (apnea-hypopnea index >5) were selected to undergo a clinical questionnaire regarding symptoms, co-morbidities and risk factors. Subjects with history of cardiac arrhythmias or having anti-arrhythmic treatment were excluded. Eligible patients underwent an overnight rhythm monitoring to screen for AF or any rhythm disturbance.

Results

We included 250 respective patients with OSA, 54% were males and 82% aged more than 35 years. The majority of patients were married (83%), of Saudi nationality (81%), and 90% were overweight or obese, apnea hypopnea index (AHI) was mild (5-14) in 30%, moderate (15-29) in 38% and severe (30 or more) in 32% of the patients. No cardiac arrhythmia was detected in all the study population, while only two patients complained of palpitations and was due to sinus tachycardia. Assessment of other risk factors showed 26% cases of diabetes mellitus, 39% of hypertension, 1% of renal failure, 9% of ischemic heart disease, 17% of thyroid dysfunction, 6% of stroke and 4% of dyslipidemia.

Conclusion

The findings of this study show null incidence of cardiac arrhythmia during the apnea-hypopnea episodes in a cohort of patients with confirmed OSA. However, in view of the frequently reported association, the screening for subclinical atrial fibrillation needs long-term rhythm surveillance and should be targeted to symptomatic patients.

Incident Comorbidities, Aging and the Risk of Stroke in 608,108 Patients with Atrial Fibrillation: A Nationwide Analysis

Background: We hypothesized that the change in stroke risk profile between baseline and follow-up may be a better predictor of ischemic stroke than the baseline stroke risk determination using the CHA₂DS₂-VASc score ((congestive heart failure, hypertension, age ≥75 years (doubled), diabetes, stroke/transient ischemic attack/thromboembolism (doubled), vascular disease (prior myocardial infarction, peripheral artery disease, or aortic plaque), age 65–75 years, sex category (female))). Methods: We collected information for all patients treated with atrial fibrillation (AF) in French hospitals between 2010 and 2019. We studied 608,108 patients with AF who did not have risk factors of the CHA₂DS₂-VASc score (except for age and sex). The predictive accuracies of baseline and follow-up CHA₂DS₂-VASc scores, as well as the ‘Delta CHA₂DS₂-VASc’ (i.e., change/difference between the baseline and follow-up CHA₂DS₂-VASc scores) for prediction of ischemic stroke were studied. Results: The mean CHA₂DS₂-VASc score at baseline was 1.7, and increased to 2.4 during follow-up of 2.2 ± 2.4 years, (median (interquartile range: IQR) 1.2 (0.1–3.8) years), resulting in a mean Delta CHA₂DS₂-VASc score of 0.7. Among 20,082 patients suffering ischemic stroke during follow-up, 67.1% had a Delta CHA₂DS₂-VASc score ≥1 while they were only 40.4% in patients without ischemic stroke. The follow-up CHA₂DS₂-VASc score and Delta CHA₂DS₂-VASc score were predictors of ischemic stroke (C-index 0.670, 95% confidence interval (CI) 0.666–0.673 and 0.637, 95%CI 0.633–0.640) and they performed better than baseline CHA₂DS₂-VASc score (C-index 0.612, 95%CI 0.608–0.615, p < 0.0001). Conclusions: Stroke risk was non-static, and many AF patients had ≥1 new stroke risk factor(s) before ischemic stroke occurred. The follow-up CHA₂DS₂-VASc score and its change (i.e., ‘Delta CHA₂DS₂-VASc’) were better predictors of ischemic stroke than relying on the baseline CHA₂DS₂-VASc score.

Validation of an algorithm based on administrative data to detect new onset of atrial fibrillation after cardiac surgery

Introduction

Postoperative atrial fibrillation (POAF) is a frequent complication of cardiac surgery associated with important morbidity, mortality, and costs. To assess the effectiveness of preventive interventions, an important prerequisite is to have access to accurate measures of POAF incidence. The aim of this study was to develop and validate such a measure.

Methods

A validation study was conducted at two large Canadian university health centers. First, a random sample of 976 (10.4%) patients who had cardiac surgery at these sites between 2010 and 2016 was generated. Then, a reference standard assessment of their medical records was performed to determine their true POAF status on discharge (positive/negative). The accuracy of various algorithms combining diagnostic and procedure codes from: 1) the current hospitalization, and 2) hospitalizations up to 6 years before the current hospitalization was assessed in comparison with the reference standard. Overall and site-specific estimates of sensitivity, specificity, positive (PPV), and negative (NPV) predictive values were generated, along with their 95%CIs.

Results

Upon manual review, 324 (33.2%) patients were POAF-positive. Our best-performing algorithm combining data from both sites used a look-back window of 6 years to exclude patients previously known for AF. This algorithm achieved 70.4% sensitivity (95%CI: 65.1–75.3), 86.0% specificity (95%CI: 83.1–88.6), 71.5% PPV (95%CI: 66.2–76.4), and 85.4% NPV (95%CI: 82.5–88.0). However, significant site-specific differences in sensitivity and NPV were observed.

Conclusion

An algorithm based on administrative data can identify POAF patients with moderate accuracy. However, site-specific variations in coding practices have significant impact on accuracy.

New-Onset Atrial Fibrillation Among Patients With Infection in the Emergency Department: A Multicenter Cohort Study of 1-Year Stroke Risk

BACKGROUND

Patients with new-onset atrial fibrillation in relation to infection are frequent in emergency departments (EDs) and may require antithrombotic therapy because of the increased risk of stroke. Our objective was to describe the 1-year risk of stroke in patients in the ED with infection, new-onset atrial fibrillation, and no antithrombotic therapy.

METHODS

This was a population-based cohort study at 4 EDs in Denmark and Sweden. Atrial fibrillation was identified by electrocardiogram (ECG) upon arrival at the ED, and infection was identified by discharge diagnosis. Patient history was followed for 12 months or until initiation of oral anticoagulant therapy, ischemic stroke, or death. Primary outcome was stroke within 12 months compared to patients with infection and no atrial fibrillation.

RESULTS

In the analysis, 15,505 patients were included; 48.7% were male and the median age was 71 (IQR, 56-83). Among the included patients, 2107 (13.6%) had atrial fibrillation of any kind and 822 (39.0%) of these had new-onset atrial fibrillation with a median CHA₂DS₂-VASc score of 3 (IQR 2-4). New-onset atrial fibrillation during infection showed an absolute postdischarge 1-year risk of stroke of 2.7% (95% CI 1.6-4.2), corresponding to a crude hazard ratio (HR) of 1.4 (95% CI 0.9-2.3), a sex and age adjusted HR of 1.0 (95% CI 0.6-1.6), and a CHA₂DS₂-VASc adjusted HR of 1.1 (95% CI, 0.7-1.8) compared to patients with infection but no atrial fibrillation.

CONCLUSIONS

Patients in the ED with infection and new-onset atrial fibrillation without current oral anticoagulant therapy had a 2.7% absolute 1-year risk of stroke. Stroke events were mainly related to sex and age and risk factors identified by the CHA₂DS₂-VASc score.

Sensitivity, specificity, positive and negative predictive values of identifying atrial fibrillation using administrative data: a systematic review and meta-analysis

Introduction

Atrial fibrillation (AF) is the commonest arrhythmia and a major cause of stroke and health care utilization. Researchers and administrators use electronic health data to assess disease burden, quality and variance in care, value of interventions and prognosis. We performed a systematic review and meta-analysis to assess the validity of AF case definitions in administrative databases.

Methods

Medline was searched from 2000 to 2018. Extracted information included sensitivity, specificity, positive and negative predictive values (PPV and NPV) for various AF case definitions. Estimates were pooled using random-effects models due to significant heterogeneity between studies.

Results

We identified 24 studies, including 21 from North America or Scandinavia. Hospital, ambulatory and mixed data sources were assessed in 10, 4 and 10 studies, respectively. Nine different AF case definitions were evaluated, most based on ICD-9 or 10 codes. Twenty-two studies assessed case definitions in patients diagnosed with AF and thus could generate PPV alone. Half the studies sampled unrestricted populations including a mix of those with and without AF to assess sensitivity. Only 13 studies included ECG confirmation as a gold standard. The pooled random effects estimates were: sensitivity 80% (95% CI 72-86%); specificity 98% (96-99%); PPV 88% (82-94%); NPV 97% (94-99%). Only 3 studies reported all accuracy parameters and included rhythm monitoring in the gold standard definition.

Conclusion

Relatively few studies examined sensitivity, and fewer still included rhythm monitoring in the gold standard comparison. Administrative data may fail to identify a significant proportion of patients with AF. This, in turn, may bias estimates of quality of care and prognosis.

Prevalence and Incidence of Atrial Fibrillation and Other Arrhythmias in the General Older Population: Findings From the Swedish National Study on Aging and Care

Aim: To study the prevalence and cumulative incidence of arrhythmias in the general population of adults aged 60 and older over a 6-year period. Study Design and Setting: Data were taken from the Swedish National Study on Aging and Care (SNAC), a national, longitudinal, multidisciplinary study of the general elderly population (defined as 60 years of age or older). A 12-lead resting electrocardiography (ECG) was performed at baseline and 6-year follow-up. Results: The baseline prevalence of atrial fibrillation (AF) was 4.9% (95% confidence interval [CI] = [4.5%, 5.5%]), and other arrhythmias including ventricular premature complexes (VPCs), supraventricular tachycardia (SVT), and supraventricular extrasystole (SVES) were seen in 8.4% (7.7%, 9.0%) of the population. A first- or second-degree atrioventricular (AV) block was found in 7.1% of the population (95% CI = [6.5%, 7.7%]), and there were no significant differences between men and women in baseline arrhythmia prevalence. The 6-year cumulative incidence of AF was 4.1% (95% CI = [3.5%, 4.9%]), or 6.9/1,000 person-years (py; 95% CI = [5.7, 8.0]). The incidence of AF, other arrhythmias, AV block, and pacemaker-induced rhythm was significantly higher in men in all cohorts except for the oldest. Conclusion: Our data highlight the prevalence and incidence of arrhythmias, which rapidly increase with advancing age in the general population.

Positive predictive value and misclassification of diagnosis of pulmonary embolism and deep vein thrombosis in Swedish patient registries

Purpose

To validate diagnoses of pulmonary embolism (PE) and deep vein thrombosis (DVT) in administrative registries. We also estimated the frequency of misclassified PE and DVT events.

Patients and methods

A registry search for ICD codes representing PE and DVT was performed between 1985 and 2014 in a large population-based cohort in northern Sweden. An additional search using an extended set of ICD codes was performed to identify misclassified events. Diagnoses were validated manually by reviewing medical records and radiology reports.

Results

Searching ICD codes in the National Patient Registry and Cause of Death Registry identified 2,450 participants with a first-time diagnosis of PE or DVT. The positive predictive value (PPV) for a diagnosis of PE or DVT was 80.7% and 59.2%, respectively. For the period of 2009 to 2014, the PPV was higher for PE (85.8%) but lower for DVT (54.1%). Misclassification occurred in 16.4% of DVT events and 1.1% of PE events.

Conclusion

Registry-based data on PE, especially in recent years, are of acceptable quality and can be considered for use in registry-based studies. For DVT, we found that data were of low quality in regards to both PPV and misclassification and should not be used without validation.

Incidence, type of atrial fibrillation and risk factors for stroke: a population-based cohort study

Purpose

The aims of this study were to estimate the incidence of atrial fibrillation and atrial flutter (AF), to assess the presence of provoking factors and risk factors for stroke and systemic embolism, and to determine the type of AF in patients with first-diagnosed AF.

Patients and methods

This cohort study was performed in northern Sweden between January 1, 2011 and December 31, 2012. Diagnosis registries were searched for the International Classification of Diseases-10 code for AF (I48) to identify cases of incident AF. All AF diagnoses were electrocardiogram-verified. Data pertaining to provoking factors, type of AF and presence of risk factors for stroke and systemic embolism according to the CHA₂DS₂-VASc score were obtained from medical records.

Results

The incidence of AF in the entire population was 4.0 per 1,000 person-years. The incidence was 27.5 per 1,000 person-years in patients aged ≥80 years. A total of 21% of all patients had a provoking factor in association with the first-diagnosed episode of AF. The CHA₂DS₂-VASc score was 2 or higher in 81% of the patients. Permanent AF was the most common type of AF (29%).

Conclusion

There was a considerable increase in the incidence of AF with age, and a provoking factor was found in one-fifth. The most common type of AF was permanent AF. Four in five patients had a CHA₂DS₂-VASc score of 2 or more.

Validation of self-reported and hospital-diagnosed atrial fibrillation: the HUNT study

Background

Self-reported atrial fibrillation (AF) and diagnoses from hospital registers are often used to identify persons with AF. The objective of this study was to validate self-reported AF and hospital discharge diagnoses of AF among participants in a population-based study.

Materials and methods

Among 50,805 persons who participated in the third survey of the HUNT Study (HUNT3), 16,247 participants from three municipalities were included. Individuals who reported cardiovascular disease, renal disease, or hypertension in the main questionnaire received a cardiovascular-specific questionnaire. An affirmative answer to a question on physician-diagnosed AF in this second questionnaire defined self-reported AF diagnoses in the study. In addition, AF diagnoses were retrieved from hospital and primary care (PC) registers. All AF diagnoses were verified by review of hospital and PC medical records.

Results

A total of 502 HUNT3 participants had a diagnosis of AF verified in hospital or PC records. Of these, 249 reported their AF diagnosis in the HUNT3 questionnaires and 370 had an AF diagnosis in hospital discharge registers before participation in HUNT3. The sensitivity of self-reported AF in HUNT3 was 49.6%, specificity 99.2%, positive predictive value (PPV) 66.2%, and negative predictive value (NPV) 98.4%. The sensitivity of a hospital discharge diagnosis of AF was 73.7%, specificity 99.7%, PPV 88.5%, and NPV 99.2%.

Conclusion

Use of questionnaires alone to identify cases of AF has low sensitivity. Extraction of diagnoses from health care registers enhances the sensitivity substantially and should be applied when estimates of incidence and prevalence of AF are studied.

Catheter ablation versus anti-arrhythmic drug therapy for the management of a trial fibrillation: a meta-analysis

PURPOSES

The current study was a meta-analysis designed to compare the therapeutic efficacy and safety of catheter ablation with those of anti-arrhythmic drugs, over the short and long term.

METHODS

Comparative studies (randomized controlled trials) of catheter ablation vs. anti-arrhythmic drugs for the treatment of AF were retrieved from MEDLINE and EM BASE. The primary (no recurrence of AF) and secondary (major adverse events) outcomes were compared by meta-analysis, with sub-group analysis of short-term (1 year or less) and long-term (>1 year) effects.

RESULTS

Of the 223 studies originally identified, 214 were excluded (duplication, non-randomized design, lack of relevance or lack of usable data). Compared with anti-arrhythmic drug therapy, catheter ablation was associated with superior efficacy (odds ratio [OR], 9.41; 95 % confidence interval [95 % CI], 5.00-17.71; P < 0.01). Treatment success was higher for catheter ablation both in the short term (OR, 10.84; 95 % CI, 5.83-20.16; P < 0.001) and long term (OR, 7.65; 95 % CI, 1.97-29.73; P = 0.03). There was a trend toward a lower incidence of adverse events in the catheter ablation group (OR, 2.19; 95 % CI, 0.99-4.85), but this did not reach statistical significance (P = 0.05).

CONCLUSION

Compared with anti-arrhythmic drugs, management of AF with catheter ablation showed superior efficacy in the short term that was maintained over the longer term.

Characterization of patients with atrial fibrillation not treated with oral anticoagulants

OBJECTIVE

An underuse of oral anticoagulants (OAC) in patients with atrial fibrillation (AF) has been suggested, as only 50% of all patients with AF receive OAC treatment. Whether this is due to contraindications, lack of an indication to treat, or an expression of underuse is sparsely investigated. This study therefore aimed to characterize individuals without OAC treatment in a real-life population of patients with AF.

DESIGN

Retrospective cross-sectional study. The medical records were scrutinized in order to identify the type of AF, risk factors for embolism and bleeding, and other factors of importance for OAC treatment.

SETTING

The municipalities of Skellefteå and Norsjö, northern Sweden.

SUBJECTS

A total of 2274 living residents with at least one verified episode of AF on or before December 31, 2010.

MAIN OUTCOME MEASURES

Prevalence of treatment with OAC and documented reasons to withhold OAC treatment.

RESULTS

Among all 2274 patients with AF, 1187 (52%) were not treated with OAC. Of the untreated patients, 19% had no indication or had declined or had experienced adverse effects other than bleeding on warfarin treatment. The most common reason to withhold OAC was presence of risk factors for bleeding, found in 38% of all untreated patients. Furthermore, a documented reason could be identified to withhold OAC in 75%.

CONCLUSIONS

Among patients with AF without OAC treatment a reason could be identified to withhold OAC in 75%. The underuse of OAC is estimated to be 25%.