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

Association Between Sodium- and Potassium-Related Urinary Markers and the Prevalence of Atrial Fibrillation

BACKGROUND

The primary prevention of atrial fibrillation (AF), which increases mortality through complications including stroke and heart failure, is important. Excessive salt intake and low potassium intake are risk factors for cardiovascular disease; however, their association with AF remains inconclusive. This study investigated the association between sodium- and potassium-related urinary markers and AF prevalence.

METHODS AND RESULTS

Data from the Tohoku Medical Megabank Project Community-based Cohort Study were used in this cross-sectional study. The urinary sodium-to-potassium (Na/K) ratio and estimated 24-h sodium and potassium excretion were calculated using spot urine samples and categorized into quartiles (Q1-Q4). The prevalence of AF was the primary outcome. Of the 26,506 participants (mean age 64.8 years; 33.2% males) included in this study, 630 (2.4%) had AF. Using Q1 as the reference group, the odds ratios for AF prevalence in Q4 were 1.35 (95% confidence interval [CI] 1.07-1.73) and 1.59 (95% CI 1.20-2.12) for 24-h estimated urinary Na/K ratio and estimated 24-h sodium excretion, respectively. Estimated 24-h potassium excretion was not associated with AF prevalence.

CONCLUSIONS

AF prevalence was positively associated with the urinary Na/K ratio and estimated 24-h urinary sodium excretion, but not with estimated 24-h urinary potassium excretion. Although further prospective studies are warranted, the findings of this study suggest that salt intake may be a modifiable risk factor for AF.

Rates of Visual Field Progression Before and After the Onset of Atrial Fibrillation

PRCIS

This case-control study investigated the effect of atrial fibrillation (AF) on the progression of glaucoma. The presence of AF and related microvascular damage was associated with a slightly faster visual field loss in glaucoma patients.

PURPOSE

To investigate the effect of atrial fibrillation (AF) on glaucoma progression.

METHODS

In this longitudinal case-control study, a total of 144 eyes from 105 patients with primary open angle glaucoma were included. Forty-eight eyes of case developed AF during the follow-up followed for 15.6 years. Ninety-six eyes of control that did not have AF at baseline or during follow-up matched for age, baseline glaucoma severity, and follow-up period were followed for an average of 14.7 years. Mixed-effects linear models were used to calculate the difference in the VF MD slopes before and after the AF. CHADS 2 and CHA 2 DS 2 -VASc scores were used to evaluate the risk of thrombosis event, and related microvascular damage was assessed based on these scores.

RESULTS

The rate of VF MD change was -0.20 (-0.42 to 0.02) dB/y before AF and -0.28 (-0.47 to -0.09) dB/y after AF for the patients with AF, and -0.21 (-0.25 to -0.17) dB/y for the control. In the multivariable models, the VF slope difference before and after the onset of AF [-0.10 (-0.14 to -0.05) dB/y, P <0.001], higher CHADS 2 score [-0.07 (-0.13 to 0.00) dB/y per 1 unit, P =0.040], and higher CHA 2 DS 2 -VASc score [-0.05 (-0.10 to 0.00) dB/y per 1 unit, P =0.039] were associated with faster VF MD loss.

CONCLUSIONS

The presence of atrial fibrillation and related microvascular damage might accelerate visual field loss. This underscores the need for a comprehensive medical history and management of cardiovascular risk factors to mitigate increased VF loss in glaucoma.

Validity of self-reported hysterectomy and oophorectomy in a population-based cohort: The HUNT study

OBJECTIVE

To validate self-reported hysterectomy and bilateral oophorectomy.

DESIGN

Validation study.

SETTING

Large population-based cohort study in Norway: The Trøndelag Health Study (HUNT).

POPULATION

The Trøndelag Health Study 2 and 3 (HUNT2 and HUNT3) included questions on gynaecological history. Women who answered questions regarding hysterectomy and/or oophorectomy were included. In total, 30 263 women were included from HUNT2 (1995-1997) and 23 138 from HUNT3 (2006-2008), of which 16 261 attended both HUNT2 and HUNT3.

METHODS

We compared self-reported hysterectomy and bilateral oophorectomy with electronic hospital procedure codes.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive predictive value and negative predictive value of self-reported hysterectomy and bilateral oophorectomy, by comparing with hospital procedure codes.

RESULTS

Self-reported hysterectomy and bilateral oophorectomy in HUNT2 and/or HUNT3 both had specificity and negative predictive value above 99%. Self-reported hysterectomy had a sensitivity of 95.9%, and for bilateral oophorectomy sensitivity was 91.2%. Positive predictive value of self-reported hysterectomy was 85.8%, but for self-reported bilateral oophorectomy it was 65.4%.

CONCLUSIONS

Self-reported hysterectomy corresponded quite well with hospital data and can be used in epidemiological studies. Self-reported bilateral oophorectomy, on the other hand, had low positive predictive value, and results based on such data should be interpreted with caution. Women who report no previous hysterectomy or bilateral oophorectomy can safely be classified as unexposed to these surgeries.

Parity, infertility, age at first birth, and risk of atrial fibrillation: data from the HUNT study

AIMS

Although parity, infertility, and age at first birth are important for later development of cardiovascular disease, research on their association with atrial fibrillation (AF) is limited.

METHODS AND RESULTS

We linked data from the population-based HUNT study and the Medical Birth Registry of Norway (MBRN) and validated medical records from local hospitals. A total of 24 015 women aged 45 years or older were followed for verified incident AF. Parity and age at first birth were retrieved from the MBRN or from self-reported questionnaires in the HUNT study. A history of infertility was self-reported on the HUNT questionnaire. Cox proportional hazards models were used to calculate hazard ratios (HRs) for the multivariable-adjusted associations of parity, infertility, and age at first birth with risk of AF. During a median follow-up of 12.8 years, 1448 (6.0%) participants developed AF. Women with higher parity (four or more births vs. two births) were at 21% higher risk of AF [HR 1.21, 95% confidence interval (CI) 1.05-1.39]. A history of infertility was also associated with the risk of AF (HR 1.20, 95% CI 1.02-1.42). Among parous women, younger age at first birth (<20 vs. 20-29 years) was associated with a 20% higher risk of AF (HR 1.20, 95% CI 1.03-1.40).

CONCLUSION

Women with four or more births, or a history of infertility, or younger age at first birth have approximately a 20% higher risk of AF among women over 45 years old.

Sex differences in early-onset atrial fibrillation in Norwegian primary care: a retrospective national database analysis

BACKGROUND

Individual variation in the need for healthcare constitutes knowledge gaps for young atrial fibrillation (AF) patients. We aimed to estimate the prevalence and primary care burden of early-onset AF in Norway, emphasising sex differences, in a nationwide healthcare database.

METHODS

We used data from the Norwegian Control and Payment of Health Reimbursement database to identify all Norwegian residents ≥18 years of age registered with a primary care physician (PCP) in 2019, with onset of AF at ≤50 years of age (early-onset AF) in the period 2006-2019. From the accumulated number of early-onset AF cases among current residents, we calculated the prevalence in 2019. The group-level primary care burden was calculated as the total number of annual AF consultations divided by the annual number of AF patients (2014-2018), and individual burden as the mean number of consultations per AF patient per year within the study period. We analysed the distribution of AF consultations between PCP and primary care emergency room (ER) services in total and by sex.

RESULTS

We identified 10 925 Norwegian residents with early-onset AF in 2019 (26.3% women, mean age 48.4 years). The prevalence of early-onset AF was 0.34% (women: 0.19%, men: 0.50%). The early-onset AF population had on average one annual primary care consultation for AF. The individual burden of annual AF consultations varied widely; <1: 66% of women and 54% of men, (1-5]: 25% of women and 36% of men, (5-10]: 6% of women and 8% of men, ≥10: 2% of women and 2% of men. A higher proportion of men (71%) than women (38%) attended both PCP and ER services due to AF.

CONCLUSIONS

The study confirmed a low prevalence of early-onset AF, with substantial sex differences and individual variation in primary healthcare needs. Our results signal a need for a higher resolution with regard to age groups in future research on burden and sex differences in early-onset AF.

Association of age at menarche, reproductive lifespan and age at menopause with the risk of atrial fibrillation: The HUNT study

BACKGROUND

Age at menarche, reproductive lifespan, and age at menopause are associated with several cardiovascular diseases, but their relationship with atrial fibrillation (AF) is uncertain.

METHODS

We linked information on all women who participated in the third survey of the population-based, longitudinal HUNT study in Norway with medical records from all local hospitals. A total of 14,632 women aged 60 or more were followed for validated incident AF. We retrieved age at menarche and age at menopause from the HUNT questionnaires. Reproductive lifespan was defined as the difference between age at menarche and age at menopause. We used Cox proportional hazards regression models to assess associations between AF and age at menarche, reproductive lifespan, and age at menopause.

RESULTS

During a median follow-up of 8.17 years (136,494 person-years), 1217 (8.3 %) participants developed AF. In multivariable-adjusted analyses, we observed no associations between early or late age at menarche and AF (hazard ratios (HRs): <12 years: 0.85 [95 % confidence interval (CI), 0.65-1.12]; ≥16 years: 0.99 [95 % CI, 0.80-1.24] compared to those who attained menarche at 13-14 years). The HR for a reproductive lifespan shorter than 30 years was 0.91 [95 % CI, 0.72-1.15] compared to 34-37 years. Likewise, there was no clear association between premature or early age at menopause and AF (HRs: <40 years: 1.21 [95 % CI, 0.83-1.75]; 40-44 years: 0.97 [95 % CI, 0.77-1.22] compared to 50-54 years).

CONCLUSIONS

In this population of women aged 60 years and over, the risk of AF was not associated with age at menarche, reproductive lifespan, or age at menopause.

Gastroesophageal reflux disease symptoms and risk of atrial fibrillation in a population-based cohort study (the HUNT study)

AIMS

Gastroesophageal reflux disease (GERD) may influence the risk of atrial fibrillation (AF). We investigated the association between symptoms of GERD and AF in the Trøndelag Health Study (HUNT).

METHODS

The study cohort comprised 34,120 adult men and women initially free of AF with information on GERD symptoms. Participants were followed from the baseline clinical examination (1 October 2006 to 30 June 2008) to March 31, 2018.

RESULTS

During a median follow-up of 8.9 years, 1,221 cases of AF were diagnosed. When looking at the whole population, participants with much GERD symptoms did not have an increased risk of AF (HR: 1.01; CI: 95%, 0.82 to 1.24) while participants with little GERD symptoms had a 14% lower risk of AF compared those with no GERD symptoms (HR: 0.86; CI: 95%, 0.76 to 0.97). Among younger participants (<40 years of age), the risk of AF had a trend towards increased risk with increasing symptom load of GERD (little GERD symptoms, HR: 3.09; CI: 95%, 0.74 to 12.94 and much GERD symptoms, HR: 5.40; 95% CI: 0.82 to 35.58). Among older participants (≥65 years of age), we saw a slightly reduced risk of AF in participants with little symptoms (HR: 0.84; CI: 0.72 to 0.97) and no association among those with much GERD symptoms (HR: 1.06; 95% CI: 0.82 to 1.36).

CONCLUSION

We did not find support for a clinically important association between symptoms of GERD and AF across all age groups but for some younger people, GERD might play a role in the development of AF. However, our estimates for this age group were very imprecise and larger studies including younger individuals are warranted.

Migraine and risk of atrial fibrillation: A 9-year follow-up based on the Trøndelag Health Study

BACKGROUND

Data from some population-based studies have indicated an increased risk of atrial fibrillation (AF) among patients with migraine, particularly among individuals with migraine with aura. The present study aimed to assess the association between primary headache disorders and AF.

METHODS

In a population-based 9-year follow-up design, we evaluated the questionnaire-based headache diagnosis, migraine and tension-type headache (TTH) included, collected in the Trøndelag Health Study (HUNT3) conducted in 2006-2008, and the subsequent risk of AF in the period until December 2015. The population at risk consisted of 39,340 individuals ≥20 years without AF at HUNT3 baseline who answered headache questionnaire during HUNT3. The prospective association was evaluated by multivariable Cox proportional hazard models with 95% confidence intervals (CIs).

RESULTS

Among the 39,340 participants, 1524 (3.8%) developed AF during the 9-year follow up, whereof 91% of these were ≥55 years. In the multivariable analyses, adjusting for known confounders, we did not find any association between migraine or TTH and risk of AF. The adjusted hazard ratios (HRs) were respectively 0.84 (95% CI = 0.64-1.11) for migraine, 1.16 (95% CI = 0.86-1.27) for TTH and 1.04 (95% CI = 0.86-1.27) for unclassified headache. However, in sensitivity analyses of individuals aged ≥55 years, a lower risk of AF was found for migraine (HR = 0.53; 95% CI = 0.39-0.73).

CONCLUSIONS

In this large population-based study, no increased risk of AF was found among individuals with migraine or TTH at baseline. Indeed, among individuals aged ≥55 years, migraine was associated with a lower risk for AF.

Stroke and bleeding risk in atrial fibrillation with CHA2DS2-VASC risk score of one: the Norwegian AFNOR study

BACKGROUND AND AIMS

The benefit of oral anticoagulant (OAC) therapy in atrial fibrillation (AF) and intermediate stroke risk is debated. In a nationwide Norwegian cohort with a non-sex CHA2DS2-VASc risk score of one, this study aimed to investigate (i) stroke and bleeding risk in AF patients with and without OAC treatment, and (ii) the risk of stroke in non-anticoagulated individuals with and without AF.

METHODS

A total of 1 118 762 individuals including 34 460 AF patients were followed during 2011-18 until ischaemic stroke, intracranial haemorrhage, increased CHA2DS2-VASc score, or study end. One-year incidence rates (IRs) were calculated as events per 100 person-years (%/py). Cox regression models provided adjusted hazard ratios (aHRs [95% confidence intervals]).

RESULTS

Among AF patients, the ischaemic stroke IR was 0.51%/py in OAC users and 1.05%/py in non-users (aHR 0.47 [0.37-0.59]). Intracranial haemorrhage IR was 0.28%/py in OAC users and 0.19%/py in non-users (aHR 1.23 [0.88-1.72]). Oral anticoagulant use was associated with an increased risk of major bleeding (aHR 1.37 [1.16-1.63]) but lower risk of the combined outcome of ischaemic stroke, major bleeding, and mortality (aHR 0.57 [0.51-0.63]). Non-anticoagulated individuals with AF had higher risk of ischaemic stroke compared to non-AF individuals with the same risk profile (aHR 2.47 [2.17-2.81]).

CONCLUSIONS

In AF patients at intermediate risk of stroke, OAC use was associated with overall favourable clinical outcomes. Non-anticoagulated AF patients had higher risk of ischaemic stroke compared to the general population without AF with the same risk profile.

Development of a tool to predict the risk of incident heart failure in a general population: the HUNT for HF risk score

AIMS

Currently, no incident heart failure (HF) risk score that is in regular use in a general population is available. We aimed to develop this and compare with existing HF risk scores.

METHODS AND RESULTS

Participants in the third wave (2006-08) of the population-based Trøndelag Health Study 3 (HUNT3) were included if they reported no previous HF. Any hospital diagnoses captured during follow-up (until the end of 2018) of HF, cardiomyopathy, or hypertensive heart disease were assessed by an experienced cardiologist. Valid HF events were defined as symptoms/signs of HF and objective evidence of structural/functional abnormality of the heart at rest. The model was compared with slightly modified HF risk scores (the Health Aging and Body Composition HF risk score, the Framingham HF risk score, the Pooled Cohort equations to Prevent HF risk score, and NORRISK 2). Among 36 511 participants (mean ± SD age of 57.9 ± 13.3 years, 55.4% female), with a mean follow-up of 10.2 ± 1.3 years, 1366 developed HF (incidence rate of 3.66 per 1000 participant years). Out of the 38 relevant clinical variables assessed, we identified 12 (atrial fibrillation being the strongest) that independently predicted an HF event. The final model demonstrated good discrimination (C statistics = 0.904) and calibration, was stable in internal validation, and performed well compared with existing risk scores. The model identified that, at enrolment, 31 391 (86%), 2386 (7%), 1246 (3%), and 1488 (4%) had low, low-intermediate, high-intermediate, and high 10-year HF risk, respectively.

CONCLUSIONS

Twelve clinical variables independently predicted 10-year HF risk. The model may serve well as the foundation of a practical, online risk score for HF in general practice.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04648852.

Effect of COVID-19 on Acute Ischemic Stroke Severity and Mortality in 2020: Results From the 2020 National Inpatient Sample

BACKGROUND

There is a paucity of nationally representative data regarding the impact of COVID-19 on acute ischemic stroke (AIS) outcome.

METHODS

We created a cross-sectional cohort of nationally weighted National Inpatient Sample nonelective hospital discharges aged ≥18 years with a diagnosis of ischemic stroke from 2016 to 2020. The outcome was in-hospital mortality and exposure was COVID-19 status. To understand the effect of COVID-19 on AIS severity, we report National Institutes of Health Stroke Scale by exposure status. In a final analysis, we used a nationally weighted logistic regression and marginal effects to compare April to December 2020 to the same period in 2019 to understand how the pandemic modified the effect of race and ethnicity and median household income on in-hospital AIS mortality.

RESULTS

We observed significantly higher AIS mortality in 2020 than prior years (2020 versus 2016-19, 7.3% versus 6.3%, P<0.001) and higher National Institutes of Health Stroke Scale in those with COVID-19 than those without (mean: 9.7±9.1 versus 6.6±7.4, P<0.001), but patients with AIS without COVID in 2020 had only marginally higher mortality (2020 versus 2016-2019, 6.6% versus 6.3%, P=0.001). Comparing April to December 2020 to 2019, the adjusted risk of in-hospital AIS mortality was most notably increased in Hispanics (2020 versus 2019: 9.2% versus 5.8%, P<0.001) and the lowest quartile of income (2020 versus 2019: 8.0% versus 6.0%, P<0.001).

CONCLUSIONS

In-hospital stroke mortality increased in 2020 in the United States because of comorbid AIS and COVID-19, which had higher stroke severity. The increase in AIS mortality during April-December 2020 was significantly more pronounced in Hispanics and those in the lowest quartile of household income.

Risk of atrial fibrillation and stroke among older men exposed to prolonged endurance sport practice: a 10-year follow-up. The Birkebeiner Ageing Study and the Tromsø Study

Aims

Endurance sport practice is associated with a high prevalence of atrial fibrillation (AF), which increases the risk of stroke in the general population. However, stroke risk in endurance athletes with AF is sparsely investigated. Most studies have been limited by design and are largely restricted to younger and middle-aged populations. Thus, we aimed to investigate AF and stroke risk in older athletes exposed to prolonged endurance training.

Method

During a 10-year period, 505 male athletes aged ≥65 years frequently participating in a long-distance ski race were compared with 1867 men of the same age from the general population. The main exposure was endurance sport practice with self-reported AF and stroke as outcomes. Stroke risk was further examined by joint modelling of AF and endurance practice. Statistical analysis was conducted with a modified Poisson model.

Results

Athletes (median age: 68, range: 65–90) participated in a long-distance ski race over a median of 14 years (range: 1–53). Prevalence (28.5% vs 17.8%) and adjusted risk of AF (risk ratio (RR): 1.88, 95% CI: 1.49 to 2.37) were higher in athletes compared with non-athletes, whereas the prevalence (5.4% vs 9.7%) and risk of stroke were lower (RR: 0.60, 95% CI: 0.37 to 0.95). Compared with athletes without AF, risk of stroke was twofold in athletes (RR: 2.38, 95% CI: 1.08 to 5.24) and nearly fourfold in non-athletes (RR: 3.87, 95% CI: 1.98 to 7.57) with AF.

Conclusion

Although older male endurance athletes experienced an increased risk of AF, the long-term risk of stroke was substantially reduced compared with non-athletes.

Post-operative atrial fibrillation and risk of heart failure hospitalization

AIMS

Post-operative atrial fibrillation (POAF) is associated with stroke and mortality. It is unknown if POAF is associated with subsequent heart failure (HF) hospitalization. This study aims to examine the association between POAF and incident HF hospitalization among patients undergoing cardiac and non-cardiac surgeries.

METHODS AND RESULTS

A retrospective cohort study was conducted using all-payer administrative claims data that included all non-federal emergency department visits and acute care hospitalizations across 11 states in the USA. The study population included adults aged at least 18 years hospitalized for surgery without a prior diagnosis of HF. Cox proportional hazards regression models were used to examine the association between POAF and incident HF hospitalization after making adjustment for socio-demographics and comorbid conditions. Among 76 536 patients who underwent cardiac surgery, 14 365 (18.8%) developed incident POAF. In an adjusted Cox model, POAF was associated with incident HF hospitalization [hazard ratio (HR) 1.33; 95% confidence interval (CI) 1.25-1.41]. In a sensitivity analysis excluding HF within 1 year of surgery, POAF remained associated with incident HF hospitalization (HR 1.15; 95% CI 1.01-1.31). Among 2 929 854 patients who underwent non-cardiac surgery, 23 763 (0.8%) developed incident POAF. In an adjusted Cox model, POAF was again associated with incident HF hospitalization (HR 2.02; 95% CI 1.94-2.10), including in a sensitivity analysis excluding HF within 1 year of surgery (HR 1.49; 95% CI 1.38-1.61).

CONCLUSIONS

Post-operative atrial fibrillation is associated with incident HF hospitalization among patients without prior history of HF undergoing both cardiac and non-cardiac surgeries. These findings reinforce the adverse prognostic impact of POAF and suggest that POAF may be a marker for identifying patients with subclinical HF and those at elevated risk for HF.

Bone mineral density and risk of cardiovascular disease in men and women: the HUNT study

The association between bone mineral density (BMD) and cardiovascular disease (CVD) is not fully understood. We evaluated BMD as a risk factor for cardiovascular disease and specifically atrial fibrillation (AF), acute myocardial infarction (AMI), ischemic (IS) and hemorrhagic stroke (HS) and heart failure (HF) in men and women. This prospective population cohort utilized data on 22 857 adults from the second and third surveys of the HUNT Study in Norway free from CVD at baseline. BMD was measured using single and dual-energy X-ray absorptiometry in the non-dominant distal forearm and T-score was calculated. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated from adjusted cox proportional hazards models. The analyses were sex-stratified, and models were adjusted for age, age-squared, BMI, physical activity, smoking status, alcohol use, and education level. Additionally, in women, we adjusted for estrogen use and postmenopause. During a mean follow-up of 13.6 ± 5.7 years, 2 928 individuals (12.8%) developed fatal or non-fatal CVD, 1 020 AF (4.5%), 1 172 AMI (5.1%), 1 389 IS (6.1%), 264 HS (1.1%), and 464 HF (2.0%). For every 1 unit decrease in BMD T-score the HR for any CVD was 1.01 (95% CI 0.98 to 1.04) in women and 0.99 (95% CI 0.94 to 1.03) in men. Point estimates for the four cardiovascular outcomes ranged from slightly protective (HR 0.95 for AF in men) to slightly deleterious (HR 1.12 for HS in men). We found no evidence of association of lower distal forearm BMD with CVD, AF, AMI, IS, HS, and HF.

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.

Effectiveness and safety of non-vitamin K antagonist oral anticoagulants and warfarin in atrial fibrillation: a Scandinavian population-based cohort study

AIMS

Using Scandinavian population-based registries, we assessed risk of stroke/systemic embolism (SE) and bleeding with non-vitamin K antagonist oral anticoagulants compared with warfarin in anticoagulation-naïve patients with atrial fibrillation (AF).

METHODS AND RESULTS

This historical cohort study included 219 545 AF patients [median age 74 years; 43% women; mean CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke or transient ischaemic attack, vascular disease, age 65-74 years, sex category) score 3.3] initiating apixaban, dabigatran, rivaroxaban, or warfarin in Denmark, Norway, and Sweden (1 January 2013 to 31 December 2016). The primary endpoints were stroke/SE and major bleeding. The median follow-up times were 9.7 (3.9-21.5) months for stroke/SE and 9.6 (3.8-21.3) months for bleeding. Apixaban and warfarin initiators were older and had higher CHA2DS2-VASc scores compared with dabigatran and rivaroxaban initiators. After 1:1 propensity score matching, three cohorts were created: apixaban-warfarin (n = 111 162), dabigatran-warfarin (n = 56 856), and rivaroxaban-warfarin (n = 61 198). Adjusted hazard ratios (HRs) were estimated using a Cox regression. For stroke/SE, adjusted HRs against warfarin were 0.96 [95% confidence interval (CI): 0.87-1.06] for apixaban, 0.89 (95% CI: 0.80-1.00) for dabigatran, and 1.03 (95% CI: 0.92-1.14) for rivaroxaban. For major bleeding, the HRs against warfarin were 0.73 (95% CI: 0.67-0.78) for apixaban, 0.89 (95% CI: 0.82-0.97) for dabigatran, and 1.15 (95% CI: 1.07-1.25) for rivaroxaban. The results in the dabigatran cohort did not hold in all dose-defined subgroups.

CONCLUSION

In this large Scandinavian study among AF patients initiating oral anticoagulation, those initiating dabigatran, apixaban, and rivaroxaban had similar rates of stroke/SE to patients initiating warfarin. Rates of major bleeding were lower with apixaban and dabigatran and higher with rivaroxaban, each compared with warfarin.

Examining the lower range of the association between alcohol intake and risk of incident hospitalization with atrial fibrillation

Background

Evidence is sparse on the association between alcohol intakes in the lower range and risk of atrial fibrillation (AF). We aimed to investigate self-reported low and moderate alcohol intakes and subsequent risk of incident AF among current drinkers.

Methods

Norwegian population-based health examination surveys assessing self-reported daily alcohol intake (mean grams per day) were linked to health and population registers. Hazard ratios (HR) (95% confidence interval) for time to incident (first) hospitalization with AF by alcohol intake level were assessed by Cox regression, with adjustment for educational level and cardiovascular risk factors except blood pressure.

Results

The study population included 234,392 participants (49% men). Incident hospitalization with AF was identified in 5043 (2.2%) persons during a mean follow-up of 9 years. Compared to a very low alcohol intake of <1 unit weekly, a moderate consumption in the range of 1 to <2 units daily increased the risk of incident AF by 18% (HR 1.18 [1.06-1.32]). The average risk of incident AF increased by 9% per daily alcohol unit of 12 g (HR 1.09 [1.03, 1.14]). In sex-stratified analyses significant associations were found in men only.

Conclusions

We found that less than two alcohol units/day significantly increased the risk of incident AF, however, in men only. Reduction of even a moderate alcohol intake may thus reduce the risk of AF at the population level.

Outcomes of oesophageal variceal bleeding among patients with atrial fibrillation: a propensity-matched analysis of a nationwide inpatient sample

Introduction

We aimed to determine the influence of atrial fibrillation (AF) on mortality, morbidity, length of hospital stay, and resource utilisation in patients with oesophageal variceal bleeding (OVB).

Material and methods

The National Inpatient Sample database (2016 and 2017) was used for data analysis using the International Classification of Diseases, Tenth Revision codes to identify patients with the principal diagnosis of OVB and AF. We assessed the all-cause in-hospital mortality, morbidity, predictors of mortality, length of hospital stay (LOS), and total costs between propensity-matched groups of OVB with AF vs. OVB alone.

Results

We identified 80,325 patients with OVB, of whom 4285 had OVB with AF, and 76,040 had OVB only. The in-hospital mortality was higher in OVB with AF (OR = 1.4, 95% CI: 1.09–1.83; p < 0.001). OVB with AF had higher odds of sepsis (OR = 1.4, 95% CI: 1.1–1.8; p = 0.007), acute kidney injury (OR = 1.2, 95% CI: 1.12–1.32; p < 0.001), and mechanical ventilation (OR = 1.2, 95% CI: 1.12–1.32; p < 0.001). Advanced age (OR = 1.06, 95% CI: 1.05–1.07; p < 0.001), congestive heart failure (OR = 1.7, 95% CI: 1.3–2.3; p < 0.001), coronary artery disease (OR = 1.4, 95% CI: 1.03–1.92; p = 0.02), and sepsis (OR = 1.3, 95% CI: 1.06–1.70; p = 0.01) were identified as predictors of mortality in OVB with AF. Mean LOS (7.5 ±7.4 vs. 6.0 ±7.2, p < 0.001) and mean total costs ($25,452 vs. $21,109, p < 0.001) were also higher.

Conclusions

In this propensity-matched analysis, OVB with AF was associated with higher odds of in-hospital mortality, sepsis, acute kidney injury, and mechanical ventilation.

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.

Physical activity, cardiorespiratory fitness, and cardiovascular outcomes in individuals with atrial fibrillation: the HUNT study

AIMS

Atrial fibrillation (AF) confers higher risk of mortality and morbidity, but the long-term impact of physical activity (PA) and cardiorespiratory fitness (CRF) on outcomes in AF patients is unknown. We, therefore, examined the prospective associations of PA and estimated CRF (eCRF) with all-cause mortality, cardiovascular disease (CVD) mortality, morbidity and stroke in individuals with AF.

METHODS AND RESULTS

We followed 1117 AF patients from the HUNT3 study in 2006-08 until first occurrence of the outcomes or end of follow-up in November 2015. We used Cox proportional hazard regression to examine the prospective associations of self-reported PA and eCRF with the outcomes. Atrial fibrillation patients meeting PA guidelines had lower risk of all-cause [hazard ratio (HR) 0.55, 95% confidence interval (CI) 0.41-0.75] and CVD mortality (HR 0.54, 95% CI 0.34-0.86) compared with inactive patients. The respective HRs for CVD morbidity and stroke were 0.78 (95% CI 0.58-1.04) and 0.70 (95% CI 0.42-1.15). Each 1-metabolic equivalent task (MET) higher eCRF was associated with a lower risk of all-cause (HR 0.88, 95% CI 0.81-0.95), CVD mortality (HR 0.85, 95% CI 0.76-0.95), and morbidity (HR 0.88, 95% CI 0.82-0.95).

CONCLUSION

Higher PA and CRF are associated with lower long-term risk of CVD and all-cause mortality in individuals with AF. The findings support a role for regular PA and improved CRF in AF patients, in order to combat the elevated risk for mortality and morbidity.

Left Atrial Volume, Cardiorespiratory Fitness, and Diastolic Function in Healthy Individuals: The HUNT Study, Norway

Background Left atrial (LA) size and cardiorespiratory fitness (CRF) are predictors of future cardiovascular events in high-risk populations. LA dilatation is a diagnostic criterion for left ventricular diastolic dysfunction. However, LA is dilated in endurance athletes with high CRF, but little is known about the association between CRF and LA size in healthy, free-living individuals. We hypothesized that in a healthy population, LA size was associated with CRF and leisure-time physical activity, but not with echocardiographic indexes of left ventricular diastolic dysfunction. Methods and Results In this cross-sectional study from HUNT (Nord-Trøndelag Health Study), 107 men and 138 women, aged 20 to 82 years, without hypertension, cardiovascular, pulmonary, or malignant disease participated. LA volume was assessed by echocardiography and indexed to body surface area LAVI (left atrial volume index). CRF was measured as peak oxygen uptake (VO_2peak) using ergospirometry, and percent of age- and-sex-predicted VO_2peak was calculated. Indexes of left ventricular diastolic dysfunction were assessed in accordance with latest recommendations. LAVI was >34 mL/m² in 39% of participants, and LAVI was positively associated with VO_2peak and percentage of age- and-sex-predicted VO_2peak (β [95% CI], 0.11 [0.06-0.16] and 0.18 [0.09-0.28], respectively) and weighted minutes of physical activity per week (β [95% CI], 0.01 [0.003-0.015]). LAVI was not associated with other indexes of left ventricular diastolic dysfunction. There was an effect modification between age and VO_2peak/percentage of age- and-sex-predicted VO_2peak showing higher LAVI with advanced age and higher VO_2peak/percentage of age- and-sex-predicted VO_2peak as presented in prediction diagrams. Conclusions Interpretation of LAVI as a marker of diastolic dysfunction should be done in relation to age-relative CRF. Studies on the prognostic value of LAVI in fit subpopulations are needed.

Low coverage whole genome sequencing enables accurate assessment of common variants and calculation of genome-wide polygenic scores

BACKGROUND

Inherited susceptibility to common, complex diseases may be caused by rare, pathogenic variants ("monogenic") or by the cumulative effect of numerous common variants ("polygenic"). Comprehensive genome interpretation should enable assessment for both monogenic and polygenic components of inherited risk. The traditional approach requires two distinct genetic testing technologies-high coverage sequencing of known genes to detect monogenic variants and a genome-wide genotyping array followed by imputation to calculate genome-wide polygenic scores (GPSs). We assessed the feasibility and accuracy of using low coverage whole genome sequencing (lcWGS) as an alternative to genotyping arrays to calculate GPSs.

METHODS

First, we performed downsampling and imputation of WGS data from ten individuals to assess concordance with known genotypes. Second, we assessed the correlation between GPSs for 3 common diseases-coronary artery disease (CAD), breast cancer (BC), and atrial fibrillation (AF)-calculated using lcWGS and genotyping array in 184 samples. Third, we assessed concordance of lcWGS-based genotype calls and GPS calculation in 120 individuals with known genotypes, selected to reflect diverse ancestral backgrounds. Fourth, we assessed the relationship between GPSs calculated using lcWGS and disease phenotypes in a cohort of 11,502 individuals of European ancestry.

RESULTS

We found imputation accuracy r2 values of greater than 0.90 for all ten samples-including those of African and Ashkenazi Jewish ancestry-with lcWGS data at 0.5×. GPSs calculated using lcWGS and genotyping array followed by imputation in 184 individuals were highly correlated for each of the 3 common diseases (r2 = 0.93-0.97) with similar score distributions. Using lcWGS data from 120 individuals of diverse ancestral backgrounds, we found similar results with respect to imputation accuracy and GPS correlations. Finally, we calculated GPSs for CAD, BC, and AF using lcWGS in 11,502 individuals of European ancestry, confirming odds ratios per standard deviation increment ranging 1.28 to 1.59, consistent with previous studies.

CONCLUSIONS

lcWGS is an alternative technology to genotyping arrays for common genetic variant assessment and GPS calculation. lcWGS provides comparable imputation accuracy while also overcoming the ascertainment bias inherent to variant selection in genotyping array design.

Symptoms of anxiety and depression and risk of atrial fibrillation-The HUNT study

BACKGROUND

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Anxiety and depression may activate the autonomic nervous system which is likely to play an important role in the etiology of AF. However, little is known about the association between symptoms of anxiety and depression and risk of AF.

OBJECTIVE

This study aimed to assess the association between symptoms of anxiety and depression and risk of AF.

METHODS

In a population-based study, 37,402 adult residents were followed for incident AF from 2006 to 2008 until 2015. Participants were classified according to data on anxiety and depression symptoms. Cox proportional regression models were used to adjust for common AF risk factors.

RESULTS

During a median follow-up of 8.1 years, 1433 (3.8%) participants developed AF. In comparisons with no anxiety symptoms, the multivariable-adjusted hazard ratios (HRs) were 1.1 (95% CI: 0.9-1.5) for mild to moderate anxiety symptoms and 1.0 (95% CI: 0.8-1.4) for severe anxiety symptoms. In comparisons with no depression symptoms, the multivariable-adjusted HRs were 1.5 (95% CI: 1.2-1.8) for mild to moderate depression symptoms and 0.9 (95% CI: 0.6-1.3) for severe depression symptoms. Recurrent anxiety/depression symptoms were not associated with increased AF risk.

CONCLUSIONS

In this large, population-based study, we found no evidence of an association between symptoms of anxiety or severe depression and AF risk, even for recurrent anxiety or depression symptoms. An unexpected association of symptoms of mild to moderate depression with increased AF risk requires confirmation in other studies. Our findings add to the sparse literature on symptoms of anxiety and depression and risk of AF.

Associations of Asthma and Asthma Control With Atrial Fibrillation Risk: Results From the Nord-Trøndelag Health Study (HUNT)

Importance

Asthma, a chronic inflammatory airway disease, and atrial fibrillation (AF) share several common pathophysiological mechanisms. Research on the association between asthma and atrial fibrillation is lacking, and to our knowledge, no previous studies have assessed the dose-response association between levels of asthma control and AF.

Objective

To assess the association between asthma, levels of asthma control, and AF.

Design, Setting, and Participants

This prospective population cohort analyzed data on adults from a second and third iteration of the survey-based Nord-Trøndelag Health Study (HUNT) in Norway. All included participants were free from AF at baseline. Atrial fibrillation was ascertained by linking HUNT data with hospital records from the 2 hospitals in Nord-Trøndelag County. Data analysis was completed from May 2017 to November 2017.

Exposures

Self-reported asthma was categorized into 3 groups: those who had ever had asthma, those who self-report being diagnosed with asthma, and those who had active asthma. Asthma control was defined according to Global Initiative for Asthma guidelines and was categorized into controlled, partly controlled, and uncontrolled cases.

Main Outcomes and Measures

Atrial fibrillation.

Results

A total of 54 567 adults were included (of whom 28 821 [52.8%] were women). Of these, 5961 participants (10.9%) reported ever having asthma, 3934 participants (7.2%) reported being diagnosed with asthma, and 2485 participants (4.6%) reported having active asthma. During a mean (SD) follow-up of 15.4 (5.8) years, 2071 participants (3.8%) developed AF. Participants with physician-diagnosed asthma had an estimated 38% higher risk of developing AF (adjusted hazard ratio, 1.38 [95% CI, 1.18-1.61]) compared with participants without asthma. There was a dose-response association between levels of asthma control and risk of AF with the highest risk for AF in participants with uncontrolled asthma (adjusted hazard ratio, 1.74 [95% CI, 1.26-2.42]; P for trend < .001).

Conclusions and Relevance

Asthma and lack of asthma control were associated with moderately increased risks of AF in a dose-response manner. Further studies are needed to explore the underlying mechanisms and clarify causal pathways between asthma and AF.

Comparative effectiveness of warfarin, dabigatran, rivaroxaban and apixaban in non-valvular atrial fibrillation: A nationwide pharmacoepidemiological study

OBJECTIVE

To compare effectiveness and safety of warfarin and the direct oral anticoagulants (DOAC) dabigatran, rivaroxaban and apixaban in non-valvular atrial fibrillation in routine care.

METHODS

From nationwide registries, we identified treatment-naïve patients initiating warfarin, dabigatran, rivaroxaban or apixaban for non-valvular atrial fibrillation from July 2013 to December 2015 in Norway. We assessed prescription duration using reverse waiting time distribution. Adjusting for confounding in a Cox proportional hazards model, we estimated one-year risks for ischemic stroke, transient ischemic attack (TIA) or systemic embolism, major or clinically relevant non-major bleeding; intracranial; gastrointestinal; and other bleeding. We censored at switch of treatment or 365 days of follow-up.

RESULTS

We included 30,820 treatment-naïve patients. Compared to warfarin, the adjusted hazard ratios (HR) for ischemic stroke, TIA or systemic embolism were 0.96 (95% CI 0.71-1.28) for dabigatran, 1.12 (95% CI 0.87-1.45) for rivaroxaban and 0.97 (95% CI 0.75-1.26) for apixaban. Corresponding hazard ratios for major or clinically relevant non-major bleeding were 0.73 (95% CI 0.62-0.86) for dabigatran, 0.97 (95% CI 0.84-1.12) for rivaroxaban and 0.71 (95% CI 0.62-0.82) for apixaban. Statistically significant differences of other safety outcomes compared to warfarin were fewer intracranial bleedings with dabigatran (HR 0.28, 95% CI 0.14-0.56), rivaroxaban (HR 0.40, 95% CI 0.23-0.69) and apixaban (HR 0.56, 95% CI 0.34-0.92); fewer gastrointestinal bleedings with apixaban (HR 0.70, 95% CI 0.52-0.93); and fewer other bleedings with dabigatran (HR 0.67, 95% CI 0.55-0.81) and apixaban (HR 0.70, 95% CI 0.59-0.83).

CONCLUSION

After 1 year follow-up in treatment-naïve patients initiating oral anticoagulation for non-valvular atrial fibrillation, all DOACs were similarly effective as warfarin in prevention of ischemic stroke, TIA or systemic embolism. Safety from bleedings was similar or better, including fewer intracranial bleedings with all direct oral anticoagulants, fewer gastrointestinal bleedings with apixaban and fewer other bleedings with dabigatran and apixaban.

Weight and weight change and risk of atrial fibrillation: the HUNT study

Aims

Although obesity has been associated with risk of atrial fibrillation (AF), the associations of long-term obesity, recent obesity, and weight change with AF risk throughout adulthood are uncertain.

Methods and results

An ambispective cohort study was conducted which included 15 214 individuals. The cohort was created from 2006 to 2008 (the baseline) and was followed for incident AF until 2015. Weight and height were directly measured at baseline. Data on previous weight and height were retrieved retrospectively from measurements conducted 10, 20, and 40 years prior to baseline. Average body mass index (BMI) over time and weight change was calculated. During follow-up, 1149 participants developed AF. The multivariable-adjusted hazard ratios were 1.2 (95% confidence interval 1.0–1.4) for average BMI 25.0–29.9 kg/m2 and 1.6 (1.2–2.0) for average BMI ≥30 kg/m2 when compared with normal weight. The association of average BMI with AF risk was only slightly attenuated after adjustment for most recent BMI. In contrast, current BMI was not strongly associated with the risk of AF after adjustment for average BMI earlier in life. Compared with stable BMI, both loss and gain in BMI were associated with increased AF risk. After adjustment for most recent BMI, the association of BMI gain with AF risk was largely unchanged, while the association of BMI loss with AF risk was weakened.

Conclusion

Long-term obesity and BMI change are associated with AF risk. Obesity earlier in life and weight gain over time exert cumulative effects on AF development even after accounting for most recent BMI.

Association Between Relevant Co-Morbidities and Dementia With Atrial Fibrillation-A National Study

BACKGROUND

The risk of dementia is increased in patients with atrial fibrillation (AF).

OBJECTIVE

To study relevant co-morbidities and incident dementia (vascular dementia, Alzheimers disease, other dementia and all dementia) in AF patients.

METHODS

All adults (n = 537,513) ≥45 years diagnosed with AF in hospitals in Sweden 1998-2012 were included. Cox regression was used to estimate hazard ratios (HR) with 95% CIs for association between co-morbidities, and incident dementia, after adjustment for age, residence place in Sweden, and socio-economic factors.

RESULTS

Totally 30,332 patients (5.6%) were diagnosed with dementia during the follow-up, with 14,097 men (4.9%) and 16,235 women (6.5%). After adjustments (HRs; 95% CI), hypertension was associated with lower risk of incident dementia (all types) in men (0.79; 0.76-0.82) and women (0.77; 0.74-0.79). Higher risk of dementia was seen in patients with stroke, diabetes, depression and anxiety. Lower risks of dementia were also seen in AF patients with concomitant coronary heart disease and congestive heart failure.

CONCLUSIONS

The findings regarding incident dementia need to be interpreted with great caution, owing to possible "survival bias" or reversed causation. However, the lower associated risks of dementia associated with hypertension could possibly be explained by protective effects of certain antihypertensive drugs.

Metabolically Healthy Obesity and Risk for Atrial Fibrillation: The HUNT Study

OBJECTIVE

Atrial fibrillation (AF) is the most common arrhythmia and has been described as a global epidemic. Although AF is associated with both obesity and its metabolic consequences, little is known about the association between metabolically healthy obesity and AF.

METHODS

In a population-based study, 47,870 adults were followed for incident AF from 2006 to 2008 until 2015. Participants were classified according to BMI and metabolic status (using waist circumference, triglycerides, high-density lipoprotein cholesterol, blood pressure, and glucose) at baseline.

RESULTS

During a median follow-up of 8.1 years, 1,758 participants developed AF. Compared with metabolically healthy individuals with BMI < 25 kg/m² , the multivariable-adjusted hazard ratios for metabolically healthy and unhealthy obesity were 1.6 (95% CI: 1.2 to 2.1) and 1.6 (95% CI: 1.3 to 1.9), respectively. AF risk increased according to the severity of obesity.

CONCLUSIONS

Metabolically healthy and unhealthy obesity increased AF risk to a similar extent. Severity of obesity was positively associated with AF risk regardless of metabolic status.

Atrial fibrillation independently linked with depression in community-dwelling older population. Results from the nationwide PolSenior project

BACKGROUND

Depression is a frequently observed comorbid condition in patients with cardiovascular diseases. In contrast to coronary heart disease and heart failure there is a limited amount of published data concerning the increased prevalence of depression among patients with atrial fibrillation (AF). Therefore, we decided to assess the prevalence of depression in Polish community-dwelling older patients with a history of AF.

METHODS

The data were collected as part of the nationwide PolSenior project (2007-2012). Out of 4979 individuals (age range 65-104 years), data on self-reported history of AF were available for 4677 (93.9%). Finally, 4049 participants without suspected moderate or severe dementia in Mini Mental State Examination test were assessed with the 15-item Geriatric Depression Scale (GDS), and a score of 6 points and more was regarded as suspected depression.

RESULTS

Mean age (±SD) of the study population was 78.1 (±8.3) years; 52% were males. The history of AF was reported by 788 (19.5%) subjects. In the univariate analysis a self-reported AF history was associated with 42% increase of suspected depression (41% vs 29%; P < 0.001). In multivariate logistic regression AF remained an independent predictor of depression (OR = 1.69; 95%CI: 1.43-2.00), stronger than heart failure, diabetes or coronary heart disease.

CONCLUSIONS

In community-dwelling geriatric Polish population AF is associated with higher prevalence of depression. This association is independent from the demographic factors, disabilities and comorbidities (including history of stroke).

Prevalence of atrial fibrillation and cardiovascular risk factors in a 63-65 years old general population cohort: the Akershus Cardiac Examination (ACE) 1950 Study

OBJECTIVES

To investigate the sex-specific prevalence of atrial fibrillation (AF), including subclinical AF found by screening in a general population aged 63-65 years. The prevalence of cardiovascular risk factors and their association with AF will also be investigated.

DESIGN

Cross-sectional analysis of an observational, prospective, longitudinal, population-based cohort study.

SETTING

General population in Akershus county, Norway.

PARTICIPANTS

Women and men born in 1950. We included 3706 of 5827 eligible individuals (63.6%); 48.8% were women.

METHODS

All participants underwent extensive cardiovascular examinations, including 12-lead ECG. History of AF and other cardiovascular diseases were self-reported. Subsequent validation of all reported or detected AF diagnoses was performed.

RESULTS

Mean age was 63.9±0.7 years. Prevalence of ECG-verified AF was 4.5% (women 2.4%, men 6.4%; p<0.001), including screen-detected AF in 0.3% (women 0.1%, men 0.6%; p<0.01). Hypertension was found in 62.0% (women 57.8%, men 66.0%; p<0.001). Overweight or obesity was found in 67.6% (women 59.8%, men 74.9%; p<0.001). By multivariate logistic regression, risk factors associated with AF were height (OR 1.67 per 10 cm; 95% CI 1.26 to 2.22; p<0.001), weight (OR 1.15 per 10 kg; 95% CI 1.01 to 1.30; p=0.03), hypertension (OR 2.49; 95% CI 1.61 to 3.86; p<0.001), heart failure (OR 3.51; 95% CI 1.71 to 7.24; p=0.001), reduced estimated glomerular filtration rate (OR 2.56; 95% CI 1.42 to 4.60; p<0.01) and at least one first-degree relative with AF (OR 2.32; 95% CI 1.63 to 3.31; p<0.001), whereas male sex was not significantly associated (OR 1.00; 95% CI 0.59 to 1.68; p=0.99).

CONCLUSION

In this cohort from the general population aged 63-65 years, we found a higher prevalence of known AF than previously reported below the age of 65 years. The additional yield of single time point screening for AF was low. Body size and comorbidity may explain most of the sex difference in AF prevalence at this age.

TRIAL REGISTRATION NUMBER

NCT01555411; Results.

Physical activity modifies the risk of atrial fibrillation in obese individuals: The HUNT3 study

Background

Atrial fibrillation is the most common heart rhythm disorder, and high body mass index is a well-established risk factor for atrial fibrillation. The objective of this study was to examine the associations of physical activity and body mass index and risk of atrial fibrillation, and the modifying role of physical activity on the association between body mass index and atrial fibrillation.

Design

The design was a prospective cohort study.

Methods

This study followed 43,602 men and women from the HUNT3 study in 2006–2008 until first atrial fibrillation diagnosis or end of follow-up in 2015. Atrial fibrillation diagnoses were collected from hospital registers and validated by medical doctors. Cox proportional hazard regression analysis was performed to assess the association between physical activity, body mass index and atrial fibrillation.

Results

During a mean follow-up of 8.1 years (352,770 person-years), 1459 cases of atrial fibrillation were detected (4.1 events per 1000 person-years). Increasing levels of physical activity were associated with gradually lower risk of atrial fibrillation ( p trend 0.069). Overweight and obesity were associated with an 18% (hazard ratio 1.18, 95% confidence interval 1.03–1.35) and 59% (hazard ratio 1.59, 95% confidence interval 1.37–1.84) increased risk of atrial fibrillation, respectively. High levels of physical activity attenuated some of the higher atrial fibrillation risk in obese individuals (hazard ratio 1.53, 95% confidence interval 1.03–2.28 in active and 1.96, 95% confidence interval 1.44–2.67 in inactive) compared to normal weight active individuals.

Conclusion

Overweight and obesity were associated with increased risk of atrial fibrillation. Physical activity offsets some, but not all, atrial fibrillation risk associated with obesity.

Does Moderate Drinking Increase the Risk of Atrial Fibrillation? The Norwegian HUNT (Nord-Trøndelag Health) Study

BACKGROUND

Compelling evidence suggests that excessive alcohol consumption increases the risk of atrial fibrillation (AF), but the effect of light-moderate alcohol consumption is less certain. We investigated the association between alcohol consumption within recommended limits and AF risk in a light-drinking population.

METHODS AND RESULTS

Among 47 002 participants with information on alcohol consumption in a population-based cohort study in Norway, conducted from October 2006 to June 2008, 1697 validated AF diagnoses were registered during the 8 years of follow-up. We used Cox proportional hazard models with fractional polynomials to analyze the association between alcohol intake and AF. Population attributable risk for drinking within the recommended limit (ie, at most 1 drink per day for women and 2 drinks per day for men without risky drinking) compared with nondrinking was also calculated. The average alcohol intake was 3.8±4.8 g/d. The adjusted hazard ratio for AF was 1.38 (95% confidence interval, 1.06-1.80) when we compared participants consuming >7 drinks per week with abstainers. When we modeled the quantity of alcohol intake as a continuous variable, the risk increased in a curvilinear manner. It was higher with heavier alcohol intake, but there was virtually no association at <1 drink per day for women and <2 drinks per day for men in the absence of risky drinking. The population attributable risk among nonrisky drinkers was 0.07% (95% confidence interval, -0.01% to 0.13%).

CONCLUSIONS

Although alcohol consumption was associated with a curvilinearly increasing risk of AF in general, the attributable risk of alcohol consumption within recommended limits among participants without binge or problem drinking was negligible in this population.