ObjectivesTo 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.DesignCross-sectional analysis of an observational, prospective, longitudinal, population-based cohort study.SettingGeneral population in Akershus county, Norway.ParticipantsWomen and men born in 1950. We included 3706 of 5827 eligible individuals (63.6%); 48.8% were women.MethodsAll 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.ResultsMean 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).ConclusionIn 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 numberNCT01555411; Results.

Background Concentrations of cardiac troponin I (cTnI) and T (cTnT) are associated with clinical cardiac outcomes, but do not correlate closely in subjects recruited from the general population. Accordingly, we hypothesized that cTnI and cTnT concentrations would be influenced by different cardiovascular (CV) and non-CV risk factors and reflect different CV phenotypes. Methods We measured cTnI and cTnT with last generation assays in 1236 women and 1157 men with no known CV disease participating in the prospective observational Akershus Cardiac Examination 1950 Study. All study participants underwent extensive CV phenotyping at baseline, including detailed echocardiography. Results Concentrations of cTnI were measurable in 60.3% and cTnT in 72.5% of study participants (P &lt; 0.001), and correlated moderately (r = 0.53; P &lt; 0.001). cTnI was more strongly associated with male sex (P = 0.018), higher education (P &lt; 0.001), history of hypertension (P &lt; 0.001), and age (P &lt; 0.001), whereas cTnT was more strongly associated with eGFR (P = 0.015). Both cTnI and cTnT were inversely associated with global longitudinal strain and positively associated with LV mass index (LVMI) in analyses adjusted for CV risk factors. The association between cTnI and LVMI was stronger than the association between cTnT and LVMI (P = 0.035). Concentrations of cTnI improved diagnostic accuracy for LV hypertrophy when added to established CV risk factors, but concentrations of cTnT did not improve these models further. Conclusions In a large community-based cohort examined with extensive echocardiography, concentrations of cTnI and cTnT are associated with subclinical LV hypertrophy and dysfunction. Concentrations of cTnI appear superior to cTnT in predicting subclinical LV hypertrophy.

Aims Increased left ventricular mechanical dispersion by 2D speckle tracking echocardiography predicts ventricular arrhythmias in ischaemic heart disease and heart failure. However, little is known about mechanical dispersion in the general population. We aimed to study mechanical dispersion in the general population and in diseases associated with increased risk of cardiovascular disease. Methods and results The present cross-sectional study consists of 2529 subjects born in 1950 included in the Akershus Cardiac Examination (ACE) 1950 study. Global longitudinal strain (GLS) was assessed from 17 strain segments, and mechanical dispersion calculated as the standard deviation of contraction duration of all segments. The cohort was divided according to the median value of mechanical dispersion, and multivariable linear regression models were performed with mechanical dispersion as the dependent variable. The prevalence of coronary artery disease (CAD), hypertension, obesity, and diabetes (P < 0.01 for all) was significantly higher in subjects with supra-median mechanical dispersion. In a multivariable clinical model, CAD (B = 7.05), hypertension (B = 4.15; both P < 0.001), diabetes (B = 3.39), and obesity (B = 1.89; both P < 0.05) were independently associated with increasing mechanical dispersion. When echocardiographic indices were added to the multivariable model, CAD (B = 4.38; P < 0.01) and hypertension (B = 2.86; P < 0.001) remained significant in addition to peak early diastolic tissue velocity e’ (B = −2.00), GLS (B = 1.68), and ejection fraction (B = 0.22; P < 0.001 for all). Conclusion In a general middle-aged population, prevalent CAD and hypertension were associated with increasing mechanical dispersion, possibly indicating elevated risk of fatal arrhythmias and sudden cardiac death. Albeit weaker, systolic and diastolic dysfunction, were also associated with increasing mechanical dispersion.