Incidence of and Risk Factors for Sick Sinus Syndrome in the General Population

AbstractBackgroundLittle is known about the incidence of and risk factors for sick sinus syndrome (SSS), a common indication for pacemaker implantation.ObjectivesThis study sought to describe the epidemiology of SSS.MethodsThis analysis included 20,572 participants (mean baseline age 59 years, 43% male) in the ARIC (Atherosclerosis Risk In Communities) study and the CHS (Cardiovascular Health Study), who at baseline were free of prevalent atrial fibrillation and pacemaker therapy, had a heart rate of ≥50 beats/min unless using beta blockers, and were identified as of white or black race. Incident SSS cases were identified by hospital discharge International Classification of Disease-revision 9-Clinical Modification code 427.81 and validated by medical record review.ResultsDuring an average 17 years of follow-up, 291 incident SSS cases were identified (unadjusted rate 0.8 per 1,000 person-years). Incidence increased with age (hazard ratio [HR]: 1.73; 95% confidence interval [CI]: 1.47 to 2.05 per 5-year increment), and blacks had a 41% lower risk of SSS than whites (HR: 0.59; 95% CI: 0.37 to 0.98). Incident SSS was associated with greater baseline body mass index, height, N-terminal pro–B-type natriuretic peptide, and cystatin C, with longer QRS interval, with lower heart rate, and with prevalent hypertension, right bundle branch block, and cardiovascular disease. We project that the annual number of new SSS cases in the United States will increase from 78,000 in 2012 to 172,000 in 2060.ConclusionsBlacks have a lower risk of SSS than whites, and several cardiovascular risk factors were associated with incident SSS. With the aging of the population, the number of Americans with SSS will increase dramatically over the next 50 years

Fish, Fish-Derived n-3 Fatty Acids, and Risk of Incident Atrial Fibrillation in the Atherosclerosis Risk in Communities (ARIC) Study

Results of observational and experimental studies investigating the association between intake of long-chain n-3 polyunsaturated fatty acids (PUFAs) and risk of atrial fibrillation (AF) have been inconsistent.We studied the association of fish and the fish-derived n-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) with the risk of incident AF in individuals aged 45-64 from the Atherosclerosis Risk in Communities (ARIC) cohort (n = 14,222, 27% African Americans). Intake of fish and of DHA and EPA were measured via food frequency questionnaire. Plasma levels of DHA and EPA were measured in phospholipids in a subset of participants (n = 3,757). Incident AF was identified through the end of 2008 using ECGs, hospital discharge codes and death certificates. Cox proportional hazards regression was used to estimate hazard ratios of AF by quartiles of n-3 PUFAs or by fish intake.During the average follow-up of 17.6 years, 1,604 AF events were identified. In multivariable analyses, total fish intake and dietary DHA and EPA were not associated with AF risk. Higher intake of oily fish and canned tuna was associated with a nonsignificant lower risk of AF (p for trend = 0.09). Phospholipid levels of DHA+EPA were not related to incident AF. However, DHA and EPA showed differential associations with AF risk when analyzed separately, with lower risk of AF in those with higher levels of DHA but no association between EPA levels and AF risk.In this racially diverse sample, dietary intake of fish and fish-derived n-3 fatty acids, as well as plasma biomarkers of fish intake, were not associated with AF risk

Hazard ratio (95% confidence interval) of atrial fibrillation by combined dietary and biomarker DHA and EPA, ARIC Minnesota field center, 1987–2005.

*<p>Adjusted for age, sex, BMI, education, energy intake, exercise levels, smoking status and amount, alcohol intake, total cholesterol, use of cholesterol lowering medications, systolic blood pressure, use of antihypertensive medications, diabetes, coronary heart disease, and ECG-defined left ventricular hypertrophy.</p><p>CI: Confidence interval. HR: hazard ratio.</p

Hazard ratios (95% confidence interval) of atrial fibrillation by categories of DHA+EPA intake, ARIC, 1987–2008.

<p>Dietary DHA and EPA adjusted for energy using the residual method. CI: Confidence interval. HR: Hazard ratio. Model 1: adjusted for age, sex, and race; Model 2: adjusted for center, age, race, sex, energy intake, BMI, education, exercise levels, smoking status and amount, alcohol intake, HDL-C, LDL-C, use of cholesterol lowering medications, systolic blood pressure, use of antihypertensive medications, diabetes, coronary heart disease, and ECG-defined left ventricular hypertrophy.</p

Baseline characteristics of ARIC participants (n = 14,222), 1987–1989.

<p>Values are % for categorical variables and mean (SD) for continuous variables. BMI: Body mass index. CHD: Coronary heart disease. DHA: Docosahexaenoic acid. ECG: Electrocardiogram. EPA: Eicosapentanoic acid.</p

Hazard ratios (95% confidence intervals) of atrial fibrillation by fish intake categories, ARIC, 1987–2008.

<p>CI: Confidence interval. HR: Hazard ratio. Model 1: adjusted for age, sex, and race; Model 2: adjusted for center, age, race, sex, energy intake, body mass index, education, exercise levels, smoking status and amount, alcohol intake, LDL cholesterol, HDL cholesterol, use of cholesterol lowering medications, systolic blood pressure, use of antihypertensive medications, diabetes, coronary heart disease, and ECG-defined left ventricular hypertrophy.</p