Airflow obstruction, lung function, and incidence of atrial fibrillation: the Atherosclerosis Risk in Communities (ARIC) study

Abstract

Background: Reduced low forced expiratory volume in 1 second (FEV1) is reportedly associated with an increased risk of atrial fibrillation (AF). Extant reports do not provide separate estimates for never smokers or for blacks, who incongruously have lower AF incidence than whites.

Methods and results: We examined 15 004 middle-aged blacks and whites enrolled in the Atherosclerosis Risk in Communities (ARIC) cohort study. Standardized spirometry data were collected at the baseline examination. Incident AF was identified from the first among the following: International Classification of Diseases codes for AF on hospital discharge records or death certificates or 12-lead ECGs performed during 3 triennial follow-up visits. Over an average follow-up of 17.5 years, a total of 1691 participants (11%) developed new-onset AF. The rate of incident AF was inversely associated with FEV1 in each of the 4 race and sex groups. After multivariable adjustment for traditional cardiovascular disease risk factors and height, hazard ratios of AF comparing the lowest with the highest quartile of FEV1 were 1.37 (95% confidence interval, 1.02-1.83) for white women, 1.49 (95% confidence interval, 1.16-1.91) for white men, 1.63 (95% confidence interval, 1.00-2.66) for black women, and 2.36 (95% confidence interval, 1.30-4.29) for black men. The above associations were observed across all smoking status categories. Moderate/severe airflow obstruction (FEV1/forced vital capacity <0.70 and FEV1 < 80% of predicted value) was also associated with higher AF incidence.

Conclusions: In this large population-based study with a long-term follow-up, reduced FEV1 and obstructive respiratory disease were associated with a higher AF incidence after adjustment for measured confounders.

Keywords: atrial fibrillation; forced expiratory volume; pulmonary disease, chronic obstructive; respiratory physiological phenomena; risk factors; vital capacity.

Figure 1

Hazard ratio (HR, solid line) with 95% confidence intervals (CI, dotted lines)of atrial fibrillation by forced expiratory volume (1s) (FEV_1, 1a) and by Forced vital capacity (FVC, 1b), adjusted for sex, race, age (continuous), sitting height, and sitting height². The curves are plotted using restricted cubic splines with multiple knots.

Figure 1

Hazard ratio (HR, solid line) with 95% confidence intervals (CI, dotted lines)of atrial fibrillation by forced expiratory volume (1s) (FEV_1, 1a) and by Forced vital capacity (FVC, 1b), adjusted for sex, race, age (continuous), sitting height, and sitting height². The curves are plotted using restricted cubic splines with multiple knots.

Figure 2

Estimated Hazard Ratio (95% confidence intervals) of incident atrial fibrillation for the quartiles of forced expiratory volume (1s) for each gender- and race- specific group, adjusted for age (continuous), sitting height, sitting height², and smoking. Y axis is plotted on a log scale.

Figure 3

Kaplan-Meier atrial fibrillation free survival curves by gender and race specific quartiles (Q1 - lowest quartile, Q4 - highest quartile) of forced expiratory volume (1s) i.e., FEV1. Data are from the Atherosclerosis Risk in Communities Study (ARIC) baseline examination (1987–89) in a subsample without prevalent atrial fibrillation and no missing information on important covariates, followed up through 2008.

Figure 4

Kaplan-Meier atrial fibrillation free survival curves by airflow obstruction defined by non-bronchodilator spirometry data using Global Obstructive Lung Disease initiative criteria. Data are from the Atherosclerosis Risk in Communities Study (ARIC) baseline examination (1987–89) in a subsample without prevalent atrial fibrillation and no missing information on important covariates, followed up through 2008.