Clinical and Echocardiographic Correlates of Left Atrial Function Index: The Framingham Offspring Study

Abstract

Background: Left atrial (LA) remodeling is a predictor of cardiovascular disease (CVD). We performed measurement of the LA function index (LAFI), a composite measure of LA structure and function, in a community-based cohort and here report the distribution and cross-sectional correlates of LAFI. Methods: In 1,719 Framingham Offspring Study participants (54% women, mean age 66 ± 9 years), we derived LAFI from the LA emptying fraction, left ventricular (LV) outflow tract velocity time integral, and indexed maximal LA volume. We used multivariable linear regression to assess the clinical and echocardiographic correlates of LAFI adjusting for age, sex, anthropometric measurements, and CVD risk factors. Results: The average LAFI was 35.2 ± 12.1. Overall, LAFI declined with advancing age (β = −0.27, P < .001). LAFI was significantly higher (37.5 ± 11.6) in a subgroup of participants free of CVD and CVD risk factors compared with those with either of these conditions (34.5 ± 12.2). In multivariable models, LAFI was inversely related to antihypertensive use (β = −1.26, P = .038), prevalent atrial fibrillation (β = −4.46, P = .001), heart failure (β = −5.86, P = .008), and coronary artery disease (β = −2.01, P = .046). In models adjusting for echocardiographic variables, LAFI was directly related to LV ejection fraction (β = −14.84, P < .001) and inversely related to LV volume (β = −7.03, P < .001). Conclusions: LAFI was inversely associated with antihypertensive use and prevalent CVD and was related to established echocardiographic traits of LV remodeling. Our results offer normative ranges for LAFI in a white community-based sample and suggest that LAFI represents a marker of pathological atrial remodeling.

Relations between plasma microRNAs, echocardiographic markers of atrial remodeling, and atrial fibrillation: Data from the Framingham Offspring study

“…In our investigation of Framingham Offspring Study Cohort Exam 8 participants, we identified 73 plasma microRNAs associated with LAFI (S3 Table), a validated marker of structural and functional left atrial remodeling [9]. We identified 20 microRNAs associated with LAFI and either prevalent or incident AF.…”

“…For the present analysis, we excluded the participants with suboptimal LA imaging, and those with incomplete data for key covariates, including components of the Cohorts for Heart and Aging Research in Genomic Epidemiology-Atrial Fibrillation (CHARGE-AF) risk score (Fig 1) [15]. The baseline characteristics of FHS Offspring participants with and without measurable LAFI did not differ [9]. The protocol for the Framingham Offspring study was approved by the Boston University Medical Center Institutional Review Board and all analyses were approved by the University of Massachusetts Medical School Institutional Review Board (IRB #H0010802).…”

“…Atrial structural remodeling, as measured echocardiographically by left atrial (LA) size and LA phasic function, is a potent intermediate phenotype that reflects prior CVD risk factor exposure intensity and has been associated with risk for development of AF [8]. We recently demonstrated strong associations between echocardiographic LA function index (LAFI), a composite measure of both LA structure and function, with incident AF and CVD in the Framingham Offspring Cohort [9]. LAFI, unlike other echocardiographic parameters, captures AF vulnerability even in the presence of normal LA size because it incorporates atrial function in addition to volume-based measurements.…”

Association of Left Atrial Function Index with Atrial Fibrillation and Cardiovascular Disease: The Framingham Offspring Study

“…[22][23][24][25] We recently reported on the distribution of LAFI as well as its clinical and echocardiographic correlates in the community-based FHS (Framingham Heart Study) Offspring Cohort. 26 In the current investigation, we related LAFI to incident AF and CVD in FHS Offspring participants and assessed its incremental contribution to prediction of these outcomes.…”

Association of subclinical atherosclerosis with echocardiographic indices of cardiac remodeling: The Framingham Study

“…[30] LAmax and LAmin were calculated by averaging LAmax and LAmin measurements from the apical two-and four chamber views. [31] We included LAEF only for the Offspring cohort (n = 885 participants), in this analysis, because LAEF data were not available for participants in the Third Generation cohort. Early transmitral Doppler flow velocity (E wave) and tissue Doppler assessment of peak early diastolic tissue velocity of the lateral mitral annulus (e') were measured by pulsewave Doppler from the apical four-chamber view.…”