Association of Left Ventricular Systolic Function With Incident Heart Failure in Late Life.

Importance: Limited data exist regarding the association of subtle subclinical systolic dysfunction and incident heart failure (HF) in late life.

Objective: To assess the independent associations of subclinical impairments in systolic performance with incident HF in late life.

Design, Setting, And Participants: This study was a time-to-event analysis of participants without heart failure in the Atherosclerosis Risk in Communities (ARIC) study, a prospective, community-based cohort study, who underwent protocol echocardiography at the fifth study visit (January 1, 2011, to December 31, 2013). Findings were validated independently in participants in the Copenhagen City Heart Study (CCHS). Data analysis was performed from June 1, 2018, to February 28, 2020.

Exposures: Left ventricular ejection fraction (LVEF), longitudinal strain (LS), and circumferential strain (CS) measured by 2-dimensional and strain echocardiography.

Main Outcomes And Measures: Main outcomes were incident adjudicated HF and HF with preserved and reduced LVEF at a median follow-up of 5.5 years (interquartile range, 5.0-5.8 years). Cox proportional hazards regression models adjusted for demographics, hypertension, diabetes, obesity, smoking, coronary disease, estimated glomerular filtration rate, LV mass index, e', E/e', and left atrial volume index. Lower 10th percentile limits were determined in 374 participants free of cardiovascular disease or risk factors.

Results: Among 4960 ARIC participants (mean [SD] age, 75 [5] years; 2933 [59.0%] female; 965 [19%] Black), LVEF was less than 50% in only 76 (1.5%). In the 3552 participants with complete assessment of LVEF, LS, and CS, 983 (27.7%) had 1 or more of the following findings: LVEF less than 60%, LS less than 16.0%, or CS less than 23.7%. Modeled continuously or dichotomized, worse LVEF, LS, and CS were each independently associated with incident HF. The adjusted hazard ratio (HR) per SD decrease in LVEF was 1.41 (95% CI, 1.29-1.55); the HR for LVEF less than 60% was 2.59 (95% CI, 1.99-3.37). Similar findings were observed for continuous LS (HR, 1.37; 95% CI, 1.22-1.53) and dichotomized LS (HR, 1.93; 95% CI, 1.46-2.55) and for continuous CS (HR, 1.39; 95% CI, 1.22-1.57) and dichotomized CS (HR, 2.30; 95% CI, 1.64-3.22). Although the magnitude of risk for incident HF or death associated with impaired LVEF was greater using guideline (HR, 2.99; 95% CI, 2.19-4.09) compared with ARIC-based limits (HR, 1.88; 95% CI, 1.58-2.25), the number of participants classified as impaired was less (104 [2.1%] based on guideline thresholds compared with 692 [13.9%] based on LVEF <60%). The population-attributable risk associated with LVEF less than 60% was 11% compared with 5% using guideline-based limits, a finding replicated in 908 participants in the CCHS.

Conclusions And Relevance: These findings suggest that relatively subtle impairments of systolic function (detected based on LVEF or strain) are independently associated with incident HF and HF with reduced LVEF in late life. Current recommended assessments of LV function may substantially underestimate the prevalence of prognostically important impairments in systolic function in this population.