Abstract MP06: Longitudinal Follow-Up of Adults in the Community with Borderline Left Ventricular Systolic Function
Background: A clear threshold of left ventricular ejection fraction (LVEF) for risk prediction is uncertain. We hypothesized that individuals with a borderline LVEF of 50-55% are at increased risk for cardiovascular (CVD) morbidity and mortality in the community.
Methods: We evaluated Framingham Heart Study Original Cohort participants with echocardiographic data at examinations 16 (1979-1981) and 20 (1988-1989), and Offspring Cohort participants with echocardiographic data at examinations 4 (1987-1990), 6 (1995-1998), and 8 (2003-2008), totaling 10,221 person-observations (mean age 60±12 yrs, 43% men). We used logistic regression to assess clinical correlates of LVEF 50-55%. Using Cox proportional hazards regression, we evaluated pooled data with up to 12 years of follow-up (mean 7.5±2.5 yrs) for the incidence of heart failure (HF) and combined HF/All-cause mortality (composite outcome). In multivariable models, we assessed the association of borderline LVEF and continuous LVEF with each outcome. Kaplan-Meier survival curves compared rates of developing each outcome by LVEF category. We used restricted cubic splines to assess linearity of relations between LVEF and (log) risk of each outcome.
Results: As compared with LVEF >55%, LVEF 50-55% was associated with male sex, baseline CVD, diabetes, and higher blood pressure. Individuals with LVEF 50-55% had age- and sex-adjusted incidence rates and multivariable-adjusted risks of outcome events intermediate between those with LVEF <50% and >55% (TABLE). Every 5% decline in LVEF was associated with a 25% increased risk of HF and 13% increased risk of the composite outcome. There was a linear increase in risk with declining LVEF for both outcomes.
Conclusions: Individuals with LVEF 50-55% have a 1.5 to 2.3-fold increased risk of morbidity and mortality compared to those with LVEF >55%. The relations between LVEF and risk for HF and HF/All-cause mortality appear continuous. Further studies are warranted to elucidate the optimal management of individuals with LVEF 50-55%.
- © 2013 by American Heart Association, Inc.