Congestive heart failure in subjects with normal versus reduced left ventricular ejection fraction: prevalence and mortality in a population-based cohort

Abstract

Objectives: The purpose of this study was to assess the relative proportions of normal versus impaired left ventricular (LV) systolic function among persons with congestive heart failure (CHF) in the community and to compare their long-term mortality during follow-up.

Background: Several hospital-based investigations have reported that a high proportion of subjects with CHF have normal LV systolic function. The prevalence and prognosis of CHF with normal LV systolic function in the community are not known.

Methods: We evaluated the echocardiograms of 73 Framingham Heart Study subjects with CHF (33 women, 40 men, mean age 73 years) and 146 age- and gender-matched control subjects (nested case-control study). Impaired LV systolic function was defined as an LV ejection fraction (LVEF) <0.50.

Results: Thirty-seven CHF cases (51%) had a normal LVEF; 36 (49%) had a reduced LVEF. Women predominated in the former group (65%), whereas men constituted 75% of the latter group. During a median follow-up of 6.2 years, CHF cases with normal LVEF experienced an annual mortality of 8.7% versus 3.0% for matched control subjects (adjusted hazards ratio = 4.06, 95% confidence interval 1.61 to 10.26). Congestive heart failure cases with reduced LVEF had an annual mortality of 18.9% versus 4.1% for matched control subjects (adjusted hazards ratio = 4.31, 95% confidence interval 1.98 to 9.36).

Conclusions: Normal LV systolic function is often found in persons with CHF in the community and is more common in women than in men. Although CHF cases with normal LVEF have a lower mortality risk than cases with reduced LVEF, they have a fourfold mortality risk compared with control subjects who are free of CHF.