Abstract
There is no clear consensus on a lower cutoff value for normal left ventricular ejection fraction (EF) and the prognostic implications of low normal EF (LNEF) are poorly understood, particularly in Blacks. Therefore, we investigated the association of LNEF and incident heart failure (HF) in a community-based cohort of Blacks. We studied 3,669 participants (mean age 54 years, 63% women) of the Jackson Heart Study without prevalent HF or coronary heart disease (CHD). Participants were divided into three groups: (1) Reduced EF (<50%), (2) LNEF (≥50%, <55%), and (3) Normal EF (≥55%). There were 197 cases of incident HF hospitalizations over a median follow-up of 10 years (interquartile range 9.4 to 10). After adjustment for conventional risk factors and incident CHD, the LNEF group had a higher rate of incident HF hospitalization than the Normal EF group (HR 1.58, 95% CI 1.04 to 2.38, p<0.05). Furthermore, this relation remained statistically significant after additionally adjusting for LV mass index but was not significant after adjusting for LV diastolic dysfunction grade. In participants with LNEF with incident HF, 63% developed HF with reduced EF and 37% developed HF with preserved EF. In conclusion, LNEF is associated with higher risk of incident HF hospitalization in comparison with normal EF in a community-based cohort of Blacks. In those with LNEF who went on to develop HF, most cases were HF with reduced EF. These findings suggest that strategies are needed for risk stratification and management to improve outcomes in patients with LNEF.