Left ventricular ejection fraction (LVEF)[1] has persisted as the primary measure of left ventricular systolic function despite flaws in this approach. Patients with heart failure are relieved when the LVEF is reported as normal, and clinicians may use the report of a depressed LVEF to persuade patients of the need for treatment. Therefore, patients often use any change in LVEF to track progress or deterioration in their condition. Although misguided, many patients will assume a report indicating a normal LVEF indicates recovery.
The best method to define a normal LVEF, or any diagnostic test result, is unclear. Investigators traditionally have evaluated populations who are assumed to be healthy and determined the distribution of the test result. They then picked a boundary of the population distribution (upper or lower 5% or 1%) to determine "normal." A recent meta-analysis of such population studies that included adults without clinical cardiovascular or renal disease, hypertension, or diabetes found that the threshold for a normal LVEF (defined as the lower 5th percentile of the distribution) varied by race or ethnicity and sex (European men 50%, women 51%; East Asian men 56%, women 57%; South Asian men 52%, women 53%; comparable data were not available for other races or ethnicities).
