Cardiac index and incidence of heart failure cells

Inverse correlations were established between the percentage of iron-laden macrophages (heart-failure cells), found in the sputum of patients with various types of heart ailment, and cardiac index. Less than 2% iron-laden macrophages were seen when cardiac index was in the region of 3 liter/min/sq mm of body surface area (BSA). This fraction increased to approximately 75% when the cardiac index attained 1 liter/min/sq mm of BSA. Since there was noticeable heterogeneity of data when the cardiac index was below 3 liters/min/sq mm of BSA and above 1 liter/min/sq mm of BSA, it was concluded that a second factor was probably at play: this was the degree of activity of the reticuloendothelial system of the subjects concerned.