The relation between CFI, PAOP and SmvO2. (a) The relationship between cardiac function index (CFI) and pulmonary artery occlusion pressure (PAOP) in patients with sepsis and acute heart failure. In patients with acute heart failure, CFI is negatively correlated with PAOP (r2 = -0.18, P = 0.006), whereas there is no significant correlation in septic patients (r2 = 0.0006, P = 0.89). (b) CFI is significantly correlated with mixed venous oxygen saturation (SmvO2) in patients with sepsis (r2 = 0.22, P = 0.004) but not in patients with acute heart failure (r2 = 0.03, P = 0.26). Dashed lines indicate CFI of 4.5 per minute, PAOP of 18 mm Hg, and SmvO2 of 70%.