Pulse pressure index (pulse pressure/systolic pressure) may be better than pulse pressure for assessment of cardiovascular outcomes.

Pulse pressure (PP) is emerging as a major pressure predictor of cardiac disease. However, there are two major limitations for PP as an evaluation index. First, PP has alterability in the same individual. Second, PP is "floating", it has no relation to an absolute BP level. In order to overcome the defects of PP, we propose a novel parameter, "pulse pressure/systolic pressure" called "pulse pressure index (PPI)" for assessment of cardiovascular outcomes. On the basis of elastic chamber theory, the following equation can be derived: PPI=pulse pressure/systolic pressure=(Cs-Cd)/(Cs-C(0)), (Cs, Cd and C(0), arterial compliance at systolic pressure, diastolic pressure and zero-pressure, respectively). PPI can overcome the defects of PP and become a useful index in clinical evaluation for assessment of cardiovascular outcomes.