Abstract 16761: Pressure-Independent Pulsatility Index (PIPI) Independently Predicts Cardiovascular Events in the Cafe Sub-Study of Ascot
Background: Prediction of cardiovascular events from the arterial pressure waveform is usually dependent on knowledge of the absolute blood pressure. However, several studies suggest that the pulsatility of the pressure waveform, rather than absolute blood pressure, may be an important predictor of cardiovascular (CV) events. We therefore hypothesised that CV events would be predictable from a pressure-independent pulsatility index (PIPI) related to wave propagation in the circulation. Aim: To identify if PIPI is an independent predictor of cardiovascular events in the CAFE sub-study of the ASCOT trial.
Methods: Radial pressure waveforms were acquired using Sphygmocor in 2070 subjects (63±8 yrs; 1675 male). A scale-independent PIPI was calculated from the normalized radial pressure waveforms by dividing the excess pressure integral by the reservoir pressure integral. A total of 243 CV events were recorded in the study participants.
Results: PIPI predicted total CV events (logistic regression odds ratio =3.65 [1.97–6.73], p<0.001), and remained significant after adjustment for age, sex, treatment, number of CV risk factors, brachial BP, central systolic pressure, central pulse pressure, AIx and heart rate (logistic regression odds ratio =3.25 [1.46–7.24], p<0.005).
Conclusions: Pressure-independent pulsatility index independently predicts CV events in the CAFE study without requiring knowledge of arterial pressure. PIPI is easily calculated from the shape of the arterial waveform and does not require calibration or the use of a generalised transfer function. PIPI simplifies cardiovascular assessment and has potential as a tool for risk evaluation and for monitoring the effects of preventive therapy.
- © 2010 by American Heart Association, Inc.