Aortic Pressure Augmentation Predicts Adverse Cardiovascular Events in Patients With Established Coronary Artery Disease

Pulse pressure (PP), a marker of arterial stiffness, predicts cardiovascular risk. We aimed to determine whether augmentation pressure (AP) derived from the aortic pressure waveform predicts major adverse cardiovascular events (MACE) and death independently of PP in patients with established coronary artery disease (CAD). We prospectively followed-up 297 males undergoing coronary angiography for 1186+/-424 days. Ascending aortic pressure tracings obtained during catheterization were used to calculate AP (difference between the second and the first systolic peak). Augmentation index (AIx) was defined as AP as a percentage of PP. We evaluated whether AP and AIx can predict the risk of MACE (unstable angina, acute myocardial infarction, coronary revascularization, stroke, or death) and death using Cox regression. All models evaluating AP included PP to assess whether AP adds to the information already provided by PP. Both AP and AIx significantly predicted MACE. The hazard ratio (HR) per 10 mm Hg increase in AP was 1.20 (95% confidence interval CI, 1.08 to 1.34; P<0.001); the HR for each 10% increase in AIx was 1.28 (95% CI, 1.11 to 1.48; P=0.004). After adjusting for other univariate predictors of MACE, age, and other potential confounders, AP remained a significant predictor of MACE (HR per 10 mm Hg increase=1.19; 95% CI, 1.06 to 1.34; P=0.002), as did AIx (adjusted HR, 1.28; 95% CI, 1.09 to 1.50; P=0.003). AP was a significant predictor of death (HR per 10 mm Hg increase=1.18; 95% CI, 1.02 to 1.39; P=0.03). Higher AIx was associated with a trend toward increased mortality (HR=1.22; 95% CI, 0.98 to 1.52; P=0.056). Aortic AP predicts adverse outcomes in patients with CAD independently of PP and other risk markers.