Peripheral Arterial Tonometry for Risk Stratification in Men With Coronary Artery Disease

Background: Coronary artery disease (CAD) risk is not fully revealed by traditional risk factors. Identification of a simple, noninvasive tool that allows for detection of high-risk CAD patients and can be applied in large populations and clinical settings would prove valuable. Hypothesis: We sought to test the hypothesis that peripheral arterial tonometry (PAT) would be associated with residual risk in men with CAD. Methods: In this study, finger PAT was used to measure pulse wave amplitude (PWA) during reactive hyperemia (RH) and taken as a measure of microvascular endothelial function in 42 men with stable CAD and well controlled tow-density lipoprotein cholesterol (LDL-C) levels. Plasma levels of high-sensitivity C-reactive protein (hs-CRP) and lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) were measured and used to reclassify men into high-risk (elevated hs-CRP and Lp-PLA(2)), moderate-risk (either elevated hs-CRP or Lp-PLA(2)), or low-risk (low hs-CRP and Lp-PLA(2)) groups. Results: PWA-RH was significantly lower in the high-risk group (1-3 +/- 0.04) compared to the moderate-risk (1.6 +/- 0.07, P < 0.05) and low-risk (2.0 +/- 0.1, P < 0.05) groups. According to binary logistic regression, PWA-RH was a significant predictor of high-risk status among men with CAD (P < 0.05). Conclusion: Measurement of peripheral microvascular endothelial function with PAT may be able to distinguish high-risk men from moderate- and low-risk men with stable CAD and well-controlled LDL-C levels and thus aid in residual risk stratification in this at risk cohort.