Characterization of arterial wave reflection in healthy bonnet macaques: feasibility of applanation tonometry

Nonhuman primates are commonly used in cardiovascular research. Increased arterial stiffness is a marker of subclinical atherosclerosis and higher CV risk. We determined the augmentation index (AI) using applanation tonometry in 61 healthy monkeys (59% female, age 1-25 years). Technically adequate studies were obtained in all subjects and required 1.5 +/- 1.3 minutes. The brachial artery provided the highest yield (95%). AI was correlated with heart rate (HR) (r = -0.65, P < .001), crown rump length (CRL) (r = 0.42, P = .001), and left ventricular (LV) mass determined using echocardiography (r = 0.52, P < .001). On multivariate analysis, HR (P < .001) and CRL (P = .005) were independent predictors of AI (R2 = 0.46, P < .001). Body Mass Index (BMI) and AI were independent predictors of higher LV mass on multivariate analysis (P < .001 and P = .03). In conclusion, applanation tonometry is feasible for determining AI. Reference values are provided for AI in bonnet macaques, in whom higher AI is related to HR and CRL, and in turn contributes to higher LV mass.