The effect of COX inhibition on augmentation index and peripheral wave reflection

We examined the effects of the COX inhibitor Indomethacin (Indo) on central arterial hemodynamics and wave reflection characteristics in young (25±2 y; 7M/5F) and old (66±2 y; 4M/4F) healthy adults. High‐fidelity radial arterial pressure waveforms were measured non‐invasively by applanation tonometry before and after oral ingestion of Indo (1.2mg/kg). Measurements were recorded before (PRE) and 120 min after (POST) Indo ingestion. Brachial blood pressures were similar PRE vs. POST in both groups; however, POST systolic and diastolic aortic pressures were elevated in old subjects (P<0.05). In addition, POST aortic and radial augmentation index were elevated in old subjects (PRE vs. POST: 27±4% vs. 34±6% and 81±6% vs. 98±7%, respectively; P<0.01 for both). In the old subjects, augmented pressure increased (Δ +9mmHg; P<0.01) and pulse pressure amplification decreased (Δ −12%; P<0.05) at POST. Furthermore, old subjects had a 60% increase in wasted left ventricular energy after Indo. In contrast, young subjects showed no significant changes in any of the variables of interest. Taken together, these results demonstrate that COX inhibition unfavorably increases central and peripheral wave reflection and augments aortic pressure in old, but not young subjects. NIH:AG16574‐11PP2