Prognostic Value of Peripheral Arterial Tonometry in Patients with Coronary Artery Disease and a High Cardiovascular Risk Profile

Aim: Data regarding the prognostic value of peripheral endothelial function testing in patients with cardiovascular disease are conflicting. Peripheral arterial tonometry (PAT) is increasingly used to measure the peripheral endothelial function. The prognostic value of this method has not been investigated thus far in patients with cardiovascular disease and/or a high cardiovascular risk profile. Methods: In 96 patients with significant coronary artery disease (CAD) or < 70% stenosis and >= three cardiovascular risk factors, reactive hyperemia was induced following upper arm occlusion and the PAT-ratio between baseline and hyperemia was calculated. The patients were followed for cardiovascular events (revascularization, acute coronary syndrome, ischemic stroke, cardiovascular death, repeat coronary angiography due to chest pain) for 44 +/- 14 months. The first event was included in the combined end point. Results: The study cohort was divided according to the median PAT-ratio (1.91). The combined end point occurred in 14 patients with a PAT-ratio below the median (1.91) and in 12 patients with a PAT-ratio of >= 1.91 (p=0.65). In a subgroup of 76 patients, the PAT-ratio was reassessed after six months. No differences in the event rate were found between the patients who exhibited deterioration (n=50) and those who exhibited an improvement in the PAT-ratio of > 0.1 (n=26; 22 vs. 32%, p=0.32). The combined end point occurred earlier in the patients with a PAT-ratio within the 1st tertile than in those with a PAT-ratio within the 2nd/3rd tertile (11.3 +/- 11.0 vs. 27.5 +/- 18.6 months, p=0.03). Conclusions: In patients with established CAD or a high cardiovascular risk profile, the PAT-ratio cannot be used to predict the risk of future cardiovascular events. However, a lower PAT-ratio may be associated with the earlier occurrence of cardiovascular events.