Abstract 10222: Usefulness of Rho-Kinase Activity in Circulating Neutrophils for Disease Activity Assessment of Vasospastic Angina
Background: We have previously demonstrated that Rho-kinase activation is the key molecular mechanism of coronary spasm in animal models and patients with vasospastic angina (VSA). However, it remains to be examined whether Rho-kinase activity is systemically enhanced in VSA patients and if so, whether a non-invasive method could be developed for disease activity assessment of VSA.
Methods: We enrolled consecutive 53 patients with chest pain who underwent acetylcholine provocation test for coronary spasm. We divided them into the 2 groups, depending on the response to the test; VSA (n=33) and non-VSA group (n=20). We also enrolled 11 patients with stable effort angina due to severe organic stenosis who required coronary stent implantation and 40 healthy subjects. Venous blood samples were collected to measure Rho-kinase activity in circulating neutrophils, as determined by the extent of phosphorylation of myosin binding subunit (MBS), a substrate of Rho-kinase.
Results: The Rho-kinase activity (phosphorylated MBS/total MBS ratio) was 0.58±0.22 in healthy subjects. The Rho-kinase activity was significantly higher in the VSA group than in the non-VSA group (1.33±0.37 vs. 0.95±0.22, P<0.001). Importantly, the level of Rho-kinase activity in the VSA patients was comparable with that in the stable angina patients with severe organic stenosis (1.31±0.44, P=0.98). Moreover, the Rho-kinase activity was significantly associated with anginal duration and frequency in the VSA group (Figure A, B). After 3-months medical treatment, Rho-kinase activity in the VSA group was significantly decreased to 1.08±0.31 (P<0.001).
Conclusions: These findings suggest that Rho-kinase activity is systemically enhanced in accordance of disease activity of VSA and thus is useful for disease activity assessment of VSA. Importantly, the presence of coronary spasm is equivalent to that of severe coronary stenosis in terms of Rho-kinase activation.
- © 2011 by American Heart Association, Inc.