Abstract 12532: Association of Flow-Mediated Dilatation and High-Sensitive C-Reactive Protein in Patients With Cardiac Syndrome X
Background: Cardiac syndrome X (CSX) is characterized by angina pectoris, a positive exercise stress test response and angiographically normal coronary arteries. The condition is more common in women than men, and coronary microvascular endothelial dysfunction appears to be the underlying cause in many patients. Apart from established cardiovascular risk factors, inflammatory processes are involved in endothelial dysfunction leading to atherogenesis. The aim of this study was to assess the relationship of high-sensitive C-reactive protein (CRP) concentrations, cardiovascular risk factors and endothelial function in patients with CSX, as assessed by flow mediated dilatation (FMD) of the brachial artery.
Methods and results: Thirty-nine consecutive CSX patients (35 female, mean age 57±9 years) were recruited from a specialised CSX clinic. Study inclusion criteria were exertional chest pain, a positive response to exercise stress testing and normal coronary angiograms (no stenosis >20%). All patients underwent computer-assisted FMD according to a standardized protocol as well as measurements of CRP concentrations. An FMD response (defined by the percentage increase in mean diameter after hyperaemia) of <5% and a CRP concentration >2mg/L were considered abnormal. Twenty-four patients (62%) showed an abnormal FMD (mean 8.0%±2.6) response and 26 (66%) had abnormal CRP concentrations (mean 10 ±12 mg/l). Statistical analysis revealed a significant association of abnormal CRP and impaired FMD responses (p=0.036).
Conclusion: Elevated CRP levels are associated with an impaired FMD response in patients with CSX, a finding that was independent of cardiovascular risk factors. These results support the concept that inflammation can play a key role as a promoter of endothelial dysfunction in CSX. Future research is needed to clarify the mechanisms involved in this process to establish rational therapeutic approaches.
- © 2010 by American Heart Association, Inc.