Endothelial Dysfunction and Plaque Vulnerability

Thinning of fibrous cap in atherosclerotic plaques is associated with plaque vulnerability. The high resolution of optical coherence tomography (OCT) provides an accurate measurement of fibrous cap thickness. Endothelial dysfunction is a key component of vulnerable plaque and digital reactive hyperemia-peripheral arterial tonometry (RH-PAT) is a non-invasive automatic and quantitative method to evaluate endothelial function. The investigators will investigate the association between endothelial function assessed by RH-PAT and plaque vulnerability determined by OCT-derived thin-cap fibroatheroma (TCFA).

Consecutive patients with acute coronary syndrome (ACS) who undergo both OCT examination and RH-PAT examination are enrolled. OCT examination is performed to observe the culprit lesion before percutaneous coronary intervention, and endothelial function is evaluated using RH-PAT before discharge.

Yokohama City University Medical Center

• 3 / non-CAD, ACS with or without TCFA
  ACS patients with thin cap fibroatheroma. ACS patients without thin cap fibroatheroma. Age-, gender-, and rate of hypertension or diabetes mellitus-matched patients who have never been diagnosed or treated for CAD are also enrolled as non-CAD patients
• non-CAD, ACS without TCFA, ACS with TCFA
  Acute coronary syndrome (ACS) patients with thin cap fibroatheroma. ACS patients without thin cap fibroatheroma. Age-, gender-, and rate of hypertension or diabetes mellitus-matched patients who have never been diagnosed or treated for CAD are also enrolled as non-CAD patients

Inclusion Criteria:

• patients with angiographically proven ACS (luminal stenosis of at least 50%) who undergo both OCT examination before coronary stent implantation and RH-PAT examination before discharge.

Exclusion Criteria:

• none