The Association of Endothelial Dysfunction and Cardiac Allograft Vasculopathy

Progressive cardiac allograft vasculopathy (CAV) is a serious complication in long-term survivors after heart transplantation. Therefore, we hypothesize that CAV is a diffuse and progressive process, and endothelial function may play an important role in predicting clinical outcome after heart transplantation. Therefore, this single-blinded study is designed to evaluate endothelial function, microvascular flow response and morphology of coronary artery in cardiac allografts,

1. The simultaneous use of IVUS and Doppler wire instrumentation in different pharmacological stress;
2. Tl-201 SPECT (dipyridamole stress/rest); to evaluate the correlation of endothelial function, coronary morphology change and Tl-201 dipyridamole stress myocardial perfusion image.

Inclusion Criteria:

1. Heart transplant receipients who undergoing the coronary angiographic follow-up as standard protocols.

Exclusion Criteria:

1. Acute illness conditions including infection, congestive heart failure (NYHA Fc III, IV), etc.
2. Coronary angiographic finding: coronary stenosis>30% (as grade III, IV by Klauss V et al, Am J Cardiol 1995; 76:463-6).
3. Creatinine >3.0 mg/dl