ABSTRACT
INTRODUCTION Quantitative Coronary Angiography (QCA) has been established as the golden standard for coronary artery stenosis assessment because visual interpretation of coronary artery is erroneous when compared with QCA.1-4 Visual assessment is a subjective evaluation with a large inter-and intraobserver variability. Angiographers tend to overestimate the severity of tight stenosis and underestimate the degree of mild ones. QCA has the advantage of being more reproducible in the assessment of coronary lesion severity; therefore, QCA has been widespread and utilized to estimate the efficacy of enormous percutaneous devices and pharmacological agents in important clinical scientific studies, especially for restenosis prevention trials.
