ABSTRACT

Coronary angiography is currently the gold standard for the diagnosis of atherosclerotic heart disease. Nevertheless, it is well known that conventional angiography has several important limitations. Although angiography is a reliable tool to evaluate the luminal dimensions of a coronary segment, its ability to estimate the flow-limiting significance of lesions classified as ‘intermediate’ (commonly defined as a diameter stenosis between 40% and 70%) is suboptimum. Angiographic analysis of intermediate lesions is well known to have a poor correlation with the induction of myocardial ischemia or with patients’ complaints. Unfortunately, intermediate or ambiguous lesions are frequently found in the daily practice of any catheterization laboratory, and often pose a diagnostic dilemma. In this chapter we discuss the advantages and disadvantages of invasive and non-invasive strategies currently available for the evaluation of intermediate lesions.