Measurement of coronary artery pressure and stenosis gradients — clinical applications

When considering a patient with ischemic heart disease for an invasive procedure such as coronary angioplasty (PTCA) or coronary artery bypass surgery (CABG), decision-making is heavily dependent on reliable tools to assess the physiological and clinical importance of the obstruction in the coronary artery. In spite of progressive refinements of computer-assisted analysis of the coronary angiogram during recent years, there are still some inherent limitations of the method that may render assessment of certain stenosis less reliable. In particular, diffuse atherosclerotic involvement, tortuous, long irregular lesions will be more difficult to evaluate. In addition, following PTCA the intimai layer of the vessel wall is frequently damaged, which may affect the angiographic picture considerably giving the appearance of haziness, intimal flaps or widespread dissection. This makes the interpretation of the angiographic picture even more difficult leaving an obvious need for complementary methods with a more physiological approach in these situations.