Clinical Indices of Stenosis Severity
Coronary patients undergo angiography in the catheterization room to evaluate their stenosis severity, which determines the consequent treatment strategy. At present however, only epicardial flow is measurable. Hence, common indices of stenosis severity (e.g. fractional flow reserve, FFR, hyperemic stenosis resistance HSR) are based on epicardial data. Yet the deep endocardial layer is the most vulnerable one to epicardial stenosis. Hence we are studying the reliability of these flow indices to the perfusion in the deep layers.
The manner by which the measurable epicardial data should be interpreted to the endocardial domain to allow for reliable assessment of the patient’s risk of endocardial ischemia, is yet unclear. Considering the excessive difficulties in measuring in-vivo intramural flow, computerized simulation is the only methodological alternative that allows for such epicardial-to-endocardial transformation.
Epicardial wire-measurement of
fractional flow reserve (FFR).
Illustration courtesy of Volcano Corp.