A new reduced-order model to assess the true fractional flow reserve of a left main coronary artery stenosis with downstream lesions and collateral circulations: an in vitro study

Good diagnosis of severity is essential for treatment of coronary stenosis. Several biomechanical reduced-order (0D) models have been developed to predict the true severity (fractional flow reserve: FFR_True) of left main (LM) stenosis with downstream lesions. These models intend to assist the interventional cardiologist in pondering the need for a revascularization procedure, so as to avoid treating nonsignificant lesions and consequently reducing unnecessary risks. Although these studies report promising results for prediction of FFR_True, they do not simultaneously consider (1) complex LM coronary stenosis configurations with two downstream lesions or (2) the influence of collateral circulation. We therefore developed a new 0D model to predict the true severity of LM stenosis, taking account of both of these factors. In vitro validation was performed to assess the accuracy and performance of the novel model. The model successfully clarified the influence of concomitant stenoses and collateral circulation on FFR amplitude in LM stenosis.