Coronary pressure drop and arterial distensibility—two dependent parameters

Blood pressure drop and arterial distensibility are important, allegedly independent, parameters that are indicative of the coronary arteries patency and atherosclerosis severity. In the present study we show that these two parameters are dependent, allowing to obtain both parameters from a single measurement, and to do so a high-resolution differential pressure measurement system is required. The objective of the study was to unveil the relationship between local fluid pressure drops and tube distensibility, through various scenarios of stenosis severity, tube diameter, and flow rate (for coronary hemodynamic conditions). The investigation was performed using validated Fluid–Structure Interaction (FSI) analysis on silicone mock arteries with intermediate size stenosis (0–65%). Highly accurate pressure drop measurements (±0.05 mmHg) were performed with our in-house fluid-filled double-lumen catheter measurement. The results indicated that our accurate pressure drop measurement method facilitated the differentiation among several levels of the mock arteries’ stiffness, with distensibilities ranging from 1 to 7%. Local pressure drops were markedly affected by the mock arteries’ stiffness and could be best described using a second-order polynomial function. These changes in pressure drop could be detected even when there was no stenosis present, and FFR values remained insensitive at 1.00. The results indicated the clinical potential of a high accuracy pressure drop-based parameter to be superior to FFR. Such a parameter would provide cardiovascular interventionalists with lesion-specific bio-mechanical and functional data, for improved real-time decision-making in the cath-lab.