Comprehensive assessment of coronary pulse wave velocity in anesthetized pigs

BACKGROUND: Coronary stiffness represents a new paradigm for interventional cardiology and can be assessed by coronary pulse wave velocity (CoPWV). Assessing CoPWV is complex because of the coexistence of backward and forward waves. OBJECTIVES: Evaluate the feasibility, repeatability, and capacity of methods assessing CoPWV to detect predictable velocity changes. METHODS: CoPWV was measured from distal and proximal pressure guidewires in the left anterior descending artery of 10 pigs under general anesthesia. Four methods were studied: the tangent intersection method applied to the forward (FW) and backward (BK) waves, as well as the dicrotic notch (DIC) and template matching (TM) methods. All were evaluated at baseline, during various arterial pressure and heart rate conditions, during simulated flow limitation (balloon inflation), and after increasing coronary stiffness (stent insertion). RESULTS: All the methods were significantly different between them (p ≤ .05) showing a systematic trend toward higher CoPWV when compared to the FW method (.05 < p<.10). Results were found to be significantly correlated only between the BK and FW methods and between the DIC and TM methods (p ≤ .05). CoPWV increased with arterial pressure increase, this increase being significant for the DIC and TM methods and partly for the FW method (p ≤ .05). Conversely, heart rate had no systematic impact on CoPWV. The lowest variability was found for the DIC and TM methods (p ≤ .05). Only the BK and TM methods remained applicable during flow limitation; stent increased CoPWV when measured by the BK method only (p ≤ .05). CONCLUSION: Although CoPWV can be measured by various methods, the BK and TM methods seem the most appropriate for clinical studies.