PP.19.04] CORONARY ARTERY PULSE WAVE VELOCITY

Abstract

Objective: Albeit of utmost importance, especially with respect to plaque rupture, the biomechanical properties of coronary arteries are poorly assessable in routine practice. A classic method of assessment is to determine vascular compliance through pulse wave velocity (PWV). This has been done for aortic PWV, a strong predictor of coronary artery disease (CAD). To our knowledge, there is no way to assess coronary PWV (CoPWV) in routine practice. The first objective of this study was to describe a method of measuring coronary PWV (CoPWV) invasively, and to describe its determinants. The second objective was to assess both CoPWV and aortic PWV, in patients presenting with acute coronary syndromes (ACS) or with stable CAD. Design and method: In fifty-three patients, CoPWV was measured from the delay in pressure wave and distance travelled, as a pressure wire was withdrawn from the distal to the proximal coronary segment. Pressure and electrocardiographic signals were recorded at a high sampling frequency, and dedicated software was used to calculate CoPWV. Similarly, Aortic PWV was measured invasively when the wire was pulled across the ascending aorta; Carotid-femoral PWV was also measured non-invasively using the SphygmoCor system. Results: Mean CoPWV was 10.3 ± 6.1 m/s. Determinants of increased CoPWV were smoking, diastolic blood pressure, and previous stent implantation in the recorded artery. CoPWV was much lower in ACS versus stable CAD patients (7.6 ± 3 m/s vs. 11.5 ± 6.4 m/s; p = 0.02), and this persisted after adjustment for confounders. On the contrary, aortic stiffness, assessed by AoPWV and by Carotid-femoral PWV, did not significantly differ. Conclusions: CoPWV seems associated with acute coronary events more tightly than AoPWV. Low coronary compliance, whether per se or because it leads to a distal shift in compliance mismatch, may expose vulnerable plaques to high cyclic stretch. CoPWV is a new tool to assess local compliance at the coronary level; it paves the way for a new field of research.