How arterial stiffness may affect coronary blood flow: a challenging pathophysiological link

Aims A relationship between arterial stiffening and coronary flow abnormalities, although not fully elucidated, has been observed. The purpose of this study was to investigate the relationship among carotid stiffness, measured using echo-tracking, and Doppler parameters of coronary blood flow, sampled at the left anterior descending (LAD) artery. Methods We studied 88 consecutive patients (49 men, mean age 51.2+/-16.2 years) with cardiovascular risk factors but without history of cardiovascular diseases. Each patient underwent echocardiographic evaluation for measurement of the diastolic velocity time integral (DVTI) and calculation of the diastolic velocity time integral coronary index (DVTICI), the ratio between DVTI and total velocity time integral of LAD artery flowx100, and carotid ultrasound for measurement of carotid intima media thickness (IMT) and stiffness parameters such as beta index and elastic modulus (Ep). Results DVTICI was significantly greater in men than in women (median 82, interquartile range 78-86 vs. median 80, interquartile range 73-83, respectively; P<0.016). After correlating DVTICI with other variables, a significant inverse relation was obtained with beta index (Rho=-0.449, P<0.001), Ep (Rho=-0.478, P<0.001), age (Rho=-0.52, P<0.001), left ventricular mass index (Rho=-0.543, P<0.001), E/E' (Rho=-0.411, P<0.001), pulse pressure (Rho=-0.417, P<0.001) and IMT (Rho=-0.480, P<0.001). With linear multiple regression analysis, only b index (P<0.001), Ep (P<0.001), male sex (P<0.001) and left ventricular mass index (P=0.008) were independently associated with reduction of DVTICI. Conclusion Increased arterial stiffness, directly affecting coronary perfusion, is associated with reduced diastolic coronary flow. Echo-tracking for feasible measurement of carotid artery stiffness parameters may be valuable in more accurate cardiovascular risk stratification.