Clinical value of pulse wave velocity: a promising marker for arterial stiffness

Pulse wave velocity (PWV) has emerged as a marker for arterial stiffness with a promising future role in cardiovascular risk stratification. The pressure wave produced by systolic pumping of the heart travels along the aorta and other vasculature throughout the body. With deterioration of the vessel wall, whether due to age, connective tissue disease or atherosclerosis, the transit time of the pulse wave from point A to B becomes shorter, meaning that PWV is directly related to the mechanical properties of the vessel. Cardiovascular disease leading to aortic dilatation typically occurs through a gradual process, although the clinical manifestation can be acute. Feared complications of aortic dilatation are dissection and rupture, with a high risk for mortality and morbidity. Indication for preventive surgical intervention is currently mostly based on aortic diameter. An added measure for detection of subclinical aortic disease is desirable for more tailored risk stratification to guide preventive intervention. Several methods are available for measuring PWV, all based on the general principle PWV = ∆d/∆t where ∆d is the distance between two planes and ∆t is the temporal shift between two waveforms. Intravascular pressure or flowderived PWV is the gold standard method, but unattractive for general implementation due to its invasive nature. Noninvasive methods include vascular applanation tonometry or Doppler ultrasound over the carotid and femoral artery (i.e. external measurement of pressure or flow velocity respectively). Their main pitfall is inaccuracy due to erroneous distance measurement, especially in obese patients. A more