Background: A more simple yet accurate method for assessing travel distance (TD) for calculation of carotid-femoral pulse wave velocity (cfPWV) is desirable to improve acceptance of the method in clinical routine.

Methods: We compared the following methods for assessment of TD, as performed during non-invasive measurement of cfPWV with the SphygmoCor system, with the invasive gold standard (aortic PWV), as measured during cardiac catheterization on alternate days, in up to 659 patients: M1 (invasive aortic PWV), M2 (“conventional” subtraction: suprasternal notch-femoral site minus suprasternal notch-carotid), M3 (estimation from body height: TD = body height/4 + 7.28), M4 (direct measurement carotid-femoral site * 0.8), M5 (subtracted method as M2 but using straight caliper instead of a tape).

Results: Transit times, as assessed invasively and with the SphygmoCor system, were in good agreement (62.8 and 63.4 msec, respectively). TD and corresponding cfPWV, as measured with M2 and M3, met the invasive values – Table. M4 overestimated invasive TD by 3.5 cm, resulting in an overestimation of PWV by 0.3 m/sec. M5 underestimated TD by 4.5 cm, resulting in an underestimation of PWV by 0.9 m/sec. Correlations with invasive method and respective coefficients of determination were not improved, when M4 or M5 was used.

Conclusion: Non-invasive estimation of TD for cfPWV (often labelled as aortic PWV) remains problematic. A simplified method, based on body height, may be of value.