Noninvasive methods to assess pulse wave velocity: comparison with the invasive gold standard and relationship with organ damage.

OBJECTIVES: To compare noninvasive methods to assess pulse wave velocity (PWV) with the invasive gold standard in terms of absolute values, age-related changes, and relationship with subclinical organ damage.
METHODS: Invasive aortic PWV (aoPWVinv) was measured in 915 patients undergoing cardiac catheterization (mean age 61 years, range 27-87 years). Carotid-femoral PWV (cfPWV) was measured with tonometry, using subtracted distance (cfPWVsub), body height-based estimated distance (cfPWVbh), direct distance × 0.8 (cfPWVdir0.8), and caliper-based distance (cfPWVcalip) for travel distance calculation. Aortic PWV was estimated (aoPWVestim) from single-point radial waveforms, age, and SBP.
RESULTS: Invasive and noninvasive transit times were strikingly similar (median values 60.8 versus 61.7 ms). In the entire group, median value of aoPWVinv was 8.3 m/s, of cfPWVsub and cfPWVbh 8.1 m/s, and of aoPWVest 8.5 m/s. CfPWVsub overestimated aoPWVinv in younger patients by 0.7 m/s and underestimated aoPWVinv in older patients by 1.7 m/s, with good agreement from 50 to 70 years of age. AoPWVestim differed from aoPWVinv by no more than 0.4 m/s across all age groups. CfPWVdir0.8, measured in 632 patients, overestimated aoPWVinv by 1.7 m/s in younger patients, with good agreement in middle-aged and older patients. CfPWVcalip, measured in 336 patients, underestimated aoPWVinv in all ages. In 536 patients with preserved systolic function, aoPWVinv and aoPWVestim were superior to cfPWVs in predicting coronary atherosclerosis, renal function impairment, left atrial enlargement, and diastolic dysfunction.
CONCLUSION: CfPWVsub, cfPWVdir0.8, and aoPWVestim are reasonable surrogates for aoPWVinv. AoPWVinv predicts subclinical organ damage better than cfPWVs, and as good as aoPWVestim.