Value of toe pulse waves in addition to systolic pressures in the assessment of the severity of peripheral arterial disease and critical limb ischemia

Purpose: Although pressure measurements are useful in the assessment of the severity of the arterial obstruction, they do not completely identify limbs with and without critical limb ischemia. Our objective was to test whether addition of the measurements of toe pulse waves (PW), which depend on distal perfusion, to pressure measurements could improve the determination of the severity of arterial disease and the presence of critical limb ischemia. Methods: We measured toe pressure (TSP) and ankle/brachial index (ABI) and recorded PW with phoroplethysmography in 358 limbs of 182 patients. Results: TSP, ABI, and PW amplitude were lower in 67 limbs with rest pain, skin lesions, or both, with mean differences of 29 mm Hg, 0.12, and 16 mm, respectively (p < 0.01). Similarly in the subgroup of 107 limbs with TSP less than or equal to 30 mm Hg, TSP, and PW amplitude, but not ABI, were lower in 53 limbs with rest pain, skin lesions, or both, with mean differences of 10 mm Hg and 7 mm (p < 0.01). Multiple logistic regression showed that after controlling was done for TSP and ABI, the odds ratio for the presence of rest pain, skin lesions, or both associated with PW amplitude less than or equal to 4 nun mas 4.3 (95% confidence interval 1.7, 11.0; p < 0.01). In the subgroup with TSP less than or equal to 30 mm Hg, this odds ratio was 3.5 (95% confidence interval 1.0, 11.6; p < 0.05). Conclusions: The findings indicate that addition of PW recording to pressure measurements is likely to increase the accuracy of assessment for critical limb ischemia.