Physiologic evaluation of translesion pressure gradients in peripheral arteries: comparison of pressure wire and catheter-derived measurements.

BACKGROUND

Catheter-derived pressure gradient (CPG) measurements across vascular lesions are used to determine the hemodynamic significance of a stenosis prior to peripheral vascular intervention. We tested the hypothesis that CPGs overestimate the true translesion gradient during hemodynamic interrogation.

METHODS

We evaluated 20 lesions (iliac, subclavian, or renal) in 16 patients undergoing angiography for peripheral vascular disease. Mean arterial pressure gradients were measured across each lesion using a 4- or 5-Fr fluid-filled catheter and compared to gradients measured with a 0.014'' pressure wire (PWG).

RESULTS

In all lesions, the CPG was higher than the PWG (28.3 +/- 4.5 mmHg vs 11.6 +/- 1.8 mmHg; P < 0.05). Both CPG and PWG correlated with diameter stenosis (CPG = 0.78 [DS]- 29; r(2)= 0.44; P < 0.05 and PWG = 0.30 [DS]- 10.5; r(2)= 0.43; P < 0.05), but the CPG overestimated the pressure gradient compared with the PWG.

CONCLUSION

Peripheral arterial vascular lesion pressure gradients assessed with large diameter catheters consistently overestimate the actual PG. Although both CPG and PWG correlated with anatomic stenosis, the overestimation of the physiologic significance of these lesions may lead to inappropriate intervention. Use of a pressure wire for hemodynamic interrogation may be a better tool for assessment of the hemodynamic significance of a peripheral vascular lesion.