A Randomised Controlled Trial to Compare two Coronary Pressure Wires using Simultaneous Measurements in Human Coronary Arteries The COMET trial.

AIMS: We examined the relative performance of the new COMET wire from Boston Scientific (BS), and the established technology from St Jude/Abbott Vascular (SJ).

METHODS AND RESULTS: We compared simultaneous readings from pairs of wires. Patients were randomised to one of three groups, BS/BS; SJ/SJ; SJ/BS. The latter group were sub-randomised to specify the wire passed first. After pressure equalisation at the guide catheter, we recorded paired observations in sequence: (a) distal to proximal pressure ratio at baseline; (b) FFR at maximum hyperaemia; (c) pressure on withdrawal into the guide catheter to quantify "drift". We randomised 106 patients, yielding 288 sets of paired recordings (BS/BS = 90; SJ/SJ = 90; SJ/BS = 108). Drift was recorded from 208 vessels (BS = 105; SJ = 103). All wires were successfully advanced to their desired positions in the coronary vasculature. The mean (±SD) differences for the randomised pairs were similar: BS/BS = 0.0016 (0.023); SJ/SJ = 0.002 (0.03); SJ/BS = 0.0013 (0.028). The primary outcome tested the hypothesis that the absolute magnitude of the difference (irrespective of sign) observed in the SJ/BS pairing would be similar to that in the SJ/SJ group. The median (IQR) values were SJ/BS = 0.015 (0.01-0.03); SJ/SJ = 0.01 (0.00-0.03); P = 0.61. The drift, expressed as the median (IQR) difference in Pd/Pa from 1.0 (irrespective of sign), was similar: BS = 0.02 (0.01-0.05); SJ = 0.02 (0.01-0.04); P = 0.14.

CONCLUSIONS: We found no significant difference between these wires in terms of safety and performance.