Evaluation of a pressure-recording guidewire in patients with coronary arterial disease.

The accuracy and feasibility of coronary arterial pressure measurements with a 0.018-in. pressure-recording guidewire (PRGW) was evaluated in patients. Transstenotic pressure gradients were measured with the PRGW and a guiding catheter, at baseline and during coronary vasodilatation. Proximal intracoronary pressure was measured with both systems before and after gradient measurements. Zero pressure was measured with the PRGW before and after intracoronary use. The average of all proximal intracoronary PRGW readings were close to guiding catheter values, but there were substantial individual deviations. Average change in proximal deviation before and after gradient measurements was -1 mm Hg, standard deviation (S.D.) 7.6, range -16 to 15. Errors in zero pressure measurements after intracoronary use (average 2.8 mm Hg, S.D. 8.8, range -9 to 35) were much greater than before use (average 0.1 mm Hg, S.D. 1.4, range -4 to 3, P < 0.001). The PRGW was successfully introduced through an 8F guiding catheter and positioned across the stenosis in 21 of 26 attempts (81%). Intracoronary advancement of the PRGW through a double-lumen multifunctional probing catheter was successful in all nine attempts. In conclusion, errors in PRGW-measurements caused uncertainty in gradient interpretation. However, we found the wire useful in several cases, particularly for exclusion of hemodynamically significant lesions. The steerability of the wire is inferior to ordinary guidewires, but it can be advanced to a distal intracoronary position through an over-the-wire catheter.