The Drift-Reduction for Improved FFR Using Fiberoptic Technology (DRIFT) Study

Background:
Pressure drift can lead to unreliable physiology measurements, with rate of pressure drift not infrequently reported as ~15% using conventional pressure wires. Overall pressure drift is due to a combination of drift in aortic pressure and/or drift of pressure from the wire itself. Additionally, the utility of a pressure wire as a workhorse guidewire during PCI could have an important impact on daily clinical practice. We sought to assess the rate of pressure drift when using a new 2^nd generation fiber optic pressure guidewire.

Methods:
This is a prospective, observational, dual-center, single-arm registry of patients with stable or unstable angina who have an intermediate proximal/mid LAD stenosis and who undergo physiological assessment with the OptoWire Deux pressure wire (OpSens Medical, Quebec, Canada) pre-PCI and post-PCI (if treated). The overall pressure drift (defined as Pd/Pa <0.97 or >1.03) is differentiated as to whether it is due to 1) drift in aortic pressure by zero verification of aortic pressure or 2) drift in pressure from the wire itself (overall pressure drift without aortic pressure drift). The primary endpoint is the rate of pre-PCI drift in pressure from the wireMajor secondary endpoints include the rate of 1) post-PCI drift in pressure from the wire if the OptoWire was used as the workhorse PCI guidewire, 2) usage of OptoWire as a workhorse PCI guidewire, and 3) positive FFR in angiographically intermediate LAD lesions. Physiology measurements will include FFR and resting pullback (focal step-up or diffuse pressure increase) pre- and post-PCI, and will be correlated with OCT findings.

Results:
This study will enroll 60 subjects, with results to be presented at SCAI 2019.

Conclusions:
Improved rates of drift coupled with the ability to use a fiberoptic pressure wire as a workhorse PCI guidewire may allow for increased utilization of FFR in daily practice.