Signal drift reported by the studies.
| Study lead author | Mean drift from pressure wire | SD | Mean drift from microcatheter | SD | Reported P value |
| Ali | 0.01 | 0.03 | 0.01 | 0.01 | 0.38 |
| Fearon | 0.015 | 0.017 | 0.014 | 0.012 | 0.66 |
| Menon | 0.06 | 0.02 | 0.02 | 0.02 | 0.014 |
| Wijntjens | 3.4 mm Hg | 1.8 mm Hg | 2.3 mm Hg | 1.5 mm Hg | 0.07 |
One study4 found a significantly higher mean drift with FFRPW than FFRMC. In this study, the mean drift was driven by three unusually large PW drift values of 6.5 mm Hg, 4.0 mm Hg and 3.4 mm Hg. All drift values are reported as FFR units except5 reported as change in distal pressure (mm Hg).
FFRMC, microcatheter fractional flow reserve; FFRPW, pressure wire fractional flow reserve; PW, pressure wire.