A novel fluid-filled pressure wire avoids hydrostatic errors in physiologic measurements

Abstract Background Hydrostatic pressure impacts intracoronary measurements, generally causing overestimation of stenosis significance in the LAD and underestimation non-LAD vessels [1–3]. Different cut-offs have been suggested for post-PCI FFR [4], corresponding to average hydrostatic effects misclassification may be avoided if are eliminated. Purpose We aimed compare effect on resting distal-to-aortic coronary ratio (Pd/Pa) FFR, using a conventional sensor-tipped- versus novel fluid-filled wire. Since wire has an outside-the-body transducer instead sensor at tip, fluid (saline) compensates that is inside patient's body. Methods placed sensor-tipped measure point same location vessel. By performing simultaneous we assess relationship between vertical height differences distal (Pd). measured difference tip guide catheter point, by changing position cath lab table assessing total distance mm two positions. Results The wires were used simultaneously 21 arteries. lower tree measurements made (e.g., LCX or RCA), higher Pd value was, compared wire; measurement was LAD), value. After corrected (0.77 mmHg/cm [2]), correlated better with (R=0.73 vs. R=0.89 rest R=0.83 R=0.96 hyperaemia). Drift also 31 measurements. demonstrated less drift than (standard deviation 0.11 0.18). With increasing number cases, observed, possibly learning curve-related. Finally, pressure-derived CFR wire, echocardiography-CFR (n=10) bolus thermodilution-CFR (n=11). Pressure-derived (R=0.69 R=0.76 respectively). Sensor-tipped did not correlate (n=11; R=−0.57). Conclusions introduces variable error Resting indices more susceptible hyperaemic. There slight curve associated use but errors physiologic can thanks wire's design external transducer. Funding Acknowledgement Type funding sources: Public grant(s) – National budget only. Main source(s): Swedish Governmental Agency Innovation Systems (Vinnova)