Construct Validity of a Novel Fiberoptic TAVR Guidewire for Invasive Pressure Measurements.
BACKGROUND A novel fiberoptic transcatheter aortic valve replacement (TAVR) guidewire was developed that enables continuous hemodynamic monitoring, easy pacing over the wire, and guiding of the valve prosthesis. OBJECTIVES This study aimed to evaluate construct validity of hemodynamic measurements obtained with the fiberoptic TAVR guidewire compared to conventional fluid-filled pigtail catheters. METHODS This prospective registry study included patients undergoing TAVR. Complete hemodynamic assessment was performed in-duplo with the fiberoptic TAVR guidewire and conventional pigtail catheters. Primary endpoint was the agreement between modalities for post-TAVR mean pressure gradient (PG). Secondary endpoints included agreement in assessing paravalvular regurgitation and in-depth signal analysis using a validated automated algorithm. RESULTS This study included 150 patients (mean age 79.7 ± 5.8 years; 46.7% female). Comparison of invasive pressure measurements yielded moderate to excellent agreement (intraclass correlation coefficient [ICC]-range: 0.65 to 0.95). Bias was observed in left ventricular end-diastolic pressure (LVEDP), with the fiberoptic guidewire measuring higher LVEDPs (+3.5 mm Hg). Post-TAVR mean PG showed a mean absolute difference of 2.7 ± 2.1 mm Hg (ICC: 0.67), minimal bias (-0.45 mm Hg), and 87% concordance with a discrete cutoff (10 mm Hg). Good overall agreement was observed for most indices of paravalvular regurgitation (ICC-range: 0.81-0.87). Automated algorithm assessment revealed fewer artefacts and calibration errors for the fiberoptic guidewire (P = 0.048), repeat analysis improved mean PG agreement (ICC-range: 0.80-0.85). CONCLUSIONS The fiberoptic guidewire effectively classified clinically relevant transvalvular gradients with limited bias post-TAVR, although it produced higher LVEDPs, possibly reflecting wire-induced leaflet interaction. Algorithm-derived assessment revealed the fiberoptic guidewire producing measurements with fewer artefacts and calibration errors, supporting its proof-of-concept potential to complement current invasive assessment standards.