Phase-dependent agreement between noninvasive and invasive blood pressure monitoring during transcatheter aortic...

We aimed to evaluate the phase-dependent agreement between continuous noninvasive blood pressure monitoring using ClearSight™ (Edwards Lifesciences Corp., Irvine, CA, USA) and invasive arterial pressure (IAP) across distinct intraoperative phases of transcatheter aortic valve replacement (TAVR).

We conducted a single-centre observational study at a tertiary academic hospital performing TAVR. We included 21 patients undergoing TAVR, contributing 987 paired invasive and noninvasive blood pressure measurements. We recorded noninvasive blood pressure monitoring using ClearSight concurrently with standard IAP monitoring as part of routine clinical care. We analyzed repeated paired measurements using Bland-Altman methods extended with linear mixed-effects modeling, with additional sensitivity analyses performed to assess robustness.

We compared invasive and ClearSight-derived systolic, mean, and diastolic pressures. ClearSight underestimated systolic and mean pressures and overestimated diastolic pressure. After excluding outliers identified by quantile-quantile plot diagnostics, mean biases (IAP minus ClearSight) were +14 mm Hg (systolic), +6 mm Hg (mean), and -3 mm Hg (diastolic). Limits of agreement narrowed after outlier removal, and intraclass correlation coefficients improved (systolic, 0.69 to 0.72; mean, 0.65 to 0.68; diastolic, 0.59 to 0.63). Phase-specific analysis showed the widest disagreement during induction/stabilization, improved accuracy during valve deployment, and the best agreement, particularly for mean arterial pressure, after protamine administration, when vascular tone and hemodynamic stability were restored.

ClearSight showed phase-dependent agreement with IAP during TAVR, typically underestimating systolic and mean pressures, with improved agreement during hemodynamic stability, most notably after protamine. These findings support ClearSight as an adjunct rather than a replacement for invasive arterial monitoring during TAVR. Broader validation studies are warranted.