Abstract 13299: Are There Differences in Left Ventricular and Aortic Pressures Measured With Fluid-Filled and Solid-State Pressure Catheters

Abstract

Purpose: To compare left-ventricular and aortic pressures obtained using fluid-filled and high-fidelity solid-state pressure catheters in subjects undergoing left heart catheterization. Methods: Twenty subjects scheduled for a left heart catheterization were enrolled and 18 subjects completed this IRB-approved study. During catheterization, left-ventricular (LV) and aortic (AO) pressures were obtained using a fluid-filled pressure catheter (standard-of-care) and a high-fidelity solid-state pressure catheter synchronously. The pressure tracings were analyzed by two independent readers to measure LV systolic (LVSP), LV minimum diastolic (LVMDP), LV end diastolic (LVEDP), AO systolic (AOSP), and AO diastolic (AODP) pressures. Derivatives of the pressure waveforms were computed to estimate the isovolumic contraction and relaxation rates (peak ± dp/dt). The measurements were made over multiple cardiac cycles and averaged results were used for comparisons using repeated measures analysis of variance, post-hoc tests with Bonferroni corrections and Bland-Altman plots. Results: A significant main effect of the pressure catheter was noted for LVSP, LVMDP and AOSP (p < 0.025). The LVSP and AOSP measured with fluid-filled pressure catheters were higher by 6.6 ± 6.9 mmHg and 4.6 ± 5.2 mmHg in comparison to the high-fidelity solid-state pressure catheter assessments. In contrast, the LVMDP measurements were 3.5 ± 5.7 mmHg lower than the solid-state pressure catheter measurements. When evaluating the differences between readers, the maximum difference was noted for LVEDP measurements (3.1 ± 2.4 mmHg; p ≤ 0.001). The differences in isovolumic contraction rate (66.4 ± 116.0 mmHg/s) and relaxation rate (60.5 ± 113.5 mmHg/s) were not significantly different between the two catheter systems after Bonferroni corrections for multiple comparisons (p > 0.06). Bland-Altman analysis revealed a bias ranging from 0.8 to 6.6 mmHg for all the pressure measurements. Conclusions: There are differences in LVSP, LVMDP, and AOSP measured using fluid-filled and high-fidelity solid-state pressure catheters. Clinicians should be aware that the fluid-filled catheters commonly overestimate the true systolic pressures in the left ventricle and aorta.