Normalizing Arterial Blood Pressure in Patients with Aortic Stenosis Does Not Prevent Grading Discrepancies Between Pre?Cardiopulmonary Bypass Transesophageal Echocardiography and Transthoracic Echocardiography

ABSTRACT

Background: Aortic stenosis (AS) grading discrepancies exist between pre?cardiopulmonary (pre?CPB) transesophageal echocardiography (TEE) and preoperative transthoracic echocardiography (TTE). Prior studies have not systematically controlled blood pressure. Aims: We hypothesized that normalizing arterial blood pressure during pre?CPB TEE for patients undergoing valve replacement for AS would result in equivalent grading measurements when compared to TTE. Setting: Single University Hospital Design: Prospective, Interventional Methods: Thirty?five adult patients underwent procedures for valvular AS between February 2017 and December 2020 at Medical University of South Carolina. Study participants had a TTE within 90 days of their procedure that documented blood pressure, peak velocity (Vp ), mean gradient (PGm), aortic valve area (AVA), and dimensionless index (DI). During pre?CPB TEE, if a patient抯 mean arterial pressure (MAP) fell more than 20% below their baseline blood pressure obtained during TTE, measurements were recorded as 搊ut of range.� Phenylephrine was administered to restore MAP to the baseline range and repeat TEE measurements were recorded as 搃n?range.� Statistical Analysis: Differences between imaging modalities and grading parameters were examined using a series of linear mixed models. P values were Bonferroni?adjusted to account for multiple comparisons. Main Results: Significant discrepancies between TEE and TTE were observed for Vp , PGm, and DI despite blood pressure normalization across all subjects and for out?of?range measures and corrected measures. There were no statistically significant differences between TEE and TTE for AVA. Conclusions: Blood pressure normalization during pre?CPB TEE is not sufficient to avoid AS grading discrepancies with preoperative TTE.