Grading Aortic Valve Stenosis With Dimensionless Index During Pre-cardiopulmonary Bypass Transesophageal Echocardiography: A Comparison With Transthoracic Echocardiography.

Objective: The authors hypothesized that grading valvular aortic stenosis (AS) with dimensionless index (DI) during intraoperative pre-cardiopulmonary bypass (pre-CPB) transesophageal echocardiography (TEE) would match the grade of AS during preoperative transthoracic echocardiography (TTE) for the same patients more often than when using peak velocity (V), mean pressure gradient (PG), or aortic valve area (AVA).

Design: Retrospective, observational.

Setting: Single university hospital.

Participants: The participants in this study included 123 cardiac surgical patients with any degree of AS, who underwent open cardiac surgery between 2010 and 2016 at the Medical University of South Carolina and had V, PG, AVA, and DI values available from reporting databases or archived imaging.

Interventions: None.

Measurements And Main Results: When using DI, pre-CPB TEE grading of AS severity was 1 grade higher 21.1% of the time and 1 grade lower 13.0% of the time compared with TTE, for an overall disagreement rate of 34.1%. The overall disagreement rates between pre-CPB TEE and TTE for V, PG, and AVA were 39.8%, 33.3%, and 33.3%, respectively.

Conclusions: The authors could not demonstrate that DI was better than V, PG, or AVA at matching AS grades between intraoperative pre-CPB TEE and preoperative TTE. When DI was used, pre-CPB TEE was more likely to overestimate than underestimate the severity of AS compared with TTE. However, when V or PG was used, pre-CPB TEE was more likely to underestimate the severity of AS compared with TTE. A comprehensive approach without overemphasis on 1 parameter should be used for AS assessment by intraoperative TEE.