Discordance in Grading Aortic Stenosis by Pre-CPB TEE aortic valve. For this reason, AVA calculation is prone to error compared with a ΔP m measurement.Although inconsistencies for grading AS with AVA and ΔP m are well known for preoperative TTE, they are routinely used for grading AS in the pre-cardiopulmonary bypass (pre-CPB) context. In this study, we investigate the frequency of discordance between grading AS with ΔP m measurements and AVA calculations during pre-CPB transesophageal echocardiography (TEE) to provide insight into their reliability for pre-CPB assessment of AS severity. Conventional AS severity cutoffs were derived from TTE studies performed in awake, spontaneously breathing patients.14-18 However, cardiac anesthesiologists perform pre-CPB TEE in anesthetized patients receiving positive pressure ventilation. Because general anesthesia and positive pressure ventilation may influence cardiac loading conditions, we hypothesized that grading discordance by pre-CPB TEE would be higher than previously reported for TTE by others.
METHODSWe obtained Duke University IRB approval, which granted waiver of consent to perform a retrospective database study for information collected between January 1, 2000, and December 31, 2012. This study was an investigator-initiated, single-center, retrospective review of the Duke University, Department of Anesthesiology perioperative echocardiography-reporting database. This database includes all adult patients who have undergone cardiac surgery at Duke University Medical Center and had a TEE report generated electronically since January 1, 2000. The Duke Health Information Technologies Solutions (DHTS) Perioperative Development Group (PDG) maintains the reporting system. A cardiothoracic anesthesiology fellow, attending, or both, generated TEE reports as part of a dedicated perioperative echocardiography training program. All imaging and reports were subsequently reviewed offline by an independent cardiothoracic anesthesiologist to confirm the accuracy of the report.
Subject SelectionWe reviewed all patients in the database, who underwent AVR with or without coronary artery bypass grafting from January 1, 2000, until December 31, 2012. Patients were included if the echocardiographer reported both a pre-CPB ΔP m and an AVA. Patients were excluded if they had emergency surgery or repeat sternotomy. Patients were also excluded if they had an ejection fraction <55%, moderate or severe mitral regurgitation (MR), or severe aortic insufficiency (AI).
Definitions of Variables
Statistical AnalysisIRB approval was obtained in early 2013; therefore, we collected retrospective data as far as possible, up through December 31, 2012. Pre-CPB TEE ΔP m and AVA values were extracted for all patients meeting clinical inclusion criteria. These values were grouped according to AS severity (mild, moderate, and severe) and compared for discordance rates based on current grading guidelines for ΔP m and AVA. Values were considered "discordant" if there was disagreement between severities bas...