Discordance in Grading Methods of Aortic Stenosis by Pre-Cardiopulmonary Bypass Transesophageal Echocardiography

Abstract

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...

In Pursuit of a Unicorn: Does the Ideal Parameter for Grading of Aortic Stenosis During Intraoperative Transesophageal Echocardiography Exist?

“…5 Additional research has shown that there is more discordance between mean PG m and AVA during precardiopulmonary bypass TEE than during preoperative TTE. 6 In a perfect world, one could perform a TEE examination and have certain parameters be in complete agreement with previously reported studies across all modalities. However, we know this not to be uniformly true.…”

Comparison of preoperative and intraoperative assessment of aortic stenosis severity by echocardiography

“…What is classified as 'mild' during surgery might in fact be at least 'moderate' in severity if the valve was examined in an awake patient, without the influences of general anaesthesia and positive pressure ventilation. 10 Expectant management is considered appropriate in mild AS because of increased mortality and morbidity in AVR combined with coronary bypass grafting compared with isolated coronary bypass grafting alone. 1 However, the current American and European guidelines suggest that AVR is reasonable or should be considered in patients with moderate AS undergoing cardiac surgery for other indications.…”

“…2 11 A recent retrospective analysis concluded that grading of AS by aortic valve area and mean pressure gradient showed higher discordance in intraoperative TOE compared with preoperative TTE. 10 Although a reduction in mean gradients under general anaesthesia was suggested to be one of the causative factors, this was not specifically evaluated. We are unaware of any previous studies that have evaluated how the echocardiographic assessment of AS severity changes in the intraoperative setting.…”

Comparison of grading of aortic stenosis between transthoracic and transesophageal echocardiography in adult patients undergoing elective aortic valve replacement surgeries: A prospective observational study

“…[5] Discrepancies are frequently observed in grading severity of AS using above parameters between transthoracic and TEE imaging. [6] In a retrospective, observational study preoperative TTE PGm and AVA values were compared with precardiopulmonary bypass (CPB) TEE, and it was found that preCPB TEE often underestimates AS severity. [7] The reason for this disparity is unclear.…”