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Adherence to physician training guidelines for pediatric transesophageal echocardiography affects the outcome of patients undergoing repair of congenital cardiac defects.

J. Geoffrey Stevenson, M.D., Seattle, WA J Am Soc Echocardiogr. 1999; 12: 165-72.

Reviewers: Stuart J. Weiss, M.D., Ph.D., Albert T. Cheung, M.D., Joseph S. Savino, M.D., University of Pennsylvania, PA

Abstract: Intraoperative TEE has been established as a useful technique in congenital cardiac surgical procedures. In a retrospective, single-center, unblinded study, Stevenson tested whether differences in the training and qualifications of the intraoperative echocardiographer affected outcome after congenital cardiac surgery in two separate 5 month intervals. In the first interval, (year 1), 115 patients had intraoperative TEE performed by dedicated echocardiographers (1 pediatric cardiolo-gist and 2 pediatric anesthesiologists) who fulfilled the TEE training criteria advocated by the Committee on Standards of the Society of Pediatric Echo-cardiography. In the second interval, (year 2), 104 patients had intraoperative TEE performed by 5 cardiac anesthesiologists who also administered the anesthetic and who did not fullfill all of the TEE training criteria. The investigator found that 96% of the recorded TEE examinations in year 1 were adequate compared to only 22% of those recorded in year 2 (p=0.001). Three of 14 residual cardiac defects were missed by TEE in year 1 compared to 14 of 19 residual defects missed by TEE in year 2 (p<0.001). TEE findings prompted the return to CPB for repair of defects in 9.6% of patients in year 1 compared to 0% of patients in year 2 (p<0.001). Six patients in year 2 required reoperation or intervention within the first 2 postoperative months for significant residual problems not detected by intraoperative TEE. The death rate was 7.0% in year 1 and 8.6% in year two and was not significantly different. The author concluded that intraoperative echocardiography improved outcome when performed by physicians who meet published guidelines for training and qualifications in echocardiography and whose sole responsibility is the performance of the intraoperative TEE examination.

Comment: The study attempted to address a controversial and difficult topic regarding which physicians are most qualified to perform intraoperative TEE for diagnostic purposes during congenital cardiac surgical procedures. It was evident from the study that physicians trained in either pediatric cardiology or pediatric cardiac anesthesiology were fully capable of utilizing the full diagnostic capability of TEE for intraoperative studies. The results of the study also suggested that the need for reoperation for residual cardiac defects could potentially be reduced by the use of intraoperative TEE. However, significant residual cardiac defects were more often detected by echocardiographers meeting the qualifications and training criteria advocated by the Society of Pediatric Echocardiography and whose sole responsibility was the performance of the TEE examination.

Several important limitations in the study must be recognized when interpreting the findings. First, the study was retrospective, unblinded, and performed at a single institution using data from a limited number of echocardio-graphers. Considering the unilateral and subjective definition of what constituted an "adequate TEE examination", "significant problems", and TEE findings that prompted the decision to return to cardiopulmonary bypass, it would have been preferable to use blinded investigators to evaluate the echo-cardiographic examinations and management of individual cases. Based on the study design, an objective assessment of the data was difficult to verify, especially if the investigator was one of echocardiographers in the study. Second, differences in outcome between the two study intervals may have been related to more changes in practice patterns over time rather than the performance of individual echo-cardiographer. Two of the "qualified" echocardiographers in year 1 also performed TEE examinations in year 2, but were re-classified as "untrained" providers. Comparing outcome between echocardio-graphers with different levels of training under similar concurrent working conditions at several different centers would have been a more appropriate test. Finally, the hypothesis that outcome was better when the sole responsibility of the echocardiographer was limited to the performance of the TEE examination was not specifically tested.

Despite the significant limitations in design, the implications of the study and the accompanying editorial comments of Fyfe (J Am Soc Echocardiogr 1999;12:343-4) were a direct criticism of the clinical competence of anesthesiologist echo-cardiographers in general. These editorial comments emphasize the importance of practicing anesthesiologist echocardio-graphers to demonstrate clinical proficiency through quality assurance programs, continuing medical education, and scientific contributions to the field.