Strengths, Limitations and Future Studies
The strength of this study is the relatively large number of patients
(n=200) who underwent surgical intervention in a single timeframe at a
single center dedicated to the care of complex, degenerative MV disease.
Further, the TEE examinations were performed on the same subset of
patients included in the internally validated and published surgical
score study by Anyanwu et al. Additionally, the examinations were rated
by two independent, board-certified cardiac anesthesiologists with a
subset of examinations evaluated by both clinicians.
The retrospective nature of our study is one of its limitations. This
study used a surgical scoring system published previously by Anyanwu et
al. as the standard of comparison for MV repair complexity
stratification. The scoring system in that study was extrapolated
retrospectively from surgical notes, rather than generated in real-time
based on intraoperative anatomic inspection. Also, the echocardiographic
scores included in this cohort are from this older study and were also
generated from retrospective review of previously performed
echocardiography examinations. However, we chose to use the previously
studied and published cohort to allow for better comparison with the
same patients.
Importantly, the echocardiographic studies in the current report were
performed using TEE imaging technology that has since been updated.
Contemporary images obtained using newer echocardiography machines and
updated software packages are of better quality, with greater temporal
and spatial resolution, better three-dimensional capacity and improved
post-processing capabilities. Accordingly, better image quality is
likely to further improve the agreement between surgical and
echocardiographic scores. Indeed, a prior investigation of echo-guided
mitral valve repair by Drake et al. demonstrated that 3D echo images of
the mitral valve were more highly concordant with intraoperative
surgical findings, further supporting that improved echo technology
(which in recent years has seen more noticeable improvements in 3D than
2D imaging), will further improve agreement between surgical and
echocardiographic scores.
Training, education, and dissemination of a standardized scoring system
is also likely to improve the agreement between TEE and surgical scores,
demonstrated by the higher level of agreement between surgical scores
and the scores given by the more experienced rater. Though further
analysis is required to assess inter-clinician reliability on a larger
scale, targeted training and education can standardize image acquisition
and reduce variability amongst echocardiographers. Additionally, the
current study used a retrospective analysis consisting of images
acquired by one clinician then interpreted by another. Future studies
applying the scoring system can intentionally focus on acquiring
specific images for subsequent interpretation. Importantly, prospective
studies are needed to validate the use of TEE in predicting
intra-operative surgical complexity scores. Once validated, assessment
of the clinical impact of the scoring system can be carried out,
ultimately in terms of its ability to improve clinical outcomes, patient
education and patient satisfaction.