Grant Title:
Unbalanced Atrioventricular Septal Defect: A CHSS Inception Cohort Study
Lay Summary: A multi-institutional study of unbalanced atrioventricular septal defect (uAVSD) being undertaken by the Congenital Heart Surgeons Society. The CHSS has a long history of multicenter clinical studies addressing specific anatomic lesions and their associated outcomes. With the support of StHS, uAVSD became only the ninth patient cohort to be the subject of a CHSS multi-institutional study.
uAVSD is an extremely challenging problem for congenital heart surgeons because of it’s complexity, and the strikingly divergent surgical strategies required to maximize survival. Indeed, the very definition of uAVSD is not well established. As regards surgical therapy, some uAVSD patients are candidates for complete repair, others must be treated as single ventricle patients, and still others may be best treated with so called “one and a half ventricle” repairs. There are subtle anatomic details (most of which require careful echocardiographic definition) and important comorbid conditions such as Trisomy 21 that significantly impact these decisions. There is measurable mortality even when these decisions are made “correctly”. When strategy and patient anatomy and other factors do not match, however, mortality is very high.
uAVSD is an extremely challenging problem for congenital heart surgeons because of it’s complexity, and the strikingly divergent surgical strategies required to maximize survival. Indeed, the very definition of uAVSD is not well established. As regards surgical therapy, some uAVSD patients are candidates for complete repair, others must be treated as single ventricle patients, and still others may be best treated with so called “one and a half ventricle” repairs. There are subtle anatomic details (most of which require careful echocardiographic definition) and important comorbid conditions such as Trisomy 21 that significantly impact these decisions. There is measurable mortality even when these decisions are made “correctly”. When strategy and patient anatomy and other factors do not match, however, mortality is very high.
The interplay of anatomy and patient factors and determination of optimal treatment strategy in light of these considerations is the goal of the uAVSD Inception Cohort Study. This will be achieved through a prospective, multi-institutional study wherein patients are enrolled when diagnosed, their echocardiograms carefully reviewed, and outcomes of subsequent surgical interventions catalogued. Associations between outcomes, anatomy, and patient factors will be sought. In this way we aim to improve significantly the outlook for patients with this very difficult problem by more clearly defining which therapies are most appropriate for each uAVSD patient.
The StHS grant provided important support as we began to design and initiate the uAVSD Inception Cohort Study. This work included:
- Creating demographic enrollment forms as well as clinical and echocardiographic data abstraction forms
- Conducting working weekends at the CHSS Data Centre where a core group of echocardiographers could together precisely define the echo criteria to be employed in the study
- Testing these criteria using a retrospective patient cohort from a small number of CHSS institutions, and in this way beginning to create a set of objective measures with which uAVSD can be universally identified
- Conducting webinars for echocardiographers from participating centers educating them about the needed echo measurements for the study, the newly identified metrics relevant to identifying uAVSD, uploading of study echos to the Data Centre, and more
- Creation of a “virtual echo lab” (something that had not previously been done) to allow expert echocardiographers from multiple centers to function as one team, overreading echo studies from the participating centers as they are submitted. The virtual core lab concept broke new ground in the arena of multi-institutional studies, has since been extended to other CHSS cohorts as well.
