1. Coarctation of the Aorta Feasibility of a long-term follow-up study
Fall 2016 CHSS Data Center Work Weekend
Good morning
At previous CHSS research wends, there was a proposal to look into the possibility of looking a different CHSS cohorts which are rich with information and then possibly looking at long term followup of these patients. This was done with the neonatal coarctation repair cohort. Database was interrogated and I would like to first give you a bref resume as to its content, and then propse how take a second look it and how it could be possiblibly be a template for a comtemporary analysis of other CHSS cohorts

2. Background CHSS Coarctation cohort
975 neonates enrolled between from 32 institutions
No follow-up beyond 1996
An important collaborator in this project is Amine Mazine, Super resident here in TO, on loan graciously on loan from the University of Montreal. He looked at the raw data of this cohort

3. One publication Quaegebeur et al., JTCVS, 1994
Therefore could tease out the impact
Double statistical power – signifcant
Where clamp tghe aorta
Quaegebeur et al., JTCVS, 1994

4. Survival
Non-risk-adjusted survival for at least 1 month among the 322 patients was 93%, and it was 84% for 24 months. The hazard function for death for coarc-tation without VSD was lower initially and more pro-longed than that for coarctation with VSD (Fig. 2).

5. Impact of VSD on hazard of death
A single moderate-sized or large VSD slightly, but not believably, decreased the non-risk-adjusted survival after repair (see Table II, Appendix Fig. 1) and believably decreased the risk-adjusted survival (Table III). Multi-plicity of VSDs was associated with a considerably decreased non-risk-adjusted and risk-adjusted survival when the aggregate size of the VSD was moderate or large. The location of a single VSD had little effect on non-risk-adjusted or risk-adjusted survival.
Coexisting obstruction at other levels in the left heart-aorta complex decreased both the non-risk-adjusted (see Table 1) and the risk-adjusted

6. Impact of technique on survival
The surgical technique for repair of the coarctation did not affect the non-risk-adjusted (Table IV) nor the risk-adjusted (see Table III) survival so long as the repair was not extended proximal to the left subclavian artery. When an end-to-end repair was extended proximal to the left subclavian artery but only to the left common carotid artery, the non-risk-adjusted (see Table IV) and risk-ad-justed (see Table III, Fig. 4) survivals were not believably different from those when end-to-end anastomosis was used in the "classic" fashion. When patch grafting was used as the technique of repair and was similarly extend-ed proximally (that is, only as far up as the level of the left common carotid artery), the non-risk-adjusted survival was not believably decreased compared with that of patch graft repair limited to the upper descending thoracic aor-ta (29%; 70% cl* 10% to 55% versus 13%; 70% CL 4%-29%, p(Fisher) = 0.4, see Table IV); the risk-adjust-ed survival was decreased by this extension of the patch graft technique (see Table III, Fig. 4). No matter what the technique, extensions proximal to the left common carotid artery were associated with decreased survival. Only eight patients (one death) had a reverse subclavian flap used as part of the initial repair of coarctation, so generalizations about survi

7. Impact of technique on reintervention

8. 22 did not undergo surgery
Updated cohort
From 1990 – 1996
975 patients
953 underwent surgery
1271 admissions
22 did not undergo surgery

9. Gender distribution

10. Race distribution

11. Major associated cardiac anomalies

12. Associated PDA

13. Use of CPB

14. Technique of coarctation repair (not mutually exclusive)

15. Morphological + technical data
Granular data entered in text form which will require manual extraction

16. Opportunities and Challenges
✘Missing data
✘Patients were not consented for follow-up
✓Large cohort
✓Covers the entire spectrum of surgical technique for CoA repair
✓Granular data

17. Potential research questions
With a larger number of patients, are short term outcomes still the same as the 1994 study?
Impact of technique on survival and reintervention rates unchanged?
Interesting however should only be a preamble to…

18. Potential research questions Long-term follow-up (20 – 26 years)
What proportion of these patients are still being followed (by their primary care physician, cardiologist, etc.)? How many have imaging?
What is the long-term survival of this cohort?
What is the long-term reintervention rate?
What is the impact of surgical strategy on long-term survival and freedom from reintervention?

19. Potential research questions
What is the long-term incidence of hypertension in this population?
What is the long-term left upper limb morbidity / functional impact associated with subclavian flap?

20. Potential impact
This could be the first study to examine these long-term outcomes in a significant number of patients
Would undoubtedly lead to a very impactful publication (NEJM? Lancet? JAMA?)

21. Thank you