1. How Many Arterial Grafts is Enough?
Bruce Lytle MD
Baylor Plano Heart Hospital

2. ITA vs SVG 10-Year Survival by Extent of Disease
100 90 80 70
100 90 80 70
100 90 80 70
93.4
90.0
P=0.05
88.0
P=0.0001
P=0.0001
Percent
82.6
79.5
71.0
ITA N=332
Vein N=440
ITA N=714
Vein N=1,063
ITA N=1,249
Vein N=2,116
One-Vessel(LAD)
Two-Vessel(LAD)
Three-Vessel
Loop. et al: NEJM 314:

3. Patency of ITA and SVG to the LAD at One-Year Intervals
100 90 80 70 60
168 48 57 51 27 44 41 8 8 76
260 23 44
302
431 93 73 62
Percent Patent 69 82 47 96 20 53 63 13
Internal Thoracic Artery N=855 Grafts
Saphenous Vein N=1445 Grafts 34
Catheterization Intervals (Years)
Loop, et al; NEJM 314:1-6, 1986

6. Are Two ITA Grafts Better Than One?

7. Survival and Reoperation 1 vs 2 ITA Grafts
100 80 60 40 20 5 4 3 2 1
(1786)
Survival
(2969)
328
453
BITA n=1989
SITA n=4147
401
P<0.001
Survival %
Reoperation (%) / year)
(2889)
Reoperation
302
(1763)
Years After CABG

8. Matched Survival
BITA %
SITA
Years

9. What is the Magnitude of the Benefit ?
And How Many Patients Benefit?

10. Survival Difference d_surviv YEARS AGE 15 10 5 -5 -10 30 20 40 15 50-5
-10 30 20 40 15 50 10 60 5 70
YEARS 80
AGE

11. The Incremental Benefit of the LITA-LAD vs SVG is, for most patients, greater than that for BITA vs LITA-LAD

12. Skeletonize the ITAs

13. ITA Preparation Pedicled
Cohen et al: JTCS 1999

14. ITA Preparation Skeletonized
Cohen et al: JTCS 1999

16. 16

18. Sequential ITA Grafts Add Substantial Complexity

21. The more ITA grafts have been done the less benefit further ITA grafts add

23. Radial Artery vs Saphenous Vein (RAPS)
510 Patients – 9 Canadian Center
269 Late Angiography (7.7 years)
Functional Graft Occlusions Radial 12% SVG 19.7% Complete Graft Occlusion Radial 8.9% SVG 18.6%
P = 0.03
P = 0.002
Deb et al JACC: 2012

24. Probability of Graft Patency
100
LITA 80
RITA RA 60
SVG
Probability of graft patency (%) 40
LITA graft n=2443
RITA graft n=991
Radial graft n=1108
SVG graft n=3238 20 3 6 9 12 15
Number of years following surgery
Tatoulis et al. 2011

27. For All Arterial Grafts Patency is Related to Coronary Stenosis

28. Risk Factors ITA Occlusion
Factor P
Lesser Proximal Stenosis <.0001
Time after CABG
Non-LAD <.0001
LAD .5
Right ITA <.0001
Smoking <.0001
Female Gender
Later Date of Surgery .01
Using multivariable, longtitudinal repeated-measures analysis we identified six risk factors associated with internal thoracic artery graft occlusion.
They were :
1) lesser degree of proximal coronary artery stenosis,
2) increasing time from coronary surgery to angiography in internal thoracic artery grafts to non-left anterior descending coronary arteries,
3) right internal thoracic arteries,
4) History of smoking,
5) female gender,
and 6) later date of surgery

29. Graft Patency vs Coronary Stenosis
100 80 60 40 20 %
P<0.01
P<0.001
P<0.01
<60
>60
<60
>60
<60
>60
LITA
RITA RA
Tatoulis et al (2004)

30. The Most Common Cause of a Failed Arterial Graft is Competitive Flow
But the decrement in patency is not large

31. Failed bypass grafts do not appear to compromise survival

32. How Many Arterial Grafts?
LITA-LAD for Everyone
A second ITA graft to the second most important stenotic vessel further improves outcomes
Radial artery grafts increase operative complexity little
Complex ITA grafting, RGEA grafting are not generic operations
Do an operation that will work on that day

33. LITA - LAD Survival & Revascularization
100 80 60 40 20
97%
91%
93%
81%
82%
69%
68% %
52%
Complete
Incomplete (n = 791)
Years