1. Radial Artery Patency and Clinical Outcomes Study: a tale of two trials
BRIAN BUXTON and philip hayward
University of Melbourne, EPWORTH and
Austin Hospitals, Melbourne
SCTS University 2016

2. Radial Artery RCTs: RAPCO : Melbourne 1996-2005
RAPS: Toronto
RSVP: London
VA: USA
SCTS University 2016

3. Radial Artery Patency and Clinical Outcomes Study
Randomization of RA, RITA or SV for the 2nd graft in primary isolated CABG
gold standard in situ LITA to LAD graft unchanged
3rd and 4th grafts as per surgeon preference
Standardized surgery and perioperative care to assess impact of conduit selection
all conduits treated alike as aortocoronary grafts
AATS 2016

4. Radial Artery Patency and Clinical Outcomes: 2 parallel trials
Age ≤70 years (≤60 years if diabetic)
radial artery vs free RITA
powered for 10% difference in patency with 10% loss
Age >70 years (>60 years if diabetic)
radial artery vs saphenous vein
powered for 15% difference in patency with 10% loss
AATS 2016

5. RA vs RITA: age ≤70 (≤60 diabetic)
Group 1
Enrolment
Randomization group RA
RITA P
Assessment n=980
Exclusion n=586
Randomized
198
196
Received allocation
186
179
Age (mean & range)
59.2 ( )
59.5 ( )
0.72*
Gender (male)
175 (88%)
178 (91%)
0.51**
Diabetes
22 (11%)
21 (11%)
1.0**
Hypertension
113 (57%)
99 (51%)
0.23**
Elective presentation
160 (81%)
161 (82%)
0.80**
No. of grafts (mean ± std dev)
3.2 ± 1.0
0.49*
Smoking history
148 (75%)
143 (73%)
0.73**
MI pre surgery
75 (38%)
68 (35%)
0.53**
SCTS University 2016

6. Clinical and Angiographic Follow up
10 years of annual follow up by cardiologist and trial nurse
survival / MI / PCI / surgery
Graft angiogram at a randomized time point between 1 month and years
Optional supplemental study (CT) at 5 and 10 years

7. RA vs RITA: 10-year angiographic outcome
Group 1
89%
RA vs RITA
p = .057
80%
Sig
Hazard
95% CI
Lower
Upper
Log Rank
.057
K-M
Cox regression
.061
1.86
.97
3.58
Figure 4
Number at risk:
169
159
153
109 71 33
157
156
142 84 56 31
AATS 2016
Group 1

8. Revascularisation (%)
RA vs RITA 10-Year Clinical Follow Up
Death (%)
MI (%)
Revascularisation (%)
RA (n=198)
18 (9)
11 (6)
22 (11)
RITA (n=196)
32 (16)
13 (7)
26 (13)
91%
RA vs RITA
p = .032
84%
RA vs RITA
p = .084
Sig RR
95% CI
Lower
Upper
Cox regression
.035
1.86
1.05
3.31
Figure 2
Number at risk:
198
194
191
189
183
179
196
193
186
178
172
164
Number at risk:
198
190
185
176
168
153
196
191
179
163
148
138
Group 1 survival
Group 1 event free survival
SCTS University 2016

9. RA vs SV: age >70 (>60 diabetic)
Group 2
Enrolment
Randomisation group RA SV p
Assessment n=902
Exclusion n=677
Randomized
113
112
Received allocation
186
179
Age (mean & range)
72.6 ( )
73.1 ( )
0.43*
Gender (male)
91 (81%)
1.0**
Diabetes
50 (44%)
52 (46%)
0.79**
Hypertension
68 (60%)
78 (70%)
0.16**
Elective presentation
87 (77%)
0.51**
No. of grafts (mean ± std dev)
3.2 ± .9
3.3 ± .7
0.26*
Smoking history
75 (66%)
76 (68%)
0.89**
MI pre surgery
43 (38%)
36 (32%)
0.40**
SCTS University 2016

10. RA vs SV: angiographic outcomes
Group 2
91%
b: Group 2
RA vs SVG
p = .029
81%
Sig
Hazard
95% CI
Lower
Upper
Log Rank
.029
K-M
Cox regression
.037
2.87
1.07
7.71
Figure 4
Number at risk: 78 70 66 40 23 11 68 61 57 29 17 5
AATS 2016

11. Revascularisation (%)
RA vs SV: 10 year Clinical Outcomes
Death (%)
MI (%)
Revascularisation (%)
RA (n=113)
31 (27)
8 (7)
7 (6)
SV (n=112)
39 (35)
10 (9)
9 (8)
73%
RA vs SVG
p = .24
RA vs SVG
p = .18
65%
Sig RR
95% CI
Lower
Upper
Cox regression
.24
1.33
.83
2.12
Figure 3
Number at risk:
113
108
103
100 94 82
112
109
106 99 87 72
Number at risk:
113
106
101 96 86 71
112 98 88 73 61
Group 2 survival
Group 2 event free survival
SCTS University 2016

12. RA ≥ RITA 10-year estimates of patency
RA: 89 +/- 2.9% log rank p=0.057
RITA: 80 +/- 3.9%
HR for failure : 1.86 ( , p=0.061)
Why might radial artery be superior ?
less easily traumatized
adequate length
proximal anastomosis similar to SV
AATS 2016

13. RA > SV 10 year estimates of patency Comparable to other trials
RA: 85 +/- 6.8% log rank p= 0.029
SV: 70 +/- 9.8%
HR for failure : 2.87 ( , p=0.037)
Comparable to other trials
RAPS Toronto: 269 /510 patients: RA 87% vs SV 79% at 7.7 years
RSVP London: 103/142 patients: RA 94% vs SV 79% at 5 years
AATS 2016

14. Discussion
The radial artery may be superior to the free RITA or saphenous vein for the second graft
Coronary bypass is the commonest procedure
9-10% difference in patency in 2nd graft (? 3rd / 4th)
at least one patient per month for typical surgeon
AATS 2016

15. Radial Artery Patency and Clinical Outcome trials

16. Acknowledgements
The authors publish on behalf of all who have contributed to the RAPCO study.
Participating Surgeons
Prof Brian Buxton, A/Prof George Matalanis, Mr Alexander Rosalion, Prof Jai Raman, Mr Siven Seevanayagam, Mr Jullien Gaer, Mr Justin Negri, Dr Masashi Komeda
Anaesthesia and Critical Care
Prof Rinaldo Bellomo, Dr Laurie Doolan, A/Prof Larry McNicol
Interventional Cardiologists
Dr John Brennan, Dr Robert Chan, Dr David Clark, Dr Ronald Dick, Dr Anthony Dortimer, A/Prof David Ecclestone, A/Prof Omar Farouque, Dr Dharsh Fernando, Dr Mark Horrigan, Dr Anthony Jackson, Dr Jennifer Johns, Dr Paul Kertes, Dr Leslie Oliver, Dr Nilesh Mehta, Dr Voltaire Nadurata, Dr Nim Nadarajah, Dr George Proimos, Dr Michael Rowe, Dr Ben Sia, Dr Christopher Webb
Clinical Cardiologists
Dr Nagesh Anaveker, A/Prof Peter Barlis, A/Prof Paul Calafiore, Dr Boniface Chan, Dr John Cotroneo, Dr Angas Hamer, Prof David Hare, Dr Elizabeth Jones, Dr David O’Donnell, Dr Stephen Sylviris, Prof Andrew Tonkin
Coronary CT radiologists
Dr Robert Fabini, Dr Leighton Kearney, Dr Ruth Lim, Dr Maurice Molan, Dr Gerard Smith, Dr Chris Wellman, Dr John Eng
Statistical and Data Management: Dr Ian Gordon, Margaret Shaw, Sandra Gerbo

18. Clinical and Angiographic Follow up
10 years of annual follow up by cardiologist and trial nurse
survival / MI / PCI / surgery
Graft angiogram at a randomized time point between 1 month and years
Optional supplemental study (CT) at 5 and 10 years

19. 30 day outcomes were equal
Group 1
Death
<30 days MI
Sternal
infection
Return to OR for bleeding
Ventilation
>24 hrs
Group 1 RA (n=198) 1 4
Group 1 RITA (n=196) 3
Group 2 RA (n=113) 2
Group 2 SV (n=112)
Short term morbidity was unrelated to conduit type, p=ns
AATS 2016

20. Return to OR for bleeding
30 day outcomes were safe
Group 2
Death
<30 days MI
Sternal
infection
Return to OR for bleeding
Ventilation
>24 hrs
Group 1 RA (n=198) 1 4
Group 1 RITA (n=196) 3
Group 2 RA (n=113) 2
Group 2 SV (n=112)
Short term morbidity was unrelated to conduit type, p=ns
AATS 2016