Resident versus Attending Surgeon Patency and Clinical Outcomes in On- versus Off- Pump Coronary Artery Bypass Surgery G Hossein Almassi, MD 1 Brendan M. Carr, MS 2 Muath Bishawi, MD, MPH 3 A. Laurie Shroyer, PhD 2 Jacquelyn A. Quin, MD 4 Brack Hattler, MD 5 Todd H. Wagner, PhD 6 Joseph F. Collins, PhD 7 Pasala Ravichandran, MD 8 Joseph C. Cleveland, MD 9 Frederick L. Grover, MD 5,9 Faisal G. Bakaeen, MD 10 for the VA #517 Randomized On/Off Bypass (ROOBY) Study Group 1 Cardiothoracic Surgery, Medical College of Wisconsin and Veterans Affairs (VA) Medical Center, Milwaukee, WI; 2 Surgery, Northport VA Medical Center and Stony Brook Medicine School of Medicine, Stony Brook, NY; 3 Surgery, Duke University, Durham, NC; 4 Cardiac Surgery, VA Boston Healthcare System, West Roxbury, MA; 5 Cardiology, VA Eastern Colorado Health Care System, Denver, CO; 6 VA Palo Alto Health Economics Resource Center, Menlo Park, CA and Department of Health Research and Policy, Stanford University, Stanford, CA; 7 Cooperative Studies Program Coordinating Center and VA Medical Center, Perry Point, Maryland; 8 Surgery, Oregon Health and Sciences University and Portland VA Medical Center, Portland, OR; 9 Surgery, University of Colorado School of Medicine at the Anschutz Medical Campus, Aurora, CO; 10 Cardiothoracic Surgery, Baylor College of Medicine and Houston VA Medical Center, Houston, TX

Presenter Disclosure No disclosure to report

Funding Cooperative Studies Program of the Department of Veterans Affairs Office of Research and Development and the Department of Veterans Affairs Central Office, Office of Patient Care Services. Offices of Research and Development at the Zablocki VA Medical Center, Northport VA Medical Center, and the VA Eastern Colorado Healthcare System.

Background  Residents must be trained to perform cardiac surgical procedures  Balance between education and what is best for the patient  Prior studies have shown no impact on CABG clinical outcomes  Little information about effect on graft patency

Background  Bakaeen et al., 2012 – residents and attendings had similar outcomes and 1-year patency  Bakaeen et al., 2009 – residents had longer operative times, perfusion and cross-clamp times, but similar outcomes  Guo et al., 2008 – residents /fellows vs. consultants had similar operative morbidity and mortality in on- pump CABG

Background  Haan et al., 2007 – hospitals with residency programs have longer perfusion times but similar outcomes  Asimakopoulos et al., 2006 – residents had similar operative morbidity and mortality in off-pump CABG  Ascione et al., 2004 – residents had similar morbidity and mortality in high-risk off-pump CABG patients

Research Questions  Do different clinical outcomes result when residents vs. attendings perform the majority of distal coronary anastomoses?  Do grafts performed during CABG by residents vs. attendings have different rates of patency at 1 year postop?  Are these results different for on-pump vs. off-pump CABG?

ROOBY Trial  VA Cooperative Study (18 centers)  February 2002 – May 2008  Prospective, randomized, single-blinded  Comparison of CABG with and without CPB  ONCAB (n = 1,099)  OPCAB (n = 1,104)  Total (n = 2,203)

Study Population  All patients = 1,272  16 centers with cardiac surgery residents  Data on resident anastomoses captured beginning July 2003  OPCAB = 639 Patients  Resident as primary surgeon: 431 (67.4%)  ONCAB = 633 Patients  Resident as primary surgeon: 493 (77.9%)

Definition  Primary surgeon:  The individual (resident or attending) who performed ≥ 50% of the distal anastomoses in a given patient

Clinical Outcomes  Short-term (30-day) composite endpoint:  Death  Reoperation  New mechanical support  Cardiac arrest  Coma  Stroke  Renal failure requiring dialysis  1-year composite endpoint:  Death from any cause within 1 year after surgery  Nonfatal myocardial infarction between 30 days and 1 year  Any revascularization procedure between 30 days and 1 year

Graft Patency  Coronary angiography at 1 year postop  FitzGibbon classification  A = An excellent/unimpaired graft  B = An impaired graft with a stenosis >50% reducing the caliber of the graft to <50% of the target artery diameter  O = A completely occluded graft

Statistical Methods  Discrete variables: Chi-square or Fisher Exact tests  Continuous variables: Student T-tests  Multivariate Regression  Significance at p < 0.01 for all ROOBY sub-studies

Results

Baseline patient characteristics Patient risk profile On-pump N=633 Off-pump N=639 Resident n/N (%) Attending n/N (%) p-value Resident n/N (%) Attending n/N (%) p-value COPD119/493 (24.1)20/140 (14.3) /431 (20.6)44/208 (21.2)0.88 Creatinine > 1.5 mg/dl30/493 (6.1)14/140 (10.0)0.1138/431 (8.8)17/208 (8.2)0.79 Cerebrovascular accident31/493 (6.3)13/140 (9.3)0.2226/431 (6.0)14/208 (6.7)0.73 Peripheral artery disease61/493 (12.4)18/140 (12.9)0.8865/431 (15.1)40/208 (19.2)0.18 Diabetes233/493 (47.3)63/140 (45.0) /431 (46.9)82/208 (39.4)0.08 Hypertension424/493 (86.0)128/140 (91.4) /431 (86.8)180/208 (86.5)0.93 Atrial fibrillation10/493 (2.0)2/140 (1.4)0.6514/429 (3.3)11/208 (5.3)0.22 LVEF by category < 35% ≥ 35% 23/485 (4.7) 462/485 (95.3) 5/132 (3.8) 127/132 (96.2) /419 (4.5) 400/419 (95.5) 17/201 (8.5) 184/201 (91.5) 0.05 Prior MI142/490 (29.0)39/138 (28.3) /427 (27.2)63/208 (30.3)0.41 β-Blocker Use302/493 (61.3)83/140 (59.3) /431 (63.8)127/208 (61.1)0.50 Aspirin411/493 (83.4)119/140 (85.0) /431 (85.8)168/208 (80.8)0.10 Urgent case60/493 (12.2)16/140 (11.4)0.8162/431 (14.4)27/208 (13.0)0.63

*NOTE: p-value is for the comparison between treatment groups Coronary anatomy On-pump N=633 Off-pump N=639 Resident n/N (%) Attending n/N (%) p-value Resident n/N (%) Attending n/N (%) p-value Territories with disease /493 (6.9) 133/493 (27.0) 322/493 (65.3) 9/140 (6.4) 31/140 (22.1) 100/140 (71.4) /431 (7.9) 132/431 (30.6) 263/431 (61.0) 11/207 (5.3) 61/207 (29.5) 132/207 (63.8) 0.35 Distals performed by Resident only Attending only Both 303/633 (47.9) 121/633 (19.1) 209/633 (33.0) 269/639 (42.1) 168/639 (26.3) 202/639 (31.6) 0.008* Coronary territories and anastomoses per primary surgeon

On-pump n/N (%) OR mean ± SD Off-pump n/N (%) OR mean ± SD ResidentAttendingp-valueResidentAttendingp-value LAD anastomoses Quality of target Good/Moderate Poor 450/482 (93.4) 32/482 (6.6) 118/136 (86.8) 18/136 (13.2) /443 (93.5) 29/443 (6.5) 159/179 (88.8) 20/179 (11.2) 0.05 Diagonal anastomoses Quality of target Good/Moderate Poor 164/176 (93.2) 12/176 (6.8) 48/51 (94.1) 3/51 (5.9) /129 (88.4) 15/129 (11.6) 62/69 (89.9) 7/69 (10.1) 0.75 Circumflex (AV) / OM anastomoses Quality of target Good/Moderate Poor 304/331 (91.8) 27/331 (8.2) 130/145 (89.7) 15/145 (10.3) /227 (91.2) 20/227 (8.8) 196/211 (92.9) 15/211 (7.1) 0.51 Ramus anastomoses Quality of target Good/Moderate Poor 40/45 (88.9) 5/45 (11.1) 15/18 (83.3) 3/18 (16.7) /41 (97.6) 1/41 (2.4) 28/30 (93.3) 2/30 (6.7) 0.38 Right main coronary anastomoses Quality of target Good/Moderate Poor 43/47 (91.5) 4/47 (8.5) 36/40 (90.0) 4/40 (10.0) /59 (94.9) 3/59 (5.1) 46/52 (88.5) 6/52 (11.5) 0.21 PDA anastomoses Quality of target Good/Moderate Poor 134/156 (85.9) 22/156 (14.1) 126/151 (83.4) 25/151 (16.6) /127 (89.0) 14/127 (11.0) 130/142 (91.5) 12/142 (8.5) 0.48 Posterolateral anastomoses Quality of target Good/Moderate Poor 21/23 (91.3) 2/23 (8.7) 14/18 (77.8) 4/18 (22.2) /14 (100.0) 0/14 (0.0) 17/18 (94.4) 1/18 (5.6) 0.37 Comparison of target vessels quality based on who actually performed the anastomoses

Operative variables by primary surgeon Patients operative profile On-pump N=633 Off-pump N=639 Resident n/N (%) Attending n/N (%) p-value Resident n/N (%) Attending n/N (%) p-value Units of packed RBC 1.0 ± 1.6 (n=493) 0.9 ± 1.6 (n=140) ± 1.5 (n=430) 1.0 ± 1.6 (n=208) 0.65 Units of fresh frozen plasma 0.4 ± 1.1 (n=493) 0.5 ± 1.4 (n=140) ± 1.3 (n=430) 0.5 ± 1.3 (n=208) 0.73 Units of platelets 0.3 ± 1.5 (n=493) 0.1 ± 0.6 (n=140) ± 1.7 (n=430) 0.4 ± 1.5 (n=208) 0.96 Take down and redo of distal 14/493 (2.8)6/140 (4.3)0.3917/431 (3.9)5/208 (2.4)0.32

Short-term Clinical Outcomes * Short-term composite endpoint included death, reoperation, new mechanical support, cardiac arrest, coma, stroke, or renal failure requiring dialysis before discharge or within 30 days after surgery On-pump n/N (%) OR mean ± SD Off-pump n/N (%) OR mean ± SD ResidentAttending p-valueResidentAttendingp-value Short-term composite*24/493 (4.9)10/140 (7.1)0.2927/431 (6.3)10/208 (4.8)0.46 Reoperation for bleeding9/493 (1.8)4/140 (2.9)0.4514/431 (3.2)4/208 (1.9)0.34 Stroke3/493 (0.6)2/140 (1.4)0.333/431 (0.7)2/208 (1.0)0.72 Renal failure requiring dialysis 2/493 (0.4)0/140 (0.0)0.453/431 (0.7)2/208 (1.0)0.72 Prolonged vent >48hrs15/493 (3.0)6/140 (4.3)0.4721/431 (4.9)9/208 (4.3)0.76 Re-intubation13/493 (2.6)5/140 (3.6)0.5616/429 (3.7)5/208 (2.4)0.38 MI18/493 (3.7)4/140 (2.9)0.6525/431 (5.8)12/208 (5.8)0.99 New mechanical sup.5/493 (1.0)1/140 (0.7)0.755/431 (1.2)4/208 (1.9)0.44 Mediastinitis4/493 (0.8)4/140 (2.9)0.063/431 (0.7)5/208 (2.4)0.07 Operative Death3/493 (0.6)2/140 (1.4)0.335/431 (1.2)1/208 (0.5)0.40 Hospital length of stay (days) 7.6 ± 5.3 (n=486) 8.1 ± 6.8 (n=139) ± 4.4 (n=425) 7.9 ± 5.6 (n=203) 0.53

1-Year Clinical Outcomes On-pump n/N (%) OR mean ± SD (n) Off-pump n/N (%) OR mean ± SD (n) ResidentAttendingp-valueResidentAttendingp-value 1-year composite*32/493 (6.5)8/140 (5.7)0.7444/431 (10.2)19/208 (9.1)0.67 All-cause death12/493 (2.4)4/140 (2.9)0.7817/431 (3.9)5/208 (2.4)0.32 Repeat revascularization† 16/493 (3.2)4/140 (2.9)0.8225/431 (5.8)11/208 (5.3)0.79 Non-fatal MI†8/493 (1.6)2/140 (1.4)0.875/431 (1.2)4/208 (1.9)0.44 * 1-year composite endpoint included death from any cause within 1 year after surgery, nonfatal myocardial infarction between 30 days and 1 year, and any revascularization procedure between 30 days and 1 year † These two late adverse outcomes were evaluated from the time of 30-days post-surgery up until 1-year follow-up

On-pumpOff-pump Resident n/N (%) Attending n/N (%) p-valueResident n/N (%) Attending n/N (%) p-value Overall A B O 590/711 (83.0) 23/711 (3.2) 98/711 (13.8) 262/318 (82.4) 8/318 (2.5) 48/318 (15.1) /636 (77.2) 27/636 (4.2) 118/636 (18.6) 328/428 (76.6) 20/428 (4.7) 80/428 (18.7) 0.94 SVG A B O 314/414 (75.8) 15/414 (3.6) 85/414 (20.5) 178/228 (78.1) 8/228 (3.5) 42/228 (18.4) /369 (70.5) 12/369 (3.3) 97/369 (26.3) 213/294 (72.4) 13/294 (4.4) 68/294 (23.1) 0.51 LIMA A B O 253/268 (94.4) 6/268 (2.2) 9/268 (3.4) 71/74 (95.9) 0/74 (0.0) 3/74 (4.1) /247 (88.7) 14/247 (5.7) 99/112 (88.4) 5/112 (4.5) 8/112 (7.1) Year FitzGibbon Patency A = An excellent/unimpaired graft B = An impaired graft with a stenosis >50% reducing the caliber of the graft to <50% of the target artery diameter O = A completely occluded graft SVG = Saphenous vein graft LIMA = Left internal mammary artery

Limitations  Attendings could have assisted residents in ways not documented  Predominantly male veteran population  Subgroup analysis  Resident anastomosis data not captured during first year of ROOBY trial  Follow-up limited to 1 year

Conclusions  For ROOBY Trial patients:  No difference in perioperative outcomes  No difference in 1-year outcomes  No difference in 1-year graft patency

Conclusion Residents can and should be trained in advanced surgical techniques with no negative impact on surgical outcomes.

Thank You