title: Outcomes of On-Pump versus Off-Pump Coronary Artery Bypass Graft Surgery in the High Risk (AusSCORE > 5).
abstract: BACKGROUND
  Coronary artery bypass graft surgery (CABG) has been established as the preferred intervention for coronary revascularisation in the high-risk population. Off-pump coronary artery bypass (OPCAB) may further reduce mortality and morbidity in this population subgroup. This study presents the largest series of high-risk (AusSCORE > 5) OPCAB patients in Australia and New Zealand.
  
  
  METHODS
  We reviewed the Australian and New Zealand Society of Cardiac and Thoracic Surgeons' (ANZSCTS) database for high-risk patients (n=7822) undergoing isolated CABG surgery and compared the on-pump coronary artery bypass (ONCAB) (n=7277) with the OPCAB (n=545) technique. Preoperative and intraoperative risk factors, and postoperative outcomes were analysed. Survival analysis was performed after cross-matching the database with the national death registry to identify long-term mortality.
  
  
  RESULTS
  The ONCAB and OPCAB groups had similar risk profiles based on the AusSCORE. Thirty-day mortality (ONCAB vs OPCAB 3.9% vs 2.4%, p=0.067) and stroke (ONCAB vs OPCAB 2.4% vs 1.3%, p=0.104) were similar between the two groups. OPCAB patients received fewer distal anastomoses than ONCAB patients (2.5±1.2 vs 3.3±1.0, p<0.001). The rates of new postoperative atrial arrhythmia (28.3% vs 33.3%, p=0.017) and blood transfusion requirements (52.1% vs 59.5%, p=0.001) were lower in the OPCAB group, while duration of ICU stay in hours (97.4±187.8 vs 70.2±152.8, p<0.001) was longer. There was a non-significant trend towards improved 10-year survival in OPCAB patients (74.7% vs. 71.7%, p=0.133).
  
  
  CONCLUSIONS
  In the high-risk population, CABG surgery has a low rate of mortality and morbidity suggesting that surgery is a safe option for coronary revascularisation. OPCAB reduces postoperative morbidity and is a safe procedure for 30-day mortality, stroke and long-term survival in high-risk patients.
authors.affiliation: Department of Cardiothoracic Surgery, Royal Prince Alfred Hospital, Sydney, NSW, Australia; The Baird Institute, Sydney, NSW, Australia; Institute of Academic Surgery, The University of Sydney, Sydney, NSW, Australia. Electronic address: vikrantdhurandhar@hotmail.com.
authors.forename: Vikrant
authors.initials: V
authors.lastname: Dhurandhar
authors.affiliation: Department of Cardiothoracic Surgery, Royal Prince Alfred Hospital, Sydney, NSW, Australia; Institute of Academic Surgery, The University of Sydney, Sydney, NSW, Australia.
authors.forename: Akshat
authors.initials: A
authors.lastname: Saxena
authors.affiliation: Department of Cardiothoracic Surgery, Royal Prince Alfred Hospital, Sydney, NSW, Australia; The Baird Institute, Sydney, NSW, Australia; Institute of Academic Surgery, The University of Sydney, Sydney, NSW, Australia.
authors.forename: Roneil
authors.initials: R
authors.lastname: Parikh
authors.affiliation: Department of Cardiothoracic Surgery, Royal Prince Alfred Hospital, Sydney, NSW, Australia; The Baird Institute, Sydney, NSW, Australia; Institute of Academic Surgery, The University of Sydney, Sydney, NSW, Australia; Department of Cardiothoracic Surgery, Australian School of Advanced Medicine, Macquarie University, Sydney, NSW, Australia.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Vallely
authors.affiliation: Department of Cardiothoracic Surgery, Royal Prince Alfred Hospital, Sydney, NSW, Australia; The Baird Institute, Sydney, NSW, Australia; Institute of Academic Surgery, The University of Sydney, Sydney, NSW, Australia; Department of Cardiothoracic Surgery, Australian School of Advanced Medicine, Macquarie University, Sydney, NSW, Australia.
authors.forename: Michael K
authors.initials: MK
authors.lastname: Wilson
authors.affiliation: Faculty of Health Sciences, The University of Sydney, Sydney, NSW, Australia.
authors.forename: Jennifer Kay
authors.initials: JK
authors.lastname: Butcher
authors.affiliation: Faculty of Health Sciences, The University of Sydney, Sydney, NSW, Australia.
authors.forename: Deborah Ann
authors.initials: DA
authors.lastname: Black
authors.affiliation: CCRE Therapeutics, DEPM, Monash University, Melbourne, Vic., Australia.
authors.forename: Lavinia
authors.initials: L
authors.lastname: Tran
authors.affiliation: CCRE Therapeutics, DEPM, Monash University, Melbourne, Vic., Australia.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Reid
authors.affiliation: Department of Cardiothoracic Surgery, Royal Prince Alfred Hospital, Sydney, NSW, Australia; The Baird Institute, Sydney, NSW, Australia; Institute of Academic Surgery, The University of Sydney, Sydney, NSW, Australia.
authors.forename: Paul G
authors.initials: PG
authors.lastname: Bannon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000401:mortality / Q000628:therapy; D001315:Australia / Q000453:epidemiology; D001803:Blood Transfusion; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects / Q000379:methods; D016208:Databases, Factual; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D009520:New Zealand / Q000453:epidemiology; D011183:Postoperative Complications / Q000209:etiology / Q000401:mortality / Q000628:therapy; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000401:mortality / Q000628:therapy; D015996:Survival Rate
keywords: CABG; Coronary artery bypass graft; Elderly; High risk; Off-pump; On-pump