Off Pump vs On Pump CABG

OVERVIEW

Off pump CABG is:

  • widely performed
  • safe
  • effective
  • and there are numerous techniques available – limited thoracotomy, video assisted

On or off pump CABG is primarily a balance of:

  • an easy, bloodless surgical field, with
  • the risks of bypass and embolic events from clamping and cannulating the aorta

Off pump CABG is generally preferred in:

  • patients with aortic disease precluding bypass
  • patients at higher risk of complications from CPB such as: ventricular dysfunction, renal insufficiency, diabetes, advanced age, and chronic lung disease

ADVANTAGES

avoids bypass

  • no aortic cannulation -> less risk of dissection, embolism
  • no atrial cannulation -> less atrial injury, arrhythmias
  • no cross-clamping -> less risk of plaque embolism, CVA, MI
  • no activation of coagulation, kallikrein, inflammation caused by tubing -> less coagulopathy, less bleeding, less transfusion
  • no cardioplegia -> no K+ load, fluid load, coronary air embolism
  • no risk of bypass machine failure -> air embolism
  • less cost
  • less equipment
  • less staff

The CORONARY study (NEJM RCT 2012) suggests off-pump performed by experts is as good as on-pump

DISADVANTAGES

  • needs skilled staff
  • technically more difficult (increased risk of anastomotic bleeding, suboptimal revascularisation, myocardial ischaemia)
  • not all coronary arteries well reached by technique
  • potential for MI without cardioplegia
  • more graft failure
  • incomplete revascularisation more frequent
  • worse long-term graft outcomes in some studies (e.g. ROOBY, 2009)
  • proposed neuropsychological benefit not shown in trial
  • more difficult in diffuse disease or small artery disease

EVIDENCE

  • larger observational studies generally favour off pump CABG than the smaller RCTs that have been performed

ROOBY trial (NEJM, 2009) [PMID: 19890125.]

  • MCRCT
  • US
  • 2002-2008
  • n = 2200
  • randomised to on pump vs off pump
  • primary short term outcomes: death, major complications (reoperation, new mechanical support, cardiac arrest, coma, stroke, renal failure requiring dialysis) within 30 days
  • primary long-term outcomes: 1 year mortality, non-fatal MI @ 1 year, repeat revascularisation @ 1 year
  • secondary endpoints: completeness of revascularisation, graft patency @ 1 year, neuropsychological test

-> no difference in primary short term outcomes -> no difference in survival -> trend towards greater complications in off pump (primary long term) -> off pump group received less grafts then were originally planned -> off pump group grafts were less patent -> no difference in neuropsychological outcomes -> less transfusions in off pump group -> off pump: longer OT times, LOS same, time of ventilation same

SUMMARY: better to do CABG on pump

Khan NE, et al. A randomised comparison of off-pump and on-pump multivessel coronary-artery bypass surgery. N Engl J Med 2004; 350:21-28. [PMID 14702424]

  • RCT
  • on pump vs off pump
  • followed up at 3 months
  • mean of 3 grafts -> on pump grafts had a significant increase in patency

GOPCABE NEJM 2012 [PMID: 23477657]

  • RCT found no difference between on-pump and off-pump CABG for elderly patients >75 years undergoing CABG (at 30 days and 12 months)

CORONARY study, NEJM April 19, 2012 [PMID: 22449296.]

  • RCT of 4752 patients
  • primary outcome = composite of 30 day death, stroke, MI or new renal failure
  • No difference between off-pump vs on-pump CABG
  • Off-pump had significant lower rates of blood-product transfusion, return to theatre for bleeding, acute kidney injury and respiratory complications, but more early repeat revascularisations ( 0.7 vs 0.2%)
  • Only surgeons familiar with off-pump involved (and no trainees as primary surgeons), and ?a higher risk group of patients
  • suggests off-pump CABG performed by experts gives good results

References and Links

  • Khan NE, et al. A randomized comparison of off-pump and on-pump multivessel coronary-artery bypass surgery. N Engl J Med. 2004 Jan 1;350(1):21-8. [PMID 14702424]
  • GOPCABE Study Group. Off-pump versus on-pump coronary-artery bypass grafting in elderly patients. N Engl J Med. 2013 Mar 28;368(13):1189-98. PMID: 23477657.
  • Hemmerling TM, Romano G, Terrasini N, Noiseux N. Anesthesia for off-pump coronary artery bypass surgery. Ann Card Anaesth. 2013 Jan-Mar;16(1):28-39. PMID: 23287083.
  • CORONARY study. Off-pump or on-pump coronary-artery bypass grafting at 30 days. N Engl J Med. 2012 Apr 19;366(16):1489-97. PMID: 22449296.
  • Pepper J. Recent data on off-pump coronary artery bypass grafting: the CORONARY and GOPCABE trials. EuroIntervention. 2013 May 20;9(1):29-32. PMID: 23685292.
  • Polomsky M, Puskas JD. Off-pump coronary artery bypass grafting–the current state. Circ J. 2012;76(4):784-90. PMID: 22451446.
  • Randomized On/Off Bypass (ROOBY) Study Group. On-pump versus off-pump coronary-artery bypass surgery. N Engl J Med. 2009 Nov 5;361(19):1827-37. PMID: 19890125.

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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