The Danish On-pump, Off-pump Randomization Study (DOORS)

The Impact of Avoiding Cardiopulmonary By-pass During Coronary Artery Bypass Surgery for Ischemic Heart Disease in Elderly Patients: The Danish On-pump, Off-pump Randomization Study (DOORS)

Background: Coronary artery bypass grafting (CABG) can be performed either with or without the use of cardiopulmonary bypass (CPB) to obtain myocardial re-vascularisation. The investigators hypothesize that CABG without the use of CPB may reduce the risk of perioperative death, stroke, myocardial infarction and other serious complications. The aim of the present study is to compare the incidence of complications and the clinical efficacy of CABG with and without the use of CPB in elderly patients.

Conventional coronary artery bypass grafting (CCABG) using cardiopulmonary bypass has for decades been applied to obtain myocardial re-vascularisation and, hence, improved quality of life and survival. It does, however, bear a risk of death, stroke, myocardial infarction and other serious complications. During recent years, an equivalent operation performed on the beating heart without cardiopulmonary bypass (off-pump coronary artery bypass grafting, OPCAB) has gained popularity helped by the advent of mechanical stabilization devices and improved surgical techniques. Observational studies suggest that this technique is associated with a lower incidence of stroke, per operative arrhythmias and even mortality than conventional CCABG. This is especially the case in elderly patients and patients with significant co-morbidity. Only few randomised, controlled trials have been conducted and most of these included mainly or only low-risk, relatively young patients. These studies have documented the safety and efficacy of OPCAB compared with CCABG, but none of the trials has had the statistical strength to determine whether the rate of serious complications is lower after OPCAB operations. One recent study found graft patency to be significantly lower after OPCAB than after CCABG operations. The investigators find that there is a need of a larger scale randomised trial to compare the results of CCABG and OPCAB operations, especially in elderly patients. This patient group is poorly represented in earlier randomised trials, whereas observational studies and theoretical considerations imply that they may benefit the most from avoiding cardiopulmonary bypass. Aims: Primarily, to compare the incidence of death, stroke and myocardial infarction after CCABG and OPCAB procedures in a population of elderly patients. Furthermore, to compare quality of life and graft patency, and cost- effectiveness after CCABG and OPCAB.

Off-pump Coronary Artery By-pass Grafting, Randomization, stroke, myocardial infarction, mortality, graft patency, quality of life

Quality of life assessed by MOS SF-36 and EuroQol questionnaires 6 months and 3 years after the operation

Total hospital costs and costs of public care provided 6 months and 3 years after the operation and difference in costs per quality adjusted life year

Inclusion Criteria: Age seventy years or above Admitted for first time coronary artery bypass operation Exclusion Criteria: Given information cannot be understood Aortic crossclamping not safe due to calcification Preoperative cardiac conditions demanding cardiopulmonary bypass Re-do cardiac surgery Patients requiring operation within the same day after conference

Houlind KC, Kjeldsen BJ, Terp KA, Madsen SN, Schmidt TA, Holme SJ, Mortensen PE. [Coronary artery bypass surgery without the use of a heart-lunch machine]. Ugeskr Laeger. 2005 May 9;167(19):2037-41. No abstract available. Danish.

Houlind K, Fenger-Gron M, Holme SJ, Kjeldsen BJ, Madsen SN, Rasmussen BS, Jepsen MH, Ravkilde J, Aaroe J, Hansen PR, Hansen HS, Mortensen PE; DOORS Study Group. Graft patency after off-pump coronary artery bypass surgery is inferior even with identical heparinization protocols: results from the Danish On-pump Versus Off-pump Randomization Study (DOORS). J Thorac Cardiovasc Surg. 2014 Nov;148(5):1812-1819.e2. doi: 10.1016/j.jtcvs.2014.02.024. Epub 2014 Feb 8.

Houlind K, Kjeldsen BJ, Madsen SN, Rasmussen BS, Holme SJ, Nielsen PH, Mortensen PE; DOORS Study Group. On-pump versus off-pump coronary artery bypass surgery in elderly patients: results from the Danish on-pump versus off-pump randomization study. Circulation. 2012 May 22;125(20):2431-9. doi: 10.1161/CIRCULATIONAHA.111.052571. Epub 2012 Apr 20.

Houlind K, Kjeldsen BJ, Madsen SN, Rasmussen BS, Holme SJ, Schmidt TA, Haahr PE, Mortensen PE; DOORS study group. The impact of avoiding cardiopulmonary by-pass during coronary artery bypass surgery in elderly patients: the Danish On-pump Off-pump Randomisation Study (DOORS). Trials. 2009 Jul 4;10:47. doi: 10.1186/1745-6215-10-47.