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

• A combined endpoint of death + stroke + myocardial infarction within 30 days from operation
  

• A combined endpoint of death + stroke + myocardial infarction during follow-up
  
• Patency of bypass grafts assessed by coronary angiography 6 months after the operation
  
• Total mortality and cardiac mortality during follow-up
  
• Need of new intervention for cardiac angina during follow-up
  
• 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
  

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.