A comparison of survival between on-pump and off-pump left internal mammary artery bypass graft surgery for isolated left anterior descending coronary artery disease: an analysis of the UK National Adult Cardiac Surgery Audit Registry
Abstract
OBJECTIVES
To determine if the use of cardiopulmonary bypass is associated with all-cause in-hospital and mid-term survival for patients undergoing left internal mammary artery (LIMA) to left anterior descending (LAD) coronary artery bypass grafting (CABG) for single coronary vessel disease.
METHODS
Data from the National Adult Cardiac Surgery Audit registry for all elective and urgent isolated CABG procedures performed between April 2003 and March 2013 in first-time cardiac surgery patients were extracted. Experienced surgeons (those with ≥300 records) were classified by their technique preference (as ‘off-pump preference’, ‘mixed practice’, ‘on-pump preference’) based on their entire isolated CABG data. In-hospital mortality and time to death were analysed using logistic and Cox proportional hazards regression models, respectively.
RESULTS
From a total of 3402 records, 65.5% were performed off-pump. There were 16 (0.47%) in-hospital deaths: 6 (0.51%) in the on-pump group and 10 (0.45%) in the off-pump group. The risk-adjusted odds ratio of in-hospital mortality in the direction of on-pump was 1.09 [95% confidence interval (CI): 0.39–3.04; P = 0.86]. The overall 5-year survival in the on- and off-pump groups was 93.1 and 93.4%, respectively. The adjusted hazard ratio (HR) for mortality in the direction of on-pump CABG was 1.15 (95% CI: 0.89–1.49; P = 0.28). Comparing off-pump cases performed by experienced CABG surgeons with a preference for the off-pump technique with on-pump cases performed by surgeons with a preference for the on-pump technique indicated a significant difference (HR for on-pump = 1.72; 95% CI: 1.19–2.47; P = 0.004).
CONCLUSIONS
Elective and urgent first-time CABG for isolated LAD disease is associated with excellent mid-term survival in the England and Wales population, conferring a 5-year survival rate of 93.1 and 93.4% in the on-pump and off-pump groups, respectively. There was no difference in risk-adjusted survival between the on-pump and off-pump techniques when analysing all procedures; however, supportive analysis demonstrated that off-pump surgery performed by experienced surgeons with a preference for the off-pump technique in their CABG caseload is associated with improved mid-term survival when compared with on-pump surgery performed by surgeons with a preference for the on-pump technique.