Stroke-related mortality in coronary surgery is reduced by the off-pump approach

Background: Stroke remains an important complication after coronary artery bypass graft surgery (CABG). We sought to determine the frequency and death-related incidence of stroke after on-pump and off-pump CABG.

Methods: We analyzed 4,869 consecutive isolated CABG performed in our institution. Of these, 3,490 (71.7%) were off-pump and 1,379 (28.3%) were on-pump. Propensity matched samples of 1,379 off-pump and 1,379 on-pump were compared on clinical presentation and The Society of Thoracic Surgeons (STS) predicted scores for risk of postoperative mortality and stroke. Univariate analyses were used to compare the relationship of off-pump and on-pump groups to postoperative mortality and stroke. Multivariate logistic regression was used to determine the unique association between all variables and occurrence of mortality after stroke.

Results: No differences were found for sex, diabetes mellitus, history of renal failure, prior stroke, or timing of surgery. Postoperative mortality occurred in 75 patients (2.7%) and stroke in 47 (1.7%). The off-pump patients had a lower rate of stroke (1.0% versus 2.4%; p < 0.01) compared with on-pump patients. Mortality after stroke occurred in 14 patients, with a lower rate occurring in the off-pump group (14.3% versus 36.4%; p = 0.07). Multivariate analyses controlling for the effect of preoperative risk factors and STS mortality risk demonstrated that off-pump status was independently associated with an 84% decrease in the risk of death after stroke (adjusted odds ratio 0.157, 95% confidence interval: 0.035 to 0.711, p = 0.016).

Conclusions: Off-pump CABG is associated with lower stroke rates and stroke-related mortality. It may be useful to consider off-pump CABG for patients who are at higher risk for postoperative stroke.