Stroke is a serious complication of coronary artery bypass grafting (CABG), occurring in around 1.3% of patients undergoing coronary surgery in the USA.  In this study, Tarakji et al. aimed to examine the prevalence and timing of perioperative stroke in the modern era, to identify patient and surgical factors associated with stroke and its timing, and to assess the association of stroke with hospital mortality and morbidity and long-term survival.

The authors conducted a prospective study from 1982 to 2009 at a single US academic medical center among 45 432 consecutive patients (mean age, 63 [SD, 10] years) undergoing isolated primary or reoperative CABG surgery. Strokes that occurred following CABG were recorded prospectively and classified as having occurred either intraoperatively or postoperatively.  4 different operative strategies were used over the course of the study (off-pump, on-pump with beating heart, on-pump with arrested heart, on-pump with hypothermic circulatory arrest), and the main outcome measures were hospital complications and late survival.

Of the 45 432 patients that underwent CABG surgery, 705 (1.6% [95% confidence interval {CI}, 1.4%-1.7%]) were diagnosed as having experienced a stroke. Overall, 279 strokes (40%) occurred intraoperatively and 409 (58%) occurred postoperatively (timing indeterminate in 17 patients), with the latter peaking at 40 hours.  Intraoperative stroke rates were lowest in off-pump CABG (0.14% [95% CI, 0.029%-0.40%]) and on-pump beating-heart CABG (0% [95% CI, 0%-1.6%]),  and highest with on-pump CABG with hypothermic circulatory arrest (5.3% [95% CI, 2.0%-11%]). However, overall the prevalence of stroke declined at 4.69% (95% CI, 4.68%-4.70%) per year from 1988 (P = .04), despite increasing patient comorbidity.

Conclusions:

The majority of strokes that complicate CABG surgery occur after the procedure, although rates have dropped over the last two decades despite an increase in the risk profile of patients undergoing CABG.

• Tarakji KG, Sabik JF, Bhudia SK et al.  Temporal Onset, Risk Factors, and Outcomes Associated With Stroke After Coronary Artery Bypass Grafting.  JAMA. 2011;305(4):381-390. doi:10.1001/jama.2011.37