Perioperative myocardial infarction or stroke are relatively frequently occurring and serious complications of surgery. Data from studies in cardiac patients suggest that the occurrence of hemorrhage is an important risk factor for (recurrent) myocardial infarction and stroke. Hemorrhage is an important complication in surgical patients. Therefore, Kamel et al. hypothesized that serious perioperative bleeding in patients undergoing general surgery could be a risk factor for myocardial infarction and stroke associated with surgery. Using data collected in the National Surgical Quality Improvement Program, the authors reviewed records of 651,775 patients in this database who had undergone a surgical procedure, excluding trauma-related, transplant, cardiac or neurologic operations. Major hemorrhage (necessitating transfusion of > 4 units of red cells) occurred in 5233 of these patients (0.8%) The incidence of perioperative Q-wave myocardial infarction was 0.24% and 0.2% of patients suffered a perioperative stroke. In Cox proportional hazard analyses (corrected for type of surgery and vascular risk factors) the occurrence of major hemorrhage was independently associated with both subsequent stroke (hazard ratio 2.5; 95% confidence interval 1.9-3.3) and subsequent Q-wave myocardial infarction (hazard ratio 2.7; 95% confidence interval 2.1-3.4).

This is a very important and relevant observation that confirms that, in surgical patients, major perioperative blood loss is an important risk factor for subsequent atherothrombotic complications. At least increased awareness for the occurrence of acute coronary or cerebrovascular events in patients with major perioperative hemorrhage is warranted. The authors rightfully comment that these results should be taken into account when designing guidelines for the perioperative use of antithrombotic agents, which may affect the risk of both bleeding and thrombosis. Their call for randomized controlled trials to guide the continued use or interruption of these agents in the perioperative period is also justified.

– Marcel Levi