Recommendations for Perioperative Acetylsalicylic Acid Management.

    Acetylsalicylic acid (ASA) is one of the cornerstones for the treatment of acute and chronic cardiovascular disease. Secondary prevention with ASA has been shown to reduce mortality, MI and cerebrovascular events in different subsets of patients with occlusive cardiovascular disease, but also to increase the risk for bleeding complications.

    Discontinuation before surgery. A meta-analysis of 13 trials with 2399 patients who had CABG that compared administration of ASA preoperatively versus no treatment or treatment with a placebo showed that treatment with ASA reduced the risk for perioperative MI [(odds ratio (OR) 0.56; 95% confidence interval (CI) 0.33–0.96] but did not reduce the mortality rate (OR 1.16; 95% CI 0.42–3.22). Postoperative bleeding, red cell transfusions and surgical re-exploration were increased with ASA. However, the included studies were of low methodological quality. A recent large randomized controlled trial (RCT) compared the administration of ASA (100 mg) on the day of the operation versus the use of a placebo in patients having CABG  and demonstrated no significant effect of treatment with ASA on thrombotic and bleeding perioperative events. However, the included patients were eligible only if they were not using ASA preoperatively or had stopped ASA at least 4 days before the operation. Therefore, a strategy of discontinuation versus continuation was not evaluated. Another RCT on pretreatment demonstrated that a large dose (300 mg) of ASA preoperatively was associated with increased postoperative bleeding but with a lower rate of major cardiovascular events at a 53-month follow-up. Similarly, a small RCT reported that patients pretreated with ASA (300 mg) had significantly more postoperative bleeding (+25%) and that this effect was more pronounced (+137%) in carriers of the glycoprotein (GP) IIIa allele PlA2 . Similar results were presented in a previous meta-analysis , where less bleeding was reported in patients receiving < 325 mg ASA daily. Of note, stopping ASA 5 days before the operation and replacing it with low-molecular-weight heparin (LMWH) increases the risk for bleeding complications and therefore should be abandoned . In summary, the continuation of ASA is associated with more blood loss but fewer ischaemic events during and after CABG surgery. Recent data suggest that the inhibiting effect of ASA on platelet aggregability is clearly susceptible to platelet transfusion , which also argues for the continuation of ASA in patients undergoing elective or urgent CABG. However, in patients who refuse blood transfusions, who undergo non-coronary cardiac surgery or who are at high risk of re-exploration for bleeding—such as complex and redo operations, severe renal insufficiency, haematological disease and hereditary platelet function deficiencies— stopping ASA at least 5 days before surgery should be considered. The increased risk for bleeding complications if ASA and other antithrombotic drugs are not discontinued must be weighed against the potentially increased risk of thrombotic complications during the preoperative cessation period. 

   

Restart after surgery. In a large prospective observational trial, patients who restarted ASA within 48 h of CABG had a mortality rate of 1.3% compared with a rate of 4.0% among those who did not receive ASA during this period (P < 0.001). ASA therapy was associated with a 48% reduction in the incidence of MI (P < 0.001), a 50% reduction in the incidence of stroke (P = 0.01), a 74% reduction in the incidence of renal failure (P < 0.001) and a 62% reduction in the incidence of bowel infarction (P = 0.01). A systematic review of 7 studies showed that administration of ASA within 6 h of CABG was associated with improved graft patency without increased incidence of bleeding complications. Therefore, ASA should be given to all patients having CABG as soon as there is no concern over bleeding.

Source: 2017 EACTS Guidelines on perioperative medication in adult cardiac surgery