Effects of a waiting period after clopidogrel treatment before performing coronary artery bypass grafting

Preoperative thienopyridine use and outcomes after surgery: a systematic review

BACKGROUND

Although studies have demonstrated excess risk of ischemic events if aspirin is withheld preoperatively, it is unclear whether preoperative thienopyridine use influences postoperative outcomes.

METHODS

We conducted a systematic review of 37 studies (31 cardiac and 6 noncardiac surgery, 3 randomized, 34 observational) comparing postoperative outcomes in patients who were versus were not exposed to thienopyridine in the 5 days before surgery.

RESULTS

Exposure to thienopyridine in the 5 days preceding surgery (compared with no exposure) was not associated with any reduction in postoperative myocardial infarction (23 studies, 12,872 patients, 3.4% vs 3.0%, odds ratio [OR] 0.98; 95% confidence interval [CI], 0.72-1.34), but was associated with increased risks of stroke (16 studies, 10,265 patients, 1.9% vs 1.4%, OR 1.54; 95% CI, 1.08-2.20), reoperation for bleeding (32 studies, 19,423 patients, 4.3% vs 1.8%, OR 2.62; 95% CI, 1.96-3.49), and all-cause mortality (28 studies, 22,990 patients, 3.7% vs 2.6%, OR 1.38; 95% CI, 1.13-1.69). Results were identical when analyses were restricted to long-term users of thienopyridines who continued versus held the medication in the 5 days before surgery. Although all associations were similar in direction for the subset of patients undergoing noncardiac surgery, 97% of the outcome data in this meta-analysis came from cardiac surgery trials.

CONCLUSIONS

These data support withholding thienopyridines 5 days before cardiac surgery; there was insufficient evidence to make definitive recommendations for elective noncardiac surgery although the direction and magnitude of associations were similar.

Perioperative management of antiplatelet-drugs in cardiac surgery

The management of coronary patients scheduled for a coronary artery bypass grafting (CABG), who are receiving one or more antiplatelet drugs, is plenty of controversies. It has been shown that withdrawal of antiplatelet drugs is associated with an increased risk of a thrombotic event, but surgery under an altered platelet function also means an increased risk of bleeding in the perioperative period. Because of the conflict recommendations, this review article tries to evaluate the outcome of different perioperative antiplatelet protocols in patients with coronary artery disease undergoing CABG.

Antiplatelet therapy in acute coronary syndromes

Acute coronary syndromes (ACS), characterized by unstable angina or a non-ST-segment elevation myocardial infarction, are caused by rupture of an atherosclerotic plaque, leading to platelet activation and aggregation, thrombus formation, and microembolization. Antiplatelet therapy is a cornerstone of therapy. Combined with aspirin, clopidogrel provides significant benefit for patients across the ACS spectrum. However, clopidogrel has limitations given its slow onset and the inconsistent level of inhibition that it achieves. Newer thienopyridine and non-thienopyridine P2Y12 receptor agonists offer the advantages of a rapid onset of action and greater and more consistent platelet inhibition.