Time from adenosine di-phosphate receptor antagonist discontinuation to coronary bypass surgery in patients with acute coronary syndrome: Meta-analysis and meta-regression

Background Adenosine di-phosphate receptor antagonists (ADPRAs) blunt hemostasis for several days after administration. This effect, aimed at preventing cardiac ischemic complications particularly in patients with acute coronary syndromes (ACS), may increase perioperative bleeding in the case of cardiac surgery. Practice Guidelines recommend withholding ADPRAs for at least 5 days prior to surgery, though with a weak base of evidence. The purpose of this study was to systematically review observational and experimental studies of early or late preoperative discontinuation of ADPRAs prior to coronary artery bypass grafting (CABG) for patients with ACS. Methods MEDLINE, EMBASE, the Cochrane Library databases up to December 2011; and reference lists. Observational and experimental studies that compared early ADPRA discontinuation with late discontinuation, or no discontinuation, in patients with ACS undergoing CABG. Results There were 19 studies, including 14,046 participants, 395 deaths and 309 reoperations due to bleeding. ADPRA late discontinuation up to CABG was associated with an increased risk of postoperative mortality (OR 1.46, 95% confidence interval (CI) 1.10 to 1.93) and reoperations due to bleeding (OR 2.18; 95% CI 1.47 to 2.62). Between-study heterogeneity was low. Meta-analysis limited to high quality or prospective studies gave consistent results. In most instances, the 95% prediction intervals for summary risk estimates confirmed the risk across study groups. Conclusions ADPRA late discontinuation prior to CABG is associated with an increased risk of death and reoperations due to bleeding in patients with ACS. The confidence in the estimates of risk for late discontinuation is moderate to high.