Impact of preoperative antithrombotic therapy in patients undergoing elective isolated coronary artery bypass grafting

OBJECTIVES: The objective of this retrospective study was to assess differences in clinical outcomes between patients on acetylsalicylic acid (ASA) monotherapy and patients on other antithrombotic (AT) regimens undergoing elective coronary artery bypass grafting (CABG). METHODS: Patients who underwent elective isolated CABG between 2017 and 2019 at the Catharina Hospital Eindhoven were eligible for this study. The primary end points were re-exploration for bleeding and postoperative blood product transfusion. Secondary end points included 30-day mortality, in-hospital stroke, in-hospital myocardial infarction and duration of hospitalization. Propensity matching was used to compare outcomes of the main study groups (ASA vs other AT therapy) and subgroups of AT therapy (guideline adherence vs non-adherence). RESULTS: A total of 1068 patients were included: 710 patients on ASA monotherapy and 358 patients on other AT regimens. In the 256 matched patients in the main study groups, using AT regimens other than ASA monotherapy was associated with increased risk of re-exploration for bleeding [6.6% vs 2.0%, P = 0.017; odds ratio (OR) 3.57 (1.29-9.83)] and increased use of blood products [37.5% vs 20.3%, P < 0.001; OR 2.35 (1.58-3.49)]. In 122 matched subgroup patients, non-adherence was associated with an increased risk of re-exploration [10.7% vs 3.3%, P = 0.044; OR 3.52 (1.11-11.12)] and increased blood product use [51.6% vs 25.4%, P < 0.001; OR 3.13 (1.83-5.38)]. Secondary end points were not significantly different among the main study groups and subgroups. CONCLUSIONS: Preoperative use of AT therapy other than ASA monotherapy in patients who elected CABG was associated with the increased postoperative use of blood products and risk of re-exploration for bleeding; this finding was even more pronounced in non-guideline-adherent patients.