Effect of combined antiplatelet and anticoagulant therapy in comparison to anticoagulants in monotherapy on CABG outcomes in patients requiring anticoagulants. Analysis of real-world data
A Segiet-Swiecicka, R DabrowskiAbstract
Introduction
A growing number of patients undergoing coronary artery bypass grafting (CABG) have indications for long-term anticoagulation. The efficacy of strategies of antithrombotic treatment in this population has not been compared in large prospective trials, and current guidelines do not specify the optimal treatment choice. While addition of antiplatelets to chronic anticoagulation after CABG is common, it may increase the risk of bleeding complications.
Purpose
The aim of the study was to compare post-CABG antithrombotic treatment strategies in terms of efficacy and safety in one-year post-CABG observation in patients undergoing CABG with indications for long-term anticoagulation, based on the real-world data.
Methods
Real-world data extracted from the THIN database was analysed. Adult patients from France and Great Britain undergoing CABG between 2010 and 2022, treated with anticoagulants within a year after the CABG and followed up at least for a year after CABG or until death were included. The outcomes were compared between patients treated with anticoagulants (VKA or NOAC) in monotherapy (AC), anticoagulants in combination with ASA (AC+ASA), or anticoagulants with oral P2Y12 inhibitor (AC+P2Y12i), with or without ASA. The efficacy was assessed in terms of the occurrence of major adverse cardiac events (MACE), and the safety in terms of occurrence of major bleeding. Inverse probability of treatment weights from propensity score model including age, sex, history of hypertension, atrial fibrillation, kidney disease, and diabetes mellitus were used to fit a weighted Cox model, to evaluate effects on balanced groups.
Results
Among 962 patients included in the analysis, 326 (33.9%) patients were on AC; 547 (56.9%) were on AC+ASA; 89 (9.2%) were on AC+P2Y12i therapies. The mean age was 74.2(±9.4) years, the majority were men (86.9%). In one-year post-CABG observation, the MACE occurred in 7.4% and major bleeding occurred in 4.0% of patients. In the analysis performed using weighted Cox model, no significant effect of type of antithrombotic treatment strategy on risk of MACE was observed: AC+ASA vs. AC HR 1.12 (95%CI 0.82-1.53); AC+P2Y12i vs. AC 1.09 (0.67-1.77). For safety outcomes, significant increase in risk of major bleeding was observed in AC+P2Y12i in comparison to AC, while in AC+ASA the effect was not statistically significant: AC+ASA vs. AC HR 1.21 (95%CI 0.75-1.94); AC+P2Y12i vs. AC 2.34 (1.20-4.56).
Conclusions
The efficacy of the antithrombotic treatment strategy measured in terms of risk of MACE was comparable among patients treated with anticoagulants in monotherapy, anticoagulants in combination with ASA, or anticoagulants combined with oral P2Y12 inhibitors. In contrast, in the population balanced for baseline characteristics, risk of major bleeding was significantly higher in group treated with anticoagulants with oral P2Y12 inhibitors in comparison to group receiving anticoagulant monotherapy.