Antithrombotic therapy in patients receiving saphenous vein coronary artery bypass grafts: a protocol for a systematic review and network meta-analysis

Prophylactic Efficacy and Safety of Antithrombotic Regimens in Patients with Stable Atherosclerotic Cardiovascular Disease (S-ASCVD): A Bayesian Network Meta-Regression Analysis

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of antithrombotic regimens and their combinations in preventing thrombotic incidents in patients with stable atherosclerotic cardiovascular disease (S-ASCVD).

METHODS

A systematic literature search was conducted in the PubMed, Embase, Cochrane Library, Scopus, and Google Scholar databases. The primary comprehensive endpoint was a major adverse cardiovascular event (MACE) composite of cardiovascular death, stroke, or myocardial infarction, while the secondary endpoints were cardiovascular death, all-cause stroke, ischemic stroke, myocardial infarction, and all-cause death. The safety endpoint was major bleeding. Bayesian network meta-regression analysis in R software was used to calculate the final effect size and to correct for the effect of follow-up time on the outcome effect size.

RESULTS

Twelve studies reporting 122,190 patients with eight antithrombotic regimens were included in this systematic review. For the primary composite endpoint, low-dose aspirin plus clopidogrel 75 mg (hazard ratio [HR] 0.53, 95% confidence interval [CI] 0.33-0.87) and low-dose aspirin plus rivaroxaban 2.5 mg twice daily (HR 0.53, 95% CI 0.34-0.82) showed significantly better efficacy than clopidogrel monotherapy, and the efficacy was comparable among the first two regimens. Unfortunately, none of the active regimens significantly decreased all-cause death, cardiovascular death branch, and all-cause stroke as part of the secondary endpoints. Low-dose aspirin plus ticagrelor 90 mg twice daily (HR 0.81, 95% CI 0.69-0.94) and low-dose aspirin plus ticagrelor 60 mg twice daily (HR 0.84, 95% CI 0.74-0.95) had a significant advantage in myocardial infarction compared with low-dose aspirin monotherapy, while low-dose aspirin plus 2.5 mg rivaroxaban twice daily (HR 0.62, 95% CI 0.41-0.94) was better than low-dose aspirin in the treatment of ischemic stroke. In the major bleeding branch, low-dose aspirin plus ticagrelor 90 mg twice daily (HR 2.2, 95% CI 1.70-2.90), low-dose aspirin plus ticagrelor 60 mg twice daily (HR 2.1, 95% CI 1.70-2.60), low-dose aspirin plus rivaroxaban 2.5 mg twice daily (HR 1.7, 95% CI 1.30-2.00), and rivaroxaban 5 mg twice daily (HR 1.5, 95% CI 1.20-1.90) showed higher major bleeding risk compared with low-dose aspirin.

CONCLUSIONS

Considering MACEs, myocardial infarction, all kinds of stroke, ischemic stroke, and major bleeding, low-dose aspirin plus rivaroxaban 2.5 mg twice daily should be considered the preferred regimen for S-ASCVD patients with low bleeding risk.

Antithrombotic treatment after coronary artery bypass graft surgery: systematic review and network meta-analysis

OBJECTIVE

To assess the effects of different oral antithrombotic drugs that prevent saphenous vein graft failure in patients undergoing coronary artery bypass graft surgery.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Medline, Embase, Web of Science, CINAHL, and the Cochrane Library from inception to 25 January 2019. ELIGIBILITY CRITERIA: for selecting studies Randomised controlled trials of participants (aged ≥18) who received oral antithrombotic drugs (antiplatelets or anticoagulants) to prevent saphenous vein graft failure after coronary artery bypass graft surgery.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was saphenous vein graft failure and the primary safety endpoint was major bleeding. Secondary endpoints were myocardial infarction and death.

RESULTS

This review identified 3266 citations, and 21 articles that related to 20 randomised controlled trials were included in the network meta-analysis. These 20 trials comprised 4803 participants and investigated nine different interventions (eight active and one placebo). Moderate certainty evidence supports the use of dual antiplatelet therapy with either aspirin plus ticagrelor (odds ratio 0.50, 95% confidence interval 0.31 to 0.79, number needed to treat 10) or aspirin plus clopidogrel (0.60, 0.42 to 0.86, 19) to reduce saphenous vein graft failure when compared with aspirin monotherapy. The study found no strong evidence of differences in major bleeding, myocardial infarction, and death among different antithrombotic therapies. The possibility of intransitivity could not be ruled out; however, between-trial heterogeneity and incoherence were low in all included analyses. Sensitivity analysis using per graft data did not change the effect estimates.

CONCLUSIONS

The results of this network meta-analysis suggest an important absolute benefit of adding ticagrelor or clopidogrel to aspirin to prevent saphenous vein graft failure after coronary artery bypass graft surgery. Dual antiplatelet therapy after surgery should be tailored to the patient by balancing the safety and efficacy profile of the drug intervention against important patient outcomes.

STUDY REGISTRATION

PROSPERO registration number CRD42017065678.