2. MATERIALS AND METHODS
This systematic review is conducted following the Preferred Reporting
Items for Systematic Reviews And Meta-Analyses (PRISMA)
statement.8 No ethical approval or patient consent was
sought for the review, which is based on all previously published
studies.
2.1 Search
Strategy
A systematic search was carried out across major databases of MEDLINE
via Ovid, PubMed, Embase, the Cochrane Library Database and Google
Scholar until August 2022 to identify eligible studies using Boolean
operators to achieve maximum sensitivity. The terms used are “CABG”,
“Coronary artery bypass grafting”, “Cardiac surgery”,
“Antiplatelet”, “Aspirin”, “Clopidogrel”, “Antithrombotic”,
“Mortality”, “Morbidity”, “Graft patency”, “Survival”,
“Resistance”, and “Platelet mapping”. Bibliographies of relevant
studies were also screened manually to identify additional suitable
studies.
2.2 Study Selection & Data
Extraction
The inclusion criteria include human studies with patients undergoing
CABG surgery who are on antiplatelet, and the studies must report at
least one outcome in patients with antiplatelet resistance such as vein
graft failure, mortality or morbidity. Animal studies, case reports and
case series, review articles and non-English articles are excluded.
Two authors independently searched the databases, reviewed the
potentially relevant articles, extracted data and evaluated the quality
and risk of bias of the included studies. Any discrepancies were
resolved by consensus or by escalating to the third author.
2.3 Risk of Bias
Assessment
The quality of observational cohort studies was evaluated using the
Newcastle-Ottawa Scale (NOS) with scores greater than 6 regarded as
high-quality studies.9 The 2015 Updated Method
Guidelines for Systematic Reviews in the Cochrane Back and Neck Group
was used for quality assessment of randomised controlled trials, and
studies are deemed the low risk of bias if they meet at least 6
criteria.10