A Critical Appraisal of a Decade of Left-Main Revascularization Meta-Analyses

Background: Determining the optimal revascularization strategy for patients with left main coronary artery disease (LMCAD) is a compelling topic. After the publication of two new trials, numerous meta-analyses on percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG) appeared in the literature. This study set out to review the extent of published meta-analyses on PCI versus CABG in LMCAD, and stipulates the need for “quality over quantity”. Methods: A systematic search in Embase, Medline Ovid and Cochrane databases was performed to identify meta-analyses on PCI versus CABG in LMCAD. Meta-analyses that reported associations between revascularization and clinical outcomes were included. Study outcomes were reported according to descriptive statistics, without pooling study outcomes. Results: Fifty-one meta-analyses were included. Of those, 33 became available after EXCEL and NOBLE trial publication. The composite of major adverse cardiac (and cerebrovascular) events were reported in 41, and 49 reported all-cause mortality. Results varied among meta-analyses, depending on (i) randomized versus observational data, or a combination of both, (ii) methodology and effect-measures to report treatment-differences, (iii) varying sample sizes, and (iv) the year of publication. Conclusions: The number of meta-analyses on PCI versus CABG in patients with LMCAD, is disproportionate and urges the need for quality over quantity. To ensure future high-quality publications, we call on all authors, editors and reviewers to appraise the evidence already available and join forces to conduct individual patient data pooled analyses instead.