Objectives The nature of the relationship between baseline platelet count and clinical outcomes following percutaneous coronary intervention (PCI) is unclear. We undertook dose–response and pairwise meta-analyses to better describe the prognostic value of the initial platelet count and clinical endpoints in patients after PCI.
Methods A search of PubMed, Scopus and Web of Science (up to 9 October 2021) was performed to identify studies that evaluated the association between platelet count and clinical outcomes following PCI. The primary outcomes of interest were all-cause mortality, major adverse cardiovascular events (MACE) and major bleeding. We performed random-effects pairwise and one-stage dose–response meta-analyses by calculating HRs and 95% CIs.
Results The meta-analysis included 19 studies with 217 459 patients. We report a J-shaped relationship between baseline thrombocyte counts and all-cause death, MACE and major bleeding at follow-up. The risk of haemorrhagic events exceeded the risk of thrombotic events at low platelet counts (<175×109/L), while a predominant ischaemic risk was observed at high platelet counts (>250×109/L). Pairwise meta-analyses revealed a robust link between initial platelet counts and the risk of postdischarge all-cause mortality, major bleeding (for thrombocytopenia: HR 1.39, 95% CI 1.30 to 1.49; HR 1.51, 95% CI 1.15 to 2.00, respectively) and future death from any cause and MACE (thrombocytosis: HR 1.60, 95% CI 1.29 to 1.98; HR 1.47, 95% CI 1.22 to 1.78, respectively).
Conclusion Low platelet counts were associated with the predominant bleeding risk, while high platelet counts were only associated with the ischaemic events.
PROSPERO registration number CRD42021283270.
- coronary artery disease
- percutaneous coronary intervention
- systematic reviews as topic
- acute coronary syndrome
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information.
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Contributors All authors contributed to the study design and conception, screening, extraction, data preparation, analyses, interpretation of the results and manuscript writing. All authors read and approved the final version of the manuscript. All authors guarantee the accuracy and integrity of the work.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Provenance and peer review Not commissioned; externally peer reviewed.
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