Higher Plasma Concentrations of Platelet Microparticles in Patients With Acute Coronary Syndrome: A Systematic Review and Meta-analysis.

Background: Platelet microparticles (PMP), shedding on platelet activation, have been proposed as key components in the procoagulant and proinflammatory process. The aim of this study was to clarify the correlation between plasma PMP concentration and the presence of acute coronary syndrome (ACS).

Methods: We searched for potential relevant studies in PubMed, EMBASE, the Cochrane Library, and Web of Science databases before December 2015. After screening for eligibility, 11 observational studies that tested the plasma concentration of PMP in patients with ACS were retrieved for comprehensive review, quality assessment, and data extraction.

Results: Seven studies (64%) provided explicit information between healthy controls and patients with ACS. Five studies (45%) addressed the plasma levels of PMP between patients with ACS and patients with stable angina. Moreover, 5 studies (45%) compared changes in PMP concentration before and after percutaneous coronary intervention (PCI) in patients with ACS. The results showed a significant difference in plasma PMP levels between the patients with ACS and healthy controls, with the pooled standardized mean difference of 1.95 (95% confidence intervals, 0.87-3.02; P < 0.0001). And the plasma concentration of PMP in patients with ACS was higher before PCI than after PCI (standardized mean difference, -0.97; 95% confidence interval, -1.91 to -0.03; P = 0.043). Four of the five studies described that patients with ACS had higher plasma PMP concentration than patients with stable angina, but there was no significant difference between these 2 patient cohorts.

Conclusions: PMP is a promising biomarker for the development of ACS. Moreover, PCI, the most common treatment for ACS, could effectively decrease the plasma concentration of PMP, indicating PMP as a prognostic factor.