BACKGROUND: It has been shown that Myeloperoxidase (MPO) is intimately involved in pathogenesis of atherosclerosis and Acute Coronary Syndrome (ACS). Small studies have shown that high levels of MPO are a poor prognostic factor in patients presenting with ACS. However, due to the small nature of these studies, the relationship between MPO and outcomes has not been confirmed. Here we aimed to examine the prognostic value of MPO in patients with ACS.
METHODS: We performed a meta-analysis to compare the long-term prognosis of ACS patients with high MPO and low MPO levels. The literature was retrieved by formal searches of electronic databases (PubMed, EMBASE, Medline, OVID, and web of knowledge) from inception to November 2013. A total of 16 trials were included in this meta-analysis involving 10572 patients. Data were analyzed using random-effects model and study quality was assessed using appropriate scales.
RESULTS: High MPO group was associated with overall worse outcomes than low MPO group in terms of recurrent myocardial infarction (9% [211 of 2336] vs. 7.7% [240 of 3101], odds ratio [OR] 1.4, 95% confidence interval [CI]: 0.92-2.15, p 0.11); all cause mortality (8% [236 of 2920] vs. 5% [209 of 4263], OR 1.83, 95% CI: 1.31-2.54, p <0.0004) and Major Adverse Cardiovascular Events (MACE) (24% [334 of 1400] vs. 14% [133 of 949], OR 2.04, 95% CI: 1.46-2.85, p< 0.0001) (Figure).
CONCLUSIONS: In this meta-analysis examining the long-term outcomes in ACS patients, high MPO levels were associated with worse outcomes. These observations support prospective trials tailoring more aggressive therapy to patients with suspected worse prognosis.