ABSTRACT
<p><b>OBJECTIVE</b>To analyze the value of neutrophils/lymphocytes ratio (NLR) on predicting the cardiovascular events at hospital discharge and ≥ 12 months follow-up for patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) by meta-analysis.</p><p><b>METHODS</b>Both English and Chinese databases, including PubMed, EMBASE, Wanfang database from their reception to June 2014 were searched to identify randomized controlled studies or non-randomized controlled studies that reported relationship between NLR and the prognosis of patients with STEMI undergoing PCI.The Newcastle-OttawaScale (NOS) system was employed to assess the quality of literatures enrolled in this study. Two reviewers assessed the quality of each trial and extracted data independently. A standardized form and RevMan 5.2 software were used to extract information, and perform quantitative analysis, respectively.</p><p><b>RESULTS</b>A total of 1 953 patients from 6 clinical trials were included in this meta-analysis. The risks of all-cause mortality (RR:0.29, 95% CI: 0.19-0.46, P<0.001), major adverse cardiac events (RR: 0.38, 95% CI: 0.31-0.46, P<0.001), nonfatal myocardial infarction (RR: 0.43, 95% CI: 0.28-0.67, P<0.001), stent thrombosis (RR: 0.32, 95% CI: 0.19-0.53, P<0.001), and TIMI flow after PCI procedure < 3 grade (RR: 0.34, 95% CI: 0.14-0.86, P = 0.020) were significantly lower in patients with NLR ≤ 3.30 compared patients with NLR > 3.30 at hospital discharge. During ≥ 12 months follow-up, the risks of death (RR: 0.33, 95% CI: 0.23-0.45, P<0.001), major adverse cardiac events (RR: 0.27, 95% CI: 0.20-0.35, P < 0.001) were significantly lower. Whereas nonfatal myocardial infarction was not significantly different (RR: 0.42, 95% CI: 0.05-3.45, P = 0.420) in patients with NLR ≤ 3.30 compared patients with NLR > 3.30.</p><p><b>CONCLUSIONS</b>Results from this meta-analysis show that the NLR could predict short- and long-term prognosis in patients with STEMI undergoing PCI. This finding needs to be validated by large-scale clinical trials in the future.</p>