Impact of neutrophil-to-lymphocyte ratio on periprocedural myocardial infarction in patients undergoing non-urgent percutaneous coronary revascularisation

Background: Pro-thrombotic conditions importantly influence myocardial perfusion and procedural results after percutaneous coronary intervention (PCI). The neutrophil-tolymphocyte ratio (NLR) has emerged as a predictor of cardiovascular events and of long-term prognosis, especially in ST-elevation myocardial infarction patients undergoing primary PCI. The aim of our study was to evaluate the role of NLR on periprocedural myocardial infarction (MI) in patients undergoing non-urgent PCI. Methods: In a consecutive cohort of 1542 patients undergoing PCI, myonecrosis biomarkers were determined at 6, 12, 24 and 48 hours post-procedure. Patients were divided into quintiles according to NLR values. Periprocedural myonecrosis was defined as a troponin I increase of 3 times the upper limit of normal or as 50% of an elevated baseline value, whereas periprocedural MI was defined as a CK-MB increase of 3 times the upper limit of normal or 50% of baseline. Results: Higher NLR was related to age, established risk factors and cardiovascular history. NLR was associated with severe coronary artery disease (p = 0.009), tighter stenosis (p < 0.001), coronary calcifications (p = 0.005), intracoronary thrombus or thrombectomy use (p < 0.001), TIMI flow pre- and post-PCI (p < 0.001), and inversely to restenosis (p = 0.04) and use of a drug-eluting stent (p = 0.001). NLR did not influence the occurrence of myonecrosis (p = 0.75; adjusted OR (95% CI) = 0.99 (0.63-1.54), p = 0.96), but was associated with a higher occurrence of periprocedural MI, even after correction for baseline differences (p = 0.03; adjusted OR (95% CI) = 1.33 (1.02-2.3), p = 0.02), with NLR ≥ 3 best predicting the risk of periprocedural MI at the receiver operating characteristic curve analysis. Conclusion: In patients undergoing non-urgent PCI, a higher NLR increases the risk of periprocedural MI, especially for values ≥ 3.