Relation of Neutrophil to Lymphocyte Ratio With Periprocedural Myocardial Damage in Patients Undergoing Elective Percutaneous Coronary Intervention

Neutrophil to lymphocyte ratio (NLR) has been proposed as a marker of cardiovascular risk. The potential relation between NLR and periprocedural myocardial damage after percutaneous coronary intervention (PCI) is unclear. We enrolled 502 consecutive patients with stable coronary artery disease undergoing elective PCI. Blood samples were drawn in all patients at baseline, 6 hours, and 24 hours after PCI for complete blood cell count and cardiac biomarkers (creatine kinase-MB and troponin T [Tn-T]) assessment. NLR was calculated as the ratio between the absolute number of neutrophil over the absolute number of lymphocyte. Periprocedural myocardial infarction (PMI) was defined according to the 2012 universal definition of myocardial infarction. In the overall population, a significant postprocedural increase in NLR was observed (3.255 [2.763 to 3.995] at baseline, 4.430 [3.390 to 6.020] at 6 hours, 4.720 [3.940 to 5.750] at 24 hours, p <0.0001). PMI occurred in 33 patients (6.6%). Baseline NLR was similar in patients with and without PMI (3.250 [2.820 to 3.885] vs 3.260 [2.750 to 4.000], p = 0.898); however, patients who developed PMI showed significantly higher NLR both at 6 hours (5.750 [4.360 to 9.095] vs 4.370 [3.370 to 5.950], p <0.001) and 24 hours (5.180 [4.440 to 8.065] vs 4.670 [3.920 to 5.710], p = 0.003). Among patients who developed PMI, periprocedural NLR increase showed a moderate positive correlation with both creatine kinase-MB (rho = 0.377, p = 0.031) and troponin T increase (rho = 0.506, p = 0.003). In conclusion, preprocedural NLR values do not impact on the occurrence of PMI during elective PCI; however, PCI procedures induce a significant increase in NLR that seems to be proportional to the magnitude of periprocedural myocardial damage.