Prognostic role of CRP-independent inflammatory patterns in patients undergoing primary percutaneous interventions

Background: Despite the key pathophysiological role of inflammation in the development of coronary artery disease (CAD), the evaluation of inflammatory status has not been clearly established in patients presenting with acute coronary syndrome (ACS). The aim of this study is to evaluate the prevalence of CRP-independent inflammatory patterns in patients referred for primary percutaneous coronary intervention (pPCI) and to determine their one-year relationship with adverse clinical outcomes. Methods: We carried out a single-centre, observational study consecutively enrolling all patients presenting at a large-volume PCI hub with a diagnosis of ST-segment elevation myocardial infarction (STEMI) and treated with pPCI. Systemic immune-inflammatory index (SII) was calculated at admission and discharge. According to different SII trajectories patients were divided into four patterns: ‘persistent-low’, ‘down-sloping’, ‘up-sloping’ and ‘persistent-high’ patterns. The primary endpoint was a composite of all-cause of death and myocardial infarction (MI) at a one-year follow-up. Results: Among the total 2353 subjects enrolled, 44% of them belonged to ‘persistent-low’, 31% to ‘down-sloping’, 4% to ‘up-sloping’ and 21% to ‘persistent-high’ pattern. The primary endpoint was observed in 8% of patients with a ‘persistent-low’, 12% with a ‘down-sloping’, 27% with an ‘up-sloping’ and 25% with a persistent-high pattern (p = 0.001). After multivariate analysis, ‘up-sloping’ (OR: 3.2 [1.59–3.93]; p = 0.001) and ‘persistent-high’ (OR: 4.1 [3.03–4.65]; p = 0.001) patterns emerged as independent predictors of one-year adverse events. Conclusions: ‘Persistent-high’ and ‘up-sloping’ CRP-independent inflammatory patterns in patients undergoing primary PCI are associated with an increased risk of adverse events at one-year follow-up. The prognostic value of these inflammatory patterns might be helpful to individualize potential therapeutic targets.