Routinely available inflammation biomarkers as predictors of adverse outcomes following coronary angiography
Authors: Steinacher E , Koller L , Hammer A , Baumer U , Hofer F , Kazem N , Lang I , Hengstenberg C , Sulzgruber P , Niessner A 
Published: November 2023

Abstract

Background
Inflammatory activation plays a pivotal role in the development and progression of atherosclerosis and subsequently in coronary artery disease (CAD). Several biomarkers of inflammation such as C-reactive protein (CRP), leucocytes, and neutrophile-to-lymphocyte ratio (NLR), are considerable predictors of adverse events in CAD patients. The presence of underlying inflammation may also affect net outcomes of patients undergoing coronary angiography and percutaneous coronary intervention (PCI). However, the association between inflammatory activation and patient outcomes after coronary angiography remain widely unclear.

Purpose
The study goal was to investigate the predictive value of routinely used inflammation biomarkers including CRP, leukocytes and NLR in a large all-comer patient population undergoing coronary angiography. We aimed to gain additional insights into the association of inflammatory markers with patient outcomes to take a step towards personalized risk stratification for CAD patients.

Methods
A total of 12 642 patients undergoing coronary angiography between 2010 and 2021 with full laboratory analysis were enrolled in this observational study. CRP, leucocytes and NLR were analysed for possible effects on all-cause and cardiovascular mortality. We further investigated target lesion revascularization (TLR) after PCI in the presence of underlying inflammation as an intervention-specific endpoint.

Results
3300 (26%) patients presented with acute coronary syndromes (ACS) and 4145 (33%) patients were treated with PCI. All investigated inflammatory biomarkers (CRP, leukocytes, NLR) were significantly associated with all-cause mortality and especially with cardiovascular mortality in both acute and elective patients. This association remained highly significant after adjusting for demographic and clinical variables. While CRP was strongly related with cardiovascular mortality in STEMI patients (ad. HR per 1 SD: 1.35 [95%-CI: 1.14 – 1.59]), no significant association was observed in NSTEMI patients (ad. HR per 1 SD: 1.04 [95%-CI: 0.92 – 1.17]; p for interaction: 0.007; figure 1).
Notably, CRP was not found to be associated with TLR in patients undergoing acute or elective PCI (ad. HR per 1 SD: 0.99 [95%-CI: 0.88 – 1.11]; p-value: 0.857). However, we found a highly significant association between NLR and TLR in both acute and elective patients (ad. HR per 1SD: 1.27 [95%-CI: 1.12 – 1.43]; p-value: &lt;0.001).

Conclusion
Inflammatory activation is associated with increased mortality in patients undergoing coronary angiography. Although the impact of inflammation on interventional outcomes may be assumed, our study did not show significant associations between CRP and TLR. However, NLR emerged as a robust predictor of adverse events after PCI. Thus, while CRP does not impact the interventional outcome of PCI, a modulation of the cellular immune response does.Figure 1