Inflammatory biomarkers in assessing severity and prognosis of immune checkpoint inhibitor-associated cardiotoxicity.

Aims: Inflammatory biomarkers, including CRP, the neutrophil-to-lymphocyte ratio (NLR), and the neutrophil-to-eosinophil ratio (NER), may predict outcomes in cancer. However, their value in immune checkpoint inhibitor (ICI) therapy-associated cardiotoxicity remains elusive. We aimed to characterize the relationship of inflammatory markers with severity of ICI-related cardiotoxicities (iRCs) and prognosis among patients with iRCs.

Methods: Patients who were diagnosed with iRCs between January 2019 and December 2021 were retrospectively enrolled and were dichotomized based on iRC severity into low-grade (grade 1-2) vs. high-grade (grade 3-4) groups.

Results: Forty-seven patients were included. The median time-to-event from first ICI infusion to onset of iRCs was 35 days (IQR: 19.0-65.5 days). When compared with respective baseline values, cardiac biomarkers and inflammatory markers were significantly elevated at onset of iRCs. Compared with low-grade iRCs, NER at iRC onset was significantly increased among patients with high-grade iRCs (Group × Time, P < 0.01). When grouped by the median NER (184.33) at iRC onset, NER ≥ 184.33 was associated with high-grade iRCs (OR: 10.77, P < 0.05) and had a 36.3% increased mortality compared to the lower NER group (HR: 2.67, P < 0.05).

Conclusions: In patients who develop iRCs, NER is significantly elevated at iRC onset, and higher NER correlates with greater iRC severity and higher mortality. Larger datasets are needed to validate these findings.