Increased levels of NT-proBNP and troponin T 2 years after coronary artery bypass grafting complicated by mediastinitis

Ivar Risnes; Pål Aukrust; Runar Lundblad; Olaf Rødevand; Thor Ueland; Stein Erik Rynning; Sahrai Saeed

doi:10.3389/fcvm.2023.1008825

Increased levels of NT-proBNP and troponin T 2 years after coronary artery bypass grafting complicated by mediastinitis

Front Cardiovasc Med. 2023 Feb 7:10:1008825. doi: 10.3389/fcvm.2023.1008825. eCollection 2023.

Authors

Ivar Risnes^{1

2

3}, Pål Aukrust^{4

5

6}, Runar Lundblad^{1

2}, Olaf Rødevand¹, Thor Ueland^{4

5}, Stein Erik Rynning³, Sahrai Saeed³

Affiliations

¹ Department of Cardiac Surgery, LHL Heart Clinic, Gardermoen, Norway.
² Department of Thoracic and Cardiovascular Surgery, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
³ Department of Heart Disease, Haukeland University Hospital, Bergen, Norway.
⁴ Research Institute of Internal Medicine, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
⁵ Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
⁶ Section of Clinical Immunology and Infectious Diseases, Oslo University Hospital, Rikshospitalet, Oslo, Norway.

Abstract

Background: Mediastinitis after coronary bypass grafting (CABG) increases the risk of the internal mammary artery (IMA) graft obstruction, and has a detrimental effect on long-term survival. The pathogenesis for this increased mortality is poorly understood. In the present study, we aimed to investigate the relationship between mediastinitis and persistently elevated cardiac-specific biomarkers [troponin T (TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP)] and C-reactive protein (CRP) at mid-term follow-up following CABG.

Material and methods: The epidemiologic design was of an exposed (mediastinitis, n = 41) vs. randomly selected non-exposed (non-mediastinitis) controls (n = 41) cohort. Serum samples for measurements of NT-proBNP, TnT, and CRP were obtained at a median follow up time of 2.7 (range 0.5-5.2) years after CABG surgery.

Results: NT-proBNP (mean 65.0 pg/ml vs. 34.8 pg/ml, p = 0.007) and TnT levels (mean 14.7 ng/L vs. 11.2 ng/L, p = 0.004) were significantly higher in the mediastinitis group than in the control group. Patients with mediastinitis had also higher body mass index (BMI) and were more likely to have diabetes and previous myocardial infarction. There was no difference in serum CRP level between the groups. After controlling for potential confounders (previous myocardial infarction, age, and BMI), the presence of mediastinitis was associated with higher levels of log NT-proBNP (p = 0.02) and log TnT (p = 0.04).

Conclusion: Mediastinitis increases the concentrations of cardiac-specific biomarkers NT-proBNP and TnT at mid-term follow-up, representing persistent myocardial injury and impaired cardiac function.

Keywords: C-reactive protein; N-terminal probrain natriuretic peptide; cardiac biomarkers in mediastinitis following coronary artery bypass grafting; coronary artery bypass grafting; mediastinitis; troponin T.