Abstract Body (Do not enter title and authors here): Background: Post-operative atrial fibrillation (POAF) is a common and serious complication following cardiac surgery, leading to increased morbidity and healthcare costs. Inflammation, particularly mediated by cytokines like IL-17A, is believed to play a significant role in the pathogenesis of POAF. We aim to investigate the association between blood IL-17A levels and the incidence of POAF.
Hypothesis: We hypothesize that elevated IL-17A levels in the blood are associated with a higher incidence of POAF in patients undergoing cardiac surgery.
Methods: Blood samples were collected from 16 patients undergoing open heart surgery. Patients were monitored during the index hospitalization for the surgery. IL-17A levels in the blood were quantified using Olink proteomics, where oligonucleotide-labeled antibodies bind to target proteins, forming a new PCR target sequence by a proximity-dependent DNA polymerization event. Quantitative PCR measured the amplicons, and the Olink NPX Manager Software calculated Normalized Protein Expression Units (NPX) by normalizing the Cq values to interpolate controls. Statistical analysis was performed using Student's t-test to compare clinical variables and IL-17A levels across the two groups.
Results: Our cohort had an average age of 63.8 ± 4.7 with 14% female participants, an average weight of 83.9 ± 14.6 kg, and an average BMI of 28.8 ± 4.7. The POAF group was slightly older (64.8 ± 3.8 years vs. 62.7 ± 4.6 years) but had a similar BMI compared to those who did not develop AF. Hypertension and hyperlipidemia were present in all POAF patients (100%) compared to 81.8% in those without AF, while anemia was more common in the POAF group (40% vs. 18.2%). IL-17A levels were significantly elevated in the POAF group (0.75 ± 0.10 NPX) compared to the non-POAF group (0.35 ± 0.05 NPX) with a p-value < 0.05. Cardiac function assessments showed non-significant differences in left atrial volume index (LAVI) (46.2 mL/m^2 vs. 36.3 mL/m^2) and left ventricular mass index (LVMI) (114.4 g/m^2 vs. 89.3 g/m^2) in the POAF group. These findings suggest a significant association between elevated IL-17A levels and POAF, with trends of differences in left atrial remodeling between the two groups.
Conclusion: Elevated blood IL-17A levels are associated with an increased risk of developing POAF. This suggests that IL-17A may serve as a critical biomarker and potential therapeutic target for preventing POAF in patients undergoing cardiac surgery.