Transient elevation of NT-proBNP after mRNA COVID-19 vaccination in healthy adults: A longitudinal biomarker analysis

Background: Cardiovascular complications such as myocarditis and pericarditis have been reported following mRNA COVID-19 vaccination, particularly after the second dose. However, little is known about the cardiac biomarker response in otherwise healthy individuals after mRNA COVID-19 vaccination. Methods: This study aimed to investigate the dynamics of high-sensitivity cardiac troponins (hs-cTnI, hs-cTnT) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) following mRNA COVID-19 vaccination. We analyzed serum samples collected at multiple time points between April and December 2021 from 83 healthy adult military personnel vaccinated with two doses of mRNA COVID-19 vaccines. Statistical analyses included mixed-effects ANOVA with Geisser-Greenhouse correction and logistic regression to assess the influence of covariates. Results: NT-proBNP levels showed a significant but transient increase, particularly within 14 days after the second vaccine dose (geometric mean 36.2 pg/mL; p < 0.0001). Nearly 49% of participants exhibited a relative increase exceeding 1.5 times their individual baseline. No participant surpassed the 450 pg/mL threshold indicative of cardiovascular complications, and troponin levels remained unchanged across all assessed 14-day intervals. The observed NT-proBNP elevation was not significantly associated with any of the assessed covariates. However, non-significant trends were noted among men, individuals without prior COVID-19 infection or comorbidities, and those vaccinated with the mRNA-1273 (Moderna) vaccine. Conclusions: In healthy adults, mRNA COVID-19 vaccination was associated with a short-term, subclinical elevation in NT-proBNP, particularly after the second dose. While not indicative of overt cardiovascular injury, this biomarker response may reflect transient myocardial stress and warrants further research.