Salivary and serum levels of NT-proBNP, troponin, and high-sensitivity C-reactive protein in patients with heart failure

Abstract

Saliva has been proposed as a non-invasive biological matrix for cardiovascular biomarker assessment. However, evidence regarding its agreement with blood-based measurements in patients with heart failure remains inconsistent.

Introduction

Heart failure (HF) represents an escalating global public health problem, associated with substantial morbidity and mortality, as well as a considerable economic impact on healthcare systems worldwide . Data from the Global Burden of Disease (GBD) study has been instrumental in characterizing the epidemiological profile of HF, providing comprehensive estimates of prevalence, mortality, and disability-adjusted life years (DALYs) across diverse regions and populations.

Materials and methods

Participants included in the present study were recruited from the Municipal University Hospital of Taubaté (HMUT), Taubaté, Brazil, within an ongoing clinical research program involving patients with heart failure conducted at this tertiary care center. Initially, an observational study was approved by the local Research Ethics Committee (CAAE: 63946522.7.0000.5501; approval number 5.708.195) and initiated in 2023 to identify and characterize eligible patients. Subsequently, participants were enrolled in an interventional clinical study approved under a second ethical protocol 

Results

The present study included a total of 52 participants aged 49–80 years. Of these, 30 were males (57.7%) and 22 were females (42.3%). The mean age of the participants was 61.1 ± 6.79 years; 61.93 ± 6.81 years (males) and 60.14 ± 6.78 years (females). At baseline, the study population presented a mean salivary flow of 0.32 + − 0.10mL/min. Additionally, the mean whole-mouth plaque and gingival index were 78.46% and 57.03%, respectively. Based on KCCQ clinical interpretation thresholds

Conclusions

In conclusion, NT-proBNP, troponin, and hs-CRP were detectable in saliva from patients with HF; however, salivary concentrations showed insufficient agreement with serum levels for NT-proBNP and troponin, limiting their applicability as substitutes for blood-based assessment. Although hs-CRP demonstrated relatively better agreement between saliva and serum, the observed variability still restricts its clinical interchangeability. Overall, these findings indicate that, under the conditions evaluated, serum remains the reference standard for cardiovascular biomarker assessment in HF.

Citation: Melo Viegas RF, Cortelli SC, Romeiro Aquino D, Costa FO, Hentges B, Pádua de Magalhães VC, et al. (2026) Salivary and serum levels of NT-proBNP, troponin, and high-sensitivity C-reactive protein in patients with heart failure. PLoS One 21(9): e0357206. https://doi.org/10.1371/journal.pone.0357206

Editor: Michele Golino, Virginia Commonwealth University, UNITED STATES OF AMERICA

Received: February 10, 2026; Accepted: August 13, 2026; Published: September 18, 2026

Copyright: © 2026 Melo Viegas et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All data underlying the findings of this study are publicly available in the NDEx repository as the dataset “heart failure dataset network” and can be accessed at https://doi.org/10.18119/N9JC8K.

Funding: This study was supported by the São Paulo Research Foundation (FAPESP), grant number 2023/07458-4 (J.R.C.), and the National Council for Scientific and Technological Development (CNPq), research productivity fellowship grant number 306161/2023-0 (J.R.C.). We also declare that funding agencies had no role in the study design, data collection, data analysis, data interpretation, or writing of the manuscript.

Competing interests: The authors have declared that no competing interests exist.