Association between NT-pro-BNP levels and endothelial dysfunction assessed by digital thermal monitoring in patients with coronary artery disease

Objective Endothelial dysfunction is a key mechanism in the progression of coronary artery disease (CAD). N-terminal pro-B-type natriuretic peptide (NT-pro-BNP), a biomarker of myocardial wall stress, has been associated with vascular abnormalities beyond overt heart failure. However, its relationship with endothelial function, as assessed via digital thermal monitoring (DTM), in patients with CAD remains unclear. Methods We conducted a cross-sectional study including 136 patients with angiographically confirmed CAD, in whom endothelial function was evaluated using the DTM-derived vascular reactivity index (VRI). VRI values of >2.0, 1.0–1.9, and <1.0 indicated good, intermediate, and poor vascular reactivity, respectively. A commercially available electrochemiluminescence immunoassay kit was used to examine serum NT-pro-BNP levels. Results Vascular reactivity categorized based on DTM-derived VRI was poor in 8.8% ( n = 12) of patients, intermediate in 49.3% ( n = 67), and good in 41.9% ( n = 57). Poor reactivity was associated with old age ( p = 0.031); high levels of serum total cholesterol ( p = 0.004), low-density lipoprotein cholesterol ( p = 0.029), and NT-pro-BNP ( p < 0.001); and low serum albumin levels ( p = 0.023). Higher NT-pro-BNP was independently associated with vascular reactivity dysfunction (combined intermediate and poor groups) after adjustment for covariates; each 1-standard deviation increase in log-transformed NT-pro-BNP was associated with a higher likelihood of vascular reactivity dysfunction ( β = 0.818, 95% confidence intervals: 0.175–1.461, p = 0.013). This association was consistently observed across penalized logistic regression models, including LASSO, Ridge, and Elastic Net regression. In the multivariable forward stepwise linear regression analysis, the log-transformed NT-pro-BNP level remained independently and inversely associated with VRI ( p < 0.001). Conclusions In patients with CAD, high serum NT-pro-BNP levels were independently correlated with reduced VRI. Hence, NT-pro-BNP is independently associated with vascular reactivity dysfunction.