Cardiac Magnetic Resonance Findings and NT-proBNP in Heart Failure with Reduced Ejection Fraction

Background/Objectives: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is an established heart failure biomarker, but its associations with cardiac magnetic resonance (CMR) parameters in patients with reduced ejection fraction remain unclear. This study examined the associations between serum NT-proBNP concentrations and CMR-derived functional, structural, and tissue characterization parameters in patients with HFrEF and evaluated which imaging parameters remained associated with NT-proBNP after multivariable adjustment. Methods: This retrospective single-center study included 92 consecutive patients with HFrEF who underwent CMR and NT-proBNP measurement within a 24 h window, with a median absolute interval of 6 h (range, 1–15 h) between the two assessments. CMR analysis included left ventricular ejection fraction (LVEF), left ventricular and left atrial (LA) cavity diameters, myocardial mass, extracellular volume fraction (ECV), the late gadolinium enhancement (LGE) burden, and the T2 signal intensity (T2-SI) ratio. Spearman correlation, univariate linear regression, and multivariable linear regression analyses were performed using log-transformed NT-proBNP values. Results: Log NT-proBNP demonstrated significant correlations with LVEF (rs = −0.359, p < 0.001), T2-SI ratio (rs = −0.332, p = 0.001), ECV (rs = 0.383, p < 0.001), and LA diameter (rs = 0.347, p < 0.001). No statistically significant correlations were observed between log-transformed NT-proBNP and LGE burden, LV cavity diameter, myocardial mass, LV wall thickness, age, or the recorded comorbidities. In multivariable analysis, LVEF, T2-SI ratio, and LA diameter remained associated with NT-proBNP after adjustment for the available covariates. Conclusions: Lower LVEF, a lower T2-SI ratio, and a larger LA diameter were associated with higher NT-proBNP levels in patients with HFrEF. The T2-SI ratio and LA diameter should be considered exploratory imaging markers requiring prospective validation.