Correlation of Ankle-Brachial Index With NT-proBNP and Left Ventricular Ejection Fraction in Patients With Type 2 Diabetes Mellitus and Heart Failure: A Cross-Sectional Study

Background and objectives: Coexistence of type 2 diabetes mellitus (T2DM) and heart failure increases the risk of morbidity and mortality.Ventricular dysfunction and lower limb ischemic changes are assessed with left ventricular ejection fraction (LVEF), NT-proBNP, and ankle-brachial index (ABI).We conducted this study to determine the correlation of ABI with NT-proBNP and LVEF.Methods: We conducted this cross-sectional study from March 2024 to February 2026 at the Kalinga Institute of Medical Sciences (KIMS), Bhubaneswar, Odisha, India.We enrolled adult diabetic patients with newly diagnosed heart failure.We categorized the participants according to their LVEF: heart failure with preserved ejection fraction (HFpEF) (LVEF ≥ 50%), heart failure with mid-range ejection fraction HFmrEF (LVEF 41%-49%), and heart failure with reduced ejection fraction (HFrEF) (LVEF ≤ 40%).These groups were assessed for ABI and NT-proBNP.We assessed the correlations of ABI with NT-proBNP and of LVEF with Spearman's correlation.The R software version 4.6.1 (R Foundation for Statistical Computing, Vienna, AUT) was used for data analysis.Results: Our study population comprised 801 patients (median age 64.0 (59.0-70.0)years; males 447 (55.81%)) with T2DM and heart failure.There were 166 (20.72%), 418 (52.19%), and 217 (27.09%) participants with HFpEF, HFmrEF, and HFrEF, respectively.The median LVEF was 44.0 (39.4-48.8)%.The median ABI of the study population was 1.06 (0.97-1.20).The median ABI values of those with HFpEF, HFmrEF, and HFrEF were 1.04 (0.98-1.17), 1.08 (0.99-1.22), and 1.05 (0.95-1.15), respectively (p < 0.001).The study population's median NT-proBNP was 1291.0 (978.0-1822.0)pg/mL.The median NT-proBNP values of those with HFpEF, HFmrEF, and HFrEF were 1007.5 (817.0-1370.5)pg/mL, 1295.5 (995.0-1752.3)pg/mL, and 1510.0 (1167.0-2098.0)pg/mL, respectively (p < 0.001).The correlation between ABI and NT-proBNP values was weakly negative (r = -0.059,95% CI = -0.129 to 0.009, p = 0.139).The correlation between ABI and LVEF was weakly positive (r = 0.057, 95% CI = -0.012 to 0.126, p = 0.293).Only the participants with HFpEF showed a statistically significant positive correlation between ABI and LVEF (r = 0.164, 95% CI = 0.012 to 0.309, p = 0.015).None of the remaining correlations were statistically significant.Conclusion: Most of the correlations of ABI with NT-proBNP and LVEF were not statistically significant.However, reduced LVEF and higher NT-proBNP levels were correlated with lower ABI values.These findings suggest the associations among elevated cardiac strain, impaired ventricular performance, and peripheral vascular disease.Our study highlighted the usefulness of ABI as a simple, non-invasive screening technique for cardiovascular disease risk.