Relationship between NT-proBNP, echocardiographic abnormalities and functional status in patients with subclinical diabetic cardiomyopathy

Abstract Background Persons with diabetes are at risk for developing a cardiomyopathy through several pathophysiological mechanisms independent of traditional risk factors for heart failure. Among those with so-called diabetic cardiomyopathy (DbCM), the relationship between natriuretic peptides, cardiac structural abnormalities and functional capacity is largely unknown. Purpose This study aimed to evaluate associations between NT-proBNP concentrations, clinical characteristics, echocardiographic findings, health status and activity, and outcomes from cardiopulmonary exercise testing Methods The Aldose Reductase Inhibition for Stabilization of Exercise Capacity in Heart Failure Trial (ARISE-HF) trial is evaluating the effects of AT-001, a novel aldose-reductase inhibitor in participants with DbCM without a prior history of heart failure (1). Participants were included if they had a known diagnosis of type 2 diabetes and age ≥60 (or ≥45 with a duration of diabetes of ≥10 years or estimated glomerular filtration rate ≤60 mL/min/1.73m2). Participants were required to have evidence of one of: structural cardiac abnormality, elevated cardiac biomarkers, or impaired exercise tolerance, defined as a peak oxygen uptake (VO2) ≤75% of predicted. In this prespecified subgroup analysis of the ARISE-HF trial, 685 participants with baseline echocardiography data, laboratory investigations, and functional assessment were included. Participants were stratified by N-terminal pro-B type natriuretic peptide (NT-proBNP) quartiles, and correlation with echocardiographic and functional parameters were assessed using Spearman correlation test. Results The mean age of participants was 67.4 years and 50% were female. The mean duration of type 2 diabetes was 14.5 years with a mean hemoglobin A1c of 6.98. The median NT-proBNP was 71 (Q1, Q3: 33, 135) ng/L. No association was observed between NT-proBNP concentrations and echocardiographic parameters of either diastolic or systolic dysfunction including global longitudinal strain, left ventricular ejection fraction, left ventricular mass index, left atrial volume index, E/e’, or right ventricular systolic pressure (Figure 1). In contrast, NT-proBNP was significantly correlated with components of the Kansas City Cardiomyopathy Questionnaire (P<0.001), the Physical Activity Scale in the Elderly (P=0.004), duration of cardiopulmonary exercise testing (P<0.001), peak VO 2 (P<0.001), and ratio of minute ventilation/carbon dioxide production (P=0.002; Figure 2). Conclusion Among highly selected patients with subclinical DbCM, elevated NT-proBNP concentrations are associated with worse health status, lower activity levels, and reduced functional capacity, but not with cardiac structural abnormalities. These findings suggest that regardless of cardiac structural abnormalities, biomarker concentrations reflect important deterioration in functional capacity in affected individuals.