The addition of cardiac biomarker testing to annual primary care diabetes screening identifying undiagnosed cardiac disease in a substantial proportion of asymptomatic individuals with diabetes

Abstract Background Individuals with diabetes are at increased risk of developing heart failure (HF) that is often preceded by Stage B HF characterized by structural and functional heart disease without HF symptoms. Early intervention can delay or even prevent the progression to Stage C symptomatic HF. While echocardiography is key for diagnosing HF, it is not practical to implement echocardiography into routine annual diabetes screening. Biomarkers such as NT-proBNP and high-sensitivity troponin can be valuable in detecting stage B HF. The intelligent Diabetes (iDiabetes) digital platform and clinical trial support a precision diabetes care model that is testing the benefit of enhanced phenotyping including routine NTproBNP and high-sensitivity troponin I (hsTnI) testing compared to standard care in consecutive individuals with diabetes in the community attending for annual screening. Purpose Our aim was to evaluate the prevalence of elevated NTproBNP and hsTnI in individuals randomised to the enhanced phenotyping arm of iDiabetes with diabetes and their diagnostic yield for structural and functional cardiac abnormalities. Methodology We evaluated 314 consecutive patients randomised to the enhanced phenotyping arm of iDiabetes. All patients in this arm had NT-proBNP and hs TnI and NT-proBNP measured at their routine annual primary care diabetes screening. Individuals with NT-proBNP exceeding 400 ng/L were invited for echocardiography, in line with UK NICE guidelines. Results In this study of 314 participants with diabetes (mean age, 67+13y; 55% Male; 7% type 1 diabetes), 26 (7.7%) had atrial fibrillation (AF), 174 (52%) had hypertension, 41 (13%) had ischaemic heart disease (IHD) and 12 (4%) had a history of heart failure. The mean NT-proBNP was 268 ng/L (± 655.80), with a median of 90 ng/mL, and the mean hsTnI was 9.4 ng/L (± 22) with a median of 4.4 ng/L. Elevated troponin levels (Reference values: Male 53 ng/L, Female 34 ng/L) were observed in 8 patients (2.5%). Additionally, 124 patients (39%) had NT-proBNP levels 125 ng/L, with 83 (25%) between 125 and 399 ng/L, 25 (8%) between 400 and 999 ng/L, and 16 (6%) 1000 ng/L (Figure 1). Of the 45 patients with NT-proBNP 400 ng/L, 41 underwent echocardiography. Among them, 16 (39%) had LV systolic dysfunction, 12 (29%) had LV diastolic dysfunction, 8 (19.5%) had both, 16 (39%) had LV hypertrophy, 6 (14.6%) had LV dilatation, 16 (39%) had LA dilatation, 8 (19.5%) had RA dilatation, and 2 (4.9%) had valvular heart disease and 1 (2.4%) had hypertrophic cardiomyopathy (Figure 2). Conclusion A substantial proportion of asymptomatic individuals with diabetes have elevated NTproBNP and hsTnI. Incorporating these biomarkers into routine primary care diabetes screening improves identification of subclinical cardiovascular disease and provides an opportunity for targeted CV risk-reducing treatments.