**6. Screening and diagnosing HF in people with diabetes**

#### **6.1 Electrocardiography (ECG)**

According to the 2021 ESC guidelines' recommendations, when patients'symptoms signal the presence of acute or chronic HF, ECG is one of the measures used to evaluate their condition [91]. If acute HF is detected, it is recommended to produce an ECG when patients are admitted to the hospital, during their stay, and before they are discharged [91]. Performing electrocardiography is mainly a step toward HF detection, such as changes in the ECG show higher chances of HF in patients and vice versa: HF is not plausible when ECG is normal [91]. Moreover, by looking at the ECG, it is possible to learn about the causes of HF and how to proceed with future treatment [91]. Based on the 2019 ESC-EASD recommendations, ECG is also proposed for "patients with diabetes who have been diagnosed with hypertension" [114].

#### **6.2 Echocardiography**

A cardiac injury manifests itself as structural changes and echocardiography is the most effective and non-invasive measure to detect those changes [115], assessing systolic and diastolic dysfunction [116]. Echocardiography is recommended by the 2021 ESC guidelines [91] and the 2019 ESC-EASD recommendations as the

#### *Diabetes Mellitus Type 2, Prediabetes, and Chronic Heart Failure DOI: http://dx.doi.org/10.5772/intechopen.106391*

first-choice tool for structural and functional evaluation of the heart of diabetic people since it can detect higher LV mass (LVM) and/or diastolic dysfunction when no symptoms of HF are present [114]. It is widely known that LVM is directly proportional with common risk factors for T2D such as age, obesity, and dyslipidemia [117], but it also relies on gender and body size [118]. It is worth mentioning that, LV hypertrophy is a common anomaly seen in asymptomatic T2D patients, such that even after omitting silent coronary disease, it was observed in one-third of individuals without hypertension [119]. Indexed LVM/bovine serum albumin (BSA) enables for the establishment of reference values for comparing subjects of various body sizes [118]. The American Society of Endocrinology defines normal LVM/BSA levels as 43–95 g/m2 for women and 49–115 g/m2 for men [118].

### **6.3 Assessment of biomarkers**

The 2021 ESC guidelines [91] and the 2022 AHA/ACC/HFSA updated guidelines [120] recommend natriuretic peptide biomarker screening (either NT-proBNP or BNP) to identify diabetic patients with pre-HF. The 2022 AHA/ACC/HFSA guidelines also recommend routine assessment of circulating biomarkers in general for supporting a diagnosis or exclusion of HF, risk stratification, and prognosis of patients with diabetes [120]. Since HF stages are defined by increased natriuretic peptide levels by the universal definition [90], routine screening of NT-proBNP or BNP is recommended in patients without current or prior HF symptoms or signs. The cut-off levels for BNP and NT-proBNP as settled by the universal definition were as following: 35 pg/mL and 125 pg/mL for ambulatory HF patients and 100 pg/mL and 300 pg/ mL for hospitalized/decompensated HF patients, respectively [90]. Nevertheless, natriuretic peptide levels are not sufficient to diagnose HF since CV and non-CV factors diminish explanatory values of those levels under conditions such as AF, increasing age, obesity, and kidney disease [91]. In order to contribute to the informative diagnostic utility of natriuretic peptides, other new biomarkers, such as independent biomarkers for myocardial fibrosis or risk stratification in HF (secreted Frizzled-related proteins) or gut microbiota-derived trimethylamine N-oxide (TMAO), are required [121–124].
