Impact of type 2 diabetes mellitus on heart failure with preserved ejection fraction depending on the presence of atrial fibrillation

Background. Cardiovascular diseases, including heart failure (HF) and heart failure with preserved ejection fraction (HFpEF), pose a global health challenge. HFpEF is on the rise, especially among the elderly and those with conditions like diabetes, obesity, and hypertension. Type 2 diabetes mellitus (T2DM) often coexists with HFpEF, and atrial fibrillation (AF) further complicates matters due to shared risk factors. The purpose of this study is to comprehensively investigate the influence of type 2 diabetes mellitus on cardiac function and biomarker profiles in patients with heart failure with preserved ejection fraction in the presence or absence of atrial fibrillation. Mate­rials and methods. This was a cohort, single-center study. Four hundred and forty-eight patients with HFpEF were examined. They were divided into 4 groups: group 1 — 189 patients with HFpEF alone; group 2 — 39 patients with HFpEF and T2DM; group 3 — 176 patients with HFpEF and atrial fibrillation; group 4 — 44 patients with HFpEF, AF, T2DM. Results. T2DM may contribute to a slightly older patient population in HFpEF, but age alone is not a primary discriminator. T2DM alone does not substantially impact left ventricular mass index but, when combined with AF, it does. T2DM is associated with an increased left atrial volume index, and AF intensifies this effect. T2DM influences diastolic function, with AF exacerbating it. T2DM affects left ventricular filling pressure, and AF worsens this in HFpEF. T2DM also influences left ventricular systolic function, further compromised when combined with AF in HFpEF patients. Galectin-3 levels are elevated in HFpEF patients with T2DM, further exacerba­ted with AF. NT-proBNP levels are influenced by T2DM and worsened with the combination of AF in HFpEF. SST2 levels are elevated in HFpEF patients with T2DM, further increased with AF, indicating myocardial fibrosis and adverse remodeling. Conclusions. The interaction between T2DM and AF in HFpEF patients creates a synergistic effect, resulting in significant cardiac structural and functional alterations. Novel biomarkers such as galectin-3, NT-proBNP, and sST2 emerge as valuable diagnostic tools, reflecting the complex pathophysiological processes in HFpEF.