Chronic heart failure (CHF) is a common syndrome, in which heart failure with preserved left ventricular ejection fraction (HFpEF) predominates. The diagnosis of this particular phenotype of СHF currently remains challenging in medicine. Over the past ten years, scientific societies have developed and implemented modern diagnostic algorithms.

Aim. To assess the prevalence of HFpEF among patients with concurrent arterial hypertension and type 2 diabetes mellitus (T2DM) using various diagnostic algorithms.

Materials and methods. A study examined 90 individuals (mean age 61.61 ± 7.94 years) with arterial hypertension and T2DM who presented with dyspnea on moderate-intensity physical exertion and fatigue between 2022–2025. All participants underwent clinical and laboratory assessments, including NT-proBNP levels, 24-hour blood pressure monitoring, standard transthoracic and speckle-tracking echocardiography, as well as a diastolic stress test. HFpEF was evaluated using the European Society of Cardiology algorithm (ESC 2021), the H2FPEF score (2018), the HFA-PEFF algorithm (2019), the European Association of Cardiovascular Imaging (EACVI, 2021) consensus-based score, and the American Society of Echocardiography guidelines (2025).

Results. The proportion of confirmed HFpEF diagnoses varied significantly across the scales, ranging from 8.9 % to 77.8 %. Disproved diagnoses ranged from 2.2 % to 86.7 %. A high proportion of indeterminate results was observed in specific scales, reaching up to 86.7 % and peaking at 100 % using the H2FPEF score.

Conclusions. The estimated prevalence of HFpEF is highly dependent on the applied diagnostic algorithm. Evaluation of NT-proBNP levels significantly enhances diagnostic accuracy to identify HFpEF. In a cohort of patients with comorbid arterial hypertension and T2DM, the H2FPEF and HFA-PEFF algorithms demonstrate limited diagnostic certainty, yielding a high percentage of indeterminate results.