Predictors of the Development of Newly Diagnosed Chronic Heart Failure in Patients with Shortness of Breath in Long-Term Post-COVID Syndrome

Aim To determine the prevalence and predictors for the development of newly diagnosed chronic heart failure (CHF) in patients with shortness of breath in long-term post-COVID syndrome.Material and methods This screening cross-sectional clinical study was performed from April 2020 through April 2024, in two stages in an outpatient setting. At the first stage, 878 patients with shortness of breath were screened three or more months after COVID-19, and the presence of at least three diagnostic criteria for CHF, that were not in their history, was verified. At the second stage, a group of 192 patients with two or more diagnostic criteria for CHF who met the inclusion criteria and had no exclusion criteria was selected. The patients selected for the second stage were divided into two groups based on the blood concentration of the N-terminal pro-brain natriuretic peptide (NT-proBNP): the first group included 108 patients with a NT-proBNP value of ≤125 pg/ml, and the second group of 84 patients with a NT-proBNP value of >125 pg/ml.Results Newly diagnosed CHF was found in 84 (9.57%) patients with dyspnea, who sought medical care for long-term post-COVID syndrome with three or more diagnostic criteria (symptoms/signs, structural and functional changes in the heart according to echocardiography, increased NT-proBNP concentration), mainly with preserved left ventricular ejection fraction (LVEF) (97.9%). With an increase in the left ventricular myocardial mass index (LVMI) >110 g/m2, the odds ratio (OR) of developing newly diagnosed CHF increased by 2.201 times and the relative risk (RR) increased by 1.801 times; with the development of pneumonia associated with COVID-19, the OR increased by 45.5% and the RR by 70.8%; with the development of pneumonia requiring hospitalization in patients with COVID-19, the OR increased by 34.7% and RR by 54.7%; with an increase in the erythrocyte sedimentation rate >11 mm/h, the OR increased by 41.7% and the RR by 74.1%; with a decrease in the blood concentration of potassium <4.43 mmol/l, the OR increased by 4.529 times and the RR by 3.189 times; with an increase in ferritin >178 μg/ml in combination with an iron transferrin saturation ratio <20%, the OR increased by 38.8% and the RR by 45.1%; with an increase in the blood concentration of caspase-6 to >28.2 pg/ml, the OR increased by 28.8% and the RR by 35.4%.Conclusion Among 878 outpatients who sought treatment at the polyclinic for shortness of breath in long-term post-COVID syndrome, the prevalence of newly diagnosed CHF verified by three or more diagnostic criteria was 9.57%, mainly with preserved LVEF. The development of CHF in these patients was related with more severe forms of previous COVID-19 complicated by pneumonia and requiring hospitalization, an increase in LVMI to >110 g/m2, activation of low-grade nonspecific inflammation, metabolic disorders due to a decrease in potassium even within the normal range, latent iron deficiency, and an increase in the PANoptosis processes.