Efficacy and safety of acetazolamide in patients with NYHA class II-IV decompensated heart failure: protocol of an open-label prospective randomized multicenter study (ORION-A)

Aim. To study the efficacy and safety of acetazolamide administered orally to patients with decompensated heart failure (HF) at the hospital stage within 72 hours from admission, compared with standard therapy. Material and methods. This open-label, prospective, randomized, multicenter study is planned to include 400 patients urgently admitted to hospital with NYHA class II-IV decompensated HF: 200 patients each in the standard therapy group and additional acetazolamide (tablets) group. The primary endpoint includes the number of patients who achieved compensation in accordance with the criteria for diuretic therapy discontinuation. There are secondary endpoints: increase in urine output in the first 72 hours of hospitalization (since randomization), weight loss, 24-hour natriuresis, length of stay in hospital, length of stay in the intensive care unit, 90-day any-cause death, 90-day cardiovascular death, 90-day death due to chronic HF decompensation or acute decompensated HF, the number of pleuro- and pericardiocentesis episodes during the hospitalization, scale for clinical condition assessment of HF patient (SHOKS) at discharge from the hospital, 6-minute walk test at discharge from the hospital. The planned follow-up duration is a hospital period with an assessment of the clinical picture and laboratory parameters. Telemedicine contact with patients is carried out after 14, 30 and 90 days using a structured questionnaire. Conclusion. Analysis of clinical, laboratory and echocardiographic parameters of patients using acetazolamide tablets will make it possible to determine the criteria for the effectiveness of diuretic therapy in patients with decompensated HF in the short and long term.