Telemonitoring of HFrEF Patients

The aim of this study is to observe the impact of the 3-month telemonitoring intervention using an electronic wristband measuring physical activity, peripheral capillary oxygen saturation and heart rate (HR) in the population of clinically stable patients with chronic heart failure with reduced ejection fraction (HFrEF), compared with the control group of patients not undergoing this intervention.

The participants are recruited in the Clinical Ward of Cardiology and the outpatient cardiology clinic of the Central Teaching Hospital of the Medical University of Lodz, Poland. During the preliminary phase of the study (Frebruary 2023-May 2024) patients were consecutively recruited to the study arm, followed by the recruitment of patients to the control arm.

During the first study visit, the patients in the intervention group received an electronic wearable wristband SiDLY CARE PRO, which monitored their physical activity, peripheral capillary oxygen saturation and heart rate, taking measurements at 15-minute intervals and transmitting the results to a database. All the participants from both the study and the control group received standard care at the cardiology clinic. The study period covered the following 3 months, during which each patient underwent 3 outpatient visits. During each visit, a physical examination was performed, the history of medical events, a potential exacerbation of heart failure and possible changes in pharmacotherapy was obtained, and the following patient's functional assessment scales were completed: the Kansas City Cardiomyopathy Questionnaire-12 (KCCQ-12), the Visual Analogue Scale (VAS) and the 6 Activities of Daily Living Scale (6ADL). At V1, the Timed Up and Go Test (TUG) was also performed.

In both groups participating in the study, the incidence of a composite endpoint defined as death or hospitalisation for acute decompensated heart failure, its two components separately, HF-related hospitalisation equivalents as well as selected physical parameters and the results of the validated questionnaires mentioned above were analysed. In the study group, the data obtained by the telemonitoring wristbands were also analysed in subgroups specified on the basis of the time since the initiation of the intervention, the results of the KCCQ-12 and the occurrence of a composite endpoint.

After the initial phase of the study and acquisition of preliminary results, the prolongation of the study is planned until the 31st of December 2028 using the same protocol as the initial phase.

Inclusion criteria

• provided written informed consent prior to any study specific procedures;
• males and females aged >18 years old at the time of consent;
• documented diagnosis of HFrEF prior to enrollment and optimally treated with pharmacological and/or device therapy;
• left ventricular ejection fraction ≤40% in a transthoracic echocardiogram from the last 12 months before recruitment;
• NYHA class II-III.

Exclusion criteria

• acute or decompensated heart failure;
• the primary cause of heart failure in the form of active myocarditis, constrictive pericarditis or a valvular heart disease that has not been treated by interventional or surgical means, as defined by the ESC guidelines;
• myocardial infarction, unstable angina, stroke or transient ischemic attack, coronary revascularization by percutaneous coronary intervention or coronary artery bypass graft, valve replacement surgery or ICD/CRT implantation within 4 weeks prior to study enrollment;
• planned coronary revascularization by percutaneous coronary intervention or coronary artery bypass graft;
• planned valve replacement surgery;
• status after heart transplantation;
• symptomatic bradycardia or third-degree atrioventricular block without a pacemaker;
• a severe non-cardiovascular disease with a life expectancy of less than 1 year, or a patient condition precluding the performance of the procedures specified in the study protocol;
• diagnosis of malignancy at the time of screening;
• history of an allergic reaction to materials contained in the wristband.