Clinical Research Directory

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.