Low recruitment rate

This study is to collect human activity and electrocardiogram (ECG) data from heart failure (HF) patients to aid in the development of a novel chronotropic incompetence (CI) algorithm designed to diagnose CI in patients with HF.

The Investigation of the Chronotropic Incompetence Diagnostic Algorithm in Heart Failure Patients (CI Algorithm Study) is an acute data collection study using market released actigraphy devices (wGT3X-BT) and holter devices (DR 180) to measure study subjects' daily activities and surface ECG data simultaneously. The data will be analyzed to develop an algorithm to diagnose CI in patients with HF.

Inclusion criteria for the case group:

• Patient is greater than 18 years of age and less than 70 years of old.
• Patient is willing and able to give informed consent.
• Patient has been diagnosed with stable chronic HF according to European Society of Cardiology 2012 HF guidance.
• New York Heart Association class I- III, including with HF with preserved ejection fraction and HF with reduced ejection fraction patients.
• Patients can perform moderate exercise.
• Left ventricular ejection fraction less than 55% but greater than 35%.

Inclusion criteria for the control group:

• Subject is greater than 18 years of age and less than 70 years of old.
• Subject is willing and able to give informed consent.

Exclusion criteria for the case group:

• Patient is unable or unwilling to sign the patient informed consent.
• Patient has implantable pacemaker, Implantable cardiovert defibrillator (ICD) or cardiac resynchronize therapy (CRT) device.
• Patient has at least one pacemaker, ICD or CRT indications.
• Patients has persistent atrial fibrillation (AF).
• Patient whose hear rate baseline at the rest is greater than 95 beats per minutes (BPM).
• Patient has contraindications for cardio-pulmonary exercise testing, including but not limited to, unstable angina, decompensated heart failure, active pericarditis or myocarditis and ECG ST-segment shift > 2mm at the resting.
• New York Heart Association Class IV.
• Less than 45 days after myocardial infarction.
• Less than 3 months after acute heart failure.
• Patient has uncontrolled hypertension.
• Patient is pregnant.
• Patient has a medical condition that would limit study participation.
• Patient is enrolled in a concurrent study that may affect the outcome of this study.

Adverse events were collected from Baseline through 12 months follow-up.

All cardiovascular AE's were collected.

Because the study was discontinued, none of objectives of the study were met, the pre-specified analyses for all objectives were not performed (per study protocol).