SUMMARY Rationale: Quality of Care registries provide valuable insight in guideline adherence and implementation of guideline recommendations in routine clinical practice.

Objective: The overall aim of the project is to study the titration of guideline directed medical therapy (GDMT) according to the European Society of Cardiology (ESC) HF 2021 guideline recommendations for patients with heart failure (HF) reduced ejection fraction (HFrEF), and mildly reduced ejection fraction (HFmrEF).

Study design: The current study is a prospective multi-center national quality of care registry (longitudinal) of regular HF care (as given).

Study population: The study population consists of patients with heart failure (de novo HF, chronic HF and worsening HF). Study setting is outpatient or inpatient (during admission). Patient sample is set at a minimum of 4000 patients, but can be expanded during the course of the registry project.

Participating sites: all hospitals with dedicated HF outpatient clinic in the Netherlands can participate.

Data: aggregated data

Intervention: none / no

Main study parameters/endpoints: The main parameters of quality of HF care are the adherence to guideline recommendation in terms of percentage (%) drug prescription, percentage (%) target dose (order, speed) and reason not to adhere to the guideline (intolerance, side-effects, maximum tolerated dose). The main endpoints for prognosis are the number of HF related hospitalizations and all-cause mortality during follow-up.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: There is no risk in participation, no intervention and no active involvement of patients for specific activities in the study. The project is a registration of care as given (standard care) to the participating subject with heart failure.

Inclusion Criteria:

In order to be eligible to participate in this registry, a subject must meet all of the following criteria:

1. Written informed consent obtained from subject aged ≥18 years.
2. Diagnosis of heart failure according to the European Society of Cardiology 2021 guideline definitions. An eligible patient must also fulfil to the category definitions of de novo HF, chronic HF or worsening HF.
3. Subjects willing and able to comply with the follow-up of regular care at the outpatient clinic. Also, sites should continue regular care for an included subject for at least 1 year (with preferably the entire project) at their outpatient HF clinic in this quality of care project.

Informed Consent: As the current research is a patient file study (registry) without an intervention of any kind. The medical ethics review board has reviewed the study and the study is declared to be not subject to the Medical Research Involving Human Subjects Act. Although informed consent is not strictly necessary, we have decided to ask permission from the patient use to their data for scientific research and comply to privacy/general data protection regulations for scientific research as well as to consent with data-coupling with other official data sources for quality of care projects in the Netherlands.

Exclusion Criteria:

1. Subjects with a life expectancy <1 years due to comorbidities according to the treating physician.
2. Subjects who have had a major cardiovascular event (e.g., myocardial infarction, open heart surgery, stroke) within 2 months interacting with prescription or dosing of HF drugs.
3. Subjects with advanced heart failure (end-stage) scheduled for or likely to undergo heart-transplantation or ventricular assist device within 6 months of baseline visit.

The current registry studies only patient with heart failure and an ejection fraction below 50%.

Type of heart failure patients

• Chronic heart failure
• Worsening heart failure
• De novo or newly-diagnosed heart failure