Heart failure with reduced ejection fraction (HFrEF) remains a major public health challenge with substantial morbidity and mortality despite the availability of effective guideline-directed medical therapy (GDMT). Although four major drug classes have been shown to significantly improve survival and reduce hospitalizations, real-world implementation remains suboptimal. In addition to underutilization by healthcare providers, poor medication adherence among patients-reported to range between 29% and 63%-represents a critical barrier to achieving optimal therapeutic benefit.

The Visualize-Pro study is a prospective, exploratory pilot study designed to evaluate a simple, patient-centered intervention aimed at improving medication adherence in patients with HFrEF. The intervention consists of patient-friendly graphical visualizations illustrating the survival benefits and risk reduction associated with optimal heart failure therapy. These materials are designed to enhance patient understanding, motivation, and engagement with prescribed treatments.

To objectively assess medication adherence, this study incorporates therapeutic drug monitoring (TDM) as a gold standard method, in addition to established patient-reported outcome measures such as quality of life and adherence questionnaires. Blood samples will be collected at predefined study visits, and drug levels (or their metabolites) will be analyzed in collaboration with a specialized laboratory to quantify adherence.

Participants will be followed over a predefined study period with serial assessments at scheduled visits.

The primary objective is to evaluate the feasibility and preliminary effectiveness of the intervention in improving medication adherence. Secondary objectives include assessing changes in patient-reported outcomes and exploring associations between adherence and clinical parameters.

As a pilot study, the results are intended to inform the design of a future large-scale, multicenter trial. Ultimately, this approach aims to provide a scalable and low-threshold strategy to improve adherence to life-saving therapies in heart failure, thereby contributing to reduced morbidity and mortality in this high-risk population.

Inclusion Criteria:

• Age ≥18 years
• Diagnosis of heart failure with reduced ejection fraction (HFrEF) (left ventricular ejection fraction ≤40%)
• Indication for guideline-directed medical therapy (GDMT) for heart failure
• Stable clinical condition at the time of enrollment
• Ability to understand the study procedures and provide written informed consent

Exclusion Criteria:

• Acute decompensated heart failure requiring immediate hospitalization
• Severe cognitive impairment or inability to understand study-related information
• Life expectancy <6 months due to non-cardiac comorbidities
• Participation in another interventional clinical trial that may interfere with this study
• Contraindications to prescribed heart failure medications
• Any condition that, in the investigator's judgment, precludes safe participation in the study