Left ventricular filling pressure (LVFP) monitoring has been associated with improved quality of life, survival and reduced hospitalization rates. However, current LVFP monitoring methods are invasive, costly, and require long-term antithrombotic therapy.

The purpose of this study is to validate Seerlinq HeartCore, a novel CE-certified, non-invasive system that enables remote LVFP monitoring using photoplethysmography (PPG) and machine learning-based signal analysis.

Heart failure (HF) affects approximately 1-2% of the adult population in developed countries, with prevalence exceeding 10% among individuals older than 70 years. Despite advancements in diagnostics and treatment guided by evidence-based medicine, HF remains associated with high morbidity and mortality; up to 17% of patients die and up to 44% require hospitalization within 12 months.

Monitoring of left ventricular filling pressure (LVFP) has been shown to improve survival, quality of life, and reduce hospitalization rates in patients with HF. However, existing methods for LVFP assessment are invasive, costly, and require long-term antithrombotic therapy, limiting their widespread application.

The purpose of this study is to validate HeartCore, a novel CE-certified, non-invasive system that enables remote LVFP monitoring using photoplethysmography (PPG) combined with machine learning-based signal analysis.

This will be a prospective, multicenter study enrolling three patient cohorts:

RHC cohort, ECHO cohort, and RPM cohort. Participants will undergo 120-second PPG recordings in both upright and supine positions using a standard pulse oximeter connected to a smartphone. The PPG signals will be transmitted to a secure server and processed by the HeartCore algorithm to estimate LVFP, expressed as the diastolic reserve index (DRI), where a higher DRI indicates lower LVFP.

The primary outcomes of the study will be:

• The discrimination performance of the PPG-based HeartCore system for detecting elevated LVFP in the RHC and ECHO cohorts, measured by receiver operating characteristic area under the curve (ROC AUC), sensitivity, and specificity.
• The change in DRI following furosemide up-titration in the RPM cohort.

The secondary outcome will be:

• The correlation between DRI and pulmonary capillary wedge pressure (PCWP) in the RHC cohort.

This study aims to demonstrate that a non-invasive, widely available, and scalable PPG-based system can provide reliable assessment of LVFP in HF patients, potentially improving the management and outcomes of this population.

Inclusion Criteria:

• Males and females aged ≥ 18 years
• Able to understand, and willing to provide written ICF
• Stated willingness to comply with all study procedures
• Confirmed diagnosis of heart failure according to the 2021 ESC guidelines

Exclusion Criteria:

• Pregnancy or female participant lactating
• Advanced renal failure (glomerular filtration rate <25 ml/min or need for renal replacement therapy),
• Active malignancy requiring chemotherapy or radiotherapy
• Complex congenital heart disease
• Ventricular assist device support
• Pulmonary hypertension classified as WHO group 1 or groups 3-5.
• Other possible unforeseen medical conditions that the investigator deems unsafe for study participation

The study population will consist of 131 adult participants aged ≥ 18 years with diagnosed HF, enrolled into three cohorts - RHC, ECHO, RPM, fulfilling all the inclusion and none of the exclusion criteria.