This study evaluates how different non-invasive and invasive measurements reflect left ventricular filling pressure, an important indicator of cardiac function. Elevated filling pressure is associated with symptoms such as shortness of breath and plays a central role in the diagnosis and management of heart failure and pulmonary hypertension.

In clinical practice, filling pressure can be estimated using echocardiography or measured during cardiac catheterisation. However, the relationships between these measurements and their ability to accurately reflect true filling pressure are not fully understood.

This retrospective study includes patients who underwent cardiac catheterisation with invasive haemodynamic assessment and temporally related echocardiographic evaluation as part of routine clinical care. The aim is to improve understanding of how different measurements relate to each other and to identify which parameters best reflect elevated filling pressure.

The results are expected to support more accurate interpretation of haemodynamic measurements and improve clinical decision-making, particularly regarding the use of non-invasive versus invasive assessment.

Inclusion Criteria:

• Adult patients (≥18 years)
• Clinically indicated left- and right-heart catheterisation under resting conditions
• Availability of invasive left ventricular end-diastolic pressure (LVEDP) measurement
• Availability of pulmonary capillary wedge pressure (PCWP) measurement
• Availability of transthoracic echocardiography within 5 days of cardiac catheterisation
• Adequate echocardiographic image quality for analysis

Exclusion Criteria:

• Missing or incomplete invasive haemodynamic measurements (LVEDP or PCWP)
• Missing or non-interpretable echocardiographic data
• Haemodynamic instability at the time of measurement
• Incomplete data required for analysis

Consecutive adult patients undergoing clinically indicated left- and right-heart catheterisation at the West German Heart and Vascular Centre Essen, University Hospital Essen, Germany, with available invasive haemodynamic measurements and echocardiographic assessment as part of routine clinical care.