Association Between Changes in Aortic Valve Area and Pulmonary Congestion After Transcatheter Aortic Valve Implantation

Patients with severe symptomatic aortic stenosis scheduled for elective transfemoral TAVI will be prospectively enrolled in this single-center observational cohort study. A total of 52 patients are planned to be included.

Pulmonary congestion will be assessed using standardized lung ultrasound examinations performed at predefined time points during the peri-procedural period. Lung ultrasound assessment will primarily quantify B-lines and will also document relevant findings such as pleural effusion and consolidation. Assessments will be performed before TAVI and repeated after the procedure to characterize temporal changes in pulmonary congestion.

Aortic valve hemodynamics, including aortic valve area, will be assessed by transthoracic echocardiography. The principal analysis will evaluate the relationship between the change in aortic valve area after TAVI and the corresponding change in lung ultrasound findings. In particular, the association between the change in aortic valve area and the change in lung ultrasound findings at 24 hours will be evaluated.

By integrating echocardiographic assessment of valve hemodynamics with serial lung ultrasound, the study aims to characterize the relationship between hemodynamic improvement following TAVI and early changes in pulmonary congestion.

• Transcatheter Aortic Valve Implantation (TAVI) (Procedure): Transfemoral transcatheter aortic valve implantation (TAVI) performed as part of routine clinical care in patients with severe symptomatic aortic stenosis. The decision to perform TAVI and procedural management are independent of study participation. No modification of the TAVI procedure is made for research purposes.

Primary outcomes

• Correlation Between Change in Aortic Valve Area and Change in Total Lung Ultrasound Score After TAVI [From preprocedural baseline to 24 hours after TAVI]: The primary outcome is the correlation between the change in aortic valve area (AVA), measured by transthoracic echocardiography and expressed in cm², and the change in total lung ultrasound (LUS) score after TAVI. Lung ultrasound will be performed at three time points: immediately before anesthesia (T1), immediately after TAVI (T2), and 24 hours after the procedure (T3). Both hemithoraces will be examined in 12 thoracic zones. Each zone will be scored from 0 to 3 according to the degree of loss of aeration: 0 = normal aeration, characterized by A-lines or fewer than 2 B-lines with lung sliding; 1 = mild alveolar-interstitial pattern, characterized by 3 or more well-spaced B-lines with lung sliding; 2 = severe alveolar-interstitial pattern, characterized by multiple crowded and coalescent B-lines occupying >50% of the scanned intercostal space with lung sliding; and 3 = severe loss of aeration, characterized by a tissue-like pattern or consolidation. The scores from all 12 zones will

Secondary outcomes

• Change in B-Line Count After TAVI [From preprocedural baseline to 24 hours after TAVI]: Change in the total number of B-lines assessed by lung ultrasound from the preprocedural baseline to 24 hours after transcatheter aortic valve implantation (TAVI). B-lines will be assessed in predefined thoracic zones, and the change in B-line count following TAVI will be evaluated as a marker of change in pulmonary congestion.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Age ≥18 years
* Diagnosis of severe symptomatic aortic stenosis
* Scheduled for elective transfemoral transcatheter aortic valve implantation (TAVI)
* Availability of preprocedural transthoracic echocardiography
* Feasibility of lung ultrasound examination
* Provision of written informed consent

Exclusion Criteria:

* Active pneumonia
* Interstitial lung disease or pulmonary fibrosis
* Massive pleural effusion
* Acute decompensated heart failure
* Severe exacerbation of chronic obstructive pulmonary disease (COPD)
* Conditions precluding adequate thoracic ultrasound examination
* Severe mitral stenosis
* Clinically significant severe mitral regurgitation
* Development of a major complication during the procedure

• Metin İlteray Kıkılı, MD, Principal investigator, Istanbul University - Cerrahpasa