The EndoTAVI Project
1. Rationale
Aortic valve stenosis is a medical condition characterised by narrowing of the aortic valve, which is responsible for regulating the blood flow from the left ventricle of the heart to the aorta. The treatment of aortic valve stenosis depends on the severity of the condition and presence of symptoms. Mild-to-moderate cases may not require immediate intervention and can be managed with regular monitoring and medication. However, intervention is mandatory for severe aortic valve stenosis or symptomatic cases.
Transcatheter aortic valve replacement (TAVR) is a less invasive alternative to open-heart conventional surgery (surgical aortic valve replacement (SAVR)) and is now offered to patients at a low risk for surgery (1).
However, concerns remain regarding both transcatheter and surgical prosthesis valve durability at distance.
The EndoTAVI project aims to assess both transcatheter and surgical prosthetic heart valve durability at follow-up and understand the predictors of valve dysfunction.
This entails the investigation of markers (micro- and micro-markers at central and peripheral level) of dysfunction.
References – suggested lectures (1. Forrest JK, Deeb GM, Yakubov SJ, et al. Low Risk Trial Investigators. 3-Year Outcomes After Transcatheter or Surgical Aortic Valve Replacement in Low-Risk Patients With Aortic Stenosis. J Am Coll Cardiol. 2023 May 2;81(17):1663-1674).
2. Trans-catheter aortic valve replacement and blood flow disruption
The self-expandable transcatheter aortic valve has a high profile, and after deployment, it partitions the native aortic root, creating an inner area (named the ‘neo-sinus’) and an outer area (named the ‘anatomical sinus’). The latter area is located between the valve cage and the aortic wall.
This newly formed geometry might disrupt the normal current of the sinuses Valsalva of the aortic root and contribute to valve degeneration (2).
References – suggested lectures 2. Cahill TJ, Kirtane AJ, Leon M, Kodali SK. Subclinical Leaflet Thrombosis and Anticoagulation After Transcatheter Aortic Valve Replacement: A Review. JAMA Cardiol. 2022;7(8):866-72.
Figure 1 . The transcatheter aortic valve, by creating artificial spaces, may disruptphysiological blood flow.
3. What is the hypoattenuated leaflet thickening?
Hypoattenuated leaflet thickening (HALT) is a rather new and common phenomenon diagnosed using multidetector computed tomography (MDCT), characterized by the thickening of one or more valve leaflets (3). Thickening (seen as a meniscal lesion on MDCT) may reduce leaflet motility and restrict leaflet movement (RELM).
Figure 2 . Different grades of hypoattenuated leaflet thickening, from mild (A) to (D) severely restricted leaflet movement (D).
The causes of HALT/RELM remain under investigation.
Nevertheless, the majority of HALT cases are asymptomatic; hence, this condition is referred
to as subclinical leaflet thrombosis (SLT).
References – suggested lectures .3. Jilaihawi H, Asch FM, Manasse E, Ruiz CE, Jelnin V, Kashif M, et al. Systematic CT Methodology for the Evaluation of Subclinical Leaflet Thrombosis. JACC Cardiovasc Imaging. 2017;10(4):461-70.
4. The EndoTAVI project aims
The EndoTAVI project has several aims. Some of these are given below:
To evaluate the reproducibility, repeatability, and reliability of transthoracic echocardiographic measures of the newly formed anatomical sinuses and how these accurate correlates to multi-detector tomographic angiography (MDCT).
To evaluate the predictors of hypoattenauted leaflet thickening, including specific inflammatory biomarkers.
To investigate the association between non-uniform prosthesis expansion and hypoattenuated leaflet thickening.
To describe the frequency and localization of hypoattenuated lesions at different valve level
- To evaluate severity and extension of hypoattenuated leaflet lesions with advanced MDCT technology
