TAVR evaluation
|
Aortic Stenosis Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Percutaneous Aortic Balloon Valvotomy (PABV) or Aortic Valvuloplasty |
|
Transcatheter Aortic Valve Replacement (TAVR) |
|
Case Studies |
|
TAVR evaluation On the Web |
|
American Roentgen Ray Society Images of TAVR evaluation |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1],Associate Editor(s)-in-Chief: Seyedmahdi Pahlavani, M.D. [2]
Overview
Patient evaluation for TAVR procedure is divided in to 3 steps. Preprocedure, periprocedure and postprocedure evaluation are important steps for successful procedure.
TAVR Evaluation
Preprocedural Evaluation
Aortic Valve Morphology
- Transthoracic Echocardiography (TTE) is performed for initial visualization of aortic valve to identify the number of leaflets; size, location, extent of calcification, leaflet motion, and a preliminary view of annular size and shape.
- If additional imaging is needed, valve anatomy and function can be evaluated by cardiac magnetic resonance imaging (CMR) or ECG-gated MDCT.[1]
Aortic Valve Function
Doppler echocardiography is superior to other imaging modalities to evaluate Aortic valve function. AS severity should be evaluated according to the ESE/ASE Recommendations for Evaluation of Valvular Stenosis and staged according to the AHA/ACC Guideline for the Management of Patients with Valvular Heart Disease.[2][3]
LV Geometry and Other Cardiac Findings
TTE also is recommended for evaluation of LV hypertrophy, chamber size, LV diastolic function, regional wall motion, and ejection fraction as well as newer measures of LV function such as global longitudinal strain. In addition, TTE is useful for assessment of aortic dilation, presence of subvalvular outflow tract obstruction, estimation of pulmonary pressures, and identification of other significant valve abnormalities.
Annular Sizing
The 3D dataset provided by MDCT are more accurate than TTE findings regarding annular size.[4] Measurement of LV outflow tract diameter on TTE has been well validated for calculation of aortic valve area and continues to be the standard for determination of AS severity. CMR can also provide comprehensive assessment of the aortic valve, annulus, and aortic root with good correlation with MDCT.[5] CMR can be a valuable tool in patients who cannot undergo MDCT.
Aortic Root Measurements
MDCT allows for the careful measurement of the size of the sinuses of Valsalva, the coronary ostia distance from the annulus, the size of the aorta at the sinotubular junction and 40mm above the annulus, and the extent and position of aortic calcifications.[6]
Presurgical Planning
MDCT also may be of use in identification of coronary artery and coronary bypass graft location and stenosis, evaluation of the RV to chest wall position, and identification of the aorta and LV apex to chest wall position in direct aortic approaches.
Noncardiac Imaging
Because of high prevalence of dementia and atherosclerosis in this elderly patient population, a preprocedural work-up including carotid ultrasound and cerebrovascular MRI might be considered prior to considering or such patients for TAVR.
Vascular Access
Because of the relatively large diameter of the delivery sheaths, appropriate vascular access imaging is critical for TAVR. It is important to evaluate the entire thoracoabdominal aorta, major thoracic arterial vasculature, carotids, and iliofemoral vasculature. MDCT is able to provide valuable dataset regarding vascular anatomy.
Periprocedural Evaluation
Interventional Planning
MDCT can assist with predicting the optimal delivery angle on fluoroscopy prior to valve deployment.
Confirmation of annular sizing
Preprocedural MDCT is the best modality to evaluate annular size. At the time of the procedure, fluoroscopy is the main imaging modality. If questions remain about the correct annular sizing, balloon inflation with contrast root injection can be performed. Also, 3D TEE is able to evaluate the annular size, at the time of the procedure.
Valve Placement
Optimal deployment angles are obtained using fluoroscopy and root injections. Deployment is done under fluoroscopy at many institutions, although TEE is an alternative approach.
Paravalvular Leak
TEE and TTE are required to assess the valve in different aspects. Also, TEE can be used to assess the immediate gradient changes after valve seating. Aortic root angiography also may be used to assess for regurgitation after valve implantation. As the volume of cases performed without general anesthesia increases, there may be an expanding role for periprocedural TTE.
Procedural Complications
Immediate complications such as annular rupture resulting in pericardial effusion and tamponade can be detected by TEE, TTE, angiography, and direct hemodynamic measurements.
Long-Term Postprocedural Evaluation
Evaluate Valve Function
- Echocardiography is recommended to evaluate the valve postprocedurally to search for valvular and paravalvular leak, valve migration, complications such as annular or sinus rupture, valve thrombosis, endocarditis, paravalvular abscess, LV size, function and remodeling, and pulmonary pressures.
- MDCT can be used to evaluate valve anatomy A and to evaluate for valve thrombosis.
- CMR can also be used to quantify AR and can be complementary to TTE for the quantification of paravalvular leak.[1]
LV Geometry and Other Cardiac Findings
TTE is used to evaluate changes in LV function after TAVR.
Contraindications
General contraindications for transcatheter aortic valve implant (TAVI) through every approach include:
- Aortic annulus size <18 mm or >25 mm for balloon expandable devices and <20 mm or >27 mm for self expandable devices.
- Severe mitral regurgitation.
- Presence of apical left ventricle thrombus.
- Aortic root dimension > 45 mm at the sino-tubular junction for self-expandable prostheses.
- Low position of the coronary ostia (<8 mm from the aortic annulus)
- Asymmetric heavy valvular calcification which may compress the coronary arteries during the procedure of TAVI.
- Bicuspid valves - because of the risk of incomplete placement of the prosthesis.
- Intracardiac mass
- Presence of vegetations is an absolute contraindication for TAVI.
- Severe aortic regurgitation
- Serum creatinine >3.0 mg/dL or patient on dialysis
- Left ventricular ejection fraction <20%
- Untreated coronary heart disease requiring revascularization.
- Hemodynamic instability
- Upper gastrointestinal bleed within the past 3 months.
- Cerebrovascular accident (CVA) or transient ischemic attack (TIA) within the last 6 months.
- Aortic aneurysm or severe ilio-femoral insufficiency disease
- Hypertrophic cardiomyopathy
- Bleeding disorders
- Active infective endocarditis
The transfemoral approach has a few specific contraindications which include:
- Severe tortuosity, calcification and narrowing of the iliac arteries
- Previous aorta-femoral bypass
- Abdominal aortic aneurysm
- Severe angulation of the aorta
- Severe atherosclerosis of the ascending aorta and arch of the aorta[7].
Contraindications for transapical approach include:
- Previous surgery to the heart
- Severe respiratory insufficiency
- Chest deformity
References
- ↑ 1.0 1.1 Makkar RR, Fontana G, Jilaihawi H, Chakravarty T, Kofoed KF, de Backer O, Asch FM, Ruiz CE, Olsen NT, Trento A, Friedman J, Berman D, Cheng W, Kashif M, Jelnin V, Kliger CA, Guo H, Pichard AD, Weissman NJ, Kapadia S, Manasse E, Bhatt DL, Leon MB, Søndergaard L (2015). "Possible Subclinical Leaflet Thrombosis in Bioprosthetic Aortic Valves". N. Engl. J. Med. 373 (21): 2015–24. doi:10.1056/NEJMoa1509233. PMID 26436963.
- ↑ Bertrand PB, Verbrugge FH, Verhaert D, Smeets CJ, Grieten L, Mullens W, Gutermann H, Dion RA, Levine RA, Vandervoort PM (2015). "Mitral valve area during exercise after restrictive mitral valve annuloplasty: importance of diastolic anterior leaflet tethering". J. Am. Coll. Cardiol. 65 (5): 452–61. doi:10.1016/j.jacc.2014.11.037. PMC 4372048. PMID 25660923.
- ↑ Baumgartner H, Hung J, Bermejo J, Chambers JB, Evangelista A, Griffin BP, Iung B, Otto CM, Pellikka PA, Quiñones M (2009). "Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice". J Am Soc Echocardiogr. 22 (1): 1–23, quiz 101–2. doi:10.1016/j.echo.2008.11.029. PMID 19130998.
- ↑ Bucher AM, De Cecco CN, Schoepf UJ, Wang R, Meinel FG, Binukrishnan SR, Spearman JV, Vogl TJ, Ruzsics B (2014). "Cardiac CT for myocardial ischaemia detection and characterization--comparative analysis". Br J Radiol. 87 (1043): 20140159. doi:10.1259/bjr.20140159. PMC 4207157. PMID 25135617.
- ↑ Jabbour A, Ismail TF, Moat N, Gulati A, Roussin I, Alpendurada F, Park B, Okoroafor F, Asgar A, Barker S, Davies S, Prasad SK, Rubens M, Mohiaddin RH (2011). "Multimodality imaging in transcatheter aortic valve implantation and post-procedural aortic regurgitation: comparison among cardiovascular magnetic resonance, cardiac computed tomography, and echocardiography". J. Am. Coll. Cardiol. 58 (21): 2165–73. doi:10.1016/j.jacc.2011.09.010. PMID 22078422.
- ↑ Achenbach S, Delgado V, Hausleiter J, Schoenhagen P, Min JK, Leipsic JA (2012). "SCCT expert consensus document on computed tomography imaging before transcatheter aortic valve implantation (TAVI)/transcatheter aortic valve replacement (TAVR)". J Cardiovasc Comput Tomogr. 6 (6): 366–80. doi:10.1016/j.jcct.2012.11.002. PMID 23217460.
- ↑ Bapat VN, Attia RQ, Thomas M (2012). "Distribution of calcium in the ascending aorta in patients undergoing transcatheter aortic valve implantation and its relevance to the transaortic approach". JACC Cardiovasc Interv. 5 (5): 470–6. doi:10.1016/j.jcin.2012.03.006. PMID 22625183.