Imaging Pearls ❯ Vascular ❯ Aortic Valves
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- Calcific AS is characterized by aortic valve leaflet lipid infiltration and inflammation with subsequent fibrosis and calcification. Symptoms due to severe AS, such as exercise intolerance, exertional dyspnea, and syncope, are associated with a 1-year mortality rate of up to 50% without aortic valve replacement. Echocardiography can detect AS and measure the severity of aortic valve dysfunction. Although progression rates vary, once aortic velocity is higher than 2m/s, progression to severe AS occurs typically within 10 years. Severe AS is defined by an aortic velocity 4m/s or higher, a mean gradient 40mmHg or higher, or a valve area less than or equal to 1.0 cm2. Management of mild to moderate AS andasymptomatic severe AS consists of patient education about the typical progression of disease; clinical and echocardiographic surveillance at intervals of 3 to 5 years for mild AS, 1 to 2 years for moderate AS, and 6 to 12 months for severe AS; and treatment of hypertension, hyperlipidemia, and cigarette smoking as indicated.
Calcific Aortic Stenosis: A Review
Catherine M. Otto, David E. Newby, Graham S. Hillis
JAMA. 2024;332(23):2014-2026. doi:10.1001/jama.2024.16477 - When a patient with severe AS develops symptoms, surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI) is recommended, which restores an average life expectancy; in patients aged older than 70 years with a low surgical risk, 10-year all-cause mortality was 62.7%with TAVI and 64.0% with SAVR. TAVI is associated with decreased length of hospitalization, more rapid return to normal activities, and less pain compared with SAVR. However, evidence supporting TAVI for patients aged younger than 65 years and long-term outcomes of TAVI are less well defined than for SAVR. For patients with symptomatic severe AS, the 2020 American College of Cardiology/American Heart Association guideline recommends SAVR for individuals aged 65 years and younger, SAVR or TAVI for those aged 66 to 79 years, and TAVI for individuals aged 80 years and older or those with an estimated surgical mortality of 8%or higher.
- “Aortic stenosis (AS), defined as valve leaflet disease with left ventricular (LV) outflow obstruction, is most commonly caused by calcification of a congenital bicuspid or normal trileaflet valve, although AS due to rheumatic heart disease occurs in areas of the world where rheumatic fever is endemic. Diagnosing AS may be challenging because symptoms of exercise intolerance, dyspnea on exertion, and dizziness occur late in the disease course and may be caused by other cardiac diseases, such as heart failure, or by pulmonary conditions, such as asthma or chronic obstructive pulmonary disease (COPD). Physical examination is not reliable for detection of Asor evaluation of Asseverity. Once patients develop symptoms, severe AS is associated with an annual mortality rate as high as 50% if not treated promptly with valve replacement.”
Calcific Aortic Stenosis: A Review
Catherine M. Otto, David E. Newby, Graham S. Hillis
JAMA. 2024;332(23):2014-2026. doi:10.1001/jama.2024.16477 - Current American College of Cardiology/American Heart Association (ACC/AHA) and European Society of Cardiology (ESC) guidelines strongly recommend prompt SAVR or TAVI in adults with symptoms due to severe AS (Figure 3). This recommendation is based on the high mortality rate associated with severe symptomatic AS, which was 50.7%at 1 year with standard medical care vs 30.7% with TAVI in the PARTNER RCT of 358 patients with AS who were not candidates for aortic valve surgery (HR [death with TAVI vs medical care], 0.55 [95%CI, 0.40-0.74]; P < .001). However, a palliative care approach may be more appropriate for patients with limited life expectancy (defined as less than 1 year) or those whose quality of life is unlikely to improve even after valve replacement, such as those with severe dementia or other substantial comorbidities.
Calcific Aortic Stenosis: A Review
Catherine M. Otto, David E. Newby, Graham S. Hillis
JAMA. 2024;332(23):2014-2026. doi:10.1001/jama.2024.16477 - “Calcific AS is a common chronic progressive condition among adults older than 65 years and is diagnosed via echocardiography. Symptomatic patients with severe AS have a mortality rate of up to 50% after 1 year, but treatment with SAVR or TAVI reduces mortality to that of age-matched control patients. The type and timing of valve replacement should be built on evidence-based professional society guidelines, shared decision-making, and involvement of a multidisciplinary heart valve team.”
Calcific Aortic Stenosis: A Review
Catherine M. Otto, David E. Newby, Graham S. Hillis
JAMA. 2024;332(23):2014-2026. doi:10.1001/jama.2024.16477
- Bicuspid Aortic Valve: Associated Conditions
- Coarctation of the aorta
- Hypoplastic left heart syndrome
- Williams syndrome
- Turner syndrome
- Marfan’s syndrome
- “ Despite advances in prosthetic heart valve design, surgical technique, and postoperative care, complications after aortic valve replacement remain a leading cause of morbidity and mortality. Routine surveillance of prosthetic heart valves with transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and fluoroscopy is important, as these techniques allow accurate detection of prosthetic valve dysfunction. However, echocardiography and fluoroscopy may not allow identification of the specific underlying cause, including paravalvular leak, dehiscence, endocarditis, obstruction, structural failure, pseudoaneurysm formation, aortic dissection, and hemolysis.”
Complications of aortic valve surgery: manifestations at CT and MR imaging.
Pham N et al.
Radiographics. 2012 Nov-Dec;32(7):1873-92. - “ However, echocardiography and fluoroscopy may not allow identification of the specific underlying cause, including paravalvular leak, dehiscence, endocarditis, obstruction, structural failure, pseudoaneurysm formation, aortic dissection, and hemolysis.”
Complications of aortic valve surgery: manifestations at CT and MR imaging.
Pham N et al.
Radiographics. 2012 Nov-Dec;32(7):1873-92. - “Magnetic resonance (MR) imaging and computed tomography (CT) have an emerging role as diagnostic tools complementary to conventional imaging for detection and monitoring of complications after aortic valve replacement. The choice between CT and MR imaging depends on individual patient characteristics, the type of prosthetic valve, and the acuity of the clinical situation. In general, screening with TTE followed by TEE is recommended. When results of TTE and TEE are inconclusive, cardiac CT and MR imaging should be considered. The choice between these imaging techniques depends on the presence of patient-specific contraindications to CT or MR imaging.”
Complications of aortic valve surgery: manifestations at CT and MR imaging.
Pham N et al.
Radiographics. 2012 Nov-Dec;32(7):1873-92. - “Magnetic resonance (MR) imaging and computed tomography (CT) have an emerging role as diagnostic tools complementary to conventional imaging for detection and monitoring of complications after aortic valve replacement. The choice between CT and MR imaging depends on individual patient characteristics, the type of prosthetic valve, and the acuity of the clinical situation.”
Complications of aortic valve surgery: manifestations at CT and MR imaging.
Pham N et al.
Radiographics. 2012 Nov-Dec;32(7):1873-92. - “MDCT and transthoracic echocardiography (TTE) were done to evaluate pannus formation, prosthetic valve dysfunction, suture loosening (paravalvular leak) and pseudoaneurysm formation. Patients indicated for surgery received an operation within 1 week. The MDCT findings were compared with the operative findings. One patient with a Björk-Shiley valve could not be evaluated by MDCT due to a severe beam-hardening artifact; thus, the exclusion rate for MDCT was 3.2% (1/31). Prosthetic valve disorders were suspected in 12 patients by either MDCT or TTE. Six patients received an operation that included three redo aortic valve replacements, two redo mitral replacements and one Amplatzer ductal occluder occlusion of a mitral paravalvular leak.”
Correctness of multi-detector-row computed tomography for diagnosing mechanical prosthetic heart valve disorders using operative findings as a gold standard
Tsai IC et al.
Eur Radiol. 2009 Apr;19(4):857-67. - “The concordance of MDCT for diagnosing and localizing prosthetic valve disorders and the surgical findings was 100%. Except for images impaired by severe beam-hardening artifacts, MDCT provides excellent delineation of prosthetic valve disorder.”
Correctness of multi-detector-row computed tomography for diagnosing mechanical prosthetic heart valve disorders using operative findings as a gold standard
Tsai IC et al.
Eur Radiol. 2009 Apr;19(4):857-67.
- “Retrospectively EKG gated acquisition is advisable for Prosthetic Heart Valve (PHV) imaging because it enables dynamic leaflet evaluation and anatomic assessment in both systole and diastole.”
Multidetector CT Angiography in Evaluation of Prosthetic Heart Valve Dysfunction
Habets J et al.
RadioGraphics 2012; 32:1893-1905 - “ PHV assessment with CT angiography is a promising cardiac CT application that is of complementary diagnostic value to the clinical routine imaging techniques-echocardiography and fluoroscopy-and can provide additional relevant anatomic information that can have an impact on patient care.”
Multidetector CT Angiography in Evaluation of Prosthetic Heart Valve Dysfunction
Habets J et al.
RadioGraphics 2012; 32:1893-1905 - Indications for Aortic Valve Replacement in Aortic Stenosis
- Severe aortic stenosis defined by either
- Aortic valve area < 1.0 CM2
- OR
- Maximum aortic velocity > 4m/sec
- AND EITHER
- Symptoms referable to aortic stenosis
- Or
- Evidence of left ventricular dysfunction (ejection fraction <50%) - “ Infectious vegetations or nodular excrescences that form on the valve cusps, most commonly on the ventricular surface of the cusps, sometimes lead to embolism in patients with bacterial endocarditis .”
CT and MR Imaging of the Aortic Valve: Radiologic –Pathologic Correlation
Bennett CJ et al.
RadioGraphics 2012;32:1399-1420 - “ Papillary Fibroelastomas are rare benign excrescences with a propensity to arise on the surface of cardiac valves. Aortic and mitral valve lesions may be somewhat more common than tricuspid valve and pulmonic valve lesions.”
CT and MR Imaging of the Aortic Valve: Radiologic –Pathologic Correlation
Bennett CJ et al.
RadioGraphics 2012;32:1399-1420 - Papillary Fibroelastomas : Facts
- Maximum diameter less than 1 cm
- Peak incidence is the 7-8th decade of life
- Usually asymptomatic and incidental finding but may be associated with embolic phenomena
- “ Multidetector computed tomographic (CT) angiography is a promising complementary technique for evaluation of prosthetic heart valves (PHV), especially in patients with PHV obstruction and endocarditis.”
Multidetector CT Angiography in Evaluation of Prosthetic Heart Valve Dysfunction
Habets J et al
RadioGraphics 2012; 32:1893-1905 - “ Retrospectively electrocardiographically gated acquisition is advisable for PHV imaging because it enables dynamic leaflet evaluation and anatomic assessment in both systole and diastole.”
Multidetector CT Angiography in Evaluation of Prosthetic Heart Valve Dysfunction
Habets J et al
RadioGraphics 2012; 32:1893-1905 - Prosthetic Heart Valves: Facts
- Two main types are biologic and mechanical prosthetic heart valves
- Biologic prosthetic heart valves require no anticoagulation but are prone to wear and will degenerate within 10-20 years
- Mechanical prosthetic heart valves require anticoagulation for life but failure is rare and reported as 0.01%-6%
- CT especially of value in biologic prosthetic heart valves when associated abscess is suspected
- Aortic Pathology
-Aneurysm
- Pseudoaneurysm
- Intramural hematoma
- Penetrating ulcer
- Dissection - Diseased Trileaflet Aortic Valve
-Calcific degeneration
-Myxomatous degeneration (collagen deficiency, mitral valve prolapse)
-Fibrosis due to neovascularization (rheumatic heart disease)
-Infection - Normal Aortic Valve
3 semilunar cusps
Diastole:
- valve closes
- coaption (central meeting)
Systole:
- leaflets retract to create
triangular opening (aortic valve area) "The CT findings were not significantly different from the intraoperative findings (p=0.99), but the echocardiographic findings were (p<0.05)."
Diagnostic Value of Cardiac CT in the Evaluation of Bicuspid Aortic Stenosis: Comparison with Echocardiography and Operative Findings
Tanaka R et al.
AJR 2010;195:895-899"The sensitivity, specificity, positive predictive value, and negative predictive value for the detection of bicuspid aortic valve were 76.5%, 60.6%, 68.4%, and 95.2%, respectively for echocardiography and 94.1%, 100%, 100%, and 97.1% respectively for CT."
Diagnostic Value of Cardiac CT in the Evaluation of Bicuspid Aortic Stenosis: Comparison with Echocardiography and Operative Findings
Tanaka R et al.
AJR 2010;195:895-899" ECG-gated cardiac CT is useful for the accurate morphologic assessment of bicuspid aortic stenosis, especially in patients with severe aortic valve disease."
Diagnostic Value of Cardiac CT in the Evaluation of Bicuspid Aortic Stenosis: Comparison with Echocardiography and Operative Findings
Tanaka R et al.
AJR 2010;195:895-899- "Aortic valve planimetry is best performed at phase starts of 50-100 milliseconds after the R peak because the area of the aortic opening is widest and image quality is best at that phase."
Feasibility and Optimization of Aortic Valve Planimetry with MDCT
Abbar S et al.
AJR 2007; 188:356-360
- "We show in this study that MDCT can potentially be used to evaluate stenotic aortic valves, which often coexist with coronary artery disease. Additional studies need to be performed to further clarify the accuracy of the technique and its role in the clinicaldecision making process."
Feasibility and Optimization of Aortic Valve Planimetry with MDCT
Abbar S et al.
AJR 2007; 188:356-360