From the Guidelines
Diagnosing Aortic Stenosis
Aortic stenosis is typically diagnosed using a combination of physical examination, echocardiography, and other imaging modalities, with no single biomarker considered diagnostic 1.
Key Diagnostic Labs and Tests
- Echocardiography is the cornerstone of the evaluation of aortic stenosis, providing valuable information on valve anatomy and function, as well as left ventricular response to pressure overload 1.
- D-dimer may be used to exclude the diagnosis of aortic stenosis in patients with a low previous probability of the disease, as a nonelevated D-dimer (<500 ng/mL) makes the diagnosis unlikely 1.
- CT, TEE, and MRI are highly accurate for the diagnosis of aortic stenosis and may be used as alternatives to echocardiography in certain cases 1.
- Aortography is rarely used due to its invasive nature and lower sensitivity compared to other imaging modalities 1.
Diagnostic Approach
The diagnosis of aortic stenosis should be based on an integrated approach including transvalvular velocity/gradient, valve area, valve morphology, flow rate, LV morphology and function, blood pressure, and symptoms 1. A step-by-step approach can help to deal with the challenge of defining severe aortic stenosis, particularly in the setting of low gradient aortic stenosis 1.
Multimodality Imaging
Multimodality imaging strategies may be necessary in some cases to confirm disease stage and guide therapeutic decision making, particularly in patients with uncertain disease severity on Doppler echocardiographic examination 1.
From the Research
Diagnostic Labs for Aortic Stenosis
The following labs and imaging techniques are used to diagnose aortic stenosis:
- Trans-thoracic echocardiogram: the main imaging technique used to diagnose AS 2
- Electrocardiogram (ECG)-gated computed tomography: to demonstrate the degree of calcification in the valve and aortic valve area 2
- Cardiac magnetic resonance imaging: to accurately quantify ventricular function and evaluate the myocardium 2
- Doppler echocardiography: an ideal tool to confirm diagnosis 3
- Exercise tests: to help in stratification risk of asymptomatic aortic stenosis 3
- Heart catheterization: mostly restricted to preoperative evaluation of coronary arteries rather than to evaluation of the valve lesion itself 3
- Dobutamine echocardiography: in low flow-low gradient aortic stenosis, distinguishes between a myopathic and valvular cause of left ventricular dysfunction 4
- Transesophageal echocardiography: an additional diagnostic tool in some cases 5
- Cardiac computed tomography: an additional diagnostic tool in some cases 5
Key Diagnostic Factors
The diagnosis of aortic stenosis involves the following key factors:
- Presence or absence of symptoms: the key decision-making element 4
- Severity of aortic stenosis: classification of the type of stenosis can be defined using transthoracic echocardiography 5
- Aortic valve calcification: adds useful information when the degree of aortic stenosis is uncertain 4
- Ventricular function: evaluation of left ventricular systolic dysfunction is important for referral for aortic valve replacement 6