From the Guidelines
For asymptomatic patients with aortic stenosis, a transthoracic echocardiogram (TTE) is the primary diagnostic tool, and transesophageal echocardiogram (TEE) is not routinely recommended for follow-up unless TTE findings are inconclusive or discordant with clinical assessment, as stated in the 2014 AHA/ACC guideline for the management of patients with valvular heart disease 1. When to order TEE for aortic stenosis in asymptomatic patients depends on various factors, including the severity of the stenosis and the presence of comorbidities.
- For patients with severe asymptomatic aortic stenosis (aortic velocity ≥4.0 m per second), TTE should be performed at intervals of 6 months to 1 year, and TEE may be considered if TTE findings are unclear or if there are changes in clinical status.
- For patients with moderate asymptomatic aortic stenosis (aortic velocity between 3.0 m per second and 3.9 m per second), TTE should be performed at intervals of 1 to 2 years, and TEE may be considered if TTE findings are inconclusive or if there are changes in clinical status.
- For patients with mild asymptomatic aortic stenosis (aortic velocity <3.0 m per second), TTE should be performed at intervals of 3 to 5 years, and TEE is generally not necessary unless TTE findings are unclear or if there are changes in clinical status, as per the guideline 1. The decision to order TEE should be based on individual patient factors, including the severity of the stenosis, the presence of comorbidities, and the clinical assessment of the patient.
- TEE provides superior visualization of valve anatomy and more accurate assessment of valve area, but it carries small risks of esophageal injury and requires conscious sedation, so it should be used judiciously when the additional information will impact management decisions, as recommended in the guideline 1.
From the Research
Asymptomatic Aortic Stenosis Management
When managing asymptomatic patients with aortic stenosis, the decision to order a TEE (transesophageal echocardiogram) depends on various factors.
- The presence of severe aortic stenosis, as indicated by a valve area of less than 1.0 cm2 2
- Left ventricular dysfunction, which can be a predictor of poor outcomes 3, 4
- Very severe AS with significantly elevated gradients, as suggested by current guidelines 3
Predictors of Poor Outcomes
Several clinical and echocardiographic characteristics can predict poor outcomes in asymptomatic patients with severe aortic stenosis, including:
- Peak aortic jet velocity greater than 5 m/s 2
- Left ventricular ejection fraction (LVEF) less than 60% 2
- Abnormal exercise test results 4
- High likelihood of rapid progression 4
Timing of Intervention
The optimal timing of intervention, such as aortic valve replacement (AVR), is still a topic of debate.
- Current guidelines suggest AVR in asymptomatic patients with specific characteristics, such as left ventricular dysfunction and very severe AS 3, 4
- Some studies suggest that early AVR may improve clinical outcomes, including all-cause, cardiovascular, and valve-related mortality 3, 2
- However, most patients in current practice are managed conservatively, with serial Doppler echocardiography every 6-12 months for severe aortic stenosis 5