American Board of Internal Medicine (ABIM) Certification Practice Exam

What defines very severe aortic stenosis by mean gradient?

1. ≥40 mm Hg

2. ≥60 mm Hg

3. ≥50 mm Hg

4. ≥30 mm Hg

The correct answer is: ≥60 mm Hg

Very severe aortic stenosis is defined by a mean transvalvular pressure gradient of 60 mm Hg or greater. This threshold is based on guidelines that classify the severity of aortic stenosis not only by the pressure gradient but also by the degree of symptoms and valve area measurements. In the context of aortic stenosis: - A mean gradient of 40 mm Hg indicates severe stenosis, but it does not reach the threshold for very severe cases. - A mean gradient of 50 mm Hg represents severe aortic stenosis and is close to the threshold for very severe classification, yet it is still lower than 60 mm Hg. - A mean gradient of 30 mm Hg indicates moderate to severe stenosis, which is not sufficient to classify the condition as very severe. Thus, the definition of very severe aortic stenosis as having a mean gradient of 60 mm Hg or greater is crucial for determining the urgency of intervention and guiding treatment decisions. This information is essential for clinicians as they evaluate patients with aortic stenosis and consider the timing and type of potential interventions, including surgical valve replacement.