Look More Closely at the Valve: Imaging Calcific Aortic Valve Disease
Outcome measures in patients with aortic stenosis Clinical trials of medical therapy to prevent progression in calcific aortic valve disease (CAVD) are hampered by the lack of sensitive measures of disease activity in the valve leaflets. Although the long-term goal of therapy is to prevent adverse cardiovascular outcomes, including mortality and aortic valve replacement, these endpoints have several limitations. First, the "hard" endpoint of mortality is frequently impacted by comorbid conditions. Patients with CAVD typically are elderly with a high prevalence of coronary and noncardiac disease so that isolating the effect of valve obstruction on survival is problematic. Second, the endpoint of valve replacement for symptom onset reflects considerable physician variation in the threshold for intervention, as well as patient preferences. In addition, some patients are not promptly referred for valve replacement at symptom onset, sometimes inappropriately but often due to concerns about surgical risk or to patient factors such as extreme age, dementia, or a severely reduced life expectancy due to coexisting conditions. Inclusion of these endpoints in clinical trials might obscure any benefit of medical therapy. Finally, clinical outcomes provide limited information about the mechanism of benefit; for example, medical therapy might improve outcomes by effects on coronary disease or ventricular function, rather than affecting the disease process in the valve leaflets. (SELECT FULL TEXT TO CONTINUE)
- Received October 27, 2011.
- Accepted November 3, 2011.
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