Abstract 12880: Is Paradoxical Low Gradient Severe Aortic Stenosis a More Advanced form of Aortic Stenosis? New Insights Gained from the Measurement of Valvular Calcium Content by Use of 256-slice MDCT
Background: Paradoxical low gradient severe aortic stenosis (PLG SAS) is a recently described subset of aortic stenosis (AS) the clinical and prognostic implications of which are a matter of intense debate. Some authors indeed consider this new entity as a more advanced form of AS, with increased interstitial fibrosis, reduced LV longitudinal function and poor prognosis, whereas others believe it represents a relatively benign form of AS, with an outcome similar to that of moderate AS. Because the severity of degenerative AS is intimately correlated with its calcium content, the aim of the present work was to directly compare the degree of valve calcification among PLG SAS and high-gradient (HG) SAS.
Methods: Forty three consecutive patients (16 men; mean age: 74±9 years) with isolated non-rheumatic SAS, preserved LVEF and regular sinusal rhythm underwent 256-slice MDCT to measure aortic valve calcium within 15 days of their echocardiographic examination. Patients were categorised according to mean transaortic gradient (MG) into PLG SAS (n=14, MG≤40 mmHg) or HG SAS (n=29, MG>40mmHg). Aortic valve calcification was assessed by use of the Agatston score. Analyses were conducted in the entire population as well as in subsets of patients matched for indexed aortic valve area (AVAi) and gender.
Results: With the exception of MG which by definition, was lower in PLG SAS than in HG SAS (30±5 vs 57±14 mmHg), PLG and HG SAS had similar baseline clinical and echocardiographic characteristics. In particular AS severity, as evaluated by the AVAi was similar in both groups (0.41±0.10 vs 0.36±0.08 cm2/m2, p=ns). By contrast, the Agatston score was significantly lower in PLG SAS than HG SAS (1684±859 vs 3209±1530, p≤0.001). This difference remained significant after matching the patients for AVAi and gender (1657±850 vs 2592±774, p=0.017).
Conclusion: Patients with PLG SAS display less calcified aortic valves by MDCT than patients with HG SAS. This suggests that the aortic valve disease process is less advanced in PLG SAS than in HG SAS.
- © 2013 by American Heart Association, Inc.