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- Jander, Nikolaus, et al.
(författare)
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Indexing aortic valve area by body surface area increases the prevalence of severe aortic stenosis
- 2014
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Ingår i: Heart. - : BMJ. - 1355-6037 .- 1468-201X. ; 100:1, s. 28-33
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Tidskriftsartikel (refereegranskat)abstract
- Background To account for differences in body size in patients with aortic stenosis, aortic valve area (AVA) is divided by body surface area (BSA) to calculate indexed AVA (AVA(index)). Cut-off values for severe stenosis are <1.0cm(2) for AVA and <0.6cm(2)/m(2) for AVA(index). Objective To investigate the influence of indexation on the prevalence of severe aortic stenosis and on the predictive accuracy regarding clinical outcome. Methods Echocardiographic and anthropometric data from a retrospective cohort of 2843 patients with aortic stenosis (jet velocity >2.5m/s) and from 1525 patients prospectively followed in the simvastatin and ezetimibe in aortic stenosis (SEAS) trial were analysed. Results The prevalence of severe stenosis increased with the AVA(index) criterion compared to AVA from 71% to 80% in the retrospective cohort, and from 29% to 44% in SEAS (both p<0.001). Overall, the predictive accuracy for aortic valve events was virtually identical for AVA and AVA(index) in the SEAS population (mean follow-up of 46months; area under the receiver operating characteristic curve: 0.67 (95% CI 0.64 to 0.70) vs 0.68 (CI 0.65 to 0.71) (NS). However, 213 patients additionally categorised as severe by AVA(index) experienced significantly less valve related events than those fulfilling only the AVA criterion (p<0.001). Conclusions Indexing AVA by BSA (AVA(index)) significantly increases the prevalence of patients with criteria for severe stenosis by including patients with a milder degree of the disease without improving the predictive accuracy for aortic valve related events.
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| 2. |
- Minners, Jan, et al.
(författare)
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Adjusting parameters of aortic valve stenosis severity by body size
- 2014
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Ingår i: Heart. - : BMJ. - 1355-6037 .- 1468-201X. ; 100:13, s. 1024-1030
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Tidskriftsartikel (refereegranskat)abstract
- Background Adjustment of cardiac dimensions by measures of body size appears intuitively convincing and in patients with aortic stenosis, aortic valve area (AVA) is commonly adjusted by body surface area (BSA). However, there is little evidence to support such an approach. Objective To identify the adequate measure of body size for the adjustment of aortic stenosis severity. Methods Parameters of aortic stenosis severity (jet velocity, mean pressure gradient (MPG) and AVA) and measures of body size (height, weight, BSA and body mass index (BMI)) were analysed in 2843 consecutive patients with aortic stenosis (jet velocity >= 2.5 m/s) and related to outcomes in a second cohort of 1525 patients from the Simvastatin/Ezetimibe in Aortic Stenosis (SEAS) study. Results Whereas jet velocity and MPG were independent of body size, AVA was significantly correlated with height, weight, BSA and BMI (Pearson correlation coefficient (r) 0.319, 0.281, 0.317 and 0.126, respectively, all p<0.001) to the effect that larger patients presented with larger AVA (less severe stenosis). Of the anthropometric measures used for linear adjustment, BSA was most effective in eliminating the correlation between AVA and body size (r=0.007), rivalled only by allometric (non-linear) models, findings that are confirmed in 1525 prospectively followed patients from the SEAS study. Predictive accuracy for aortic valve events and cardiovascular death during 46 months of follow-up was unchanged by adjusting AVA, regardless of measure of body size (area under the receiver operating curve for AVA 0.72 (CI 0.58 to 0.87) versus, for example, AVA/BSA 0.75 (CI 0.61 to 0.88), p=0.22). Conclusions In the assessment of aortic stenosis, linear adjustment of AVA by BSA improves comparability between patients with diverging body size without, however, increasing the predictive accuracy for clinical events in a population with mild to moderate stenosis.
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