Prognostic value of aortic valve area normalized to body size in native aortic stenosis

Introduction and objectives: Although guidelines recommend the use of a cutoff value of 0.60 cm²/m² for aortic valve area (AVA) normalized to body surface area (BSA) for severe aortic stenosis, there is little evidence of its prognostic value. Our aim was to test the value of AVA normalized to body size for outcome prediction in aortic stenosis.

Methods: One-hundred and ninety patients with at least moderate aortic stenosis (AVA <1.50 cm²) were prospectively enrolled. AVA was normalized to BSA and height. The primary endpoint was cardiovascular death under medical management. A receiver operating characteristic curve was plotted to determine the best cutoff value for predicting cardiovascular death.

Results: An AVA/BSA cutoff value of 0.50 had a sensitivity of 96% and specificity of 51%. An AVA/height cutoff value of 0.49 showed a sensitivity of 96% and a specificity of 52%. During a mean follow-up of 247±190 days, there were 24 cardiovascular deaths, with higher cardiovascular mortality in patients with AVA/BSA <0.50 cm²/m² (21% vs 2.5%, P <.001) and AVA/height <0.49 cm²/m (25% vs 12%, P <.001). Two-year survival was 95±5% in patients with AVA/BSA> 0.50 cm²/m² and was 37±5% in patients with AVA/BSA <0.50 cm²/m² (P <.001). Cardiovascular death risk was higher in patients with AVA/BSA <0.50 cm²/m² (adjusted 10.9 [1.2-103.7], P=.037), but cardiovascular mortality was not significantly higher in multivariate analysis for patients with AVA/height <0.49 cm²/m (2.0 [0.6-6.0], P=.22).

Conclusions: We could identify a subgroup of patients at high risk of cardiovascular death when they were medically treated. Consequently we recommend using an AVA/BSA cutoff value of 0.50 cm²/m² to identify a subgroup of patients with higher cardiovascular risk.