Outcome Implication of Aortic Valve Area Normalized to Body Size in Asymptomatic Aortic Stenosis

Abstract

Background— Current guidelines define severe aortic stenosis in patients with aortic valve area normalized to body surface area (AVA/BSA) <0.6 cm 2 /m 2 ; yet, this cutoff has never been validated. Moreover, it is not known whether AVA normalization to other body size indexes allows improved outcome prediction. We aim to test the value of AVA normalized to body size for outcome prediction in asymptomatic aortic stenosis. Methods and Results— We included 289 patients with asymptomatic aortic stenosis, preserved ejection fraction, and AVA<1.3 cm 2 at diagnosis. The outcome measure was the occurrence of aortic valve replacement or all-cause death or during follow-up. AVA was normalized to BSA, height, weight, and body mass index. For each normalized index, patients in the lowest tertile were at high risk of events whereas outcome was similar for the other tertiles. High risk of events was observed with AVA/BSA <0.4 cm 2 /m 2 (adjusted hazard ratio [HR], 3.42 [2.09–5.60]), AVA/height <0.45 cm 2 /m (adjusted HR, 3.99 [2.42–6.60]), AVA/weight <0.01 cm 2 /kg (adjusted HR, 3.37 [2.07–5.49]), and AVA/body mass index <0.029 cm 2 /kg per meter square (adjusted HR, 3.23 [1.99–5.24]). Mortality risk was high with AVA/height <0.45 cm 2 /m (adjusted HR, 2.18 [1.28–3.71]), followed by AVA/BSA <0.40 cm 2 /m 2 (adjusted HR, 1.84 [1.09–3.11]), AVA/weight <0.01 cm 2 /kg (adjusted HR, 1.78 [1.07–2.98]), and AVA/body mass index <0.029 cm 2 /kg per meter square (adjusted HR, 1.75 [1.04–2.93]). AVA/height showed better predictive performance than AVA/BSA with improved reclassification and better discrimination (net reclassification improvement: 0.33 versus 0.28; integrated discrimination improvement: 0.10 versus 0.08; C statistic: 0.67 versus 0.65), whereas AVA/weight and AVA/body mass index showed lower predictive capacity. Conclusions— Among AVA normalization methods, AVA/height <0.45 cm 2 /m followed by AVA/BSA <0.40 cm 2 /m 2 seem as robust parameters for defining high risk in asymptomatic aortic stenosis. The prognostic value of AVA/height deserves future research.

Risk Stratification of Severe Aortic Stenosis With Preserved Left Ventricular Ejection Fraction Using Peak Aortic Jet Velocity

“…In clinical practice, assessment of the severity of AS in asymptomatic patients should not rely on a single parameter but on a multiparameter approach that combine data derived from flow indices as peak transaortic velocities (or gradients which are similar) with less flow-dependent indices as AVA and indexed AVA. 25 Global longitudinal strain is useful in risk-stratifying patients with AS 26,27 and could be a useful tool in the VSAS population. We can hypothesize that patients who are asymptomatic with Vmax ≥5 m/s could be further risk stratified on the basis of global longitudinal strain, thus providing clinicians with more robust tools to decide optimal timing of surgery in these patients.…”

Asymptomatic aortic stenosis: An assessment of patients’ and of their general practitioners’ knowledge, after an indexed specialized assessment in community practice

“…Among all consecutive patients diagnosed with aortic stenosis, in the echocardiography laboratory of Saint Philibert Hospital (GHICL, Lille Catholic University, France) and included in a prospective registry[4], sixty-nine patients referred for exercise stress echocardiography of AS were retrospectively identified. Exclusion criteria were ( i ) left ventricular ejection fraction (LVEF) < 50%, ( ii ) more than mild-to-moderate concomitant aortic or mitral regurgitation.…”

Computed tomography and magnetic resonance imaging assessment of aortic valve stenosis: an update

“…As per current guidelines, severe AS is defined as the aortic valve area normalized to body surface area (AVA/BSA) < 0.6 cm 2 /m 2 . According to Tribouilloy et al[36], AVA/height showed better predictive performance than AVA/BSA withbetter reclassification and discrimination (net reclassification improvement, 0.33 vs. 0.28; integrated discrimination improvement, 0.10 vs. 0.08; C statistic, 0.67 vs. 0.65) than AVA/weight and AVA/body mass index. Inconsistency of hemodynamic characterization in severe AS between echocardiography (AVA < 1.0 cm 2 ) and catheterization (mean pressure gradient > 40 mm Hg) is observed in about half of the patients, and this is only partly explained by low-flow (low LV ejection fraction [EF]) conditions [37].…”