Different clinical outcomes in patients with asymptomatic severe aortic stenosis according to the stage classification: Does the aortic valve area matter?

Background: The ACC/AHA guidelines introduced a new classification of severe aortic stenosis (AS) mainly based on maximum jet velocity (Vmax) and mean pressure gradient (mPG), but not on aortic valve area (AVA). However, prognostic value of this new classification has not yet been fully evaluated.
Methods and Results: We studied 1512 patients with asymptomatic severe AS enrolled in the CURRENT AS registry in whom surgery was not initially planned. Patients were divided into 2 groups: Group 1 (N=122) comprised patients who met the recommendation for surgery; high-gradient (HG)-AS (Vmax≥4.0m/s or mPG≥40mmHg) with ejection fraction (EF)<50%, or very HG-AS (Vmax≥5.0m/s or mPG≥60mmHg), and Group 2 (N=1390) comprised patients who did not meet this recommendation. Group 2 was further subdivided into HG-AS with preserved EF (HGpEF-AS, N=498) and low-gradient (LG)-AS, but AVA<1.0cm ² (N=892). The excess risk of Group 1 relative to Group 2 for the primary outcome measure (a composite of aortic valve-related death or heart failure hospitalization) was significant (adjusted HR: 1.92, 95%CI: 1.37-2.68, P<0.001). The excess risk of HGpEF-AS relative to LG-AS for the primary outcome measure was also significant (adjusted HR: 1.45, 95%CI: 1.11-1.89, P=0.006). Among LG-AS patients, patients with reduced EF (<50%) (LGrEF-AS, N=103) had extremely high cumulative 5-year incidence of all-cause death (85.5%).
Conclusion: Trans-aortic valve gradient in combination with EF was a good prognostic marker in patients with asymptomatic AS. However, patients with LGrEF-AS had extremely poor prognosis when managed conservatively.
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