Low-Gradient Severe Aortic Stenosis: Insights From the CURRENT AS Registry-2

Area of Science:

• Cardiology
• Aortic Stenosis Research
• Clinical Outcomes

Background:

• Low-gradient (LG) aortic stenosis (AS) remains less understood than high-gradient (HG) AS regarding cardiac damage, frailty, and outcomes.
• Characterizing distinct hemodynamic types of LG AS is crucial for understanding disease progression and patient stratification.

Purpose of the Study:

• To compare clinical characteristics and outcomes across different hemodynamic subtypes of LG AS and HG AS.
• To identify specific LG AS phenotypes associated with adverse clinical events.

Main Methods:

• Analysis of 3,363 patients from the CURRENT AS Registry-2, categorized into four groups: LG AS with reduced LVEF, paradoxical low flow, low gradient (LFLG) AS, normal flow, low gradient (NFLG) AS, and HG AS.
• Exclusion of patients lacking indexed stroke volume or LVEF data.

Main Results:

• LG AS with reduced LVEF and paradoxical LFLG AS exhibited more comorbidities, cardiac damage, and frailty, with less severe valve calcification compared to HG AS.
• The 3-year cumulative incidence of death or heart failure hospitalization was higher in LG AS with reduced LVEF and paradoxical LFLG AS.
• Adjusted analysis revealed independent associations of LG AS with reduced LVEF (HR: 1.82) and paradoxical LFLG AS (HR: 1.43) with increased risk of death or heart failure hospitalization, unlike NFLG AS (HR: 1.03).

Conclusions:

• Clinical outcomes are significantly worse for LG AS with reduced LVEF and paradoxical LFLG AS compared to HG AS.
• NFLG AS demonstrates comparable clinical outcomes to HG AS.
• These findings highlight the importance of differentiating LG AS subtypes for risk stratification and treatment decisions.