Clinical outcomes and haemodynamic response after blinded stress assessment of moderate aortic stenosis.

Invasive transvalvular gradient increased significantly from rest to dobutamine stress in patients with moderate aortic stenosis.

• Invasive transvalvular gradient increased from 25±9 mmHg at rest to 42±14 mmHg during dobutamine stress.
• Study population consisted of 52 prospectively enrolled patients with moderate AS and preserved LVEF who were symptomatic without an alternative explanation.
• Assessments included echocardiography at rest, bicycle and dobutamine stress, calcium scoring, and invasive haemodynamic measurements.

The aortic-to-left ventricular pressure ratio (SAVI) declined substantially from rest to stress conditions.

• The aortic-to-left ventricular pressure ratio declined from 0.82 (IQR 0.78-0.88) at rest to a SAVI of 0.70 (IQR 0.63-0.79) under stress.
• The SAVI quantifies the relative reduction in maximal flow.
• The SAVI was measured but remained blinded throughout the management period.

Nearly half of patients with moderate AS demonstrated a SAVI comparable to a severe AS cohort.

• 25 out of 52 patients (48%) demonstrated a SAVI ≤0.70, comparable with a severe AS cohort studied separately.
• This subgroup was not identified by conventional resting metrics.
• These patients had only moderate AS by resting classification despite abnormal stress physiology.

Resting aortic valve area did not predict stress haemodynamics, indicating physiological heterogeneity among patients with moderate AS.

• Resting aortic valve area (AVA) did not predict stress haemodynamics.
• The authors noted this finding 'underscor[es] physiological heterogeneity' in the moderate AS population.
• This finding suggests that resting AVA is insufficient to characterize the full haemodynamic burden in symptomatic patients with moderate AS.

Blinded SAVI scores independently predicted the need for clinical aortic valve intervention, whereas AVA and sex-specific calcium thresholds did not.

• Blinded SAVI independently predicted the need for clinical aortic valve intervention with a hazard ratio of 5.7 (p=0.007).
• AVA did not independently predict the need for AV intervention.
• Sex-specific calcium thresholds did not independently predict the need for AV intervention.
• Patients were managed according to current standards without knowledge of the SAVI and followed for ≥1 year.

The study supports stress haemodynamic assessment as a basis for a future randomised trial in patients with moderate aortic stenosis.

• The authors describe this as a pilot study.
• Patients with abnormal stress physiology despite only moderate AS at rest may benefit from AV intervention.
• The study prospectively enrolled 52 patients with moderate AS and preserved LVEF.
• Comprehensive assessment included echocardiography, calcium scoring, and both invasive and non-invasive assessments at rest and during stress.