Low-gradient severe aortic stenosis referred as deconditioning — case discussion

Objectives

1. Reclassify a low-gradient valve with the 2025 ESC/EACTS categories before any decision to withhold intervention. ^[1]
2. Use CT calcium scoring to confirm severity, knowing its thresholds and pitfalls. ^[1]
3. Recommend the mode of intervention from age, valve anatomy, access and Heart Team review. ^[1]
4. Plan antithrombotic therapy, complication consent and follow-up. ^{[1] [36]}

Candidate brief

You are the cardiology consultant receiving this referral in clinic. Present your assessment, the investigation that settles severity, your recommendation to the Heart Team and the discharge plan after the procedure. Practice scenario; clinical content is drawn from the topic's evidence pack. ^[1]

Expected actions

• Take the symptom seriously. ACC/AHA 2020 notes that exertional breathlessness or reduced exercise tolerance is the most common first symptom of AS. ESC/EACTS 2025 adds that patients may gradually limit their activity over several years and deny symptoms that exercise testing can unmask. ^{[2] [1]}
• Examine, but do not rely on the examination to grade severity. In the meta-analysis by Shellenberger et al., low-quality observational evidence gave a diminished second heart sound and a delayed carotid upstroke moderate accuracy for at least moderate AS; Munt et al. concluded that echo is still needed to exclude severe obstruction reliably when it is suspected. ^{[57] [58] [2]}
• Classify the valve. Mean gradient below 40 mm Hg, AVA ≤1 cm², SVi ≤35 mL/m² and LVEF ≥50%: low-flow, low-gradient AS with preserved LVEF. ACC/AHA 2020 notes that measurements made during hypertension may underestimate or, less often, overestimate severity, and its stage D3 criteria require measurements when normotensive (systolic BP below 140 mm Hg); this study was recorded at 126/74 mm Hg, which meets that criterion. ^{[1] [2]}
• Confirm severity. A calcium score above 2000 AU in men indicates severe AS (sensitivity and specificity about 85%). His 2600 AU is above that threshold. The guideline's caution concerns patients who can have severe AS without pronounced calcification (for example bicuspid valves, concomitant amyloidosis or predominantly fibrotic stenosis associated with post-rheumatic, radiation-induced or inflammatory disease), in whom the score must be interpreted cautiously. Separately, transthyretin amyloidosis may coexist with AS in older patients. ^[1]
• State the indication. ESC/EACTS 2025: intervention should be considered in symptomatic low-flow (SVi ≤35 mL/m²), low-gradient (below 40 mm Hg) AS with normal LVEF (≥50%) after careful confirmation that AS is severe (class IIa, level B). Other explanations for a small valve area with a low gradient despite preserved LVEF, such as measurement error, uncontrolled blood pressure and conditions lowering stroke volume, are frequent and must be carefully excluded. Counsel that, in a meta-analysis of 19 observational TAVI studies, paradoxical low-flow, low-gradient AS carried higher 5-year mortality than high-gradient AS (HR 1.20). ^{[1] [41]}
• Choose the route. At 70 years or older with tricuspid AS, ESC/EACTS 2025 recommends TAVI if the anatomy is suitable (transfemoral access, annulus dimensions, device landing-zone calcification pattern and coronary obstruction risk) (class I, level A). Coronary artery assessment is recommended to evaluate the need for revascularisation when valve surgery or an intervention is planned; in chronic coronary syndrome, omitting invasive angiography should be considered in TAVI candidates if the procedural planning CT angiogram is of sufficient quality to rule out significant coronary disease (class IIa, level B). ^[1]
• Present to the Heart Team. The core team is a cardiologist with imaging expertise, an interventional cardiologist and a cardiac surgeon. The recommendation weighs objective risks and benefits, and ends in a shared decision with the patient and family. ^[1]
• Consent for trade-offs. TAVI carries more vascular complications, paravalvular leak and new pacemakers; SAVR carries more severe bleeding, acute kidney injury and new atrial fibrillation. In the meta-analysis by Ullah et al., pacemaker predictors included male sex, baseline atrioventricular conduction delay, intraprocedural atrioventricular block and self-expanding or mechanically expandable valves. ^{[1] [60]}
• Antithrombotic plan. No indication for anticoagulation, so low-dose aspirin (75–100 mg/day) is recommended for 12 months (class I, level A), and long-term low-dose aspirin after the first 12 months should be considered in patients without a clear indication for anticoagulation (class IIa, level C). In POPular TAVI cohort A, both primary outcomes over 12 months were lower with aspirin alone than with aspirin plus clopidogrel for 3 months: all bleeding 15.1% versus 26.6%, and non-procedure-related bleeding 15.1% versus 24.9%. Most bleeding at the TAVI puncture site was counted as non-procedure-related. Routine use of oral anticoagulation after TAVI is not recommended in patients without a baseline indication (class III, level A), and nor is DAPT to prevent thrombosis after TAVI without a clear indication (class III, level B). ^{[1] [36]}
• Follow-up. Early echo within the first weeks for baseline prosthetic function, then annual clinical and echo review with a bioprosthesis. Because the clinical significance of leaflet thickening remains uncertain, routine CT to look for it is not indicated. ^[1]

Marking

Pass:

• rejects the deconditioning label and treats the symptom as possible valve disease.
• classifies low-flow, low-gradient AS with preserved LVEF with the correct criteria.
• uses the sex-specific calcium threshold to confirm severe AS.
• recommends transfemoral TAVI under the ESC/EACTS age-70 tricuspid-valve criterion with suitable anatomy (transfemoral access, annulus dimensions, device landing-zone calcification pattern and coronary obstruction risk), after Heart Team review.
• consents for TAVI-versus-SAVR complication trade-offs.
• prescribes low-dose aspirin for 12 months after TAVI, considers long-term continuation, and plans early and annual echo.

Fail:

• accepts the low gradient as moderate AS and discharges with surveillance alone.
• applies the female calcium threshold or omits confirmation of severity.
• recommends SAVR without addressing the ESC/EACTS criterion for TAVI at 70 years or older with a tricuspid valve and suitable anatomy (transfemoral access, annulus dimensions, device landing-zone calcification pattern and coronary obstruction risk).
• prescribes routine dual antiplatelet therapy or a DOAC after TAVI.
• orders routine CT to look for leaflet thickening.