#valvular-heart-disease #aortic-stenosis #guideline

Aortic Stenosis

Definition

Aortic stenosis (AS) is progressive obstruction of LV outflow due to calcification/fibrosis of aortic valve cusps or rheumatic involvement, leading to increased LV afterload and, if untreated, LV dysfunction and death. It is the most common primary valve lesion referred for intervention in Europe and North America.

Key Concepts

Epidemiology

Prevalence rising with ageing population; degenerative calcific aetiology dominates in high-income countries
Bicuspid AV (BAV): dominant morphology in younger patients requiring AV replacement; associated with aortic dilatation in >50%
Rheumatic AS common in low/middle-income countries; usually presents combined with rheumatic MV disease sources/vhd-esc-2025 very high

Echocardiographic Grading

High-gradient (severe): mean PG ≥40 mmHg, Vmax ≥4.0 m/s, AVA ≤1 cm² (AVAi ≤0.6 cm²/m²) — severe regardless of flow/EF
Low-flow, low-gradient with reduced LVEF (<50%): AVA ≤1 cm², SVi ≤35 mL/m², mean PG <40 mmHg — distinguish true severe from pseudo-severe using DSE (flow reserve = ≥20% increase in stroke volume) or CCT calcium scoring
Low-flow, low-gradient with preserved LVEF (≥50%): AVA ≤1 cm², SVi ≤35 mL/m², mean PG <40 mmHg — often elderly women; multimodality workup required
Normal-flow, low-gradient with preserved EF: usually moderate AS; prognosis similar to moderate AS unless multimodality confirms severe
CCT AV calcium score: >2000 AU (men) / >1200 AU (women) = severe AS with ~85% sensitivity and specificity; <1600 AU (men) / <800 AU (women) makes severe AS unlikely sources/vhd-esc-2025 very high

Additional Diagnostic Parameters

GLS <−15% identifies high-risk asymptomatic patients
Natriuretic peptides help arbitrate symptom sources and identify high-risk asymptomatic patients (>3× age/sex normal = adverse marker)
Exercise testing: unmask symptoms and haemodynamic intolerance (fall in BP >20 mmHg = adverse)
Transthyretin cardiac amyloidosis co-exists in elderly AS patients — screen with immunofixation + bone scintigraphy if suspected; valve intervention still beneficial despite co-existing ATTR sources/vhd-esc-2025 very high

Medical Therapy

No proven medical therapy delays AS progression; statins ineffective despite pre-clinical promise
Treat concomitant hypertension (renin-angiotensin blockers preferred, careful titration to avoid hypotension)
HF and reduced LVEF: initiate GDMT before and up-titrate after valve intervention sources/vhd-esc-2025 very high

CAVD Molecular Mechanisms and Emerging Therapies

CAVD pathogenesis: shear/mechanical stress → VEC disruption → lipid infiltration, inflammation, oxidative stress → osteogenic transformation of VICs → ECM disruption and extracellular vesicle-mediated calcification sources/vhd-mechanism-aha-2024 (very high)
Calcification initiated in the fibrosa, typically the noncoronary cusp first
Disease initiation vs progression are distinct processes: Lp(a) and LDL-C have independent causal roles in CAVD initiation (Mendelian randomization); however, Lp(a) is NOT associated with progression of established valve calcification — explains statin trial failures sources/vhd-mechanism-aha-2024 (very high)
Statin paradox: strong genetic evidence implicates lipids in CAVD onset, yet statins (SALTIRE trial) showed no benefit on AS progression — consistent with initiation/progression mechanistic divergence sources/vhd-mechanism-aha-2024 (very high)
CHIP (clonal hematopoiesis of indeterminate potential): somatic variants in hematopoietic stem cells; present in CAVD and portend worse prognosis after AVR; augments NLRP3 inflammasome-mediated programs sources/vhd-mechanism-aha-2024 (very high)
See concepts/CAVD-Mechanisms for full molecular pathway detail
Ongoing trials targeting AS progression: pelacarsen (Lp(a) lowering, NCT05646381); colchicine (CHIANTI, COPAS); PCSK9 inhibitor (NCT04968509); evogliptin DPP4 inhibitor (EVOID-AS); ARBs (ARBAS); pioglitazone sources/vhd-mechanism-aha-2024 (very high)

Indications for Intervention — Symptomatic Severe AS

Class I: All eligible symptomatic patients with high-gradient AS (life expectancy >1 year)
Low-flow, low-gradient + reduced LVEF: Class I B if severe AS confirmed (DSE or CCT); pseudo-severe AS → GDMT only
Low-flow, low-gradient + preserved LVEF: Class IIa — intervention after confirming severe AS
Normal-flow, low-gradient + preserved EF: usually moderate AS; regular surveillance unless multimodality confirms severe sources/vhd-esc-2025 very high

Indications for Intervention — Asymptomatic Severe AS

Class I: LVEF <50% without other cause
Class IIa (new 2025): Early intervention as alternative to watchful waiting in patients with high-gradient AS, LVEF ≥50%, confirmed asymptomatic (normal exercise test if feasible), and low procedural risk — supported by EARLY TAVR, RECOVERY, AVATAR, EVoLVeD trials and meta-analysis
Additional adverse features favouring early intervention: very high Vmax (≥5 m/s), severe calcification + Vmax progression ≥0.3 m/s/year, markedly elevated BNP/NT-proBNP (>3× age/sex-corrected normal on repeated measurements), LVEF <55%
Moderate AS: intervention only if undergoing CABG, ascending aorta, or other valve surgery; evidence emerging for moderate AS + HFrEF but insufficient for routine intervention sources/vhd-esc-2025 very high

EARLY TAVR Trial — Asymptomatic AS (NEJM 2025)

Design: Prospective multicenter open-label RCT; 75 US/Canadian centres; 901 patients randomised 1:1 to early TAVR (transfemoral SAPIEN 3/3 Ultra) vs guideline-based clinical surveillance; March 2017–December 2021; median follow-up 3.8 years sources/tavi-earlytavr-nejm-2025 very high
Population: Age ≥65 years (mean 75.8); STS-PROM 1.8%; 83.6% low surgical risk; LVEF ≥50% (mean 67.4%); confirmed asymptomatic by negative treadmill stress test in 90.6%; peak AV velocity 4.3 m/s; KCCQ 92.7
Primary endpoint (death + stroke + unplanned CV hospitalisation): 26.8% TAVR vs 45.3% surveillance; HR 0.50 (95% CI 0.40–0.63; P<0.001) — superiority demonstrated
Death from any cause: 8.4% vs 9.2% (HR 0.93; NS) — no mortality benefit
Stroke: 4.2% vs 6.7% (HR 0.62; 95% CI 0.35–1.10; NS) — lower with TAVR but not statistically significant; unexpected finding
Unplanned CV hospitalisation: 20.9% vs 41.7% (HR 0.43) — dominant driver of composite; includes early crossovers counted as events
Exploratory HF hospitalisation: HR 0.32 (95% CI 0.18–0.58) — strongly favours early TAVR
Favorable outcome at 2yr (alive + KCCQ ≥75 without ≥10-point decline): 86.6% vs 68.0% (P<0.001) ✓
Integrated LV/LA health at 2yr: 48.1% vs 35.9% (P=0.001) ✓ — subclinical cardiac damage accumulates during surveillance
New-onset AF: 13.0% vs 12.4% (not significant in hierarchical testing) — no difference despite TAVR procedure
Clinical surveillance crossover: 87.0% of surveillance patients underwent AVR (median 11.1 months); 39.2% had advanced symptoms before conversion; 11 deaths before conversion (6 cardiovascular, 3 sudden)
Cardiac deterioration during surveillance: NT-proBNP rose from 298.6 to 462.2 pg/mL; KCCQ decreased 14.8 points; LVEF ≤60% rose from 12.7% to 20.7%; 6MWT decreased 46.4 m — evidence of progressive damage sources/tavi-earlytavr-nejm-2025 very high

RECOVERY Trial 10-Year Data (NEJM 2026)

Population: 145 asymptomatic patients with very severe AS (AVA ≤0.75 cm² + Vmax ≥4.5 m/s); enrolled 2010–2015 at Korean high-volume centres; median follow-up 144 months (12 years)
Primary composite (operative mortality + CV death): early SAVR 3% vs conservative care 24%; HR 0.10 (95% CI 0.02–0.43; P=0.002); 10-year cumulative incidence 1% vs 19%
All-cause mortality: 15% vs 32%; HR 0.42 (95% CI 0.21–0.86); NNT=6 (CV death), NNT=7 (all-cause mortality)
Heart failure hospitalisation: 0% (early surgery) vs 19% (conservative care) — zero HF admissions in early surgery arm
Kaplan-Meier curves continued to diverge throughout 10 years — no attenuation of benefit; sustained, not waning, long-term advantage
In the conservative care arm: 85% eventually underwent AVR (median 1048 days), but 10 died before reaching AVR; 19% of delayed AVR patients required urgent/emergency surgery
Sensitivity: as-treated and per-protocol analyses concordant with ITT; bioprosthetic-valve degeneration/thromboembolism concerns did not negate survival benefit at 10 years sources/as-recovery-nejm-2026 very high

TAVI vs SAVR — Mode of Intervention

Heart Team decision integrating: age, life expectancy, procedural risk (STS/EuroSCORE), anatomical suitability, patient preference, and lifetime management
TAVI non-inferior to SAVR in low-risk, intermediate-risk, and high-risk symptomatic patients at mid-term follow-up (PARTNER 3, Evolut Low Risk, DEDICATE-DZHK6 trials)
DEDICATE-DZHK6 (NEJM 2024; industry-independent; pragmatic): n=1,414; median STS-PROM 1.8%; mean age 74; 38 German sites; any CE-marked device; 1-year follow-up; primary (death or stroke): TAVI 5.4% vs SAVR 10.0% (HR 0.53; 95% CI 0.35–0.79; P<0.001 noninferiority); all-cause death 2.6% vs 6.2% (HR 0.43); disabling stroke 1.3% vs 3.1% (HR 0.42); new-onset AF 12.4% vs 30.8% (HR 0.36); pacemaker 11.8% vs 6.7% (HR 1.81); major bleeding 4.3% vs 17.2% (HR 0.24); comparable hemodynamics at 1 year; SAVR event rates higher than PARTNER 3 (COVID-19 pandemic enrollment + higher female proportion); most generalisable real-world TAVI evidence sources/tavr-dedicate-nejm-2024 very high
PARTNER 3 5-year (low-risk): No significant difference in composite death/stroke/rehospitalization at 5 years (TAVR 22.8% vs SAVR 27.2%; P=0.07); the early TAVR superiority (1–2 years) was attenuated by year 5; valve durability similar (bioprosthetic-valve failure 3.3% vs 3.8%); AF markedly lower with TAVR (13.7% vs 42.4%); valve thrombosis higher with TAVR (2.5% vs 0.2%); pacemaker more frequent with TAVR (13.5% vs 10.4%) sources/tavr-partner3-5yr-nejm-2023 very high
BHV preferred for most patients ≥65 years (aortic) or ≥70 years (mitral)
MHV preferred for patients <60 years (aortic) or <65 years (mitral) with long life expectancy and no contraindication to OAC
Anatomical factors favouring SAVR: low coronary ostia, narrow aortic root, commissural misalignment, BAV morphology, severe LVOT calcification
TAVI for BAV stenosis at high surgical risk (new Class IIb B 2025): if anatomy suitable per Heart Team sources/vhd-esc-2025 very high
See also: concepts/TAVI

Concomitant AV Replacement During Other Surgery

Class IIa: SAVR in patients with moderate AS undergoing surgery for another valve
Class IIb: SAVR in patients with moderate AS undergoing CABG or ascending aorta surgery sources/vhd-esc-2025 very high

ACC/AHA 2020 — TAVI vs SAVR Age-Based Framework

Class I A: Age <65 years or life expectancy >20 years → SAVR recommended (TAVI durability data extend only to ~5 years)
Class I A: Age 65–80 years + no contraindication to transfemoral TAVI → either SAVR or transfemoral TAVI after shared decision-making
Class I A: Age >80 years or life expectancy <10 years + no contraindication → transfemoral TAVI recommended in preference to SAVR
Class I A: High or prohibitive surgical risk, predicted post-TAVI survival >12 months → TAVI regardless of age
These age-specific thresholds contrast with the ESC 2025 approach which uses a Heart Team decision rather than fixed age thresholds sources/VHD-AHA-2020 very high

Invasive Hemodynamic Assessment of AS

Catheterization is reserved for cases where Doppler echo is inconclusive or discordant with clinical findings; if mean gradient ≥40 mmHg and clinical findings are consistent, no further invasive hemodynamic data are needed (except when CO >6.5 L/min) sources/hemodynamics-circ-2012 high
Optimal technique: simultaneous LV and central aortic pressure via side-hole catheters; mean gradient (integrated systolic ejection period) preferred — peak-to-peak gradient is non-physiological (peak LV and peak Ao pressure occur at different times) sources/hemodynamics-circ-2012 high
Never use femoral artery pressure as a surrogate for central Ao: peripheral amplification and vascular stenosis cause false under/over-estimation; there is also a temporal delay affecting mean gradient calculation sources/hemodynamics-circ-2012 high
Carabello sign: the catheter crossing critical AS (AVA ≤0.7 cm²) with a 7–8F catheter causes additional obstruction — recognise by noting a further pressure drop during catheter pullback; do not attribute solely to valve pathology sources/hemodynamics-circ-2012 high
Gorlin formula (1951): A = F / (Cc × Cv × √2gh); empirical constant used only for mitral valve; coefficients assumed = 1 for aortic valve (a theoretical impossibility); valve areas have clear limitations — must be interpreted alongside gradient, pressure contours, and ventricular contractile state sources/hemodynamics-circ-2012 high
Hakki equation (bedside check): valve area = cardiac output / √mean gradient; use to verify computer-generated Gorlin calculation sources/hemodynamics-circ-2012 high
Pressure contour analysis: Fixed valvular obstruction → parvus et tardus upstroke from time of AV opening; dynamic LVOTO (HCM) → spike-and-dome contour with late-peaking LV pressure sources/hemodynamics-circ-2012 high
Braunwald-Brockenborough sign: Post-PVC beat: valvular AS → increased pulse pressure; HCM → decreased pulse pressure — distinguishes fixed from dynamic obstruction sources/hemodynamics-circ-2012 high
Dobutamine challenge for low-flow/low-gradient AS (reduced LVEF): True severe AS: gradient increases, valve area remains small (≤0.7 cm²); Pseudo-AS: gradient unchanged, valve area normalises (≥1.2 cm²); Inotropic reserve (SV increase ≥20%) stratifies operative risk sources/hemodynamics-circ-2012 high
Nitroprusside challenge for low-flow/low-gradient AS (preserved LVEF): High peripheral resistance contributes to low CO; lowering afterload with vasodilators uncovers true severe AS (fixed valve area, rising gradient) sources/hemodynamics-circ-2012 high
Cardiac output pitfall: assumed O₂ consumption tables introduce up to 40% Fick error; thermodilution unreliable in low-output states, TR, arrhythmias, or intracardiac shunts sources/hemodynamics-circ-2012 high

ACC/AHA 2020 — Asymptomatic AS Intervention Criteria

Class I B-NR: LVEF <50% (Stage C2) → AVR
Class IIa B-R: Very severe AS (Vmax ≥5 m/s) + low surgical risk → AVR reasonable
Class IIa B-NR: Asymptomatic + BNP >3× normal + low risk → AVR reasonable
Class IIa B-NR: Vmax progression ≥0.3 m/s/year + low risk → AVR reasonable
Class IIa B-NR: Exercise-induced symptoms or ≥10 mmHg BP fall + low risk → AVR reasonable
Class IIb B-NR: Progressive LVEF decline to <60% on ≥3 serial studies → AVR may be considered
Note: ESC 2025 upgraded asymptomatic severe AS early intervention to Class IIa (broader criteria); ACC/AHA 2020 was more conservative with multiple Class IIa/IIb criteria sources/VHD-AHA-2020 very high

Perioperative Management of AS and NCS

Severe symptomatic AS is one of the four "active cardiac conditions" warranting cardiac evaluation before any NCS (except emergency). (sources/periop-aha-2024, rating: very high)
Evaluate for AVR before elevated-risk NCS (COR 2a): Symptomatic severe AS should be evaluated for aortic valve replacement (SAVR or TAVI) prior to elevated-risk elective NCS — see concepts/TAVI for NCS timing after TAVI. (sources/periop-aha-2024, rating: very high)
Echo within 1 year: If prior echo exists and symptoms are unchanged, repeat echo is not routinely required within 1 year; however, any new symptoms or examination changes warrant reassessment before surgery. (sources/periop-aha-2024, rating: very high)
Asymptomatic severe AS + preserved LVEF: Can safely proceed with low-risk NCS without prior valve intervention; elevated-risk NCS requires careful shared decision-making with cardiology input. (sources/periop-aha-2024, rating: very high)
Balloon valvuloplasty as bridge (COR 2b): In patients with severe symptomatic AS who are not surgical candidates and require urgent NCS, percutaneous balloon aortic valvuloplasty may be considered as a temporising bridge — only if NCS cannot be deferred and TAVI is not immediately feasible. (sources/periop-aha-2024, rating: very high)
Haemodynamic goals: Avoid hypotension (MAP <65 mmHg), tachycardia, and significant preload reduction; maintain sinus rhythm and adequate systemic vascular resistance to preserve coronary perfusion across the stenotic valve. (sources/periop-aha-2024, rating: very high)

Contradictions / Open Questions

DEDICATE vs PARTNER 3 — SAVR mortality discordance: SAVR all-cause death at 1 year was 6.2% in DEDICATE vs ~2% in PARTNER 3 despite similar STS-PROM scores. Investigators attribute this to COVID-19 pandemic enrollment (majority of DEDICATE patients) and higher female proportion. This inflates the apparent TAVI benefit in DEDICATE relative to industry-sponsored trials and makes direct comparisons unreliable. sources/tavr-dedicate-nejm-2024 very high sources/tavr-partner3-5yr-nejm-2023 very high
Long-term TAVI valve durability beyond 8–10 years is unknown — critical for decisions in younger patients
Moderate AS + HFrEF: one small underpowered RCT; insufficient evidence for routine TAVI in this group
Optimal timing and staging of PCI before TAVI remains unresolved (NOTION-3 vs ACTIVATION); no definitive guidance for moderate stenosis
Whether routine early intervention in ALL asymptomatic low-risk patients is appropriate or over-treatment requires further RCT data
RECOVERY vs EARLY TAVR apparent discordance on all-cause mortality: EARLY TAVR (3.8-year median, TAVR, HR 0.93 NS) showed no significant all-cause mortality difference; RECOVERY 10-year (144-month median, SAVR) showed HR 0.42 — likely explained by: (1) insufficient follow-up in EARLY TAVR to detect mortality signal; (2) 87% of EARLY TAVR surveillance arm underwent TAVR at median 11.1 months, substantially diluting any conservative-care arm mortality effect; (3) RECOVERY enrolled very severe AS (Vmax ≥4.5 m/s) vs EARLY TAVR severe AS (mean Vmax 4.3 m/s) sources/as-recovery-nejm-2026 very high sources/tavi-earlytavr-nejm-2025 very high
RECOVERY generalisability: Only Korean high-volume centres; N=145; excluded >80 years and major comorbidities; real-world elderly/frail patients with competing risks may derive less net benefit; SAVR-only — TAVR equivalence for very severe asymptomatic AS remains unproven
ACC/AHA 2020 vs ESC 2025 asymptomatic AS divergence: ACC/AHA 2020 had fragmented criteria (multiple Class IIa/IIb); ESC 2025 introduced a single Class IIa for early intervention in appropriate patients (EARLY TAVR, RECOVERY, AVATAR, EVoLVeD meta-analysis) sources/VHD-AHA-2020 very high vs sources/vhd-esc-2025 very high
EARLY TAVR primary endpoint interpretation — surrogate vs hard outcomes: The composite primary endpoint reduction (HR 0.50; P<0.001) in EARLY TAVR is substantially driven by unplanned CV hospitalisation (HR 0.43) which includes 105 surveillance-arm conversions to AVR within 6 months counted as events. Death and stroke individually were not significantly reduced. The 87% crossover rate means the trial effectively compares immediate vs delayed TAVR (median 11.1 months) rather than TAVR vs indefinite surveillance. sources/tavi-earlytavr-nejm-2025 very high
Stroke reduction in EARLY TAVR unexplained: Stroke occurred in 4.2% TAVR vs 6.7% surveillance (HR 0.62; 95% CI 0.35–1.10; P=NS) — directionally lower with early TAVR but underpowered for significance. Mechanism unclear: fewer calcific emboli from untreated valve? More procedures in surveillance arm cumulatively? Requires confirmation in future trials. sources/tavi-earlytavr-nejm-2025 very high
ACC/AHA 2020 vs ESC 2025 TAVI age thresholds: ACC/AHA uses fixed age breakpoints (65/80 years); ESC 2025 uses Heart Team decision integrating age, life expectancy, and anatomical factors without fixed thresholds sources/VHD-AHA-2020 very high vs sources/vhd-esc-2025 very high

Connections

Related to concepts/Valvular-Heart-Disease
Related to concepts/TAVI
Related to concepts/Structural-Valve-Deterioration
Related to entities/ATTR-Amyloidosis
Related to entities/Heart-Failure
Related to concepts/Perioperative-Cardiovascular-Assessment
Related to sources/periop-aha-2024