Severe aortic stenosis — structured viva

Stem

Practice scenario. You are the consultant in the structural heart clinic. A 74-year-old woman has exertional breathlessness. Echo: mean gradient 44 mm Hg, peak velocity 4.2 m/s, valve area 0.7 cm², LVEF 60%. Tricuspid valve. STS-predicted mortality 2.1%. CT shows suitable annulus dimensions, no bulky annular or LVOT calcium, low coronary obstruction risk (coronary heights above cusp height, sinuses of Valsalva not shallow, no high calcium burden of the cusps facing the coronary ostia) and iliofemoral arteries suitable for transfemoral access. She asks for TAVI. ^{[1] [2]}

Branch A — Is this severe AS, and does she need a valve?

Examiner: Grade it and give the indication. ^[1]

Strong answer: This is high-gradient severe AS: mean gradient ≥40 mm Hg, Vmax ≥4.0 m/s and AVA ≤1 cm². ESC/EACTS 2025 treats that as severe irrespective of flow or LV function. Mean gradient is the most robust parameter. She is symptomatic, so intervention is recommended (class I, level B); the ESC/EACTS 2025 text adds that early intervention is strongly recommended in all patients with an estimated life expectancy above 1 year. ^[1]

Follow-up: What would her examination have told you? Answer: In the meta-analysis by Shellenberger et al., a diminished second heart sound (LR 10.87) and a delayed carotid upstroke (LR 9.04) raise the likelihood of at least moderate AS, and absence of a murmur radiating to the neck argues against it (LR 0.11). That evidence is low-quality and observational, and gives the two positive signs only moderate accuracy; absence of a radiating murmur is equally accurate in excluding at least moderate AS. In the cohort by Munt et al., no sign had both high sensitivity and high specificity for severe obstruction, so echo is still needed. ^{[57] [58]}

Follow-up: Would you exercise-test her to be sure? Answer: No. ACC/AHA 2020 notes that exercise testing is avoided in symptomatic AS because of a high risk of complications, including syncope, ventricular tachycardia and death. ^[2]

Branch B — Which valve, by which route?

Examiner: Quote the age thresholds, and do not blend the guidelines. ^{[1] [2]}

Strong answer: ESC/EACTS 2025 recommends TAVI at 70 years or older with tricuspid AS if the anatomy is suitable (transfemoral access, annulus dimensions, device landing-zone calcification pattern and coronary obstruction risk) (class I, level A); its text cites fewer early adverse outcomes and faster recovery. Below 70 years, SAVR is recommended if surgical risk is low, meaning STS-PROM and EuroSCORE II below 4% with Heart Team assessment (class I, level B). For all remaining patients in whom an aortic bioprosthesis is considered, SAVR or TAVI is recommended according to Heart Team assessment (class I, level B). The mode of intervention is recommended to be based on Heart Team assessment of clinical, anatomical and procedural characteristics, lifetime management and estimated life expectancy (class I, level C). Aortic valve interventions are recommended in Heart Valve Centres that report local expertise and outcomes, with on-site interventional cardiology and cardiac surgery and a structured collaborative Heart Team (class I, level C). Non-transfemoral TAVI should be considered in patients unsuitable for surgery and transfemoral access (class IIa, level B). In severe bicuspid AS, TAVI may be considered at increased surgical risk if the anatomy is suitable (class IIb, level B). Balloon aortic valvotomy may be considered as a bridge to SAVR or TAVI in haemodynamically unstable patients, and if feasible before urgent high-risk non-cardiac surgery in severe AS (class IIb, level C). For adults in whom bioprosthetic AVR is appropriate, ACC/AHA 2020 considers it most prudent, based on the published evidence, to recommend SAVR below 65 years unless life expectancy is limited by comorbid cardiac or non-cardiac conditions. It calls both routes effective at 65 to 80 years in symptomatic severe AS, and states that its age breakpoints are a starting point for shared decision-making and are not absolute values for chronological age. ACC/AHA notes that the TAVI-versus-SAVR RCTs enrolled high-velocity severe AS (stage D1). ACC/AHA calls the less robust observational and registry data on TAVI for symptomatic low-flow, low-gradient severe AS (stages D2 and D3) encouraging, and makes the same recommendations for symptomatic patients with confirmed severe AS regardless of flow rate. She meets the ESC/EACTS TAVI criterion; the Heart Team confirms the recommendation and the decision is shared with her. ^{[1] [2]}

Branch C — The evidence

Examiner: She is low risk. Give me the trials. ^{[12] [17] [3] [2]}

Strong answer: All figures are TAVI versus surgery. PARTNER 3 (balloon-expandable, transfemoral): death, stroke or rehospitalisation at 1 year 8.5% versus 15.1% (HR 0.54; significantly lower). Evolut Low Risk (self-expanding): death or disabling stroke at 2 years 5.3% versus 6.7% (non-inferior). DEDICATE (low or intermediate risk): death or stroke at 1 year 5.4% versus 10.0% (HR 0.53; non-inferior). According to ESC/EACTS 2025, meta-analyses of RCTs show less death and disabling stroke with TAVI at 1 year in low-risk patients, with no difference at longer follow-up or in intermediate- or high-risk patients. ^{[12] [17] [16] [3] [1]}

Follow-up: Does it hold over time? Answer: TAVI versus surgery: PARTNER 3 (low-risk, severe symptomatic AS) at 7 years showed no significant difference in either primary end point. The first (death, stroke or procedure-, valve- or heart failure-related rehospitalisation) was 34.6% versus 37.2% (difference −2.6 points, 95% CI −9.0 to 3.7). The second (a hierarchical composite) had a win ratio of 1.04 (95% CI 0.84 to 1.30). Evolut Low Risk at 5 years: death or disabling stroke 15.5% versus 16.4% (P = 0.47). ^{[18] [16]}

Branch D — What she must consent to

Examiner: What are the trade-offs? ^{[1] [33] [34]}

Strong answer: ESC/EACTS 2025 notes that vascular complications and paravalvular leak are consistently more frequent after TAVI, while severe bleeding, acute kidney injury and new atrial fibrillation are more frequent after SAVR. New pacemakers are more frequent after TAVI, particularly with self-expanding valves; in the systematic review by van Rosendael et al., rates after new-generation valves ranged from 2.3% to 36.1%. In the review by van Wely et al., any degree of paravalvular regurgitation is associated with higher mortality, although results for mild regurgitation are conflicting and most pooled studies were unadjusted cohorts. It can be treated by post-dilation, a vascular plug or a second device. ESC/EACTS 2025 notes that in RCTs it did not seem to change the TAVI-versus-SAVR comparison of clinical outcomes. ESC/EACTS 2025 adds that TAVI offers quicker recovery and shorter stays. ^{[1] [33] [34]}

Follow-up: Who is most likely to need a pacemaker? Answer: In the meta-analysis by Ullah et al. of 78 studies, predictors included male sex, baseline AV conduction delay, baseline right bundle branch block (unadjusted OR 2.48), intraprocedural AV block and self-expanding or mechanically expandable valves. In the network meta-analysis by Ravaux et al., pooled rates were 19.2% with balloon-expandable and 24.7% with self-expanding valves. In the meta-analysis by Zito et al. of 31 observational studies, a pacemaker after TAVI was associated with higher long-term all-cause death, its primary endpoint (RR 1.18). ESC/EACTS 2025 describes the long-term data on new pacemakers or left bundle branch block as conflicting. ^{[60] [62] [61] [1]}

Branch E — Discharge prescription

Examiner: No other indication for antithrombotic therapy. Write it. ^{[1] [36] [38]}

Strong answer: ESC/EACTS 2025 recommends low-dose aspirin (75–100 mg/day) for 12 months after TAVI in patients without an indication for oral anticoagulation (class I, level A). Long-term (after the first 12 months) low-dose aspirin 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% (RR 0.57), and non-procedure-related bleeding 15.1% versus 24.9% (RR 0.61). Most bleeding at the TAVI puncture site was counted as non-procedure-related. GALILEO randomised 1644 patients without an established indication for oral anticoagulation after successful TAVI to rivaroxaban 10 mg daily (with aspirin 75–100 mg daily for the first 3 months) or aspirin 75–100 mg daily (with clopidogrel 75 mg daily for the first 3 months). The data and safety monitoring board stopped it early for safety concerns, with more death or thromboembolism with the rivaroxaban strategy (HR 1.35; P = 0.04) and a non-significant excess of major, disabling or life-threatening bleeding (HR 1.50; P = 0.08). Routine use of oral anticoagulation after TAVI is not recommended in patients without a baseline indication (class III, level A), and DAPT is not recommended to prevent thrombosis unless there is a clear indication (class III, level B). ^{[1] [36] [38]}

Follow-up: And if she had atrial fibrillation? Answer: ACC/AHA 2020 advises assessing thromboembolic risk in patients with valve disease and AF and anticoagulating those at high risk. In the same paragraph it lists DOACs as an alternative to VKAs in AF with a bioprosthetic valve more than 3 months after implantation. Its supportive text on postoperative AF after valve intervention notes conflicting data on DOACs early after bioprosthetic implantation; until more data are available, the writing committee favours a VKA for patients with AF in the first 3 months after surgical or transcatheter bioprosthetic implantation. Its text also notes that VKAs may be more effective than DOACs for reducing death, myocardial infarction and cerebrovascular events after TAVI with an indication for anticoagulation. For patients already on oral anticoagulation for an appropriate indication, POPular TAVI cohort B found both primary outcomes over 12 months lower with the anticoagulant alone than with clopidogrel added for 3 months: all bleeding 21.7% vs 34.6%, non-procedure-related bleeding 21.7% vs 34.0%. Procedure-related bleeding was defined as BARC type 4 severe bleeding, so most puncture-site bleeding counted as non-procedure-related. ESC/EACTS 2025 recommends oral anticoagulation for TAVI patients with another indication for it (class I, level B), with no definitive recommendation on VKA versus DOAC. ^{[2] [37] [1]}

Branch F — Same echo, no symptoms

Examiner: Watch or intervene? ^{[1] [31]}

Strong answer: First, exercise-test her: in roughly one-third of asymptomatic patients with severe AS, exercise testing can uncover symptoms or reduced exercise capacity attributable to AS, and they are treated as symptomatic. An LVEF below 50% without another cause makes intervention recommended (class I, level B). Otherwise, with asymptomatic high-gradient AS (confirmed by a normal exercise test, if feasible), LVEF of 50% or more and low procedural risk, ESC/EACTS 2025 says intervention should be considered as an alternative to close active surveillance (class IIa, level A). In asymptomatic severe AS with LVEF of 50% or more and low procedural risk, intervention should also be considered if one feature is present (class IIa, level B). The features are very severe AS (mean gradient ≥60 mm Hg or Vmax above 5.0 m/s), or severe calcification (ideally on CT) with Vmax progression of 0.3 m/s or more per year. They also include BNP or NT-proBNP more than three times the age- and sex-corrected normal range, confirmed on repeat without other explanation, or LVEF below 55% without another cause. Intervention should also be considered with a sustained blood pressure fall above 20 mm Hg during exercise testing (class IIa, level C). EARLY TAVR cut its primary composite of death, stroke or unplanned cardiovascular admission from 45.3% with clinical surveillance to 26.8% with early TAVI (HR 0.50). ESC/EACTS 2025 notes that the result was driven by the 26.2% of the surveillance group who converted to TAVI within 6 months of randomisation because of symptoms or adverse prognostic factors, with no significant difference in stroke or all-cause mortality over 5-year follow-up. ESC/EACTS 2025 cites a meta-analysis of the four RCTs of early intervention versus surveillance that showed significantly fewer unplanned cardiovascular or heart failure admissions and strokes, but no significant reduction in all-cause or cardiovascular mortality. ESC/EACTS 2025 notes that the pooled trials were heterogeneous and the analysis was study-level. ^{[1] [31]}

Branch G — Lifetime management

Examiner: She may outlive the valve. What do you plan now? ^{[1] [28]}

Strong answer: Available data do not suggest a systematic durability difference. RCTs and observational studies have reported comparable SVD-related valve failure up to 10 years, although potential selection and survival bias, variable SVD definitions, limited follow-up, differential attrition, competing risk of death and mixed surgical valve types may limit direct comparison. In NOTION at 10 years, the primary composite of all-cause mortality, stroke or myocardial infarction was 65.5% after both TAVI and SAVR (HR 1.0). Among the bioprosthesis outcomes, severe structural deterioration was lower after TAVI (1.5% vs 10.0%; P = .02), while bioprosthetic valve failure was similar (9.7% vs 13.8%; P = .4). NOTION defined severe structural deterioration as a transprosthetic gradient of 30 mm Hg or more with a rise of 20 mm Hg or more, or severe new intraprosthetic regurgitation. Bioprosthetic valve failure combined valve-related or unexplained death after valve dysfunction, aortic valve reintervention, or severe structural deterioration. The ESC/EACTS 2025 text calls a meticulous CT-based anatomical analysis paramount when estimated life expectancy exceeds the assumed valve durability. Based on individual assessment, anticipating the feasibility and risks of a possible future TAV-in-TAV at the index TAVI should be considered, taking into account related technical aspects (device choice, neo-skirt height, commissural alignment and implantation depth). Valve-in-valve TAVI is associated with lower peri-procedural risk than redo SAVR, but raises the risk of severe prosthesis-patient mismatch, particularly TAV-in-SAV, and coronary access may be difficult or impossible in a relevant proportion of patients afterwards, especially after TAV-in-TAV. Surgical explant of a TAVI valve is rare but carries early mortality as high as 12% to 17%. ^{[1] [28]}

Branch H — Change the valve to bicuspid

Examiner: Same patient, bicuspid valve with heavy cusp calcification and a calcified raphe. ^[1]

Strong answer: The age-70 TAVI recommendation applies to tricuspid AS with suitable anatomy (transfemoral access, annulus dimensions, device landing-zone calcification pattern and coronary obstruction risk). Bicuspid patients were excluded from almost all landmark TAVI-versus-SAVR trials, and heavy cusp calcification, particularly with a calcified raphe, is associated with increased risk of aortic root injury, paravalvular leak and mortality after TAVI. ESC/EACTS 2025 keeps SAVR as the primary treatment for stenotic bicuspid valves, particularly if patients are young or have coexistent aortopathy or unfavourable valve morphology. For severe bicuspid AS, TAVI may be considered at increased surgical risk with suitable anatomy (class IIb, level B). The final choice rests with the Heart Team, which ESC/EACTS 2025 recommends should base the mode of intervention on clinical, anatomical and procedural characteristics, lifetime management and estimated life expectancy (class I, level C). ^[1]