What are the guidelines for treating severe aortic stenosis?

Management Guidelines for Severe Aortic Stenosis

Symptomatic Severe Aortic Stenosis

Aortic valve replacement (AVR) is indicated for all patients with symptomatic severe aortic stenosis, regardless of surgical risk, as medical management alone is associated with dramatically worse survival. 1, 2

Treatment Selection Algorithm by Surgical Risk

• Low surgical risk (STS-PROM <3%): SAVR is preferred, though TAVR is a reasonable alternative in selected patients after Heart Team evaluation 1, 3

• Intermediate surgical risk (STS-PROM 4-8%): Either TAVR or SAVR is appropriate, with the Heart Team considering patient anatomy, frailty, comorbidities, and patient preference 1, 3

• High surgical risk (STS-PROM >8%): TAVR is preferred over SAVR 1, 2

• Prohibitive surgical risk (STS-PROM >15% or life expectancy <1 year): TAVR is the only reasonable option if life expectancy exceeds 1 year and patient is a candidate for rehabilitation 1, 3

Age-Based Considerations

• Age <65 years: SAVR is preferred 1

• Age 65-75 years: SAVR is generally preferred over TAVR 1

• Age 75-80 years: Either SAVR or TAVR is appropriate based on individual factors 1

• Age >80 years or life expectancy <10 years: TAVR is preferred if no anatomical contraindication to transfemoral access exists 1

Asymptomatic Severe Aortic Stenosis

Most asymptomatic patients with preserved left ventricular function should undergo watchful waiting with clinical and echocardiographic follow-up every 6-12 months. 3

Indications for AVR in Asymptomatic Patients

AVR is appropriate (rated 8-9) in the following scenarios:

• Reduced left ventricular ejection fraction (<50%) without another cause, regardless of surgical risk 1, 3

• Very severe aortic stenosis (Vmax ≥5 m/sec or mean gradient ≥60 mmHg) when operative mortality is <1% 1, 2

• Abnormal exercise stress test (development of symptoms, hypotension, or complex arrhythmias during exercise) 1

• Undergoing cardiac surgery for another indication (CABG, ascending aortic surgery, or other valve surgery) 1, 3

• High-risk profession (airline pilot) or lifestyle (competitive athlete) or anticipated prolonged time away from medical supervision, in low surgical risk patients 1

AVR May Be Appropriate in Asymptomatic Patients With:

• Predictors of rapid progression: Vmax increase >0.3 m/s/year, severe valve calcification, elevated BNP, or excessive LV hypertrophy without hypertension 1

• LVEF decline to <60% on serial echocardiography without another cause 1

Special Populations

Low-Flow, Low-Gradient Aortic Stenosis with Reduced LVEF

• Perform dobutamine stress echocardiography to distinguish true-severe from pseudo-severe aortic stenosis 1, 2, 3

• AVR is indicated if flow reserve is present (stroke volume increases ≥20%) and truly severe AS is confirmed (aortic valve area remains ≤1.0 cm² with increased flow) 1, 2, 3

Low-Flow, Low-Gradient Aortic Stenosis with Preserved LVEF

• Carefully confirm severity using multimodality imaging including cardiac CT for calcium scoring 1

• AVR is recommended if AS is confirmed as the most likely cause of symptoms after excluding other etiologies 1

Anatomical Considerations Favoring TAVR

• Porcelain aorta or hostile chest anatomy 1

• Prior cardiac surgery with patent grafts at risk during reoperation 1

• Small aortic annulus (prosthesis size <21 mm) 1

• Oxygen-dependent lung disease 1

• Cirrhosis with MELD >14 1

• Dialysis-dependent renal failure 1

Anatomical Contraindications to Transfemoral TAVR

• Excessive aortic root calcification 1

• Annulus size out of range for available devices 1

• Severe peripheral vascular disease precluding transfemoral access (consider alternative access routes) 1

Balloon Aortic Valvuloplasty

Balloon aortic valvuloplasty has extremely limited indications and should only be considered as:

• Bridge to AVR or TAVR in hemodynamically unstable patients where immediate AVR is not feasible 1

• Bridge to decision when contribution of AS to symptoms remains unclear in patients with severe comorbidities (COPD, poor LV function) 1

• Palliative therapy before urgent major non-cardiac surgery 1

Medical Management

There is no evidence supporting specific medical treatment to prevent progression or improve outcomes in aortic stenosis. 1

• Statins should not be used to prevent AS progression 3

• Maintain adequate preload and avoid aggressive diuresis 3

• Control heart rate to preserve diastolic filling time 3

• Avoid vasodilators and positive inotropes which can worsen hemodynamics 3

• Control blood pressure and other cardiovascular risk factors 3

Critical Pitfalls to Avoid

• Delaying intervention in symptomatic patients: Observational data demonstrate that asymptomatic patients who do not undergo AVR have survival rates of only 67% at 1 year, 56% at 2 years, and 38% at 5 years, compared to 94%, 93%, and 90% respectively in those who undergo AVR 4

• Overlooking reduced LVEF: Even asymptomatic patients with LVEF <50% due to AS require AVR, as this represents stage C2 disease with Class I indication 1, 3

• Missing very severe AS: Patients with Vmax ≥5 m/sec or mean gradient ≥60 mmHg are at higher risk for rapid symptom onset and adverse outcomes, warranting consideration for AVR even when asymptomatic 1, 2

• Failing to involve a Heart Team: All complex decisions require multidisciplinary evaluation including cardiac surgery, interventional cardiology, cardiac imaging, anesthesiology, and geriatrics expertise 1, 2, 3

• Accepting patient denial of symptoms: Symptoms are subjective and patients may unconsciously limit activity; exercise stress testing can unmask symptoms in apparently asymptomatic patients 1

Comparative Outcomes: TAVR vs SAVR

• Mortality: No significant difference in all-cause mortality at 30 days, 1 year, or 5 years between TAVR and SAVR 5

• Stroke: No significant difference in overall stroke rates, though some studies show reduced 30-day stroke with TAVR 5

• Hospital stay: TAVR associated with significantly shorter hospital stay (mean difference -3.08 days) 5

• Major bleeding and acute kidney injury: Significantly reduced with TAVR 5

• New-onset atrial fibrillation: Significantly reduced with TAVR 5

• Major vascular complications: Significantly increased with TAVR 5

• Permanent pacemaker requirement: Significantly increased with TAVR (particularly with self-expanding valves) 5

• Paravalvular regurgitation: Moderate or severe paravalvular AR occurs in 6.8% of TAVR patients vs 0% in SAVR patients at 3 years 6

• Valve hemodynamics: TAVR demonstrates superior hemodynamics with lower mean gradients (7.6 mmHg vs 11.4 mmHg at 3 years) 6