Aortic stenosis resident survival guide
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alejandro Lemor, M.D. [2]
Aortic Stenosis Resident Survival Guide Microchapters |
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Overview |
Causes |
FIRE |
Diagnosis |
Treatment |
Do's |
Don'ts |
Overview
Aortic stenosis is the progressive narrowing of the diameter of the aortic valve (normal valve area is 3 - 4 cm²). Symptoms of aortic stenosis are evident when the stenosis is ≤ 1.0 cm². The symptoms are caused by a decrease in the stroke volume and the subsequent decreased perfusion to peripheral tissues. The most common etiology is calcific aortic valve disease. The management of aortic stenosis depends on whether the patient is symptomatic or asymptomatic. Aortic valve replacement is the treatment of choice for symptomatic patients.
Causes
Life Threatening Causes
Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.
Common Causes
Click here for the complete list of causes.
FIRE: Focused Initial Rapid Evaluation
A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention. The algorithm below is based on the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease [1] .
Abbreviations: STEMI: ST elevation myocardial infarction; AVR: aortic valve replacement
Boxes in the salmon color signify that an urgent management is needed.
Identify cardinal findings that increase the pretest probability of acute aortic stenosis ❑ Systolic ejection murmur
❑ Severe dyspnea | |||||||||||||||||||||||||||||||||||||||||||||||
Does the patient have any of the following findings that require urgent management? ❑ Tachycardia | |||||||||||||||||||||||||||||||||||||||||||||||
Yes | No | ||||||||||||||||||||||||||||||||||||||||||||||
❑ Assess airway, breathing, and circulation ❑ Administer oxygen if necessary ❑ Monitor vitals continuously | |||||||||||||||||||||||||||||||||||||||||||||||
❑ Treat the underling cause of the decompensation ❑ Do not give nitrates (could cause severe hypotension) | |||||||||||||||||||||||||||||||||||||||||||||||
Suspect if: ❑ Loss of consciousness of:
❑ Determine the etiology of the syncope | |||||||||||||||||||||||||||||||||||||||||||||||
Click here for acute heart failure resident survival guide | Click here for atrial fibrillation resident survival guide | Click here for syncope resident survival guide | Click here for STEMI resident survival guide Click here for NSTEMI resident survival guide | ||||||||||||||||||||||||||||||||||||||||||||
Patients with severe aortic stenosis and failure to improve with medical therapy: ❑ Perform urgent AVR | |||||||||||||||||||||||||||||||||||||||||||||||
Complete Diagnostic Approach
A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention.[1]
Abbreviations: AF: atrial fibrillation; AVR: aortic valve replacement; CXR: chest X-ray; ECG: electrocardiogram; LBBB: left bundle branch block; LVH: left ventricle hypertrophy; TAVR: transcatheter aortic valve replacement; TTE: transthoracic echocardiography; VHD: valvular heart disease
Characterize the symptoms: ❑ Asymptomatic ❑ Dyspnea on exertion ❑ Exertional dizziness ❑ Syncope ❑ Chest pain ❑ Palpitations | |||||||||||||||||||||||||||||||||||||
Examine the patient: Vitals
❑ Respiratory rate
❑ Pulses
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Order imaging and adjuvant studies: ❑ ECG (shows non-specific findings):
❑ Chest X-ray:
❑ TTE (most important evaluation test) (Class I; Level of Evidence: B)
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Interpret results from TTE | |||||||||||||||||||||||||||||||||||||
No stenosis ❑ Valve area 2.5-3.5 cm² ❑ No pressure gradient across the valve | Mild stenosis ❑ Valve area 1.5-2.5 cm² ❑ Pressure gradient ≤ 25 mmHg | Moderate stenosis ❑ Valve area 1.0-1.5 cm² ❑ Pressure gradient 25-40 mmHg | Severe stenosis ❑ Valve area ≤ 1.0 cm² ❑ Pressure gradient ≥ 40 mmHg | ||||||||||||||||||||||||||||||||||
Treatment
Shown below is an algorithm for the treatment of aortic stenosis according to the stage of the disease based on the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease [1]
Interpret results from TTE | |||||||||||||||||||||||||||||||||||||||||||||||||
No stenosis (Stage A) ❑ Valve area 2.5-3.5 cm² ❑ No pressure gradient | Mild to moderate stenosis (Stage B) Mild ❑ Valve area 1.5-2.5 cm² ❑ Pressure gradient ≤ 25 mmHg Moderate ❑ Valve area 1.0-1.5 cm² ❑ Pressure gradient 25-40 mmHg | Severe stenosis ❑ Valve area ≤ 1.0 cm² | |||||||||||||||||||||||||||||||||||||||||||||||
Asymptomatic patients ❑ Control hypertension (Class I; Level of Evidence: B) ❑ Perform a periodic echocardiogram (Class I; Level of Evidence:B)
| Asymptomatic (Stage C) ❑ Pressure gradient ≥ 40 mmHg | Symptomatic (Stage D) | |||||||||||||||||||||||||||||||||||||||||||||||
❑ Control hypertension (Class I; Level of Evidence: B) | Normal LVEF (Stage C1) | LVEF < 50% (Stage C2) | High gradient (ΔP ≥ 40 mmHg) (Stage D1) | ||||||||||||||||||||||||||||||||||||||||||||||
Perform a periodic echocardiogram every 6 - 12 months (Class I; Level of Evidence: B) | ❑ Schedule for AVR (Class I; Level of Evidence: A) | ❑ Schedule for AVR (Class IIa; Level of Evidence: B-C) Click here for Low flow low gradient aortic stenosis resident survival guide | |||||||||||||||||||||||||||||||||||||||||||||||
If aortic velocity ≥ 5 m/s or there is a decrease in exercise tolerance: ❑ Schedule for AVR (Class IIa; Level of Evidence: B) | |||||||||||||||||||||||||||||||||||||||||||||||||
Choice of Intervention
Shown below is an algorithm summarizing the choice of the intervention to aortic stenosis based on the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease [1]
Patient scheduled for AVR | |||||||||||||||||||||||||||||||||
High risk | Low to moderate risk | ||||||||||||||||||||||||||||||||
❑ A multidisciplinary group should decide intervention (Surgical AVR or TAVR) (Class I; Level of Evidence: C) ❑ Schedule for TAVR (Class IIa; Level of Evidence: B)[1] [2] | ❑ Schedule for surgical AVR (Class I; Level of Evidence: A) | ||||||||||||||||||||||||||||||||
Evaluation of Surgical and Interventional Cardiac Risk
Shown below is a table to assess the surgical and interventional risk which combines the STS risk estimate, frailty, major organ system dysfunction and procedure-specific impediments.[1]
Society of Thoracic Surgeons Predicted Risk of Mortality Score [3] |
Frailty* | Major organ system compromised without postoperative improvement | Specific procedural impediment ** | |
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Low risk | <4% AND |
None AND |
None AND |
None |
Intermediate risk | 4% to 8% OR |
1 index OR |
1 organ system OR |
Possible |
High risk | >8% OR |
≥2 indices (moderate to severe) OR |
No more than 2 organ systems OR |
Possible |
Prohibitive risk | >50% of predicted risk of death or major morbidity at 1 year OR |
>50% of predicted risk of death or major morbidity at 1 year OR |
≥3 organ systems | Severe |
*Seven frailty indices: Katz Activites of Daily Living (self-sufficient in feeding, bathing, dressing, transferring, toileting and urinary continence) and self-sufficient in deambulation (no walking aid or assist required or 5-meter walk in <6 s).
**Examples of specific procedural impediment: tracheostomy present, heavily calcified ascending aorta, chest malformation, arterial coronary graft adherent to posterior chest wall or radiation damage.
Type of Valve and Discharge Anticoagulation Therapy
Determine: ❑ Age ❑ Contraindications for anticoagulation
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❑ Patients ≤ 60 years old (Class IIa; Level of Evidence: B), AND ❑ No contraindication for anticoagulation | ❑ Patients 60 - 70 years old ❑ No contraindication for anticoagulation | ❑ Patients ≥ 70 years old (Class IIa; Level of Evidence: B), OR ❑ Patients with contraindications for anticoagulation therapy (Class I; Level of Evidence: C) | |||||||||||||||||||||||||||||||
Mechanical Prosthesis Avoid the use of direct thrombin inhibitors or anti-Xa agents in patients with mechanical prosthesis (Class III; Level of Evidence: B) | Either a bioprosthesic or mechanical valve is reasonable (Class IIa; Level of Evidence: B). | Bioprosthesis | |||||||||||||||||||||||||||||||
Patient with risk factors† | Patient without risk factors† | Surgical AVR | |||||||||||||||||||||||||||||||
Do's
❑ Give ACE inhibitors to control hypertension in patients with asymptomatic aortic stenosis. [4]
❑ Perform a TTE after aortic valve replacement for evaluation of valve hemodynamics (Class I; Level of Evidence: B).
❑ Perform a TTE when clinical symptoms or signs suggest prosthetic valve dysfunction (Class I; Level of Evidence: C).
❑ Consider exercise testing in asymptomatic patients with AS to elicit exercise-induced symptoms and abnormal blood pressure responses (Class IIb; Level of Evidence: B).
❑ Consider dobutamine stress echocardiography to evaluate patients with low-flow/low-gradient AS and LV dysfunction (Stage D3) (Class IIa; Level of Evidence: B)
❑ Consider aortic balloon valvotomy as a bridge to surgery in hemodynamically unstable adult patients with AS who are at high risk for AVR or cannot be performed because of serious comorbid conditions.(Class IIb; Level of Evidence: C).
Don'ts
❑ Do not perform a stress test in a symptomatic patient with stage D aortic stenosis (Class III; Level of Evidence: B).
❑ Do not administer statins to prevent hemodynamic progression in patients with mild to moderate calcific aortic valve disease (Class III; Level of Evidence: A).
❑ Do not perform a TAVR in patients in whom existing comorbidities would preclude the expected benefit from correction of AS (Class III; Level of Evidence: B)
❑ Do not administer vasodilators to patients with severe AS as they may cause severe hypotension.
❑ Do not administer endocarditis prophylaxis in patients with AS. [5]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Nishimura, R. A.; Otto, C. M.; Bonow, R. O.; Carabello, B. A.; Erwin, J. P.; Guyton, R. A.; O'Gara, P. T.; Ruiz, C. E.; Skubas, N. J.; Sorajja, P.; Sundt, T. M.; Thomas, J. D. (2014). "2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines". Circulation. doi:10.1161/CIR.0000000000000031. ISSN 0009-7322.
- ↑ Smith, Craig R.; Leon, Martin B.; Mack, Michael J.; Miller, D. Craig; Moses, Jeffrey W.; Svensson, Lars G.; Tuzcu, E. Murat; Webb, John G.; Fontana, Gregory P.; Makkar, Raj R.; Williams, Mathew; Dewey, Todd; Kapadia, Samir; Babaliaros, Vasilis; Thourani, Vinod H.; Corso, Paul; Pichard, Augusto D.; Bavaria, Joseph E.; Herrmann, Howard C.; Akin, Jodi J.; Anderson, William N.; Wang, Duolao; Pocock, Stuart J. (2011). "Transcatheter versus Surgical Aortic-Valve Replacement in High-Risk Patients". New England Journal of Medicine. 364 (23): 2187–2198. doi:10.1056/NEJMoa1103510. ISSN 0028-4793.
- ↑ "Online STS Risk Calculator". Retrieved 7 March 2014.
- ↑ Chambers, J. (2005). "The left ventricle in aortic stenosis: evidence for the use of ACE inhibitors". Heart. 92 (3): 420–423. doi:10.1136/hrt.2005.074112. ISSN 1355-6037.
- ↑ Bonow, RO.; Carabello, BA.; Chatterjee, K.; de Leon, AC.; Faxon, DP.; Freed, MD.; Gaasch, WH.; Lytle, BW.; Nishimura, RA. (2008). "2008 Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease): endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons". Circulation. 118 (15): e523–661. doi:10.1161/CIRCULATIONAHA.108.190748. PMID 18820172. Unknown parameter
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