TAVR Patient selection

# Overview
Patient selection is critical prior to performance of transcatheter aortic valve implant (TAVI). TAVI candidates must have severe aortic stenosis with a contraindication(s) to surgery.  The patients selected for this procedure should have a potential for functional improvement after valve replacement.  Selection criteria depend on thorough evaluation of the aortic valve, mitral valve, ejection fraction, vascular access and coronary angiography.  A thorough echocardiographic evaluation of the aortic valve is necessary to determine the valve area, calcification, peak velocity, the transvalvular gradient and aortic annulus size. Aortic incompetence should be assessed as well since more than moderate aortic incompetence before the procedure is a contraindication for TAVI.  Tortuosity, calcification and minimal luminal diameter of the aorta, iliac and femoral arteries would also influence patient selection and the technical approach used during the procedure.
TAVR potential candidates should be assessed for AS symptoms and severity, baseline clinical situation, cardiac comorbidities and non-cardiac comorbidities. In addition functional assessment is a key step for patient evaluation.

# Patient selection

## Initial assessment

## Functional Assessment
Abbreviations:
BMI: body mass index; CV: cardiovascular; MMSE: mini mental state examination; MNA: mini nutritional assessment.

### Frailty
- Evaluation for frailty, physical function and independence in the activities of daily living (ADL) such as, feeding, bathing, toileting and transferring).
- Evaluation should be start with screening for independence, cognition and slow walking speed (gait speed, 3 timed trials over a 5 meter distance).
- Those with gait speed over 0.83 m/s, preserved cognition and independence are likely not frail.

### Physical functioning
To assess the physical functioning, the 6 minute walk test should be done. It is possible to perform this test in outpatient setting.

### Cognitive Functioning
The Mini Mental Status Examination (MMSE) is utilized to assess the cognitive status and scores less than 24 are considered as abnormal. Also, evaluation for depression must be done by using a validated tool such as, the Center for Epidemiologic Studies Depression Scale.

### Futility
Those patients with <1 year life expectancy and who has a chance of survival with benefit of <25% at 2 years. 
Survival with benefit means, survival with improvement by at least 1 New York Heart Association class in heart failure or by at least 1 Canadian Cardiovascular Society class angina symptoms, improvement in quality of life or improvement in life expectancy.

## Risk Assessment
Underlying risk for SAVR is basic component to consider patient for TAVR. This risk assessment is based on several components that include:
- The Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score. To calculate this score please click here.
- Frailty
- Main organ system dysfunction
- Procedure-specific impediments
 Seven frailty indices include: Katz Activities of Daily Living (independence in feeding, bathing, dressing, transferring, toileting,and urinary continence) and independence in ambulation (no walking aid or assist required or 5-meter walk in <6 s).
 Examples of major organ system compromise:
- Cardiac: severe LV systolic or diastolic dysfunction or RV dysfunction, fixed pulmonary hypertension
- CKD stage 3 or worse
- Pulmonary dysfunction with FEV1 <50% or DLCO <50% of predicted
- CNS dysfunction (dementia, Alzheimers disease, Parkinsons disease, CVA with persistent physical limitation)
- GI dysfunction: Crohns disease, ulcerative colitis, nutritional impairment, or serum albumin <3.0
- Cancer: active malignancy
- Liver: any history of cirrhosis, variceal bleeding, or elevated INR in the absence of VKA therapy.
 Examples: tracheostomy present, heavily calcified ascending aorta, chest malformation, arterial coronary graft adherent to posterior chest wall, or radiation damage.

## Integrated Benefit-risk of TAVR and Shared Decision-making