Aortic Valve Stenosis and TAVR: Putting it all together. Maria L. Held, MSN CNS Valve Clinic Coordinator at The Cleveland Clinic Alliance of Cardiovascular Professionals April 14 th, 2018
Brief Anatomy Review
Occurrence It is estimated that 2.5 million people in the US over 75 suffer from the disease. This number will more than double between now and 2050 to almost 80 million people. Unfortunately, about 60% of patients that have aortic stenosis are untreated and cannot have surgery due to demand. Stenosis of a bicuspid aortic valve typically occurs at an earlier age (fifth to sixth decade) than does tricuspid valve stenosis (seventh to eighth decade) because 2 cusps, instead of 3, are forced to absorb the shearing stress of blood flow leaving the left ventricle.
What is Aortic Stenosis (AS)? Mechanical stress or disease causes the normal cells of the valve leaflets to transform from a normal state of maintenance and repair to a state where myofibroblasts and osteoblasts develop, promoting calcification. calcium nodules located within the layers of the leaflet bulge outward, causing restricted leaflet motion.
Causes of AS Mechanical Stress: blood crossing the aortic valve damages membrane of the leaflets. Disease: rheumatoid arthritis, chronic inflammatory diseases, lupus, syphilis, hypertension, aortic aneurysms, connective tissue diseases, some types of chemotherapy drugs and radiation for cancers
Diagnosis ECHO is primary diagnostic tool. Based upon 3 parameters: aortic jet velocity, mean aortic valve pressure gradient, and aortic valve area. Graded as: mild, moderate or severe Can also have low flow, low gradient AS (Stroke volume index) Movement of the leaflets is critical in diagnosis
Pathology of AS Aortic stenosis is considered hemodynamically important when the valve area is less than 1.0 cm2 The degree of obstruction resulting in signs and symptoms is widely variable. AS can be defined as follows: the degree of valve obstruction at which symptoms occur from the obstruction.
Signs and Symptoms Aortic stenosis can present with various symptoms which can often be associated with other conditions. Symptoms include: shortness of breath, especially on exertion chest pain dizziness and/or fainting palpitations noticeable decline in activity level.
Treatment options for AS Medical management mostly consist of treating associate symptoms ( volume overload, blood pressure management, etc) SAVR TAVR Palliative management
STEP I: Pre-Screening Review
STEP II: High Risk AVR Evaluation - Pt Expectations
High Risk AVR Evaluation Pathway
STEP II: Evaluation Any patient that is diagnosed with aortic valve stenosis should be treated as a potential surgical evaluation. The surgical evaluation includes comprehensive testing and consultation with cardiologists and surgeons.
Diagnostic Evaluation : Key Studies Echocardiography (Transthoracic and/or TEE) Dobutamine Stress Echo (when appropriate) CT Angiography Chest/Abd/Pelvis (GFR > 45) Cardiac MRI + Noncontrast CTA (GFR < 45) Cardiac Catheterization/ Coronary Angiography Right Heart Catheterization Pulmonary function testing Carotid artery ultrasound
Diagnostic Evaluation: Additional Studies
Step II: HR AVR Evaluation - Functional Assessment Quality of life is important in deciding treatment options for patients Current functional state (ambulatory, living situation, etc) Frailty assessment KATZ activities of daily living check list, grip strength test, 15 foot walk and albumin Frailty is linked to poor outcomes for the traditional surgical patient A score of 1 or more on the frailty assessment can elevate one s STS score.
Surgical Risk Assessment STS score Calculates mortality/morbidity for patients about to undergo traditional open heart surgery. Fails to capture certain comorbidities such as: pulmonary hypertension, cirrhosis, anemias, mental status, anatomical parameters (porcelain aorta, MAC), and Frailty
Step II: HR AVR Evaluation Surgical Risk Assessment STS Score Surgical Risk Treatment Options 4%-8% Intermediate risk SAVR or TAVR 8%-15% High Risk TAVR >15% Extreme risk TAVR or medical management
Step IV: Heart Valve Team Consensus
TAVR Procedure Approach needs to be determined. Transfemoral (TF) is the primary route. Alternative approaches: subclavian, transaortic or transapical Typically performed in a hybrid OR ( cardiothoracic OR with fluoroscopy) TF approach can be done with conscious sedation Alternative access requires general anesthesia
Current 2 approved devices in the United States Edwards Sapien (S3) Bovine Tissue Medtronic Evolute-R Porcine Tissue
Procedure
Risks of TAVR (Based upon the national TVT registry) Bleeding Stroke Pacemaker Major organ failure Death (<1%)