TAVI Treatment: Minimally Invasive Aortic Valve Replacement

What is Aortic Valve Disease?

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The aortic valve is the “door” between the heart’s left ventricle and the aorta, the body’s main artery. It ensures that blood flows in the correct direction as it’s pumped from the heart to the rest of the body. A normal aortic valve consists of three leaflets (tricuspid) that open and close with perfect synchronization with each heartbeat. Over time, however, this valve can deteriorate for various reasons, leading to two main problems:

Aortic Stenosis (Aortic Valve Narrowing)

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Definition and Mechanism:

Aortic stenosis is a condition where the valve becomes stiff, calcified, and unable to open fully. Calcium deposits form on the valve leaflets, restricting their movement. As a result, the area through which blood can flow narrows, and the heart has to work much harder to pump blood through this narrowed valve.

Causes:

• Age-Related Degenerative Aortic Stenosis: The most common cause in people over 65. Over the years, wear and tear, along with calcium buildup, develops on the valve leaflets.
• Bicuspid Aortic Valve: A congenital anomaly where the valve has two leaflets instead of the normal three. These patients typically develop aortic stenosis earlier, in their 40s or 50s.
• Rheumatic Heart Disease: Scar tissue forms on the valve leaflets following rheumatic fever, leading to narrowing over time. This remains an important cause in developing countries.

Symptoms:

Aortic stenosis usually progresses slowly and may not cause symptoms for a long time. However, when the narrowing becomes severe, the following symptoms appear:

• Shortness of Breath (Dyspnea): Especially with exertion, climbing stairs, or walking
• Chest Pain (Angina): Due to the heart muscle not receiving enough blood
• Fainting or Dizziness (Syncope): Especially during exercise, resulting from insufficient blood flow to the brain
• Fatigue and Weakness: The body not receiving adequate blood supply
• Heart Failure Symptoms: In advanced stages, shortness of breath, leg swelling, difficulty breathing while lying down at night

Aortic Regurgitation (Aortic Valve Insufficiency)

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Definition:

Aortic regurgitation occurs when the valve doesn’t close properly, allowing some blood to leak back into the heart instead of being pumped out to the body. This causes the heart to work harder and eventually enlarge over time.

Causes:

• Degeneration of valve leaflets
• Enlargement of the aortic root (aortic aneurysm)
• Infective endocarditis (valve infection)
• Rheumatic heart disease
• Trauma or aortic dissection

Symptoms:

• Palpitations (especially when lying down)
• Shortness of breath
• Fatigue
• Chest pain
• Ankle swelling

The Importance of Aortic Valve Disease

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If left untreated, these diseases lead to heart failure, sudden death, and a significant decline in quality of life. Patients with severe aortic stenosis have an average life expectancy of 2-3 years after symptoms begin. Therefore, early diagnosis and appropriate treatment are vital. TAVI is a revolutionary treatment option, especially for patients with severe aortic stenosis who are at high surgical risk.

What is TAVI?

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TAVI (Transcatheter Aortic Valve Implantation), also known as TAVR (Transcatheter Aortic Valve Replacement), is a procedure where a new biological aortic valve is delivered to the heart and placed inside the diseased native valve. This is done without opening the chest, typically through an artery in the groin (the femoral artery), using a catheter.

History and Development of TAVI

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First performed by French cardiologist Alain Cribier in 2002, TAVI was initially a beacon of hope only for patients at very high risk for open-heart surgery. At that time, many elderly patients were experiencing symptoms due to severe aortic stenosis but could not be treated because their surgical risk was too high.

Technological Advancement:

TAVI technology has shown incredible development over the past 20 years:

• First Generation Valves (2002-2010): Larger catheters, higher complication risk
• Second Generation Valves (2011-2015): Smaller catheters, better deployment, reduced complications
• Third and Fourth Generation Valves (2016-present): Very small catheters, repositionable valves, minimal paravalvular leak

Clinical Trials:

Major clinical trials have proven the effectiveness of TAVI:

• PARTNER Trial: Showed that TAVI is as effective as surgery in high-risk patients
• CoreValve Trial: Demonstrated that TAVI is safe and effective in intermediate-risk patients
• NOTION and PARTNER 3 Trials: Revealed that TAVI provides results as good as surgery even in low-risk patients

Today, TAVI has become a standard and safe treatment for intermediate and even low-risk patients. This method eliminates the challenges associated with traditional surgery, such as a large incision, general anesthesia, and a long recovery period.

TAVI Valve Types

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Balloon-Expandable Valves:

• Edwards SAPIEN series (SAPIEN 3, SAPIEN 3 Ultra)
• Valves deployed by inflating a balloon
• More precise deployment control
• Generally lower risk of conduction block

Self-Expanding Valves:

• Medtronic CoreValve, Evolut series
• Boston Scientific ACURATE neo
• Made from nitinol (nickel-titanium) alloy
• Self-expands at body temperature
• Repositionable feature

Both valve types have biological leaflets made from bovine or porcine pericardium (heart sac tissue) and demonstrate excellent hemodynamic performance.

Who is Eligible for TAVI?

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Patient selection for TAVI is conducted by a multidisciplinary “Heart Team,” which includes a cardiologist, a heart surgeon, an anesthesiologist, and imaging specialists. Each patient is evaluated in detail. Generally, the patient groups who are candidates for TAVI include:

• High Surgical Risk Patients: Those of advanced age (typically over 80), patients with other organ failures (like lung or kidney disease), or those who have had previous heart surgery.
• Intermediate Surgical Risk Patients: A group whose surgical risk is neither very high nor very low. Recent studies have shown TAVI to be at least as effective and safe as surgery in this group.
• Low Surgical Risk Patients: TAVI is increasingly being considered for younger, low-risk patients, especially those with specific anatomical conditions or who prefer a minimally invasive treatment.

Contraindications (When it’s not performed):

• Very short life expectancy
• Presence of an active infection
• Anatomical obstacles (unsuitable blood vessel pathways)

How is TAVI Performed?

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The TAVI procedure is performed in a sterile, high-tech environment like a hybrid operating room or a catheterization lab. The steps of the procedure are generally as follows:

1. Anesthesia: The procedure is usually performed under sedation (a state of deep sleep) and local anesthesia, rather than general anesthesia. This allows the patient to have a more comfortable experience and wake up faster.
2. Access Route: The most common and least invasive method is the transfemoral approach. The surgeon makes a small incision in the artery in the groin. If this artery is not suitable, alternative routes such as transapical (through a small incision in the chest wall at the heart’s apex), transaortic (through the front of the chest), or subclavian (under the collarbone) may be used.
3. Catheter Advancement: A thin tube (catheter) is inserted through the access point and advanced through the blood vessels to the heart’s aortic valve. This entire process is visualized in real-time using fluoroscopy (a type of X-ray) and echocardiography.
4. Valve Placement: The compressed new biological valve, located inside the catheter, is precisely positioned within the diseased valve. The valve is then deployed either by inflating a balloon (for balloon-expandable valves) or by self-expansion (for self-expanding valves).
5. Final Checks: Once the new valve is in place, its function is checked with echocardiography and angiography. The team checks for any leaks, and then the catheters are withdrawn and the access site is closed.

The procedure typically lasts between 1 and 2 hours.

TAVI vs. Open-Heart Surgery

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Pre-TAVI Preparation

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Pre-TAVI preparation is crucial for proper patient selection and a successful procedure. The following steps are taken during this process:

• Multidisciplinary Heart Team Evaluation: The patient’s overall condition, risks, and suitability for TAVI are discussed.
• Echocardiography (Echo): Performed both on the chest (transthoracic) and through the esophagus (transesophageal) to examine heart function and valve structure in detail.
• Computed Tomography (CT) Angiography: This is the most critical step in TAVI planning. The diameter of the aortic valve and the width and angles of the arteries (aorta and leg arteries) are measured in 3D. This scan determines the correct valve size and the most suitable access route.
• Cardiac Catheterization (Angiography): This is done to check for any blockages in the coronary arteries. If a significant blockage is found, a stenting procedure may be required before or during the TAVI session.
• Blood Tests and Pulmonary Function Tests: These are requested to assess the patient’s overall health status.

Post-TAVI Recovery

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One of the greatest advantages of TAVI is the rapid recovery process.

• Hospital Stay: Patients are typically discharged within 1-3 days after the procedure.
• Intensive Care: Most patients are monitored in the intensive care unit for a short period (a few hours) post-procedure before being moved to a regular room.
• Activity: Patients can usually get out of bed and start walking the day after the procedure.
• Return to Normal Life: Most patients can return to their normal daily activities within 1-2 weeks. Activities like driving and light exercise can be resumed with the doctor’s approval.

Advantages of TAVI

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• Minimally Invasive: No large surgical incision.
• Fast Recovery: Hospital stay and return to normal life are much shorter.
• Less Pain: Pain and discomfort are minimal compared to surgery.
• Lower Surgical Risk: A safer option, especially for the elderly and those with comorbidities.
• Avoids General Anesthesia Risks: Can often be performed with sedation.

Risks and Complications

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Although TAVI is a very safe procedure, like any medical intervention, it carries some risks:

• Vascular Complications: Bleeding, vessel damage, or clotting at the access site (usually the groin).
• Paravalvular Leak (PVL): A small amount of blood leaking around the edges of the new valve. It is usually mild and may decrease over time.
• Heart Rhythm Disorders: New-onset conduction blocks can occur post-procedure, and some patients (5-15%) may require a permanent pacemaker.
• Stroke: A rare but serious complication that can occur if a clot or piece of calcification travels to the brain during the procedure. Protective devices can be used to reduce this risk.
• Kidney Injury: Temporary kidney damage can occur, especially related to the contrast dye used.

Success Rates and Long-Term Outcomes

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The procedural success rate for TAVI is now over 95%. This impressive success rate has continuously increased over the years with technological advancement and operator experience.

Clinical Trial Results

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Short-Term Outcomes (30 Days):

• Procedural success rate: 95-98%
• Hospital mortality: 1-3% (in high-risk patients)
• Major complication rate: 5-10%
• Average hospital stay: 2-4 days

Mid-Term Outcomes (1 Year):

• 1-year survival: 85-90% (in high-risk patients)
• Symptom improvement: Over 90%
• Significant improvement in quality of life
• Increased functional capacity (improvement in NYHA class)

Long-Term Outcomes (5-10 Years):

• 5-year survival: 60-70% (in high-risk patients), 80-85% (in low-risk patients)
• 10-year survival: 40-50% (in high-risk patients)
• Preservation of valve function: Over 90%

Valve Durability

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Regarding valve durability, 10-15 years of data from the first-generation valves are very promising:

• Structural Valve Degeneration: Less than 5% at 10 years
• Valve Function: Excellent hemodynamic performance continues in most patients
• New Generation Valves: Expected to last even longer due to better design and materials

Quality of Life Improvement

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Patients report dramatic improvements in quality of life after TAVI:

• 80-90% reduction in shortness of breath symptoms
• Return to daily activities: Within 1-2 weeks
• Increased exercise capacity
• Preservation of ability to live independently
• Reduction in hospital admissions

Modern, new-generation valves are expected to be even more durable, and ongoing clinical studies show that the long-term outcomes of TAVI are comparable to surgery.

Life After TAVI

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To maintain a healthy life after TAVI, patients should pay attention to several points:

• Medication: Blood-thinning medications (like aspirin and clopidogrel) are usually prescribed for a period to prevent clot formation.
• Follow-up: It is important for patients to have a cardiology check-up and an echocardiogram at 1 month, 6 months, 1 year, and then annually thereafter.
• Endocarditis Prophylaxis: To prevent infective endocarditis (inflammation of the heart’s inner lining), prophylactic antibiotics are recommended before certain surgical procedures, such as dental extractions.
• Lifestyle: Heart-friendly lifestyle changes, such as a healthy diet, regular exercise, and smoking cessation, should be adopted.

Frequently Asked Questions (FAQ)

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When Should You See a Doctor?

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Aortic valve diseases can be treated much more successfully when diagnosed early. You should consult a cardiology specialist without delay in the following situations:

Emergency Situations:

• Sudden onset of severe chest pain
• Inability to breathe, severe shortness of breath
• Fainting or loss of consciousness
• Bluish discoloration of lips or skin

Symptoms Requiring Evaluation:

• Shortness of breath with exertion (climbing stairs, walking)
• Chest pain or tightness
• Frequent dizziness or feeling faint
• Palpitations or irregular heartbeats
• Fatigue and weakness (difficulty performing daily activities)
• Ankle swelling
• Shortness of breath while lying down at night

Screening if Risk Factors Present:

• Individuals over 65 years of age
• Those with a known heart murmur
• Those diagnosed with a bicuspid aortic valve
• Those with a family history of aortic valve disease
• Those who have had rheumatic fever

Conclusion

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TAVI is one of the most significant advancements in cardiology in the last two decades. It has offered hope to thousands of patients with severe aortic stenosis, especially those at high risk for open-heart surgery. With less pain, faster recovery, and high success rates, TAVI is a life-saving procedure that rapidly improves patients’ quality of life.

Modern TAVI technology, new-generation valves, and experienced Heart Teams have continuously increased the success rates of the procedure. Today, TAVI has become a safe and effective treatment option not only for high-risk patients but also for intermediate and even low-risk patients.

If you or a loved one has aortic stenosis, do not hesitate to be evaluated by a Heart Team to find out if TAVI is a suitable option for you. With early diagnosis and appropriate treatment, you can regain your quality of life and lead an active life.

Make an Appointment

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To get detailed information about your aortic valve disease, find out if you are a candidate for the TAVI procedure, and for a comprehensive evaluation, you can make an appointment.