Symptoms

Symptoms Indicating the Need for Heart Valve Replacement

Heart valve issues can lead to a range of symptoms that may indicate the need for valve repair or replacement. Recognizing these symptoms early can help in seeking timely medical intervention. Here are the common signs:

1. Shortness of Breath
   • Difficulty breathing, especially during physical activity or when lying flat, is a common symptom as the heart struggles to maintain efficient blood flow.
2. Fatigue and Weakness
   • Persistent tiredness or an overall feeling of exhaustion that makes everyday activities difficult or impossible.
3. Chest Pain or Discomfort
   • Pain or pressure in the chest, which can worsen with exertion and may be a sign of reduced blood flow due to valve dysfunction.
4. Heart Palpitations
   • Rapid, fluttering, or irregular heartbeats that may feel as though the heart is racing or skipping beats.
5. Swelling (Edema)
   • Buildup of fluid in the legs, ankles, feet, or abdomen, indicating that the heart is not effectively pumping blood.
6. Dizziness or Fainting (Syncope)
   • Lightheadedness or episodes of fainting, which can occur when there is a sudden drop in blood pressure or inadequate blood flow to the brain.
7. Coughing or Wheezing
   • A persistent cough or wheezing, sometimes with blood-tinged mucus, caused by fluid accumulation in the lungs.
8. Rapid Weight Gain
   • Sudden weight gain due to fluid retention, which can be a sign that the heart is unable to handle the volume of blood returning from the body.
9. Reduced Exercise Tolerance
   • Difficulty maintaining stamina or performing activities that were once manageable, due to decreased heart function.
10. Bluish or Pale Skin (Cyanosis)
    • Skin that appears blue or pale, especially in the fingers, lips, or toes, indicating poor oxygenation due to inadequate blood flow.

When to Seek Medical Attention

If any of these symptoms are present and are persistent or worsening, it is important to consult with a cardiologist. Early diagnosis and treatment of heart valve issues can prevent more severe complications and improve quality of life.

Risk Factors

Risk Factors for Heart Valve Disease Leading to Replacement

Understanding the risk factors associated with heart valve disease is crucial for early detection and prevention. Here are the key risk factors:

1. Age
   • Increased Risk with Age: As people age, the heart valves may thicken or stiffen, leading to valve dysfunction. Most heart valve issues requiring replacement are seen in individuals over 60 years old.
2. Congenital Heart Defects
   • Born with Valve Abnormalities: Some people are born with malformed or abnormal heart valves, which can lead to issues that require surgical correction later in life.
3. Rheumatic Fever
   • History of Rheumatic Fever: This illness, which can develop after untreated strep throat, may cause scarring and damage to the heart valves, increasing the risk of valve disease.
4. Infections
   • Endocarditis: A serious infection of the inner lining of the heart (endocardium), often caused by bacteria, can damage or destroy heart valves and necessitate replacement.
5. High Blood Pressure and Heart Disease
   • Hypertension and Coronary Artery Disease: These conditions can cause the heart to work harder than normal, leading to valve damage over time.
6. High Cholesterol
   • Atherosclerosis Risk: Elevated cholesterol levels contribute to plaque buildup in the arteries and can extend to valve tissue, causing thickening and reduced function.
7. Aortic Aneurysm
   • Weakened Aorta: An enlarged or weakened aorta can affect the aortic valve and lead to complications that might require valve replacement.
8. Lifestyle Factors
   • Unhealthy Habits: Smoking, excessive alcohol consumption, poor diet, and lack of exercise can contribute to overall heart health decline and valve issues.
   • Obesity: Being overweight places extra stress on the heart and can accelerate valve wear.
9. Previous Heart Attack
   • Impact on Valve Function: A past heart attack can weaken the heart’s muscles and valves, leading to regurgitation or stenosis that may require surgical intervention.
10. Radiation Therapy
    • Radiation Exposure: Those who have undergone radiation treatment to the chest area for conditions like cancer may have an increased risk of heart valve damage.
11. Connective Tissue Disorders
    • Conditions like Marfan Syndrome: Certain genetic conditions affect the body’s connective tissue and can lead to issues with valve structure and function.
12. Chronic Conditions
    • Diabetes and Chronic Kidney Disease: These conditions can increase the risk of developing heart valve problems due to their impact on overall cardiovascular health.

Mitigating Risk Factors

• Healthy Lifestyle Choices: Adopting a heart-healthy diet, maintaining a healthy weight, exercising regularly, and avoiding tobacco can reduce the risk of heart valve disease.
• Regular Check-Ups: Monitoring blood pressure, cholesterol, and heart health with regular medical check-ups can help detect and manage risk factors early.
• Managing Chronic Conditions: Keeping conditions like diabetes and hypertension under control with medication and lifestyle changes can reduce the impact on heart valves.

Conclusion

Awareness and proactive management of these risk factors can help prevent the progression of heart valve disease and reduce the likelihood of needing valve replacement surgery. Early intervention and preventive care are essential for maintaining heart health and minimizing the impact of these risks.

Prepration of Surgery

Preparation for Heart Valve Replacement Surgery

Proper preparation for heart valve replacement surgery is essential to ensure a smooth and successful procedure. Here is a step-by-step guide on how to prepare for the surgery:

1. Comprehensive Medical Evaluation
   • Initial Assessments: A full medical history and physical examination are conducted to assess the patient’s overall health.
   • Diagnostic Tests: These may include echocardiograms, chest X-rays, cardiac catheterization, and blood tests to determine the condition of the heart and valves.
   • Specialist Consultations: Meetings with cardiologists, surgeons, and anesthesiologists to discuss the details of the surgery, potential risks, and expected outcomes.
2. Medication Review and Management
   • Current Medications: The patient’s current medications will be reviewed to avoid any potential complications during surgery. Some medications, especially blood thinners, may need to be paused or adjusted.
   • New Prescriptions: In some cases, pre-surgery medications such as antibiotics or anticoagulants may be prescribed to prevent infection and manage clotting risks.
3. Lifestyle Adjustments
   • Dietary Recommendations: Patients may be advised to follow a heart-healthy diet that is low in sodium and saturated fats to optimize heart function leading up to the surgery.
   • Smoking and Alcohol Cessation: Patients should stop smoking and limit alcohol intake well before surgery to reduce surgical and post-operative risks.
   • Exercise Guidance: Light exercise may be recommended to improve physical conditioning, but strenuous activities should be avoided.
4. Pre-Surgery Instructions
   • Fasting: Patients are usually required to avoid eating or drinking for at least 8-12 hours before surgery.
   • Pre-Surgery Cleaning: Special antiseptic washes or wipes may be given to reduce the risk of infection.
   • Hospital Admission Plan: Patients are admitted to the hospital either the day before or the morning of the surgery, depending on hospital protocol.
5. Psychological Preparation
   • Counseling and Support: Some patients may benefit from speaking with a counselor or joining support groups to manage anxiety or emotional concerns about the surgery.
   • Family Involvement: Encouraging family members to participate in pre-surgery discussions helps them understand the process and provide emotional support.
6. Logistics and Arrangements
   • Transportation Planning: Arrange for transportation to and from the hospital.
   • Accommodation for Family Members: For international or out-of-town patients, making accommodation arrangements for accompanying family members is recommended.
   • Financial Planning: Confirm payment plans, insurance coverage, and other financial aspects to ensure a stress-free process.
7. Consent and Documentation
   • Informed Consent: Patients will need to sign consent forms acknowledging their understanding of the procedure, potential risks, and outcomes.
   • Medical Records: Ensure that all necessary documents, including identification and medical records, are readily available.

Day of the Surgery

• Arrival and Preparation: Patients arrive at the hospital as instructed and are prepped for surgery, including placement of IV lines and administration of pre-anesthesia medications.
• Anesthesia Preparation: The anesthesiologist will discuss the anesthesia plan and begin the process to ensure the patient is fully unconscious during surgery.
• Final Review: The surgical team performs a final check to ensure all pre-surgery protocols have been met.

Conclusion

Adequate preparation for heart valve replacement surgery helps minimize risks and sets the stage for a smoother surgical process and recovery. Following medical advice and adhering to preparation guidelines are key to a successful outcome.

Procedure

Heart Valve Replacement Surgery Procedure

Heart valve replacement is a surgical procedure to replace a damaged heart valve with an artificial or biological valve. The surgery can be performed using traditional open-heart methods or minimally invasive techniques. Here is a step-by-step outline of the procedure:

1. Pre-Surgery Preparation
   • Anesthesia: The patient is given general anesthesia to ensure they remain unconscious and pain-free during the procedure.
   • Monitoring Equipment: The patient is connected to monitoring devices that track vital signs, including heart rate, blood pressure, and oxygen levels.
2. Incision and Access
   • Open-Heart Surgery: A median sternotomy is performed, where the surgeon makes a vertical incision along the chest and separates the breastbone to access the heart.
   • Minimally Invasive Surgery: Small incisions are made between the ribs for specialized instruments and a camera, if applicable.
3. Connecting to the Heart-Lung Machine
   • Cardiopulmonary Bypass: The patient is connected to a heart-lung machine that takes over the function of the heart and lungs, maintaining blood circulation and oxygenation throughout the surgery.
4. Stopping the Heart
   • The heart is temporarily stopped using a solution of cold potassium to allow the surgeon to work on the valve without blood flow interference.
5. Valve Replacement
   • Removal of the Damaged Valve: The surgeon carefully removes the damaged valve.
   • Insertion of the New Valve: A prosthetic or biological valve is placed and secured in position using sutures. The type of valve used depends on the patient’s condition and the surgeon’s recommendation:
     • Mechanical Valves: Made of durable materials and can last a lifetime but require lifelong blood-thinning medication.
     • Biological Valves: Made from animal tissue or donated human tissue; they do not usually require lifelong blood thinners but may need to be replaced after 10-20 years.
6. Restarting the Heart
   • Once the valve is in place, the heart is restarted. The heart-lung machine is gradually withdrawn as the new valve begins to function and the heart resumes pumping.
7. Checking for Proper Function
   • The surgical team ensures that the new valve is functioning correctly and that there are no leaks or issues with blood flow.
8. Closing the Incision
   • Sternum Closure: If open-heart surgery was performed, the breastbone is rejoined and secured with surgical wires.
   • Skin Closure: The skin is sutured or stapled, and a sterile dressing is applied to protect the incision site.
   • Drain Tubes: Temporary tubes are placed to drain any excess fluid from the chest and prevent buildup.

Post-Surgery Process

1. Transfer to ICU: The patient is moved to the intensive care unit (ICU) for close monitoring and support as they recover from anesthesia.
2. Ventilator Support: The patient may remain on a ventilator for several hours or a day to assist with breathing.
3. Pain Management: Pain medications are provided to ensure patient comfort during the initial recovery period.

Recovery and Monitoring

• Initial Hospital Stay: The patient typically stays in the hospital for 5-7 days, depending on recovery progress.
• Physical Therapy: Rehabilitation and light physical activity are gradually introduced to help regain strength.
• Follow-Up Appointments: Regular check-ups are scheduled to monitor heart function and ensure the new valve is working effectively.

Potential Risks

• Bleeding: Can occur during or after surgery.
• Infection: The risk of infection at the incision site or within the heart.
• Blood Clots: May lead to stroke or other complications.
• Valve Dysfunction: Rarely, the new valve may not function properly and require additional treatment.

Conclusion

Heart valve replacement surgery is a complex but highly successful procedure that can significantly improve a patient’s quality of life and heart function. Proper preparation, skilled surgical techniques, and diligent post-operative care contribute to positive outcomes and long-term health benefits.

Post Procedure

Post-Procedure Care After Heart Valve Replacement Surgery

The recovery phase following heart valve replacement surgery is crucial for ensuring a successful outcome and long-term heart health. Here is what patients can typically expect after the procedure:

1. Immediate Post-Surgery Care
   • ICU Monitoring: Patients are taken to the intensive care unit (ICU) immediately after surgery for continuous monitoring. This period usually lasts 1-2 days, during which vital signs, heart function, and fluid levels are closely observed.
   • Ventilator Support: The patient may be connected to a ventilator for several hours or overnight to assist with breathing until they are stable enough to breathe on their own.
   • Pain Management: Medications are provided to manage pain and ensure patient comfort.
2. Hospital Recovery
   • Transfer to a Standard Recovery Room: Once stable, the patient is moved to a regular hospital room to continue recovery. The stay in this phase typically lasts 3-5 days.
   • Wound Care: The surgical incision is monitored and kept clean to prevent infection. Dressings may be changed regularly, and sutures or staples are inspected.
   • Physical Therapy: Patients are encouraged to start moving and walking with assistance to prevent complications such as blood clots and to help regain strength.
   • Monitoring for Complications: Nurses and doctors will monitor for any signs of infection, blood clots, or valve dysfunction.
3. Medication Management
   • Anticoagulants: Patients who receive mechanical valves will need lifelong blood-thinning medication to prevent blood clots. Those with biological valves may require anticoagulants for a shorter period.
   • Immunosuppressants and Antibiotics: Depending on the patient’s condition, medications to prevent infection or manage immune response may be prescribed.
   • Pain Relievers and Other Supportive Medications: Prescribed as needed for pain control and overall comfort.
4. Initial Post-Operative Follow-Ups
   • Regular Monitoring: Blood tests and echocardiograms may be conducted to assess the functioning of the new valve and monitor for any signs of complications.
   • Stitch or Staple Removal: Typically done within the first 1-2 weeks after surgery, during a follow-up visit.
5. Rehabilitation and Lifestyle Adjustments
   • Cardiac Rehabilitation: Enrolling in a cardiac rehabilitation program helps patients regain strength, learn heart-healthy habits, and improve overall cardiovascular health. This program typically includes guided exercise routines, nutrition counseling, and lifestyle coaching.
   • Diet and Nutrition: A heart-healthy diet low in sodium and saturated fats is recommended to support recovery and prevent future heart issues.
   • Physical Activity: Light activities and exercises are gradually introduced as the patient’s condition allows. Strenuous activities should be avoided until cleared by the doctor.
6. Long-Term Care and Monitoring
   • Regular Check-Ups: Scheduled follow-up appointments are essential to monitor the valve’s function and overall heart health. This helps detect any early signs of issues or complications.
   • Ongoing Medication Review: Medications may be adjusted based on the patient’s response and any side effects experienced.
   • Lifestyle Changes: Continued adherence to a healthy lifestyle, including not smoking, maintaining a healthy weight, and managing chronic conditions such as diabetes or high blood pressure, is important for long-term heart health.
7. Signs to Watch For
   • Emergency Symptoms: Patients are advised to seek immediate medical attention if they experience signs of complications, such as sudden shortness of breath, chest pain, irregular heartbeats, fever, or significant swelling.
   • Routine Concerns: Mild discomfort, fatigue, and a slight increase in body temperature are normal initially but should be monitored if they persist or worsen.
8. Emotional and Psychological Support
   • Mental Health: It is common to experience emotional changes or anxiety post-surgery. Patients are encouraged to seek support from counselors or join support groups to manage their mental well-being.
   • Family Involvement: Family members are encouraged to participate in the patient’s recovery process to provide support and motivation.

Expected Recovery Timeline

• Initial Recovery: 4-6 weeks for basic recovery and return to light daily activities.
• Full Recovery: Most patients feel stronger and more capable within 2-3 months and may return to normal activities, depending on individual progress and doctor’s clearance.

Conclusion

Post-procedure care after heart valve replacement is as crucial as the surgery itself. Adhering to medical advice, taking prescribed medications, attending follow-up visits, and making lifestyle adjustments contribute to a successful recovery and long-term health. With proper care, most patients enjoy improved quality of life and heart function.

Cost Breakup

Cost Breakup for Heart Valve Replacement Treatment

Heart valve replacement involves various components, including pre-surgery evaluations, the surgical procedure, and post-operative care. Below is a detailed cost breakdown for heart valve replacement treatment within the price range of $10,000 to $15,000.

1. Pre-Surgery Costs

• Medical Evaluations and Consultations: $1,000 – $2,000 USD
  Consultations with cardiologists and cardiac surgeons to assess the patient’s condition and develop a treatment plan.
• Diagnostic Tests: $1,500 – $3,000 USD
  Includes echocardiograms, ECGs, blood tests, and imaging (CT or MRI) to evaluate heart function and plan for surgery.
• Preoperative Medications: $300 – $500 USD
  Medications prescribed to prepare the patient for surgery and manage existing health conditions.

2. Surgery Costs

• Surgical Fees: $3,000 – $5,000 USD
  Covers the fees for the cardiac surgeon, anesthesiologist, and surgical team.
• Operating Room Charges: $2,000 – $3,000 USD
  Use of the surgical room and specialized heart surgery equipment.
• Anesthesia: $1,000 – $2,000 USD
  Administration and monitoring of anesthesia during the procedure.

3. Hospital Stay and Immediate Postoperative Care

• ICU Stay (2-5 Days): $1,500 – $3,000 USD
  Intensive monitoring immediately after surgery for stabilization.
• General Ward Stay (5-7 Days): $1,000 – $2,000 USD
  Room charges, nursing care, and routine monitoring during recovery.
• Postoperative Medications: $800 – $1,500 USD
  Includes anticoagulants, antibiotics, and other medications to prevent complications.
• Pain Management: $300 – $500 USD
  Pain relief and supportive treatments during the recovery phase.

4. Follow-Up Care and Long-Term Medications

• Initial Follow-Up Visits (First 3-6 Months): $500 – $1,000 USD
  Regular check-ups to monitor recovery and heart function.
• Rehabilitation and Physical Therapy: $500 – $1,000 USD
  Guided rehabilitation sessions to help the patient regain strength and improve cardiac health.

5. Miscellaneous Costs

• Travel and Accommodation for Family Members: $300 – $500 USD (optional)
  Lodging and travel expenses for family members accompanying the patient.
• Support Equipment: $200 – $300 USD
  Equipment such as heart monitors or mobility aids needed during recovery.
• Dietary and Nutritional Counseling: $100 – $200 USD
  Dietitian support to ensure proper nutrition during recovery.

Total Estimated Cost

• Minimum Cost: $10,000 USD
• Maximum Cost: $15,000 USD

Note: The actual cost may vary based on the hospital, specific patient needs, type of valve used (mechanical or biological), and any complications or additional services that may be required during or after treatment.

Conclusion

Heart valve replacement treatment involves various stages, each contributing to the overall cost. Understanding this cost breakdown helps patients and their families budget effectively, ensuring that all treatment aspects, from pre-surgery assessments to post-surgery care, are adequately covered for a successful outcome and recovery.

Sucess Rate

Success Rate of Heart Valve Replacement Surgery

Heart valve replacement surgery is considered a highly effective treatment for patients with severe valve disease. Advancements in surgical techniques, post-operative care, and prosthetic valve technology have significantly improved success rates. Here is an overview of the success rate:

1. Overall Success Rate
   • Immediate Post-Surgery Survival: The success rate of surviving the actual procedure and initial recovery phase is approximately 95-98%, making it a reliable and commonly performed surgery.
   • One-Year Survival Rate: More than 90-95% of patients survive the first year after surgery.
   • Five-Year Survival Rate: Approximately 85-90% of patients are alive five years post-surgery.
   • Ten-Year Survival Rate: The survival rate at ten years post-surgery is around 70-80%, depending on factors such as age, general health, and type of valve used.
2. Factors Influencing Success
   • Type of Valve: Mechanical valves tend to last longer (potentially a lifetime) but require lifelong anticoagulation therapy. Biological valves may need replacement after 10-20 years but do not typically require lifelong blood thinners.
   • Patient Age and Overall Health: Younger and healthier patients generally have better long-term outcomes. Older patients or those with other health conditions may have slightly lower success rates.
   • Surgical Expertise: The experience of the surgical team and the quality of the medical facility play a significant role in the success rate of the procedure.
   • Post-Surgery Care: Adherence to follow-up visits, medication regimens, and lifestyle changes significantly impacts the long-term success of the surgery.
3. Quality of Life Improvements
   • Symptom Relief: Most patients experience a significant reduction in symptoms such as shortness of breath, fatigue, and chest pain, leading to an improved quality of life.
   • Activity Levels: Many patients return to normal or near-normal levels of physical activity and daily functioning within a few months of recovery.
4. Risk of Complications
   • Low Complication Rates: While there is a risk of complications such as blood clots, infection, or valve dysfunction, the rates are relatively low with proper post-operative care and monitoring.
   • Reoperation: Biological valves may need to be replaced after 10-20 years, but mechanical valves generally do not require reoperation unless complications arise.
5. Long-Term Outcomes
   • Mechanical Valves: Typically last a lifetime but require consistent anticoagulation management to prevent blood clots.
   • Biological Valves: Offer good functionality for 10-20 years and are preferred for patients who cannot take blood thinners long-term.

Conclusion

Heart valve replacement surgery has a high success rate and provides long-term benefits for patients, including improved heart function and quality of life. With advances in surgical techniques and post-operative care, most patients can expect favorable outcomes and a return to a more active lifestyle. Regular follow-up, adherence to medical advice, and a heart-healthy lifestyle are crucial for maintaining these positive results.

FAQs

FAQs About Heart Valve Replacement Surgery

1. What is heart valve replacement surgery? Heart valve replacement surgery is a procedure to replace a damaged heart valve with a new valve, either mechanical or biological, to improve heart function and alleviate symptoms of valve disease.
2. Who needs heart valve replacement surgery? Patients with severe heart valve disease, such as valve stenosis (narrowing) or regurgitation (leakage), who have symptoms that cannot be managed with medication may require valve replacement.
3. What types of valves are used in replacement surgery?

• Mechanical Valves: Made of durable materials and designed to last a lifetime but require lifelong blood-thinning medication.
• Biological Valves: Made from animal tissue (usually pig or cow) or donated human tissue. They do not typically require long-term blood thinners but may need replacement after 10-20 years.

4. How long does the surgery take? The surgery usually takes between 2 to 4 hours, depending on the complexity of the case and whether it’s an open-heart or minimally invasive procedure.
5. What is the recovery time after heart valve replacement? Initial recovery in the hospital lasts about 5-7 days, followed by 4-6 weeks of gradual recovery at home. Full recovery can take 2-3 months, including cardiac rehabilitation.
6. What are the risks associated with heart valve replacement surgery? Risks include infection, blood clots, bleeding, and valve dysfunction. However, with modern surgical techniques, these risks are relatively low.
7. Will I need to take medication after surgery? Yes, most patients will need to take medication post-surgery. Mechanical valve patients require lifelong anticoagulants, while those with biological valves may need short-term blood thinners and other medications as prescribed by their doctor.
8. How long do replacement valves last?

• Mechanical Valves: Can last a lifetime with proper management.
• Biological Valves: Typically last 10-20 years before needing replacement.

9. What lifestyle changes should I make after surgery? Patients are advised to follow a heart-healthy diet, maintain a regular exercise routine, avoid smoking, limit alcohol intake, and manage stress. These changes support heart health and improve long-term outcomes.
10. What symptoms indicate that I might need valve replacement surgery? Common symptoms include shortness of breath, fatigue, chest pain, swollen ankles, and rapid or irregular heartbeat. If these symptoms are severe or worsening, a consultation with a cardiologist is recommended.
11. Can I live a normal life after heart valve replacement surgery? Yes, most patients can return to a normal or near-normal life, including work and moderate physical activities, after full recovery. Regular follow-up visits and a commitment to a healthy lifestyle help maintain heart health.
12. How do I prepare for heart valve replacement surgery? Preparation includes diagnostic tests, consultations with a cardiologist and surgeon, medication review, and adhering to pre-surgery instructions such as fasting and stopping certain medications.
13. How soon after surgery can I return to work? Most patients can return to work within 6-8 weeks, depending on the nature of their job and their recovery progress. Light or desk work can often be resumed sooner than physically demanding tasks.
14. What should I watch for after surgery? Watch for symptoms such as fever, excessive pain, shortness of breath, or signs of infection around the incision site. If any of these occur, contact your medical provider immediately.
15. Will I need follow-up appointments after the surgery? Yes, regular follow-up appointments are essential to monitor the function of the new valve, adjust medications, and ensure there are no complications.
16. Is heart valve replacement surgery covered by insurance? Coverage varies by insurance provider and policy. It is important to check with your insurance company to understand the extent of coverage and out-of-pocket costs.
17. How do I choose between a mechanical and a biological valve? Your doctor will help you decide based on your age, lifestyle, medical condition, and ability to take anticoagulant medication.
18. What are the signs of valve failure after replacement? Signs of valve failure include shortness of breath, fatigue, chest pain, and swelling. If these symptoms appear, contact your cardiologist immediately for evaluation.
19. Can heart valve replacement be done minimally invasively? Yes, in some cases, minimally invasive surgery is an option. This method involves smaller incisions and generally leads to a quicker recovery, less pain, and a reduced hospital stay.
20. How do I maintain my new heart valve? Regular check-ups, adhering to medication regimens, and making heart-healthy lifestyle choices are key to maintaining the function of a replacement heart valve.