A ventricular assist device (VAD) is a type of device that is designed to take over function for either or both of the heart’s ventricles. The ventricles are responsible for pumping blood through the lungs and out to the body. Most often, VADs are used in patients who are awaiting a heart transplant, thus they are called “bridges to transplantation.” There are, however, other situations in which a VAD might be recommended.

VADs may be short-term, intermediate-term or long-term, depending on the needs of each patient. A VAD that supports only the left ventricle in known as a left ventricular assist device (LVAD), and a VAD that supports that right ventricle is known as a right ventricular assist device (RVAD). Devices that support both ventricles are known as bi–ventricular assist devices (BiVADs).

The most common VADs used in the United States are implanted during open-heart surgery. They are powered by a pump that remains outside of the body and pumps the blood through tubes that are connected to the patient’s circulatory system. Some VADs require constant supervision in a medical setting, while others are portable and allow the patient to return to a more natural lifestyle.

Although VADs were first developed in the 1960s, it took almost 20 years of clinical experimentation before they were put into general use. Since then, VADs have continued to increase in sophistication, becoming smaller and more efficient. Today, studies have shown that patients on VADs who are awaiting heart transplant may be successfully weaned off the VAD without a transplant. This is possible because the VAD allows the heart to rest, enabling it to regain function.

In addition, a permanent model has been approved by the U.S. Food and Drug Administration (FDA) for use in some terminally-ill patients not eligible for heart transplantation. This permanent support using a VAD is called destination therapy. Clinical trials demonstrated that destination therapy doubled the one-year survival rate of patients with end-stage heart failure, as compared to drug treatment.

In 2004, the American College of Cardiology and the American Heart Association recommended that left ventricular assist devices (LVADs) be viewed as permanent rather than temporary therapy for certain late-stage heart disease patients.

Nevertheless, there are significant side effects associated with VADs, including blood infection and blood clots, and many patients are not suitable candidates for VADs. Researchers are continually working to develop new and better models to address these concerns.

There is one VAD currently approved for use in children. It is designed for children 5 to 16 years of age with severe left ventricular heart failure. The VAD may allow children with this heart problem to survive while awaiting a heart transplant. Researchers are continuing to work on pediatric VADs that may be implanted in children, however, there are none currently approved on the market.

A ventricular assist device (VAD) is a battery-operated device that is designed to help either one or both ventricles of the heart pump blood. It does not replace the heart but instead helps the patient's own heart pump blood through the body. There are three groups of patients that may benefit from this therapy, including:

A VAD that supports only the left ventricle is known as a left ventricular assist device (LVAD), while a VAD that supports only the right ventricle is known as a right ventricular assist device (RVAD). Some patients may need both ventricles supported by a bi-ventricular assist device (BiVAD).

The first VADs were developed to be used on a temporary basis, usually for individuals waiting for a donor heart. There are now VADs that can be used on a permanent basis in patients who are not candidates for heart transplant. In general, there are three categories of VADs:

• Short term. These devices are typically used in high-risk patients who cannot sustain life over the long-term. They may be implanted in patients who cannot be weaned from the heart-lung machine or who have experienced a traumatic cardiac event that requires short-term help. The complication rate of these devices is relatively high, with ventricular arrhythmias occurring in more than 25 percent of patients with short-term LVADs. However, their use is justified because these patients would be unable to survive without the VAD.
  
  
• Intermediate term. These devices are the most commonly used VADs, frequently employed as bridges to transplantation among patients who are awaiting a heart transplant but deteriorate before a donor heart becomes available. These devices have been known to support patients for up to 500 days. The most common intermediate VAD has a 60 percent success rate, but unfortunately, it also has a high rate of complications, including bleeding, blood clots and infection. In these devices, the pump remains outside the body while the tubes that transport blood pass through the skin barrier, raising the risk of infection.
  
  
• Long term. These devices are designed for chronic or permanent use in patients with advanced heart failure. There are only two long-term VADs approved for use in the United States. They are designed to permit rehabilitation and hospital discharge after implantation, allowing patients to experience life outside a medical setting until their donor heart becomes available. They also may be used in patients who are not able to undergo a heart transplant.

In addition, a new VAD was recently developed that can be used in children and smaller patients. It is intended for use in children age 5 to 16 with severe left ventricular heart failure. This VAD may allow children to survive until a donor heart becomes available.

One potential benefit to VADs is possible rehabilitation for patients who are waiting for a donor heart. In up to 7 percent of cases, the heart function improves to the point where the VAD can be removed and no heart transplant is necessary. This improvement may occur because the VAD allows the heart muscle to rest and heal.

Patients who may not be appropriate candidates for a VAD include those who:

• Have severe disease in organs other than the heart, such as the lungs, kidneys or liver.
  
  
• Are in an advanced stage of cancer.
  
  
• Infections that do not respond to antibiotics.
  
  
• Have certain heart valve abnormalities.
  
  
• Had aortic dissection or aortic aneurysm.
  
  
• Have advanced aortic or peripheral vascular disease.
  
  
• Have artificial heart valves.
  
  
• Have a blood clotting or platelet disorder such as hemophilia.
  
  
• Are very short or thin with small body surface area.

Intermediate and long-term VAD implantation is often scheduled as open-heart surgery. Short-term VAD implantation frequently takes place during the course of another surgery in which the patient cannot be weaned from the heart-lung machine.

If the VAD implantation is a scheduled procedure, patients should prepare in advance for a hospital stay of at least a week. The patient is usually admitted on, or a day before, the scheduled date for surgery. In the hospital, the patient will undergo a battery of tests. Even if these tests were already done days or weeks before surgery, they will be done again just before surgery to be sure that the patient’s medical condition has not changed. They include:

Eight to twelve hours before surgery, all patients are placed on NPO (non per os; nothing by mouth) status. This means they are not permitted to eat, drink or take anything by mouth until after their surgery. Smokers will have been instructed to completely avoid smoking for at least two weeks before their surgery to prevent problems in blood flow, clotting or breathing. Certain medications may need to be reduced or stopped temporarily, so patients should discuss their medication schedules with their cardiologist before surgery. Patients will receive detailed information about necessary preparation, what will happen during surgery and what to expect during recovery from their physicians.

Immediately before surgery, the patient will be given specific pre-operative medications and then “prepped” for surgery. First, the chest area is shaved. Next, the surgical team creates a sterile environment by swabbing the patient’s chest with an antiseptic solution and covering the area with sterile surgical drapes. An intravenous (IV) line will also be started, usually in the forearm or back of the hand.

The patient is then given a sleep-inducing medication through the IV line. Once asleep, the patient will continually breathe a mixture of oxygen and anesthetic gas (general anesthesia) to make sure that he or she remains asleep throughout the entire surgery.

After the patient is asleep, a device called the Swan-Ganz catheter is often inserted into the jugular vein in the neck and threaded to the pulmonary artery (which goes from the lungs to the heart). The catheter can be used to give medication and measure the oxygen levels in the blood. A breathing tube (endotracheal tube) will also be inserted into the mouth and down the windpipe (trachea) to maintain an airway and deliver the anesthesia. A urinary catheter is also inserted and connected to a collection bag to measure the patient’s urine output.

The surgeon will then make the necessary incision(s). If the surgeon is implanting a left ventricular assist device (LVAD), he or she will connect a tube from the LVAD to the left ventricle and another tube from the external part of the LVAD through the abdomen and to the aorta. Sometimes a heart-lung machine is used during the procedure to support the patient’s circulation during LVAD installation. If the surgeon is implanting a right ventricular assist device (RVAD), he or she will connect a tube from the RVAD to the right ventricle and another tube from the external part of the RVAD to the pulmonary artery. In some patients, both an LVAD and a RVAD will be implanted.

Once the procedure is completed, the incisions in both the heart and the chest are closed (sutured). The entire procedure can take several hours.

After surgery, the patient is moved from recovery to the cardiac surgical intensive care unit. Heart rate and blood pressure monitoring devices continuously monitor the patient for 12 to 24 hours. In most cases, family will be able to visit periodically. Medications that regulate circulation and blood pressure may be administered through the IV (intravenously). A breathing tube (endotracheal tube) may remain in place until the physicians are confident that the patient is awake and ready to breathe comfortably on his or her own. The patient may be groggy and somewhat disoriented, and the incision site in the chest may be sore. Medicine to relieve pain will be given as needed.

Patients usually stay in the hospital for at least five days. During this time, tests will be conducted to assess and monitor the patient’s condition. The cardiologist will discuss further medical treatment, including the use of pain medications, antibiotics or anticoagulants. He or she will also update any medications that the patient had already been taking. Information will be provided about caring for the VAD (if it is not implanted) and any restrictions in the patient's activities.

Following the VAD surgery, it is not uncommon for patients to experience:

Some models of the VAD require patients to remain connected to a bedside console and power unit. However, intermediate and long-term VADs often allow patients to go back to a more natural lifestyle after being cleared by their physician. They will need to make sure they are carrying battery packs, either at the waist or in a shoulder harness (which should not interfere with clothing). Some patients may also need to plug a cord from the device in their body into an electrical outlet at night.

Researchers are exploring the possibility of a VAD that could be fully implantable and, ideally, permanent. A permanent device could eliminate the need for a heart transplant, which in turn could reduce the number of patients who die while waiting for a transplant. Less than 2,000 donor hearts become available each year. Other ventricular assist devices are designed to function as a rotary pump, keeping blood circulating continuously rather than following the heart’s natural “lub-dub” pattern of alternately pumping and resting.

There is currently one pediatric VAD approved for use in children 5 to 16 years of age. It is designed for children with severe left ventricular heart failure who are awaiting a donor heart. The VAD may allow these children to survive until they can undergo heart transplant surgery. Without the VAD, many children would die waiting for a donor heart. There are no implantable devices currently on the market for use in children.

The immediate benefit of a VAD is that it may save a patient's life. VADs have shown improvements in both ejection fraction and dilated cardiomyopathy in some patients. Researchers are not sure precisely how this occurs, but recovery may be rooted in a theory put forth by heart specialists almost 60 years ago: that the weakened heart needs rest. As a result, patients may find that symptoms such as shortness of breath and fatigue are relieved. Moreover, a small number of heart transplant candidates who have had a VAD over a period of months while waiting for a donor heart have had such dramatic improvement in their own heart function that they no longer needed the VAD or a heart transplant.

However, VAD use does carry risks, such as:

Patients are urged to discuss any questions they may have about these devices with their cardiologist. In the meantime, these devices continue to evolve.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to ventricular assist devices (VADs):

1. Why do you think a VAD is the right choice for my condition?
   
   
2. What type of VAD will I receive?
   
   
3. Will it be implanted or outside my body?
   
   
4. What are my risks with the VAD?
   
   
5. How quickly will I need to have this surgery?
   
   
6. What can I expect in terms of recovery?
   
   
7. What are my restrictions with a VAD?
   
   
8. How long can I stay on the VAD?
   
   
9. How will I be monitored while I am on this device?
   
   
10. What signs or symptoms indicate a medical emergency with a VAD?
    
    
11. How will I know if the device is working properly?
    
    
12. Will I need to take any special medications using this device?
    
    
13. Will I require any other cardiac procedures after being connected to the VAD?
    
    
14. Do I have other options if I do not get a donor heart?
    
    
15. What are the chances that I can avoid a heart transplant by using a VAD?