Understanding Heart Transplants

Heart transplantation is the gold standard treatment for patients with advanced heart failure. This means no treatment is considered better.

The good news is that more people who need a heart transplant are getting one. For many years, only 2,000 to 2,500 patients a year received a new heart. Over the past couple of decades, that number has been rising. In 2021, 3,817 people in the United States received heart transplants.

Unfortunately, there still aren't enough healthy hearts available to ensure that everyone who needs a new heart can get one. Healthcare providers are looking for new ways to reimagine the organ donation system so that those at highest risk are transplanted first.

This article looks at why heart transplants are needed, who should receive one, and when a mechanical pump might be an option. It also discusses organ donation. 

Why Someone Might Need a Heart Transplant

An estimated 6.2 million adults in the U.S suffer from heart failure. This means their hearts can’t pump as strongly as they should. Heart failure can have a number of causes, including:

• Damage from a heart attack
• High blood pressure
• Diabetes
• A deformed valve
• Cardiomyopathy, a progressive disease that causes heart damage

Symptoms of heart failure may include:

• Extreme shortness of breath
• Fatigue
• Excess fluid accumulation in the legs and ankles
• Trouble breathing when lying down

People with heart failure need medication to help their hearts contract more strongly, eliminate excess fluid, and increase blood flow. Medications can also slow the progression of heart failure, keep patients out of the hospital, and prevent death.

Over time, however, the medications may stop working. At that point, a heart transplant may be the only option.

Who Should Get a Heart Transplant

The guidelines for heart transplant qualification are vague. Each transplant center decides for itself which patients it will take.

Pulmonary hypertension is one of the only medical conditions that disqualify a patient from heart transplantation. People with this condition have high blood pressure inside the pulmonary artery, which is a large blood vessel that carries blood to the lungs.

After transplant, medications help prevent the body from rejecting the new heart. Most centers will not do a transplant if the patient is unlikely to take these medications after surgery.

Most centers also require candidates to be free of drugs and alcohol for two years before a heart transplant. People who smoke are expected to quit and remain smoke-free for a period of time in advance of the surgery.

There is no age limitation for heart transplantation, but:

• Adults over age 70 are at higher risk, because they are likely to have other medical conditions.
• Most heart transplants are done in people between the ages of 50 and 64. People in this age group tend to do well and have survival rates similar to those of younger patients.
  
• Patients in their late teens and early 20s tend to be risk-takers and often stop taking their medication. When they do, it can lead to organ rejection.
• Babies who need a heart transplant tend to do well since their immune system is under development and parents make sure they take their medications.

Preventing Rejection

Anti-rejection medications depress the immune system. This helps keep the body from viewing the new heart as a foreign body. For years, Gengraf (cyclosporine) was used to prevent rejection. Today, most patients take Prograf (tacrolimus).

Prograf is more potent, so patients need less of it. This also helps reduce side effects. Gengraf may still be used for patients who are less likely to reject their donor heart.

Substituting a Mechanical Pump

Ventricular assist devices (VADs) and total artificial hearts can be used temporarily to help a failing heart while the patient is waiting for a transplant. This is sometimes called "bridge to transplant."

Every patient with one of these devices is entered in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS). Over time, the information in this database will help healthcare providers decide if artificial devices could be a safe and effective alternative to a human heart.

Organ Donation

Where you live affects your chances of receiving a new heart or dying before a heart is found. According to a 2020 study, between one and eight people die each day for every 1,000 people on the waitlist. That rate varies by state.

Patients who live far away from the nearest heart transplant center are less likely to receive a heart than those who live closer.

Currently, waiting patients are placed in broad categories, including:

• Blood type
• Size
• Age

There is growing interest in identifying the factors that put a patient at increased risk of dying before they can receive a heart. This would allow available hearts to go to the sickest patients first, no matter where they live.

Still, the need for hearts from healthy, younger organ donors exceed the supply. You can help by registering to become an organ donor and checking the box on your driver’s license. Even if you are too old to donate a heart at the time of your death, your eyes, skin, or other organs may benefit one or more people.

Summary

Heart transplantation can extend the life of someone with heart failure. Unfortunately, there are more people who need a transplant than there are donor hearts.

Each transplant center has different guidelines for who they will accept as a patient. In general, they choose people who are alcohol- and drug-free and who are likely to take their anti-rejection medication after transplant. This medication stops the body from rejecting the donor organ.

Mechanical pumps may help patients who are waiting for a transplant. Healthcare providers are also working on ways to improve prioritization for the patients who need a new heart the most.