Test Identifies Rejected Hearts Suitable for Transplant

Stress echocardiography pinpoints previously rejected hearts viable for transplantation

(RxWiki News) The heart transplant waiting list isn't short, and if anything, only continues to grow. So doctors have taken another route. They've found a method for screening previously rejected hearts that would deem viable ones suitable for transplant.

The hearts that were previously turned down for transplantation were mostly due to the age of the donor or risk factors for problems such as coronary heart disease. However, researchers have found that pharmacological stress echocardiography can detect which of those previously rejected hearts may be suitable for transplantation.

Commonly called a stress echo, the inexpensive imaging test detects blockages in the heart's arteries or bypasses and also provides information regarding the heart muscle and circulation to the heart.

"Ask your cardiologist about treatment options for heart failure."

Tonino Bombardini, MD, lead researcher and the scientific coordinator of the Aged Donor Heart Rescue by Stress Echo (ADONHERS) Project from Italy, noted that every year in Europe about 4,500 donated hearts go unused even though there is a severe donor organ shortage. In part this is because the average age of organ donors has increased, and because the proposed donor may have died from a stroke.

Dr. Bombardini said that many of those rejected hearts could be used if confidence that the transplants would be successful was increased.

Heart transplants are most commonly offered to patients with end-stage heart failure. Some patients may receive an implanted mechanical pump while they await a transplant.

Criteria has been expanded to include donor hearts over the age of 55, yet doctors are still hesitant to use them.

"The use of stress echocardiography to select hearts ‘too good to die’ may be a possible approach to resolving the mismatch between organ supply and demand,” said Dr. Bombardini.

During the ADONHERS Project, researchers investigated 66 candidate donor hearts which previously would not have been considered because of age or risk factors between 2005 and 2012. The average donor age was 55.

Researchers considered 47 of the hearts eligible for transplantation, and performed dipyridamole stress echocardiography on 44 to search for coronary artery disease or heart muscle abnormalities. The other three hearts underwent dobutamine stress echocardiography. Dipyridamole is a medication that prevents blood clots, while dobutamine is a heart failure drug.

The testing revealed that 35 did not have heart disease and were eligible for transplantation. For six of those hearts, a matching recipient could not be found. However, a cardiac autopsy confirmed that the hearts were free of significant coronary artery disease or heart muscle abnormalities.

The other 29 hearts were successfully transplanted in emergency patients. After one month, 26 of the patients had normal heart structure and function as assessed by several tests including angiography. However, three of the patients were found to have minor single vessel disease. After 27 months, 26 patients were still alive.

Dr. Bombardini said the findings support shifting the donor age cut-off upward to 65 if a stress echo screening determines that the donor heart is healthy.

“Pharmacological stress echo is already an established technique that is used to assess and risk stratify patients with known or suspected coronary artery disease," said Dr. Bombardini.

"We have shown that it can also be used to identify hearts suitable for transplantation that would previously have been unused. This requires cardiologists with experience of stress echo and ideally a second opinion from a cardiologist in a core lab (using tele-echocardiography), who can give the green light for donation.”

The study was recently presented at EUROECHO and other Imaging Modalities 2012, the annual meeting of the European Association of Cardiovascular Imaging, a registered branch of the European Society of Cardiology, in Athens, Greece.

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Review Date: 
December 7, 2012