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Every 10 minutes, someone is added to the national transplant waiting list, and every day, 22 people on average die waiting for a match, according to the United Network for Organ Sharing. But, thanks to innovations in bioengineering, all of that could change.

Conceived nearly 60 years ago, the total artificial heart (TAH) has helped sustain the sickest biventricular failure patients waiting for a transplant. While the design of the primary TAH used today has mostly remained stagnant since the ’80s, when it was first implanted in a patient, new models and clinical trials may lead to a better device and, one day, a permanent solution.

The longest an individual has lived with the most widely used device worldwide, the SynCardia temporary TAH, was nearly four years.

At the Cleveland Clinic and the Texas Heart Institute, scientists are exploring how continuous-flow total artificial hearts (CFTAH) may suit patients with biventricular failure who aren’t eligible for an organ transplant, or either don’t have access to the SynCardia temporary TAH or are ineligible to receive it due to its size. The SynCardia temporary TAH can only fit in large chest areas. Researchers at the Cleveland Clinic have completed a three-month study on two calves implanted with their CFTAH, which operates without a diaphragm or valves, and doesn’t require an external driver like the SynCardia temporary TAH.

According to data from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS), of the upwards of 40 percent of patients with end-stage heart failure— a majority of which suffer from biventricular failure— only less than 3 percent receive a TAH.  

The shortage of heart transplants and the need for a solution

In the late 1960s, when patients began receiving heart transplants, supply was relatively high and demand was low, Donald Isaacs, vice president of communications for SynCardia, told FoxNews.com. The Department of Health and Human Services (HHS) estimates about 4,000 people wait for donor heart transplants each day, while only about 2,300 hearts are donated.

Heart disease is the No. 1 cause of death in the U.S., claiming more than 611,000 lives in 2015, according to the Centers for Disease Control and Prevention (CDC).

“The big question, which no one knows the answer to, is ‘What are the long-term ramifications of continuous flow in the arterial system?” Manning told FoxNews.com, “and that, unfortunately, has not yet been determined because there hasn’t been a study to look at that.”

“Everyone talks about tissue engineering a heart— that’s a long way away— so there are people that are desperate for this technology,” Manning said. “I think it has the potential to save a lot of people’s lives, and with donor hearts not really increasing and in fact decreasing, there’s got to be a solution.”

“Your blood pressure and heart rate are similarly changed by exercise and beta blockers,” said Gerald Fletcher, M.D., Professor of Medicine at the Mayo Clinic in Jacksonville, Florida.  “When you become exercise-trained your heart slows and your blood pressure lowers.”

“Exercise hard – to the point of being tired – but not excessively hard,” Dr. Fletcher said. “If you reach a point where it is hard to talk, that is probably too much.”