Doctors call heart device leap forward

Published 5:00 am Thursday, March 24, 2011

Two Houston surgeons have successfully implanted the world’s first continuous-flow artificial heart in a human patient, a significant advance that promises a smaller and much more durable alternative to existing artificial hearts.

Drs. Bud Frazier and Billy Cohn took out the dead heart of 55-year-old Craig Lewis on March 10 at the Texas Heart Institute.

After harmful proteins built up in his heart to the point it could no longer work, Lewis lived only with the aid of external breathing, dialysis and heart support machines.

Maybe a day to live

The Houston man had maybe a day to live when Frazier and Cohn were given the opportunity to test their device — a pair of turbines cobbled together to mimic the function of the heart’s left and right ventricles — that had been implanted only in 37 valves. So far Lewis is recovering well, doctors say.

“It was time to take this leap forward,” Frazier said.

The leap is an evolution away from devices that push blood into the body in pulses, like the natural heart.

Turbine approach

Frazier was one of the earliest and probably most outspoken evangelists for a new approach, that of pumps using a tiny turbine spinning thousands of times per minute to provide a continuous flow of blood.

In 1988 he implanted the world’s first left-ventricular assist device with a continuous-flow pump, and the next-generation HeartMate II pump he helped develop has now been put into 11,000 patients.

Continuous flow pumps are smaller and more durable. Pulsatile pumps must beat 100,000 times a day, and 35 million times a year to match the heart.

Pumps and artificial hearts with this pumping action tend to break down in months or a few years.

“This is the real beauty of continuously flowing pumps,” Frazier said. “We’ve never spun one to failure.”