The registry that now is being maintained will provide the needed information, said Dr. John V. Conte, director of the heart transplant and cardiovascular circulatory support program at Johns Hopkins University, but the findings of the new study can safely be disregarded, anyway, he said.
"The pump looked at in this study are not the pumps that primarily are used today," Conte said. "No second-generation pumps had yet been approved" at the time the study was conducted, he noted.
"This is a well-intentioned study, but in no way, shape or form should anyone make any conclusions based on this study," Conte contended.
First-generation VADs relied on a system of valves, subject to wear and tear, to control blood flow, he explained. "By 2003, we were starting to look at second-generation pumps that are smaller and more reliable. The ones available during this time period we know were not designed for long-term, many-year use," he said.
One second-generation VAD, which uses a rotating impeller to move blood, is now in general use, with more awaiting approval, Conte said. Third-generation pumps, which use electromagnetic impellers, have also made their appearance.
The latter "have no moving parts that can wear out," he said. "The second-generation pumps have bearings that can wear out."
And so a study of the first VADs to be implanted "is like talking about how the Model T works in today's environment," Conte said.
The study did make one valid point, he said. It found that results were best in hospitals that implanted many VADs and poorest in facilities implanting only one or two a year.
"Those people who do a large or moderate volume of procedures probably do a better job at it," Conte said. "We found a similar result in a study of heart transplants."
Information on the true value of VADs will start to emerge from the national registry, Conte said. "The pat
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