In January this year, the Food and Drug Administration (FDA) approved Medtronic Inc.'s CoreValve system for individuals who have severe aortic stenosis, the narrowing of the aortic valve of the heart that could lead to the weakening of the heart muscle and eventually heart failure, blood clots and even death, who are too sick and weak to undergo open heart surgery.

Compared with open surgery, which is currently the gold standard treatment for treating the condition, that requires making an extensive cut in the chest and stopping the heart to implant a new valve into place, transcatheter aortic valve replacement (TAVR) with the CoreValve system only needs a small incision to replace the diseased heart valves.

While the approval for CoreValve was initially for patients deemed to be at extreme risk to undergo open heart surgery, the treatment is now available for a larger group of patients. On Tuesday, Medtronic announced that the FDA has given the nod to its CoreValve system for patients who may be healthy but are considered to be at high risk to undergo open heart surgery.

FDA's decision was based on clinical study that showed patients who were less ill but considered as high risk for the standard treatment fared better with CoreValve TVAR compared with those who had open heart surgery. Of the patients who received CoreValve, 85.8 percent were still alive a year after the procedure whiles the survival rate among those who had the traditional surgery was only 80.9 percent.

"We compared TAVR with the CoreValve self-expanding prosthesis with surgical aortic-valve replacement in patients with symptomatic, severe aortic stenosis who were at increased surgical risk," wrote the investigators of the study "Transcatheter Aortic-Valve Replacement with a Self-Expanding Prosthesis" which was published in the New England Journal of Medicine on May 8. "The rate of death from any cause at 1 year was significantly reduced with TAVR performed with the self-expanding prosthesis."

About 50,000 Americans with aortic stenosis undergo open heart surgery every year to replace their diseased aortic valve. David Adams, from the Department of Cardiothoracic Surgery at the Mount Sinai Hospital in New York City and one of the investigators of the CoreValve U. S. pivotal trial, said that the result gives doctors more confidence when making decisions for TAVR treatment.

"With this approval, we can treat more patients due to the broad range of CoreValve sizes, and we have an option compared to surgery that provides a greater chance for a longer life while minimizing the risk of stroke," Adams said .