Orange County’s largest publicly traded company, Edwards Lifesciences, is nearly doubling the size of its Irvine headquarters, according to the Orange County Business Journal. The expansion will create hundreds of new jobs.

The company, which specializes in artificial heart valves and other groundbreaking medical technologies, has helped make Irvine the medical device capital of the world.

With nearly 4,400 employees, Edwards Lifesciences ranks as the county’s 15^th largest employer. Its medical devices have helped treat millions of people around the world.