Irvine-based Edwards Lifesciences Corp. is buying privately held CardiAQ Valve Technologies Inc. for $350 million in cash and up to $50 million in regulatory milestone payments.

CardiAQ also is based in Irvine and is developing less-invasive replacement mitral heart valves.

Edwards said it bought CardiAQ to expand its portfolio of those products. The company stopped enrolling patients in a clinical trial for its own less-invasive mitral valve known as Fortis about two months ago.

The company released its news Friday afternoon, after markets closed. Edwards’ shares were up 2% today in midday trading to a market value of $16.2 billion.