NEW YORK (AP) — St. Jude Medical will spend $3.4 billion in cash to acquire Thoratec, further bulking up its array of devices that are used to treat heart conditions.

Heart failure devices have become pivotal for the St. Paul, Minnesota company since the Food and Drug Administration approved its remote patient monitoring system CardioMems HF last year.

Thoratec’s key product is an implantable device that helps patients’ hearts pump more blood.

About 5.8 million people in the U.S. have heart failure, in which the heart cannot pump enough blood to meet the body’s oxygen needs, and St. Jude is positioning itself to satisfy the need for better technology.

St. Jude will pay $63.50 for Thoratec Corp., a 30 percent premium to its closing price on Tuesday. The deal is expected to close in the fourth quarter and includes a go-shop period, during which the Pleasanton, California, company will solicit other proposals through August 20.

Thoratec Corp. will be required to pay a termination fee of about $30 million if it backs out of the deal during the go-shop period, and about $111 million if it backs out after August 20.

The deal allows St. Jude Medical Inc. access to new markets totaling more than $1 billion that are expected to grow about 10 percent annually, the company said. St. Jude is also touting the strong relationships both companies have with heart failure physicians and cardiac surgeons as key benefit to selling Thoratec’s new heart pump, the HeartMate PHP.