St. Jude Medical Inc. agreed to buy Thoratec Corp., a maker of implants that aid failing hearts, for $3.4 billion in cash.

The offer of $63.50 a share represents a 40 percent premium over Thoratec’s average trading price in the 30-day period that ended last week, the companies said Wednesday in a statement. The deal will add to St. Jude’s adjusted earnings beginning next year, the company said.

Medical-device manufacturers are making acquisitions to get access to new technology as hospital customers push for lower prices on older products. Medtronic Plc, which competes with St. Paul, Minnesota-based St. Jude to sell cardiac devices, has made three small purchases since June and last year agreed to acquire Covidien Plc for more than $46 billion.

Buying Thoratec would bolster St. Jude’s push into new and faster-growing markets as sales stagnate for its established products.

The agreement allows Thoratec to seek other takeover offers through Aug. 20. If it finds a better deal by then, it must pay St. Jude a $30 million breakup fee.

Bloomberg reported Tuesday that the companies were nearing an agreement. Shares of Thoratec and its chief competitor, HeartWare International Inc., surged Tuesday on the report.

Pumps by Thoratec and Framingham, Massachusetts-based HeartWare help patients in need of heart transplants survive until a donor organ is available. The devices are attached to the left ventricle, the heart’s main pumping chamber. A tube runs around the heart and connects to the aorta, which funnels oxygen-rich blood to the rest of the body. A small electric motor ensures the blood is continuously moving between the two.

Former U.S. Vice President Dick Cheney received a Thoratec HeartMate II implant in 2012.

Thoratec’s product sales dropped 5 percent last year to $477.6 million after reports of blood clots developing in patients, competition from HeartWare and limits on manufacturing capacity.

The company’s HeartMate II was tied to potentially fatal clots in patients relying on the device to pump blood for their failing hearts, according to a study published in 2013.

Thoratec issued an urgent warning last year to patients who used a pocket controller when trying to change to a backup controlled from their main system after four patients died. Still, the company began to slow the pace of total revenue declines and even to expand sales in the U.S. Thoratec is now developing its next-generation device, called the HeartMate III, with a U.S. study underway and European approval expected this year.

St. Jude also reported second-quarter results on Wednesday. Earnings, excluding certain items, were $1.03 a share, beating the 99-cent average of analysts’ estimates compiled by Bloomberg. Sales were $1.41 billion, 2.6 percent lower than a year before.

The company raised its revenue forecast for 2015, projecting an increase of 4 percent to 6 percent, excluding the impact of foreign exchange rates. Full-year adjusted earnings will be $3.96 to $4 a share, up from an earlier forecast of $3.92 to $3.97 a share.

 

--With assistance from Matthew Campbell and Manuel Baigorri in London, Michelle Fay Cortez in Minneapolis and Ed Hammond in New York.