Shares of heart valve maker Edwards Lifesciences Corp. surged early Thursday after the company said its first-quarter profit grew 34 percent on improving sales, but they sagged as the session continued.

The stock fell $1 to close at $83.36 Thursday, giving back the gains made earlier in the session. The stock had opened at $87.51, or 3.7 percent higher from the prior close of $84.36.

Late Wednesday, Edwards said its profit rose to $63.9 million, or 53 cents per share, from $47.7 million, or 40 cents per share in the year-ago quarter. Excluding one-time charges, the company said its profit totaled 51 cents per share. Revenue rose 19 percent, to $404.5 million from $340.5 million.

Analysts had expected profit of 42 cents per share and revenue of $383.9 million, according to a FactSet survey.

The company said its heart valve therapy revenue grew 25 percent to $244.9 million, mainly on expanding European sales of the Sapien XT valve, which is designed to replace diseased heart valves. Sapien is designed to be guided to the heart through an artery in the leg. Typically, the diseased valves are removed through open heart surgery, which is a more complicated procedure.

Edwards said its critical care revenue rose 15 percent to $120.6 million, while cardiac surgery system revenue grew 6 percent to $26.1 million. Vascular sales slipped to $12.9 million from $13.9 million.

The company expects second-quarter profit between 49 cents and 51 cents per share, while analysts expected about 47 cents per share.

For the full year, the company increased its profit range by 10 cents to between $2.01 and $2.07 per share, while analysts expected about $1.95 per share. The company also expects sales between $1.66 billion and $1.74 billion, at current foreign currency exchange rates. Analysts had expected sales of $1.63 billion.