July 24 (Reuters) - Edwards Lifesciences ( EW ) missed

second-quarter revenue estimates on Thursday, hurt by

lower-than-expected demand for its artificial heart valves.

Shares of the California-based company were down 14.3% at

$74.50 after the bell.

Edwards reported revenue of $1.39 billion, falling short of

analysts' estimates of $1.65 billion, according to LSEG data.

Investor expectations for medical device makers have been

high in recent quarters, driven by sustained demand for surgical

procedures, especially among older adults.

Separately, Edwards, which sold its critical care products

unit to Becton Dickinson ( BDX ) last month, said it will

acquire heart device makers JenaValve Technology and Endotronix

to expand its structural heart portfolio.

The deals, valued at approximately $1.2 billion, further

solidify Edwards' transition to becoming a pure-play structural

heart company, with its lead product being the transcatheter

aortic valve replacement (TAVR) device, which is used for

minimally invasive heart surgeries.

Sales from the TAVR unit rose 5% to $1.0 billion in the

quarter ended June 30, compared to estimates of $1.06 billion.

However, the company revised the sales forecast for TAVR

devices for the second half of the year to a 5% to 7% increase,

down from the previous guidance of 8% to 10%.

The company forecast third-quarter sales to be between $1.56

to $1.64 billion, assuming critical care is included for the

entire third quarter.

On an adjusted basis, the company reported a second-quarter

profit of 70 cents per share, narrowly beating analysts'

estimates of 69 cents per share.