Edwards Lifesciences (NYSE:EW) investors have had a tough year, to put it mildly. This heart device maker's stock has cratered in 2013 as Wall Street has grown disappointed with the growth of Edwards' flagship product, its Sapien transcatheter heart valve. The Sapien has managed to capitalize on an exclusive position as the sole device of its type on the U.S. market, but that advantage might come to an end soon.

Rival Medtronic (NYSE:MDT), which has dueled with Edwards for sales in Europe's transcatheter heart valve, has pushed up the launch date of its competing CoreValve product from mid-2014 to the first quarter of next year. Meanwhile, fellow cardiac device maker Boston Scientific (NYSE:BSX) recently won European regulatory approval for its own heart valve, the Lotus.

With competition baring down from all sides, can Edwards keep up its growth in this market, or will the Sapien's diminishing advantages spell doom for this slumping stock? Find out in the video below, where Fool contributor Dan Carroll tells you all you need to know about Edwards' latest challenges and how they could affect your investments.