What happened

Edwards Lifesciences (EW -0.91%) shares outpaced the market last month by rising 13% compared to a 1.8% uptick in the S&P 500, according to data provided by S&P Global Market Intelligence.

The rally put the stock up more than 20% so far in 2019, versus a 15% rise in the broader market.

Surgeons at work in an operating room.

Image source: Getty Images.

So what

The medical device giant, whose products specialize in treating structural heart disease, got a boost from investors when the company revealed in mid-March that its Sapien 3 transcatheter aortic valve is proving successful over traditional surgeries. Specifically, a randomized trial has found a 46% reduction in death and rehospitalizations one year after patients received the valve replacement as compared to patients undergoing open-heart surgery. Put another way, just 1% of patients faced death or a disabling strong a year into the treatment, compared to 2.9% who underwent surgery.

Now what

Thanks to this positive data, Edwards Lifesciences is optimistic that Sapien 3 will soon be approved for a wider range of patients suffering from severe aortic stenosis. That might help the company improve upon its stable market share position in 2018 in this key industry niche.