Clinical trials find stents improve survival rate for stroke patients

Surgeons who operate on blood vessels in the brain are hailing new data that suggest many more patients would survive strokes if they were treated with removable stents in addition to drugs.

Medtronic Inc. is cheering the news, since it now owns the Solitaire, a brain blood clot-removal device that commands a large market share for thrombectomy gadgets. The device came with Covidien, acquired by Medtronic last month, and is part of a Covidien neurovascular division expected to generate $451 million in sales this year.

Doctors, however, said the findings of lower mortality and better recovery are applicable to several companies' devices, not just Covidien's. That's partly why they say the findings — first reported in December and confirmed in three publications in the New England Journal of Medicine this week — will ultimately lead to changes in national treatment guidelines for some types of stroke.

"Within the stroke community, this was one of the bigger events that has occurred in the last 20 years," said Dr. Andrew Grande, a University of Minnesota neurosurgeon and an investigator on one of three studies published this week at the International Stroke Conference in Nashville.

In one of the clinical trials reported Wednesday, called Escape, the death rate of stroke patients eligible for simultaneous drug therapy and mechanical clot removal was 10 percent, compared with 19 percent in the control group. Another study published this week, Extend-IA, found 71 percent of patients returned to "functional independence" after the dual treatment, compared with 40 percent who were treated with the IV drug alone.

Stroke is considered the fifth-leading cause of death, and one of the top causes of disability, in the United States. The 800,000 strokes per year experienced by Americans cost about $54 billion, measured in health care services and missed days of work, according to the Society of NeuroInterventional Surgery.

The studies found that more stroke patients survived and recovered when doctors used a temporary stent attached to the end of a long catheter to capture blood clots in the brain and fish them out with the device, while also receiving IV drug therapy. Medtronic's Solitaire competes with Stryker's Trevo device, with several models of aspiration catheters.

Even with those limitations, the findings probably apply to more than 100,000 strokes per year, said Dr. Michael Hill, a neurosurgeon at the University of Calgary and an investigator on Escape.

"It's still a lot," he said. "If you could take 100,000 people and achieve a 50 percent relative reduction in mortality, it would start to reduce the overall mortality from stroke."

It's not clear how quickly hospitals will ramp up to deliver the complex therapy. Some large hospitals in metro areas are already equipped to do clot-removal procedures on stroke patients, but most smaller and regional hospitals are not. In addition, doctors will have to be trained on how to rapidly assess medical imaging and make treatment decisions, as was done for the patients in the studies who were all treated within hours of a stroke.

A company spokeswoman was mum on how Medtronic expects the studies to affect sales of Solitaire devices. The company doesn't publish historical sales for specific products in its neurovascular division, and it is prohibited from making sales projections because of a "quiet period" ahead of next Tuesday's quarterly earnings announcement.

Hill noted that advocates for treating stroke with a combination of thrombectomy procedure and IV drugs will have to make sure their zeal doesn't translate into too many patients getting the procedure, which is a risk because hospitals are reimbursed "quite well" for it. He didn't give exact reimbursement figures.

"You've got to get to the hospital as quickly as possible," he said. "If you have any symptoms, go."

Joe Carlson • 612-673-4779