Study bolsters CSI technology to treat heart blockages

A recent study from St. Paul-based Cardiovascular Systems Inc. shows that its technology that sands away calcified lesions in coronary arteries is safe and effective in the vast majority of procedures, a breakthrough that could lead to more effective treatment for patients with coronary artery disease.

The company's orbital atherectomy technology is designed to use a rotating diamond-tipped device to safely chip off hard, calcified blockages in the blood vessels that supply the heart. Nearly 90 percent of patients who received the Cardiovascular Systems Inc. (CSI) treatment suffered no adverse coronary event — a heart attack, hospitalization or death — within 30 days. Stents to keep arteries open were successfully implanted 98 percent of the time, said Dr. Jeffrey Chambers of Metropolitan Heart and Vascular Institute, who presented the ORBIT II study results at the American College of Cardiology conference in San Francisco over the weekend.

"We are extremely excited about the results," he said. "It will be a way to treat people we haven't been able to treat before."

Company officials plan to submit their application for approval by the Food and Drug Administration by the end of March. Analysts said Monday that FDA approval could come this year and would tap into a segment worth an estimated $1.5 billion or more in the United States each year.

"This will greatly expand the market opportunity for the company," Feltl and Co. analyst Ben C. Haynor wrote in a note to investors Monday. CSI, which is traded on Nasdaq, saw its share price climb more than 16 percent to close at $19.23 Monday.

Coronary artery disease is a leading cause of death in men and women in the United States and occurs when fatty material — called plaque — builds up on the walls of arteries that supply blood to the heart. The plaque buildup causes the arteries to harden and narrow, reducing blood flow. The condition affects an estimated 16.8 million people in the United States and is the most common form of heart disease.

Moderate to severe arterial calcium is present in nearly 40 percent of patients who need a balloon angioplasty to open blocked arteries and a stent to keep them open. Such calcium makes it harder to clear away plaque, and patients with moderate to severe calcification have higher rates of death and major coronary complications.

The study involved 443 patients at 49 U.S. medical centers in November 2012. More than half of the patients had diabetes or a coronary artery bypass graft and nearly two-thirds were smokers.

"ORBIT II represents the only study to-date of this hard-to-treat patient population," Chambers said. "Past studies haven't attempted to treat severely calcified lesions, due to the challenge of meeting endpoints and overall treatment success."

David L. Martin, CSI president and chief executive officer, said he is excited by the opportunity to help an underserved population.

"Some people refer to calcium as a rockpile," he said. "It is an impossible place to deploy a balloon or use stent technology."

Many patients with severe calcified blockages have little more than medication available to them, Martin said. That could change with FDA approval, he said.