Few people realize that the arteries in their legs can clog much like those leading to the heart -- and often with the same fatal consequences as a heart attack or stroke.

Researchers found in a recent study involving the University of Minnesota that treatment of a "heart attack below the belt" -- the condition known as peripheral artery disease, or PAD -- is downright expensive, too. Each year, the U.S. spends roughly $21 billion on PAD-related hospitalizations. Not surprisingly, the costs escalate as the condition grows worse.

The study, funded by drugmakers Sanofi-Aventis and Bristol-Myers Squibb, was published recently in the medical journal Circulation.

More than 8 million Americans suffer from PAD -- a number that's expected to rise as baby boomers age. Although treatments range from drugs to surgery to stents that prop open clogged arteries, as well as lasers and drills that bust up hardened plaque, there's no real "gold-standard" as fixes go, according to Venkat Rajan, a medical technology industry analyst with Frost & Sullivan.

Rajan estimates the current market for all peripheral vascular products at $3.4 billion.

Others agree that the PAD market is one of the most-promising in medical technology. "PAD is an under-penetrated market with lots of medical devices that can treat the disease and get people back on their feet," said Thomas Gunderson, an analyst with Piper Jaffray Cos. "From a stock market standpoint, the market is growing 10 percent. When compared to zero to 2 percent growth in the coronary stent market, that looks pretty good."

This presents an alluring challenge for medical technology firms. Many med-tech companies based locally or with local operations, including Boston Scientific Corp., Medtronic Inc., Covidien (which recently bought Plymouth-based EV3), Cardiovascular Systems Inc., Väsamed Inc., Vascular Solutions Inc. and Lutonix Inc., have developed or are working on PAD products.

Most companies are trying to prove their product is the best treatment in the wake of escalating health care costs and the advent of health care reform, which calls for more comparative-effectiveness research.

Dr. Alan Hirsch, a professor of epidemiology and community health at the University of Minnesota who was a co-author of the study, said its results are unique because they consider the global aspects of PAD care.

"Usually if you have a patient come in for treatment of PAD, they figure if the artery is open, the problem is fixed," he said. But often follow-up procedures are required, or there are costs related to complications. His conclusion: There's much that can be done by business (and others) to improve PAD care.

The study followed 25,763 patients who either suffered from a prior heart attack or stroke; had risk factors for atheroschlerosis, a condition in which fatty material collects in the arteries; or were already diagnosed with PAD.

Of those, 2,396 or 9 percent, were diagnosed with symptomatic PAD, the most-common symptom being muscle cramping or discomfort in the lower legs. A much smaller number of PAD patients in the study -- 213 or 0.8 percent -- had no symptoms at all.

Researchers examined the rate of hospitalizations and related costs for these patients at one- and two-year intervals. Data for the 1,543 patients with symptoms who remained in the study indicated that 31 percent were hospitalized at least once for vascular-related issues during the two-year follow-up, while 23 percent of the 134 remaining asymptomatic patients were hospitalized in the same period.

The average cumulative hospitalization costs ranged from $7,000 to $11,700 per patient, depending on the treatment and severity of the condition.

"Americans now are trying to think, 'What are the total costs that we pay in health care?' This study tries to get at that," Hirsch said.

In that vein, the work of Hirsch and his colleagues continues. A second study funded by the National Heart, Lung and Blood Institute called CLEVER (www.clever study.org) is underway at the U, Abbott Northwestern Hospital and Park Nicollet to determine the best treatments for PAD, both clinically and economically.

Janet Moore • 612-673-7752