A call to action to increase the awareness, detection and treatment of peripheral arterial disease (PAD) among healthcare professionals was published last month in the Archives of Internal Medicine by the Prevention of Atherothrombotic Disease Network, an independent, international, multidisciplinary group of specialists supported by a grant from the Sanofi-Synthelabo/Bristol-Myers Squibb Pharmaceuticals Partnership. PAD is characterized by arterial stenosis and occlusions in the peripheral arterial bed. It can be symptomatic or asymptomatic, with symptomatic PAD ranging in severity from intermittent claudication (IC) to critical limb ischemia.
Regardless of symptomology, PAD is an indicator of diffuse and significant atherothrombotic disease and, therefore, of increased risk of myocardial infarctions (MIs) and strokes. The report also highlights that PAD is grossly under-diagnosed in patients at highrisk of cardiovascular and cerebrovascular morbidity and mortality, despite the availability of an effective 10-minute diagnostic tool - the ankle brachial index (ABI).
The network, comprised of independent experts in the fields of vascular medicine, neurology, diabetology, nephrology, cardiology and primary care, has called for greater education for clinicians about the ischemic burden of PAD. The report also called for the initiation of greater improvement in the detection and treatment of PAD, which it says affects more than 27 million people in Europe and North America. Regardless of whether symptoms are evident, patients with PAD have an increased risk of subsequent MI and stoke and are six times more likely to die within 10 years than patients without PAD.
Professor Jill Belch, network chair and affiliated with Ninewells Hospital and Medical School (Dundee, Scotland), said, "PAD is a devastating disease affecting the lives of millions of people worldwide. It is imperative that an international awareness campaign be initiated to help improve the rate of diagnosis of PAD. The initiation of an ABI screening program to identify those asymptomatic patients at high risk of PAD will help save lives."
Recent developments in the diagnosis and management of PAD are the key drivers behind the publication. In particular, evidence supports the use of the ABI a simple, non-invasive test as a diagnostic and risk-assessment tool. The ABI is measured by having the patient lie in the supine position, with subsequent performance of the ankle and brachial blood pressure measurements using a 5 mHz to 7 mHz hand-held Doppler device. Additionally, clinical data shows the substantial cardiovascular and cerebrovascular risk reduction that can be achieved through pharmacological intervention such as antiplatelet therapy and management of atherothrombotic risk factors, including smoking, high blood pressure, high blood lipid levels and lack of exercise.
The Call to Action paper notes that a data-derived screening protocol for high-risk patients is critical, since the majority of patients with PAD are asymptomatic, and many symptomatic patients do not report their symptoms to a medical care provider. In addition, a recent U.S. study has shown that clinicians who rely on a classic history of claudication alone to detect PAD will miss from 85% to 90% of patients with this high-risk atherothrombotic disease.
Authors of the Call to Action paper also evaluated the role of risk factor management and antiplatelet therapy (ASA and clopidogrel) in the prevention of atherothrombotic events associated with PAD. Risk factor control, including smoking cessation, high blood pressure control, high lipid level management and supervised exercise are all well accepted and proven therapies in PAD.
Even pictures don't alter risky behavior
A picture is supposed to be worth a thousand words, but even a vivid picture of clogged blood vessels isn't enough to force large changes in behavior that risks heart health, according to a report in the May 7 issue of the Journal of the American Medical Association. A group led by Patrick O'Malley, MD, chief of the division of general and internal medicine at Walter Reed Army Medical Center (Washington), used images of calcified deposits in the heart and blood vessels, showing them to 450 symptom-free active duty Army personnel aged 39 to 45. The images made using electron beam tomography were clear early indicators of future troubles.
The subjects were divided into four groups, each handled differently in how the images were used. Some were shown the EBT images immediately and left on their own. Others were not told about their results for a year, without advice about lifestyle changes. A third group got advice about lifestyle changes and were shown the EBT images a year later. People in the fourth group saw their EBT images immediately and were given continuing advice on changing lifestyle. One year later, an overall reduction in risk factors smoking, blood pressure, better diet was seen only in that fourth group, according to the study results. Using the assessment scale developed by the Framingham Heart Study, which includes all known cardiovascular risk factors, they found a reduction about double that of the other groups.
It's an important finding because "this [EBT] technology has been widely used, based on a self-referral basis," O'Malley says. There are for-profit EBT centers around the country that will provide blood vessel images, leaving the follow-up to a family doctor or cardiologist. Maintaining a healthy heart requires a lifestyle shift for many, according to O'Malley, who says that "general behavioral change is a difficult thing. Life is complex. Health can be affected by societal reasons, social reasons." The fact that the people in the study were young and healthy might have influenced the results, he speculates. "This is worth testing in a group with higher prevalence of coronary disease. We're looking for funding for a study of a higher-prevalence cohort."
Med-tech push right up Medical Alley
Medical Alley (St. Louis Park, Minnesota), a trade association that promotes Minnesota's healthcare industry, is enjoying a major growth spurt even as the industry on which it is centered, like most others, battles economic uncertainty. Don Gerhardt, president and CEO of Medical Alley, says that over the last two years, "we've had 45% growth each year." That has seen its rolls swell to about 340 members of all sizes, from med-tech industry colossus Medtronic (Minneapolis, Minnesota) to start-ups not much beyond the "well, we have this idea ..." stage. Medical Alley's purpose, put simply, is to focus more attention on Minnesota and the surrounding region birthplace of many cardiovascular innovations as a place where the healthcare products and services industry is flourishing. While the people who work in, put their money into or just write stories about the medical products sector know of the region's solid place in that universe, for others the view is skewed toward Southern California, the San Francisco Bay area or perhaps Boston and environs.
While the "alley" in Medical Alley is centered on a corridor that extends from Rochester in the southeastern part of Minnesota through the Twin Cities to the northern reaches of the state, it actually now has expanded to reach into Canada and the neighboring states of Wisconsin, Iowa, Illinois and the Dakotas. And even though Medical Alley is home to more than 800 medical device manufacturers, "there are a lot of people who don't know" about how this part of the Upper Midwest is the home to much that is new in med-tech, Gerhardt says. "This has been a quiet development," he says, adding that "maybe that quiet has helped us grow as a region," away from the bright lights that have shone on some other parts of the country.
The fact is that the substantial swath of geography that represents the membership of Medical Alley is home to some of the most interesting developments occurring in an industrial sector where "Innovation" should be part of each company's name. With the attention regularly garnered by such sector mainstays as Medtronic and St. Jude Medical, along with emerging companies such as Acorn Cardiovascular and CHF Solutions, the Medical Alley tag may become as familiar a commercial reference point as Silicon Valley was at the height of the dot-com madness.
An interesting initiative in the formative stages is establishment of a venture fund known as Alley Ventures that will provide seed and early-stage financing for medical device and other life sciences companies. The investment size target is expected to be in the $50,000 to $1 million range. "We're building Alley Ventures because there is a vacuum in very early stage funding availability for emerging companies," says Gerhardt. "There is very little ability to get any funding in this range," he said, adding that "nurturing small businesses is extremely important." He expressed confidence that "we'll be on the ground with funds available inside this year."