J.L. WEBB

An aging population and an obesity epidemic are increasing the threat of peripheral arterial disease in America. Yet, even though this serious vascular condition already affects about 8 million people, three out of four respondents surveyed in 2007 didn’t know what it is, much less how to avoid it, according to the national P.A.D. Coalition.

That lack of awareness surprises neither Dr. Marc Bloom, chief of cardiovascular surgery at the Pepin Heart Hospital at University Community Hospital in Tampa, nor Dr. Barry Weinstock, an interventional cardiologist who practices at Orlando Regional Medical Center. That’s because many of the symptoms of P.A.D. are not apparent to a lay-person. But it does underscore the need for primary care physicians to be more responsive to the subtle signs of the disease and refer patients for diagnosis and treatment.

P.A.D. mostly affects people 50 and older. Smokers, diabetics and the obese are at greatest risk, but patients who have hypertension, high cholesterol or a history of heart disease or stroke also are more susceptible. According to the Coalition, P.A.D. causes arteries to harden and narrow as plaque builds up. Although it can affect any artery outside the heart, including the ones that carry blood to the brain, kidneys and abdomen, P.A.D. is found more often in the legs.

P.A.D. sufferers typically complain of pain in the calves, toes or buttocks while exercising or walking, said Weinstock. “The pain goes away when they rest,’’ he said, so many people think it’s a routine consequence of aging. Many patients don’t think it is important enough to mention to their doctor.
“Only about 20 to 25 percent of patients experience classic symptoms,’’ Weinstock said, and the starting point for a primary care physician evaluating those symptoms is to test the blood pressures with the ankle- or toe-brachial index or lower-extremity Doppler exam. If any of those tests are abnormal, it’s probably time to refer the patient to a specialist, Weinstock said.

Bloom, 53, said which tests are done by the primary care doctor “depend on his comfort level. He can order non-invasive arterial studies like ultrasounds, the ABI or the TBI. But once the patient is referred to a vascular surgeon, the first test he’ll order is a CT angiogram or MRA, Bloom said.

Easier to detect, but more difficult to treat, are the patients whose P.A.D. has progressed from the intermittent claudication stage (leg pain goes away when resting) to critical limb ischemia, where the pain persists while resting.

“That pain is usually at the top of their foot,’’ Bloom said. “They’ll say that after they’re in bed for a while they have very intense pain, so they dangle their foot over the side of the bed or stand up. But they’re cheating. Their blockages are so bad, they are using gravity to help pull the blood down into their feet.’’

Critical limb ischemia is “particularly disabling,’’ said Weinstock, 46. “From there, they can progress to developing non-healing ulcers and ultimately gangrene. If not treated, it can lead to amputations. A large number of patients who have amputations never become ambulatory again, and their morbidity and mortality is greatly increased,’’ he said. “The sooner (critical limb ischemia) patients can get revascularized, the better chance they have at salvaging the affected limb.’’

Weinstock said at his practice, Mid-Florida Cardiology Specialists in Orlando. “We do a lot of work with a 64-slice CT angiogram so we can actually get very, very good high-resolution pictures of the circulation in the legs, even the small vessels doing down to the foot. Most of these patients will be candidates for some sort of catheter-based procedure.’’

“There are a lot of new devices that are becoming more successful (at opening the arteries),’’ Weinstock said. “We’re well past the simple age of balloon angioplasty and stents. There are a lot of atherectomy devices that clean out the artery by removing the plaque.’’

Weinstock described three such atherectomy devices:

“One is a plaque-shaving device that actually shaves the plaque and collects it in a nosecone and removes it. Then there’s orbital atherectomy, which is a Roto-Rooter-like device that spins at a very high speed and has a diamond tip-coated surface that sands down the plaque into microscopic particles that wash away in the circulation. Another approach would be to use excimer laser, which essentially goes in and vaporizes the plaque.’’

The choice of device “sometimes depends on the type of plaque, whether it is hard or soft,’’ Weinstock said, but “all of these have been used successfully in treatment of below-the-knees narrowing of vessels.’’

In some cases, however, Weinstock acknowledged “that’s impossible and the patient may need to have bypass surgery with a vascular surgeon to save the limb.’’

Bloom is one such surgeon, but he says the minimally-invasive techniques are becoming the norm at his practice, Cardiac Surgery Associates of Tampa.

“Ten to 20 years ago, those patients had surgery,’’ Bloom said. “Now, that’s the minority of patients because our interventional techniques are so much better. I probably do one vascular surgery for every five stents, angioplasty or laser atherectomy procedures,’’ said Bloom, who will be on a P.A.D. seminar panel at Pepin Hospital Feb. 16.

Weinstock has high hopes for research to identify the genes that are responsible for P.A.D. “They’re looking for ways to trim off those genes and essentially cure people,’’ he said. Another promising research field is angiogenesis, where “they are injecting stem cells into the affected area and basically growing new vessels,’’ he said.

“We’re really focusing on better ways to keep diseased arteries open,’’ Weinstock said. “One of the Achilles heels of any kind of interventional procedure is the chance of re-narrowing. We are developing new procedures to try to get a durable result that lasts for years, so the patient isn’t coming back to the cath lab six months or even two years later with the same problem,’’ he said.

For now, though, Bloom implores primary care physicians to be mindful of the danger P.A.D. presents in other parts of the body, such as diseased carotids or aneurysms. “Those patients will not have any complaint (such as leg pain), so it’s up to the doctor to listen to their necks for bruits. I tell my patients when they go to their primary care doctor, if he listens to your heart or lungs, tell him to put that stethoscope on your neck. That should be a part of all examinations these days,’’ Bloom said.

Doctors should use P.A.D. as a marker for more serious coronary disease, too, Bloom said. “You have to assume that with patients who have P.A.D., there’s a good chance they have blockages all over the place,” he said. “They should be screened for evidence of vascular and cardio disease … because if it’s in your neck, your abdomen or your legs, there’s no reason to believe that it’s not in you heart.’’



February 2008