AOMI, for walking training to be effective, it must hurt!

What is AOMI?
Obliterative arteriopathy of the lower limbs (AOMI) or arteritis is a frequent chronic vascular disease most often of atheromatous origin. It is defined as the narrowing by cholesterol plaques (stenosis) or occlusion of one or more arteries of the lower limbs. These arteries are located in the abdomen (iliac arteries), thighs (femoral arteries), knees (popliteal artery) or calves (anterior and posterior tibial arteries, fibular artery). Many arterial patients are asymptomatic. Even if asymptomatic, this disease must be taken seriously, with correction of cardiovascular risk factors. The most common symptoms are exertional claudication: crushing/constricting/tightening pain in a muscular region downstream of the affected artery appears after a maximum walking distance. Pain may be localized to the calf (most often), the thigh or even the buttocks. The pain forces the patient to stop, and usually subsides within ten minutes. These symptoms reflect insufficient vascularization of the leg muscles, which suffer on exertion. Treatment of AOMI involves first and foremost the correction of cardiovascular risk factors: smoking cessation, medication to treat hypertension, diabetes and cholesterol, weight loss through hygienic-dietary measures and physical activity adapted to needs, principally walking for at least 30 minutes 3 times a week. On a case-by-case basis, an antiplatelet agent such as aspirin may also be prescribed. The aim is to control and halt the evolution of atherosclerotic plaques in the arteries. In addition to these medicinal measures, the vascular physician will prescribe supervised vascular rehabilitation through walking, in order to improve blood flow in non-diseased arteries, and thus develop small natural bypass arteries, without surgical intervention.

The American study
This recent study published in the Journal of the American Heart Association evaluated the effects of more or less intense walking in 264 people with OAMI. Patients who walked at a pace that caused leg pain increased their walking speed and distance more than those who walked at a more comfortable, symptom-free pace.
Previous research has found that active walking, particularly on a treadmill under the supervision of a healthcare professional, improves walking ability and distance in people with OAMI. What remained unclear was the potential effects of walking at a faster pace, even to the point of causing painful leg cramps, on speed, strength and balance.



This study evaluated the effects of home walking in 264 people with OAMI who were taking part in a randomized clinical trial, called Low-Intensity Exercise Intervention in PAD (LITE) between September 2015 and December 2019, at four US medical centers. The average age was 69, 48% were women. Patients were randomly assigned to one of three groups for 12 months.
The first group (38%) walked at a comfortable pace; the second group (41%) walked at a pace that induced symptoms in the legs; while the third group (21%) did not exercise .
Both exercise groups wore a device (ActiGraph) that monitored walking intensity and time. Data from the device during walking activity - frequency, intensity and duration of exercise - were uploaded to the study website.
At the start of the study and at 6 and 12 months, participants performed three tests to assess their abilities: walking speed over a distance of four meters at the usual pace, walking speed over a distance of four meters at the fastest and shortest pace, performance battery consisting of a walking speed of four meters at a usual pace, a standing balance test and the time of five repeated chair lifts.
The main results were as follows:
- At six months, participants whose walking pace induced leg pain or discomfort walked 11 feet per minute faster, (0.2 km/ h) and at 12 months, they walked over 16 feet per minute faster (0.29 km / h) than participants whose walking pace did not induce leg pain or discomfort. Compared with patients who did not engage in activity, participants in the group who walked for exercise at a pace that induced leg pain or discomfort walked nearly 13 feet per minute faster at six months (0.24 km/h).
- At 12 months, those who walked for exercise with leg pain or discomfort scored nearly 1 point higher on the sum of the three tests than those who walked at a comfortable pace without leg pain. For those walking for exercise at a comfortable pace, there was no improvement in walking speed at six months or 12 months.

Based on these results, Doctors should advise patients to walk for exercise at a pace that induces discomfort in the legs, instead of a comfortable pain-free pace. Exercise that causes leg pain is beneficial, albeit more difficult.

In May 2022, the American Heart Association and 24 other organizations launched the PAD (peripheral artery disease) National Action Plan, a guide to help prevent complications of Peripheral Arterial Disease, treat cardiovascular risk and improve quality of life for those affected. Atheromatous vascular disease is a chronic, environmental disease, but those affected can lead long, active lives with regular cardiovascular monitoring.

If you notice that walking is becoming more difficult, that it's hard to keep up with others, or that you feel pain in your calf, thigh or buttock when walking, speak to a doctor so that he or she can prescribe a consultation with a vascular physician, who will carry out the necessary assessment and institute atheromatous disease treatments.

Reference:
Effects of Walking Exercise at a Pace With Versus Without Ischemic Leg Symptoms on Functional Performance Measures in People With Lower Extremity Peripheral Artery Disease: The LITE Randomized Clinical 27Jul 2022 : Journal of the American Heart Association. 2022;0:e025063