Peripheral arterial disease (PAD) affects 8 to 12 million people in the US.(1) PAD is a condition where blood vessels that carry blood to the legs become clogged.  They become clogged due to atherosclerosis, a condition where  plaques form on the walls of these vessels. PAD is associated with a risk of heart attack and stroke because the buildup of plaques are likely to build up in the heart and vessels leading to the brain as well as in the legs. Older age, diabetes, high cholesterol, high blood pressure and smoking are all risk factors for PAD.  Patients with PAD may experience pain in their legs when walking. This is referred to as ‘intermittent claudication'. This can cause many people with PAD to have trouble tolerating walking or exercising.

Until now, treatment for PAD has focused on reducing pain and modifying risk factors such as high blood pressure and coronary artery disease. Traditional treatments have included exercise and certain drugs that reduce the blood’s ability to clot (Trental, Pletal, aspirin and clopdogrel).  Exercise programs have been shown to increase walking distance 110% to 150%. Trental and Pletal have shown more modest improvements in symptoms. Statins, a class of drugs that can lower your cholesterol, have been used to decrease the risk of heart vessel problems in PAD patients.  Now, statins are being studied for the direct treatment of PAD itself.

 
 Recently a study on atorvastatin (Lipitor) showed a 63% improvement in walking distance versus 38% in the placebo (sugar pill) group.(2) This study used a high dose of atorvastatin of 80mg daily. A Scadinavian study that looked at simvastatin (Zocor) showed that a dose of 20 to 40 mg daily reduced the incidence of intermittent claudication by 38%. Another study of simvastatin showed that 40mg daily improved that distance patients with PAD could walk pain free.(3)  

It should also be noted that the dose of atorvastatin of 80mg is much higher than the dose traditionally used for other conditions such as high cholesterol. This is concerning as statins can have rare but serious side effects, including a condition called rhabdomylisis. This is a condition where damage occurs to the muscles. It usually starts as a pain in the muscle and can actually progress to a loss of muscle tissue. It can also lead to kidney failure and death. For this reason, unexplained joint or muscle pain should be brought to the attention of your doctor right away if you are taking a statin. 

Unfortunately, there needs to be more studies done at lower doses to see if atorvastatin would still have the same effect. In addition to contributing to more side effects, this higher dose would be substantially more expensive than a lower dose.

Most people with PAD are already taking a statin to reduce their risk of cardiovascular disease.  There is still little evidence to recommend higher than usual doses of statins for the treatment PAD. However we must remember that 70% of patients with PAD will die of heart disease and that there is plenty of evidence to suggest treating patients with PAD with a statin can help slow the progression of atherosclerosis and lessen the risk of coronary artery disease. If you have PAD and are not taking a statin, talk to your doctor about possibly adding one.

REFERENCES:

1. Hirsch AT, Criqui MH, Treat-Jacobson D, et al. Peripheral arterial disease detection, awareness and treatment in primary care. JAMA 2001;286:1317-24.
2. Pedersen TR, Kjekshus J, Pyorala K, et al. Effect of simvastatin on ischemic signs and symptoms in the Scandinavian Simvastatin Survival Study (4S). Am J Cardiol 1998;81:333-5.
3. Mondillo S, Ballo P, Barbati R, et al. Effects of simvastatin on walking performance and symptoms of intermittent claudication in hypercholesterolemic patients with peripheral vascular disease. Am J Med 2003;114:359-64