Lower extremity artery disease: a neglected major CV diseaseDr. Rafel Ramos - Girona, Spain
General practitioners from about 20 European countries travelled to Barcelona to attend the Annual EPCCS CV Summit for Primary Care. In addition to the lively discussions and interaction between primary care physicians of different corners of Europe, an important objective of this summit is to produce guidance documents specifically aimed at primary care. Sessions were set up in such a way that not only the current evidence on a subject was reviewed, but that specific considerations for primary care were discussed and challenges and gaps in the evidence were identified. These sessions focused on diabetes and vascular care, managing lipids, hypertension and heart failure.
In addition to the sessions dedicated to major issues in CV medicine, about which EPCCS guidance documents will be written, the evidence base on diagnosis and management of peripheral artery disease (PAD) was presented, by dr. Rafel Ramos, from Girona in Spain. He was happy to have been invited to speak about PAD, as he notes that it is a largely neglected, but important CVD.
The majority of lower extremity artery disease (LEAD) occurs in the femoral and popliteal arteries, and it is more common in men than in women. Atherosclerosis is a systemic disease, and the disease progresses in a similar way in the lower limb (4 stages according to the Fontaine classification). 1 to 2 persons in every 10 individuals over the age of 65 years has LEAD (ankle-brachial index [ABI] <0.9), but only 1 in 10 patients may present with symptoms. It should be noted, however, that an asymptomatic form may just be the cause of a person not being able to walk enough to exert symptoms, for instance in case of heart failure, or a person may have reduced pain sensitivity due to diabetic neuropathy.
Since it can still be a severe disease in the absence of symptoms, it is important to screen for LEAD. Individuals with LEAD are at higher risk of lower limb events, CVD and death. Mortality risk increases as ABI is lower, and ABI has predictive value on top of Framingham risk categories. LEAD has similar risk factors to atherosclerosis, but the weight of the factors differs somewhat. Diabetes and smoking are most important in case of LEAD.
Therapy can reduce CVD and mortality risk. Implementation of recommended secondary prevention measures in patients with PAD has, however, been described to be inadequate. Too few persons with PAD who smoked entered a smoking cessation programme and a small proportion entered a walking exercise program. Antiplatelet agents and lipid-lowering agents were prescribed in about 60% and about 50% of patients with PAD respectively in the European Heart Registry, and more men were treated than women. Patients with existing CVD were treated better.
LEAD is diagnosed by measurement of ABI: dividing the highest ankle systolic blood pressure (SBP) by the highest arm SBP in each leg, while the individual is in supine position, after 5-10 minutes rest. The lowest ABI should be considered for CV risk stratification purposes. In short, ABI <0.9 is abnormally low, between 0.90 and 1.00 is borderline, between 1.00 and 1.40 is considered normal, and above 1.40 is abnormally high. Patients with a clinical suspicion for LEAD, in whom ABI should be measured, include those with intermittent claudication, or other non-joint-related exertional lower extremity symptoms, those with impaired walking function, or with ischemic rest pain in the anamnesis. Individuals with known atherosclerotic disease in another vascular bed or with conditions such as abdominal aortic aneurysm, chronic kidney disease or heart failure are at increased risk of LEAD. Ramos and his team have developed REASON: a risk score to identify candidates to screen for PAD, based on ABI.
Therapy of LEAD should start with lifestyle changes, as the best medical therapy includes non-pharmacological measures, especially smoking cessation and regular physical exercise, and also a healthy diet and weight loss. Smoking cessation not only reduces the risk of CV events and mortality, it also provides the most noticeable improvement in walking distance, when combined with regular exercise. Pharmacotherapy may also be employed to stimulate smoking cessation.
Medical therapy advised for the treatment of LEAD include antiplatelet therapy, oral anticoagulants, lipid-lowering agents, such as statins, and the benefit of the PCSK9 inhibitor evolocumab over statins alone in patients with PAD has recently been demonstrated. Distinctions in treatment recommendations are made between symptomatic and asymptomatic LEAD. Walking impairment may be pharmacologically treated with cilostazol and naftidrofuryl, but the evidence is limited.
In order to minimize tissue loss, patients with PAD and diabetes should be counseled about self-foot examination and healthy foot behaviours. Prompt diagnosis and treatment of foot infection are important to avoid amputation. Revascularisation can be a reasonable solution in those with lifestyle-limiting claudication with inadequate response to lifestyle changes and medical therapy.