末梢動脈の動脈硬化と心血管死亡率

The getABI trial shows that even mild peripheral atherosclerosis is associated with substantial increase in all-cause and cardiovascular mortality, according to a presentation at the annual meeting of the European Society of Cardiology.

The German epidemiological study on Ankle Brachial Index (getABI) was initiated in 2001 to answer questions about whether a simple screening test for atherosclerosis can identify it at an early stage, and if so, estimate what risk such patients carry in the future.

Professor Curt Diehm from the Clinic Karlsbad-Langensteinbach, an affiliated teaching hospital of the University in Heidelberg, and his co-workers from various renowned medical institutions in Germany presented a five-year study follow-up.

Professor Diehm explained: “We used the ankle brachial-index (ABI), which is simple to understand and to apply by physicians and nurses. In an individual in the supine position, the blood pressure in the leg arteries is equal to or a little higher than in the arm arteries. If atherosclerotic stenoses in the legs manifests, blood flow after the obstruction decreases, and the pressure in the leg artery is lower than in the arm. This sign is almost as reliable as angiography to identify your atherosclerotic risk patient.”

The study included a total of 6,880 unselected patients in primary care, which underwent ABI testing by their primary care physician. Mean age of the patients was 72.5 years, 58 percent were women, 46 percent were past or current smokers, 74 percent had hypertension, 24 percent had diabetes mellitus and 52 percent had lipid disorders.

Of all patients, 18.0 percent had a pathological ABI test, but the majority of these patients had no clinical signs or complaints.

After a five-year observation period, all-cause mortality was 24 percent in patients with symptomatic peripheral atherosclerosis, 19 percent with asymptomatic peripheral atherosclerosis, and 9 percent in patients without peripheral disease. Even when all other known risk factors for cardiovascular death were accounted for by statistical means, peripheral disease had the best ability to predict future death, stroke or myocardial infarction.

Professor Diehm said, “The bad news is we showed that in primary care every fifth patient aged 65 years or older has atherosclerosis in the leg arteries. Because atherosclerosis is not a local process but at the same time progresses in the heart and brain vessels, such patients usually die from heart attacks or stroke. The good news is that the ABI test is not limited to expert use but can be performed in general practice. Thus, family physicians can identify high risk patients and initiate and maintain effective treatment in this large group.”

The study also showed that the extent of the blood pressure difference between legs and arms matters: The higher the spread between both pressures is (in other words, the lower the ankle brachial index), the higher was the mortality of patients.