Ramipril to the rescue

Important news for PAD patients: underdiagnosed and undertreated no more

By Christopher J Lipowski

For some time now, peripheral arterial disease (PAD) has been regarded as underdiagnosed and undertreated. This is due to a tendency to focus on atherosclerosis of the coronary arteries and the resulting complications. A growing body of research, however, is providing strong evidence that atherosclerosis of the peripheral arterial system greatly contributes to morbidity and mortality in patients — important news considering PAD affects millions of people in North America, most of whom aren't aware that they have the disease. Nearly 10% of men aged 65 and 20% of men and women aged 75 have PAD.

Now, a new research study published in the January edition of the European Heart Journal shows that ramipril, an angiotensin converting enzyme (ACE) inhibitor, reduces the risk of cardiovascular events in patients with clinical PAD. There is good news for doctors as well. The standard definition of PAD is an abnormal value of the ankle-brachial index (ABI), which is obtained with a standard blood pressure (BP) cuff and a Doppler device. This test uses measurements of BP at the ankle and at the arm, which the physician can easily compare. It has been suggested that the ABI test is not performed as often as it should be. This may be due to the expense of the Doppler equipment. However, the ramipril study found that a simpler measurement of the ABI using routine BP measurement in the arm and palpitation of the foot pulse is a reliable way to diagnose the disease and risk.

The study was based on patients over 55 years of age with existing cardiovascular disease or diabetes and an additional coronary risk factor. These subjects were participants in the Heart Outcomes Prevention Evaluation (HOPE) trial. Patients were randomized to treatment with ramipril or placebo and followed for four and a half years. The ABI was measured mainly by digital palpitation of the foot pulse in a total of 8,986 patients. A subnormal ABI was recorded in 3,099 patients and a normal one in 5,887 participants. The researchers found a statistically robust relationship between low ABI and prediction of morbidity and mortality even in patients with no clinical symptoms of PAD. At least 18% of patients with an ABI lower than 0.6 experienced a combined endpoint of cardiovascular death, non-fatal myocardial infarction or stroke. ABI was also used to predict all cause mortality. In patients with no clinical PAD, death from all causes was 8.5% while in those with clinical PAD the figure more than doubled to 17.5%. In this study, ramipril was shown to reduce the risk of cardiovascular events in all groups of patients with clinical or subclinical PAD regardless of ABI.

Reducing risk of cardiovascular events in PAD patients should be the primary goal of treatment, and healthy lifestyle changes are clearly the first step. It's understood that early intervention in cardiovascular disease is key. If patients stop smoking, control their diabetes, normalize their BP with either diet or medication and reduce their cholesterol levels, it can help slow the progression of the disease and significantly lower risk of heart attack or stroke. Also, drugs play a key role in treatment of PAD and ramipril shows much promise.