Abstract 3078: The Poor Prognosis of Diabetic Patients with High Ankle-Brachial Index Depends on the Presence of Masked Peripheral Arterial Disease
Background: A high ankle-brachial index (ABI >1.40) is associated with poor prognosis. An underlying peripheral arterial disease (PAD) is frequent in diabetic patients with high ABI, although it cannot be adequately diagnosed by the ankle pressure measurement, due to stiff arteries. We hypothesized that in diabetic patients, the poor cardiovascular disease (CVD) prognosis associated with high ABI would depend on the coexistence of masked PAD.
Methods: We reviewed the data of 403 consecutive diabetic patients who had a Doppler assessment of their lower limbs between 1999 and 2000. They were classified as “normal” when Doppler waveform patterns (DWP) were normal and ABI within the 0.91–1.39 range, “PAD only” in case of ABI ≤0.90, “stiff only” if ABI ≥1.40 with normal DWP, and “mixed disease” when ABI ≥1.40 with abnormal DWP. Patients were followed until 04/2008. The primary endpoint was the occurrence of any of the following events: death, stroke or myocardial infarction.
Results: The patients (age: 65.6 ± 13.2 yrs, 54.6% females; 90.2% type-2 diabetes) were classified as “normal” (14.4%), “PAD only” (48.4%), “stiff only” (16.4%) and “mixed disease” (20.8%). During a mean follow-up of 6.5 years, the event-free survival curves of “PAD only” and “mixed disease” groups showed poorer prognosis than the “stiff only” and “normal” groups (figure⇓). In a model adjusted for age, sex, diabetes type and duration, traditional CVD risk factors, renal failure and CVD history, only the presence of PAD was significantly associated with the primary endpoint (OR: 3.36 (1.25 – 4.44), p=0.008).
Conclusions: In diabetic patients with high ABI (>1.40), only those with an associated PAD have a poorer prognosis.