Objective: to study the association between the ankle–brachial pressure index (ABPI), premature death and the need for surgical treatment for lower limb ischaemia.
Design: population based cohort study.
Subjects: three hundred and fifty-three men and women, 50–89 years old, underwent a leg pain questionnaire and measurement of ABPI and was then followed for 10 years.
Outcome Measures: all cause mortality, vascular procedures and major amputations.
Results: a low ABPI was independently associated with premature all cause mortality in the multiple regression analysis, carrying a relative risk of 3.4 (95% confidence interval 2.0–5.9) and 2.1 (1.3–3.3) for ABPIs ≤0.50 and 0.51–0.80, respectively, compared to those with ABPI ≥1.0. Individuals with an ABPI in the interval 0.81–0.99 suffered only a slight, not statistically significant risk increase compared to normals. A low ABPI at baseline implied a continuous constant increased risk of death throughout the study period. The same risk was observed among elderly (70–89, median 77 years), and in the middle aged (50–69, median 63 years) individuals. The vast majority of those subjected to vascular intervention or major amputation during follow-up had an ABPI≤0.8 at baseline (83 and 89%, respectively). However, within that group, the individual ABPI was not predictive for surgical intervention.
Conclusion: the association found between an ABPI ≤0.8 and premature mortality in this cohort of symptomatic subjects implies that the ABPI is a powerful, independent predictor for premature death. The prognostic information carried by an ABPI in the interval 0.81–0.99 remains uncertain. Septuagenarians and octogenarians carry the same risk increase associated with a low ABPI as those in the middle ages.
2002. Vol. 24, no 5, 405-410 p.