INCIDENCE, NATURAL-HISTORY AND CARDIOVASCULAR EVENTS IN SYMPTOMATIC AND ASYMPTOMATIC PERIPHERAL ARTERIAL-DISEASE IN THE GENERAL-POPULATION

Background. intermittent claudication is associated with a poor progno sis, but less is known of the risks associated with asymptomatic perip heral arterial disease. The aims of this study were to determine the i ncidence and natural history of claudication, and the incidence of car diovascular events in symptomatic and asymptomatic peripheral arterial disease. Methods. In 1988, 1592 subjects aged 55-74 years were select ed randomly from the age-sex registers of 10 general practices in Edin burgh, Scotland. The presence of peripheral arterial disease was deter mined by the World Health Organization questionnaire on intermittent c laudication, the ankle brachial pressure index and a reactive hyperaem ia test, This cohort was followed prospectively over 5 years for subse quent cardiovascular events and death. Results. One hundred and sixtee n new cases of claudication were identified (incidence density 15.5 pe r 1000 person-years). Of those with claudication at baseline, 28.8% st ill had pain after 5 years, 8.2% underwent vascular surgery or amputat ion, and 1.4% developed leg ulceration. Claudicants had a significantl y increased risk of developing angina compared with normals (RR : 2.31 , 95% CI : 1.04-5.10), and asymptomatic subjects had a slightly increa sed risk of myocardial infarction and stroke. Deaths from cardiovascul ar disease were more likely in both claudicants (RR :2.67, 95% CI : 1. 34-5.29) and subjects with major (RR : 2.08, 95% CI : 1.13-3.83) or mi nor asymptomatic disease (RR : 1.74, 95% CI:1.09-2.76). Subjects with major asymptomatic disease also had an increased risk of non-cardiovas cular death (RR :2.19, 95% CI : 1.33-3.59), and therefore had the high est overall risk of death (RR :2.44, 95% CI : 1.59-3.74). Conclusions. Subjects with asymptomatic peripheral arterial disease appear to have the same increased risk of cardiovascular events and death found in c laudicants.