Population-based study of event-rate, incidence, case fatality, and mortality for all acute vascular events in all arterial territories (Oxford Vascular Study)

Abstract

Conclusion: Even outside of the coronary circulation, there is a high rate of acute vascular events that increases steeply with age. Summary: Vascular events involving the coronary, cerebrovascular, and peripheral circulations have common risk factors, pathology, and preventative treatments. These multiple circulatory beds are rarely studied concurrently, however. In this study, the authors compared the incidence of acute vascular events in the coronary, cerebrovascular, and peripheral territories and related these events to aging of the population. This was a prospective study of data collected between 2002 and 2005 assessing 9106 individuals in Oxfordshire, United Kingdom, for an acute vascular event of any type. There were 2,004 acute vascular events in 1,657 individuals. There were 918 cerebrovascular events (45%), of which 618 were stroke, and 300 were transient ischemic attack. There were 856 coronary events (42%), of which 316 were non-ST elevation myocardial infarction, 159 were ST elevation myocardial infarction, 218 were unstable angina, and 163 were sudden cardiac death. Nine percent of the acute vascular events were peripheral vascular events (n = 188). These included 92 episodes of critical limb ischemia, 53 episodes of visceral or limb ischemia secondary to emboli, and 43 aortic events. There were also 62 unclassifiable deaths. Compared with coronary events, the relative incidence of cerebrovascular events was 1.19 (95% confidence interval [CI], 1.06 to 1.13). For nonfatal cerebrovascular events, the relative incidence compared with coronary events was 1.40 (95% CI, 1.23 to 1.59). If transient ischemic attacks and unstable angina were excluded, the relative incidence of cerebrovascular events to coronary events was 1.21 (95% CI, 1.04 to 1.41). A steep rise occurred in the incidence of vascular events in all territories with age. Case fatality rates increased with age, and 47% of the 1561 nonfatal events occurred at age ≥75 years. Comment: There is nothing particularly surprising in this study except that perhaps cerebrovascular events were more common than coronary events. It is also interesting that half of all events occurred in patients ≥75 years. The age distribution of vascular events suggests that trials designed to assess interventions for atherosclerotic vascular disease must include a large proportion of older patients. Limiting studies to patients <80 years, as is frequently done, will exclude that segment of the population with the largest number of events.