Long-Term Outcome following Attendance at a Transient Ischemic Attack Clinic

Abstract

Background and purpose Many patients who attend transient ischemic attack clinics have a noncerebrovascular diagnosis. The long-term outcomes in this group are not well described. We evaluated these in a cohort referred to a transient ischemic attack clinic with a suspected transient ischemic attack. Methods Patients were clinically classified as having stroke or a transient ischemic attack or a noncerebrovascular diagnosis (nontransient ischemic attack). Follow-up was via electronic record linkage. The primary endpoint was cardiovascular death or a major cardiovascular event. Secondary outcomes included incident neurological disease (excluding stroke or transient ischemic attack) and the need for permanent pacemaker insertion. Outcomes in the transient ischemic attack and nontransient ischemic attack cohorts were compared using Cox's proportional hazards models. Mortality outcomes were further compared with those in a contemporary control group of individuals with hypertension. Results Of the 3533 patients who attended the transient ischemic attack clinic, 53·5% had a transient ischemic attack. Of these, 769 (40·7%) suffered a cardiovascular endpoint, compared with 458 (27·9%) with a nontransient ischemic attack (hazard ratio 1·53, 95% confidence interval 1·36–1·72). The risk remained higher but was attenuated following adjustment (hazard ratio 1·21, 95% confidence interval 1·05–1·41). Cardiovascular mortality in both groups was higher than that in hypertensive controls. The risk of a subsequent nonstroke neurological event was higher in those without a transient ischemic attack. Conclusions Patients without a transient ischemic attack referred to a transient ischemic attack clinic have a high risk of future vascular events that exceeds risk in a cohort with hypertension. All patients attending transient ischemic attack clinics should undergo assessment of their cardiovascular risk and the use of methods to reduce this risk should be explored.