Self-report of stroke, transient ischemic attack, or stroke symptoms and risk of future stroke in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study

Abstract

Background and purpose: History of stroke and transient ischemic attack (TIA) are documented risk factors for subsequent stroke and all-cause mortality. Recent reports suggest increased risk among those reporting stroke symptoms absent stroke or TIA. However, the relative magnitude of increased stroke risk has not been described across the symptomatic spectrum: (1) asymptomatic, (2) stroke symptoms (SS) only, (3) TIA, (4) distant stroke (DS), and (5) recent stroke (RS).

Methods: Between 2003 and 2007, the REasons for Geographic And Racial Differences in Stroke (REGARDS) study enrolled 30 239 black and white Americans ≥45 years of age. DS and RS were defined as self-report of physician diagnosis of stroke >5 or <5 years before baseline, respectively. SS was defined as a history of any of 6 sudden onset stroke symptoms absent TIA/stroke diagnosis. Kaplan-Meier and proportional hazards analysis were used to contrast stroke risk differences.

Results: Over 5.0±1.72 years of follow-up, 737 strokes were validated. Compared with asymptomatic persons, those with SS, TIA, DS, and RS all had increased risk of future stroke. After adjustment for age, race, sex, income, education, alcohol intake, current smoking, and a history of diabetes mellitus, hypertension, myocardial infarction, atrial fibrillation, and dyslipidemia, there was 1.20-fold (not statistically significant) increased stroke risk for SS (95% CI, 0.96-1.51), 1.73-fold for TIA (95% CI, 1.27-2.36), 2.23-fold for DS (95% CI, 1.61- 3.09), and 2.85-fold for RS (95% CI, 2.16-3.76).

Conclusions: Results suggest a spectrum of risk from stroke symptoms to TIA, DS, and RS, and imply a need for establishing these categories in health screenings to manage risk for future stroke, reinforcing the clinical importance of stroke history including the presence of stroke symptoms.

Figure 1

Risk of future stroke (Kaplan-Meier) following self-report stroke, TIA or stroke symptoms in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study. Self-report was obtained at baseline between 2003 and 2007. Participants have been followed for stroke events which are confirmed by a physician (baseline strokes were not physician verified) for a mean of 5.0 ± 1.72 years. A older stroke is defined as a stroke that occurred 5 years or further from baseline interview. Recent stroke, distant stroke, TIA and stroke symptoms were all ascertained by self-report.