Differences in the role of black race and stroke risk factors for first vs recurrent stroke

Abstract

Objectives: To assess whether black race and other cerebrovascular risk factors have a differential effect on first vs recurrent stroke events.Methods: Estimate the differences in the magnitude of the association of demographic (age, back race, sex) or stroke risk factors (hypertension, diabetes, cigarette smoking, atrial fibrillation, left ventricular hypertrophy, or heart disease) for first vs recurrent stroke from a longitudinal cohort study of 29,682 black or white participants aged 45 years and older.Results: Over an average 6.8 years follow-up, 301 of 2,993 participants with a previous stroke at baseline had a recurrent stroke, while 818 of 26,689 participants who were stroke-free at baseline had a first stroke. Among those stroke-free at baseline, there was an age-by-race interaction (p 5 0.0002), with a first stroke risk 2.70 (95% confidence interval: 1.86-3.91) times greater for black than white participants at age 45, but no racial disparity at age 85 (hazard ratio 5 0.91; 95% confidence interval: 0.70-1.18). In contrast, there was no evidence of a higher risk of recurrent stroke at any age for black participants (p . 0.05). The association of traditional stroke risk factors was generally similar for first and recurrent stroke. Conclusion:The association of age and black race differs substantially on first vs recurrent stroke risk, with risk factors playing a similar role. Risk factors for first stroke have been well studied, 1 providing a framework for primary stroke prevention. Multivariable risk functions developed in the Framingham 2 and Cardiovascular Health Study 3 cohorts have identified age, sex, hypertension, diabetes, cigarette smoking, left ventricular hypertrophy, atrial fibrillation, and heart disease as predictors of incident stroke in a stroke-free population. A limitation of those studies was their inability to address the role of race (black race specifically) as a risk factor for stroke; however, there are substantial differences in stroke incidence between black and white persons, with incident stroke in black persons approximately 3 times higher between the ages of 45 and 65 years, but with disparities attenuating by age 85. [4][5][6][7][8] While substantial data document the risk factors for first stroke, there are fewer data establishing the risk factors for recurrent stroke (that is, risk factors for a subsequent stroke in a population with a previous stroke). The

No Racial Difference in Rehabilitation Therapy Across All Post-Acute Care Settings in the Year Following a Stroke

“…Of these possibilities, medical factors have been the most widely studied and while some racial differences exist, they are generally of small magnitude and unlikely to explain the wide differences in outcomes. 25, 26 Further research is needed to understand racial differences in post-stroke disability.…”

Where to Focus Efforts to Reduce the Black–White Disparity in Stroke Mortality

“…Of the estimated 795,000 stroke events in the US, about 185,000 (23%) are recurrent events. 31 While much less is known about the role of risk factors and the Black-White disparities for secondary stroke events, 32 data from REGARDS have shown no Black-White differences in the risk of recurrent stroke, 33 and as such it is relatively unlikely that secondary stroke prevention is a pathway to reducing the Black-White disparity in stroke mortality.…”

Cardiovascular Health in African Americans: A Scientific Statement From the American Heart Association

“…In the REGARDS study, most of the traditional risk factors (eg, hypertension, diabetes mellitus, smoking, atrial fibrillation, left ventricular hypertrophy) play a similar role in predicting incident and recurrent stroke; however, a history of heart disease was associated with an RR of 1.42 (95% CI, 1.20-1.67) for incident stroke but only a nonsignificant (RR, 1.09; 95% CI, 0.85-1.40) risk for recurrent stroke. 229 The substantial (P=0.0002) age-by-race interaction for incident stroke (with HRs of ≈3.0 at age 45 but 1.0 for age 85) was absent (P=0.99) for recurrent stroke, and no difference could be detected between the risk of recurrent strokes in African Americans and whites. 229…”

“…229 The substantial (P=0.0002) age-by-race interaction for incident stroke (with HRs of ≈3.0 at age 45 but 1.0 for age 85) was absent (P=0.99) for recurrent stroke, and no difference could be detected between the risk of recurrent strokes in African Americans and whites. 229…”