Poor neighborhood socioeconomic status and risk of ischemic stroke after myocardial infarction

Abstract

Background: Data linking neighborhood socioeconomic status (SES) to stroke risk are scarce. We examined long-term stroke incidence according to neighborhood SES in a population-based cohort of patients hospitalized with first myocardial infarction (MI).

Methods: Consecutive patients aged 65 years or less, discharged from 8 hospitals in central Israel after incident MI in 1992-1993, were followed for stroke through 2005. Individual demographic, socioeconomic, and clinical data were obtained at study entry. We estimated neighborhood SES through a composite census-derived index developed by the Israel Central Bureau of Statistics.

Results: During a median follow-up of 13 years, 196 incident ischemic strokes occurred in 1410 patients. Accounting for death as a competing risk, patients residing in disadvantaged neighborhoods had higher rates of ischemic stroke (cumulative survival estimates: 81%, 88%, and 89% in increasing tertiles of neighborhood SES). Upon multivariable adjustment for individual SES measures (including income, education, and employment), cardiovascular risk factors, MI characteristics and severity indices, and acute management, the overall hazard ratio for stroke in the lower versus upper tertile of neighborhood SES was 1.5 (95% confidence interval [CI] = 1.0-2.3); after 13 years, the adjusted absolute risk difference was 7.9 incident stroke cases per 100 participants with MI (95% CI = 1.7-14.1).

Conclusions: Poor neighborhood SES is associated with increased risk of ischemic stroke post-MI. The association is only partly attributable to individual SES and other baseline characteristics. The potential mechanisms for this association require further study.