Trends in Stroke Recurrence in Mexican Americans and Non-Hispanic Whites.

BACKGROUND AND PURPOSE: Stroke incidence and mortality are declining rapidly in developed countries. Little data on ethnic-specific stroke recurrence trends exist. Fourteen-year stroke recurrence trend estimates were evaluated in Mexican Americans and non-Hispanic whites in a population-based study. METHODS: Recurrent stroke was ascertained prospectively in the population-based BASIC (Brain Attack Surveillance in Corpus Christi) project in Texas, between 2000 and 2013. Incident cases were followed forward to determine 1- and 2-year recurrence. Fine & Gray subdistribution hazard models were used to estimate adjusted trends in the absolute recurrence risk and ethnic differences in the secular trends. The ethnic difference in the secular trend was examined using an interaction term between index year and ethnicity in the models adjusted for age, sex, hypertension, diabetes mellitus, smoking, atrial fibrillation, insurance, and cholesterol and relevant interaction terms. RESULTS: From January 1, 2000 to December 31, 2013 (N=3571), the cumulative incidence of 1-year recurrence in Mexican Americans decreased from 9.26% (95% CI, 6.9%-12.43%) in 2000 to 3.42% (95% CI, 2.25%-5.21%) in 2013. Among non-Hispanic whites, the cumulative incidence of 1-year recurrence in non-Hispanic whites decreased from 5.67% (95% CI, 3.74%-8.62%) in 2000 to 3.59% (95% CI, 2.27%-5.68%) in 2013. The significant ethnic disparity in stroke recurrence existed in 2000 (risk difference, 3.59% [95% CI, 0.94%-6.22%]) but was no longer seen by 2013 (risk difference, -0.17% [95% CI, -1.96% to 1.5%]). The competing 1-year mortality risk was stable over time among Mexican Americans, while for non-Hispanic whites it was decreasing over time (difference between 2000 and 2013: -4.67% [95% CI, -8.72% to -0.75%]). CONCLUSIONS: Mexican Americans had significant reductions in stroke recurrence despite a stable death rate, a promising indicator. The ethnic disparity in stroke recurrence present early in the study was gone by 2013.

Loss of the Mexican American survival advantage after ischemic stroke.

BACKGROUND AND PURPOSE: Mexican Americans (MAs) were previously found to have lower mortality after ischemic stroke than non-Hispanic whites. We studied mortality trends in a population-based design. METHODS: Active and passive surveillance were used to find all ischemic stroke cases from January 2000 to December 2011 in Nueces County, TX. Deaths were ascertained from the Texas Department of Health through December 31, 2012. Cumulative 30-day and 1-year mortality adjusted for covariates was estimated using log-binomial models with a linear term for year of stroke onset used to model time trends. Models used data from the entire study period to estimate adjusted mortality among stroke cases in 2000 and 2011 and to calculate projected ethnic differences. RESULTS: There were 1974 ischemic strokes among non-Hispanic whites and 2439 among MAs. Between 2000 and 2011, model estimated mortality declined among non-Hispanic whites at 30 days (7.6% to 5.6%; P=0.24) and 1 year (20.8% to 15.5%; P=0.02). Among MAs, 30-day model estimated mortality remained stagnant at 5.1% to 5.2% (P=0.92), and a slight decline from 17.4% to 15.3% was observed for 1-year mortality (P=0.26). Although ethnic differences in 30-day (P=0.01) and 1-year (P=0.06) mortality were apparent in 2000, they were not so in 2011 (30-day mortality, P=0.63; 1-year mortality, P=0.92). CONCLUSIONS: Overall, mortality after ischemic stroke has declined in the past decade, although significant declines were only observed for non-Hispanic whites and not MAs at 1 year. The survival advantage previously documented among MAs vanished by 2011. Renewed stroke prevention and treatment efforts for MAs are needed.

Persistent ischemic stroke disparities despite declining incidence in Mexican Americans.

OBJECTIVE: To determine trends in ischemic stroke incidence among Mexican Americans and non-Hispanic whites. METHODS: We performed population-based stroke surveillance from January 1, 2000 to December 31, 2010 in Corpus Christi, Texas. Ischemic stroke patients 45 years and older were ascertained from potential sources, and charts were abstracted. Neurologists validated cases based on source documentation blinded to ethnicity and age. Crude and age-, sex-, and ethnicity-adjusted annual incidence was calculated for first ever completed ischemic stroke. Poisson regression models were used to calculate adjusted ischemic stroke rates, rate ratios, and trends. RESULTS: There were 2,604 ischemic strokes in Mexican Americans and 2,042 in non-Hispanic whites. The rate ratios (Mexican American:non-Hispanic white) were 1.94 (95% confidence interval [CI] = 1.67-2.25), 1.50 (95% CI = 1.35-1.67), and 1.00 (95% CI = 0.90-1.11) among those aged 45 to 59, 60 to 74, and 75 years and older, respectively, and 1.34 (95% CI = 1.23-1.46) when adjusted for age. Ischemic stroke incidence declined during the study period by 35.9% (95% CI = 25.9-44.5). The decline was limited to those aged ≥60 years, and happened in both ethnic groups similarly (p > 0.10), implying that the disparities seen in the 45- to 74-year age group persist unabated. INTERPRETATION: Ischemic stroke incidence rates have declined dramatically in the past decade in both ethnic groups for those aged ≥60 years. However, the disparity between Mexican American and non-Hispanic white stroke rates persists in those <75 years of age. Although the decline in stroke is encouraging, additional prevention efforts targeting young Mexican Americans are warranted.