Rates of recurrent stroke have been on the decline in recent years—reaching a rate similar to that of non-Hispanic whites by 2013.
While most studies examining racial and ethnic disparities in cardiovascular care usually return disappointing findings, a recent study suggests the rate of recurrent strokes has declined significantly among Mexican Americans in recent years.
Results of the study, which was a prespecified analysis of the BASIC study, indicate Mexican Americans experienced significant reductions in stroke recurrence, with disparities between Mexican Americans and non-Hispanic white counterparts disappearing by end of the study period.
"Throughout this long-term study, this is the first time that we have encountered an improvement in any major marker of ethnic stroke disparities," said lead investigator Lewis Morgenstern, MD, professor of neurology and epidemiology at the University of Michigan's Medical School and School of Public Health, in a statement.
As a result of advances in care and major public health efforts, cardiologists have seen the rates of stroke incidence and mortality decline rapidly in recent years. However, despite this progress, information on the rates and trends of stroke recurrence remains scarce when it pertains to certain ethnic groups. To further illustrate the trends in stroke recurrence among Mexican Americans, investigators designed a study to examine recurrence trend estimates in Mexican Americans compared against non-Hispanic whites using data from the Brain Attack Surveillance in Corpus Christi (BASIC) study.
A primary, prespecified analysis of BASIC, investigators had data related to a cohort of 3533 incident stroke patients who were followed to determine the 1- and 2-year recurrence between 2000-2013. Of these patients, 56.2% (n=2006) identified as Mexican Americans. Investigators noted Mexican Americans were younger and had a greater prevalence of diabetes mellitus and hypertension while non-Hispanic whites had a greater prevalence of atrial fibrillation, were more likely to smoke, and were more likely to be insured.
Of note, age, sex, atrial fibrillation, cholesterol, diabetes mellitus, hypertension, smoking status, and insurance were included as covariates in adjusted analyses. Additionally, the calendar year of the index event was used as a continuous predictor.
At the 1-year follow-up, 206 recurrent events occurred in the study group and 683 deaths occurred before any recurrence was observed. At the 2-year follow-up, 293 recurrent events occurred in the study group and 883 deaths occurred before any recurrence was observed.
In 2000, the cumulative 1-year recurrence rate among Mexican Americans was 9.26% (95% CI, 6.9-12.43%) and this rate fell to 3.42% (95% CI, 2.25-5.21%) in 2013. In comparison, among non-Hispanic whites the adjusted cumulative incidence of 1-year recurrence in 2000 was and the rate fell to 3.59% (95% CI, 2.27-5.68%) in 2013. Investigators pointed out the recurrence trend change from 2000-2013 reached significance in Mexican Americans, but not among non-Hispanic whites (-2.08; 95% CI, -4.51 to 0.4%).
Furthermore, investigators found a significant ethnic disparity in stroke recurrence in 2000, but this disparity was no longer present in 2013. However, investigators highlighted the competing 1-year mortality risk for non-Hispanic whites decreased over the study period (-4.67%; 95% CI, -8.72 to -0.75%) while the rate for Mexican Americans was stable over time.
"These results suggest that stroke recurrence continues to decline in both populations, but faster in Mexican Americans, perhaps because their rates were so high to begin with," Morgenstern added. "Individuals should work to reduce their chance of having a stroke by following national healthy living guidelines such as the American Heart Association's Life's Simple 7."
This study, “Trends in Stroke Recurrence in Mexican Americans and Non-Hispanic Whites,” was published in Stroke.