Grace Y. Kuo, MD, MS, BA
Sozener CB, Lisabeth LD, Shafie-Khorassani F, Kim S, Zahuranec DB, Brown DL, Skolarus LE, Burke JF, Kerber KA, Meurer WJ, et al. Trends in Stroke Recurrence in Mexican Americans and Non-Hispanic Whites. Stroke. 2020.
Stroke prevention, treatment and management have crossed many milestones in the last 20 years in developed countries, with studies showing that recurrent strokes have declined over the last 50 years. As medical options become more publicly available, health disparities between those who have benefit from secondary stroke prevention become more apparent. Epidemiological data breaking down trends in stroke recurrence will be critical to public health planning as we strive for more equity in stroke care. In this article from the Brain Attack Surveillance in Corpus Cristi (BASIC) project, we see a glimpse of hope in closing the disparity gap.
This study examines the trend in stroke recurrence in an urban population in Nueces County, Texas, of Mexican Americans (MAs) and Non-Hispanic Whites (NHWs) over 14 years. The MA population are predominantly non-immigrant, second and third generation U.S. citizens, with low incidence of return migration. Patients were eligible for database enrollment if they were at least 45 years old and resided in Nueces County at least six months per year. Mortality data was obtained from the Texas Department of State Health Services.
First-ever stroke cases were identified between January 1, 2020 and December 31, 2013, and these were followed until December 31, 2015 for stroke recurrence within one or two years. A total of 3,533 stroke patients were subsequently identified for follow-up. Within the first-ever stroke cases, it was noted that 1,989 were MA, while 1,544 were NHW. MA stroke patients were overall younger, with a significantly greater prevalence of diabetes and hypertension. NHW first-time stroke patients were older with a significantly greater prevalence of atrial fibrillation, smoking, and insured status.
206 recurrent events were observed in the 1-year follow-up, and 683 deaths occurred before any recurrence. 293 recurrent events were observed in the 2-year follow-up period, with 883 deaths before any recurrence was observed. In 2000, the adjusted cumulative incidence of 1-year recurrence amongst MAs was 9.26%, which decreased to 3.42% in 2013; this trend was statistically significant (95% CI 2.27%-5.68%). NHWs, similarly, saw a reduction in recurrence, from 5.67% to 3.59%; however, this was not statistically significant (95% CI -4.51% – 0.4%).
The greatest ethnic disparity was found in year 2000 in absolute risk comparison between MA and NHW, with a risk difference of 3.59% (95% CI 0.94%-6.22%). It must be noted that the MA group had a lower 1-year mortality risk, as death was a competing event to stroke recurrence, which may contribute to the increased number of strokes in the MA group. However, the subdistribution hazard ratio comparisons still indicated that there could be an actual effect of ethnicity. The disparity between 1-year recurrent stroke risk was no longer statistically significant by 2013. In general, the 2-year follow-up data mimic the results for 1-year follow-up.
This study is one of the few studies that have shown an improvement in measures of ethnic disparity in stroke care, concluding that ethnic disparity in stroke recurrence has improved in this particular study population. Possibilities that this result was seen in the study population include greater improvements in risk factor control over time in MAs. It is important to note that this population of MAs are more acculturated with superior English fluency, being mostly non-immigrant, second and third generation Mexican Americans. This improves their likelihood to be more responsive to public health messages regarding cardiovascular disease preventions and dietary recommendations. It must be noted that national data during this study period still suggest that MAs receive less treatment for hypertension, and improvements in treatment were less in MAs compared to NHWs. Further research into why improving trends exist in a certain minority community could provide insight for broader public health planning to improve secondary stroke prevention in minority populations.