ANN ARBOR, Mich. -- Having a stroke is bad enough. But having another one after surviving the first one is especially bad, more than doubling a person's risk of dying in the next two years, a new study finds.
The risk of a second stroke is especially high among members of the largest and fastest-growing subgroup of Latinos in the United States: Mexican-Americans. The new study finds that they are more likely than their non-Latino white neighbors to suffer another stroke in the first two years after living through one.
The study, published in the Annals of Neurology by a team from the University of Michigan Stroke Program in conjunction with colleagues in Texas, highlights the importance of what doctors call 'secondary prevention.'
In other words, those who live through a stroke should get special attention from their physicians and other health professionals to reduce their risk of having another one. And, because of their extra risk of suffering another stroke, those efforts should be especially stepped up in Mexican-Americans, the researchers say.
"This finding completes a picture that has been taking shape through research on ethnic differences in stroke," says lead author Lynda Lisabeth, Ph.D. "We know that Mexican-Americans have a higher overall risk of stroke, tend to have strokes starting at younger ages, and generally have a better chance of surviving their first stroke, compared with non-Hispanic whites. Now, by finding this higher rate of recurrence, we have a better idea of the overall burden of stroke in this population."
Lisabeth, an assistant professor of epidemiology at the U-M School of Public Health, performed the study with her colleagues from the U-M Medical School, who have led a study of stroke in the southeastern coastal area of Texas near the city of Corpus Christi for several years. That area was chosen because of its large population of Mexican-Americans; they make up just over half the population.
Because of the predominance of Mexican-Americans and non-Latino whites in the study population, results for other Latino subgroups and African-Americans are not available.
The study followed 1,345 people who had their first strokes between 2000 and 2004 -- 53 percent of whom were Mexican-Americans -- and determined the frequency of recurrence through the end of 2004 and recorded details about their demographics, other health problems, and whether or not they had had another stroke.
They then compared these recurrent stroke patients with the other stroke survivors who had not had a second stroke; in all the study includes data from 124 recurrent stroke patients and 417 deaths among 1,311 stroke survivors for whom complete data were available.
Mexican-American ethnicity was a strong factor in a person's risk of a second stroke. The risk of recurrent stroke at two years among the first-time stroke survivors was 11 percent.
When the researchers looked at the risk of dying from any cause during the study period, the impact of having a second stroke was dramatic. Stroke survivors who suffered a second stroke were 2.67 times more likely to die than stroke survivors who did not have a second stroke in the study period. The increased risk from recurrent stroke was present for both ethnic groups even after the researchers corrected for other health factors, age and gender.
Now, Lisabeth says, she hopes other researchers will attempt to confirm these findings in other Latino subgroups and in other samples of Mexican Americans. And, it will be important to find out what factors – including genetics, cultural and lifestyle differences, and underlying health problems – contribute to the ethnic differences.
In the meantime, she and her colleagues suggest that people of any background who have survived a stroke or "mini stroke" (also called a transient ischemic attack or TIA) should talk with their doctors often about what steps to take to reduce the risk of another stroke. Quitting smoking, keeping cholesterol and blood pressure levels down, controlling blood sugar for people with diabetes, and having a healthy diet and exercise routine can all help.
The authors also call for better awareness of stroke prevention methods and stroke symptoms among all at-risk individuals, to help prevent a first stroke or speed the recognition of a stroke when it occurs. Stroke symptoms include sudden onset of weakness or numbness on one side of the body, difficulty speaking or understanding, sudden clumsiness or unexplained falls and suddent loss of vision in one of both eyes.
In addition to Lisabeth, the new paper's authors are Melinda Smith, MPH, Devin Brown, M.D., M.S., Lemuel Moye, M.D., Ph.D., Jan Risser, Ph.D., and Lewis Morgenstern, M.D., of the U-M Medical School and the University of Texas Health Science Center at Houston.
The U-M Stroke Program, directed by Morgenstern, is part of the U-M Cardiovascular Center; for more information, visit www.med.umich.edu/stroke.
Journal
Annals of Neurology