According to the American Heart Association, approximately every 40 seconds, someone in the U.S. will have a heart attack.
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The study is among the first to examine both the short- and long-term impact of a sudden cardiac event on mental cognitive abilities.
Researchers analyzed data in six long-term studies conducted between 1971 and 2017: Atherosclerosis Risk in Communities Study; Coronary Artery Risk Development in Young Adults Study; Cardiovascular Health Study; Framingham Offspring Study; Multi-Ethnic Study of Atherosclerosis; and Northern Manhattan Study.
Of the 31,377 study participants: 56% were women, 23% were Black adults, 8% were Hispanic adults and 69% were white adults. Participants were a median age of 60 years at the time of the first cognitive assessment. To be included in the study, participants could not have had a heart attack or have been diagnosed with dementia.
Because the studies used different cognitive measures and tested participants at different time intervals, a team of neuroscientists and statisticians “harmonized” the data before this analysis to adjust for differences among the study groups and the cognitive measure screening methods.
Cognitive tests were categorized into three areas: memory (such as the ability to memorize something initially and to later recall or recognize what you memorized); executive functioning (such as the ability to pay attention, plan, organize and make complex decisions) and global cognition (overall performance on cognitive tests, which includes both memory and executive functioning).
Results were adjusted for numerous demographic factors, heart disease risk factors, and cognitive test results before a heart attack. Participants who had a stroke during the follow-up period were no longer included in the analysis since a stroke can impact cognition.
During the time participants were followed (between 4.9 to 19.7 years, with a median of 6.4 years), 1,047 had a heart attack. Researchers found that compared with those who did not experience a heart attack, participants who had a heart attack did not have a significant decline in any measure of cognition soon after the time of the heart attack.
Participants who had a heart attack did have significantly faster declines in memory, executive functioning, and global cognition in the years following the heart attack.
Documenting the association between heart attack and cognitive decline opens the door to future research to identify the mechanisms that are involved.
Researchers noted several mechanisms may be attributed to this link, such as ongoing damage to the brain from silent strokes, which is a stroke not large enough to be recognized as a stroke yet still impairing the supply of blood or oxygen to the brain.
Shared risk factors for heart attack and dementia (smoking and high blood pressure), or having a heart attack could change the structure of the heart and increase the risk of mini-clots going to the brain and reducing oxygen reaching the brain.
Although the study documented an association between heart attack and faster cognitive decline, it is unable to establish that a heart attack directly causes cognitive decline.
Because the studies all took place in the United States, the results are likely to be generalizable to people in countries with similar medical resources. However, the findings may not be generalizable to people in countries where there is less access to medical care.
Source: Medindia
