AMI rates rose during stock market crash
MedWire News: Acute myocardial infarction (AMI) rates in the USA rose markedly as stock market values plunged during the severe recession spanning the end of 2008 and early 2009, research suggests.
"We observed a significant unadjusted relation between a period of stock market decrease… and the occurrence of AMI in our local cohort, which was even stronger using a 1-month lag," report Mona Fiuzat (Duke University Medical Center, Durham North Carolina, USA) and colleagues in the American Journal of Cardiology.
They add: "The association remained statistically significant when adjusted for seasons during the 1-month lag period."
Fiuzat and colleagues looked at rates of AMI, based on events occurring within 3 days before cardiac catheterization versus total angiographies, using data from the Duke Databank for Cardiovascular Disease for the period January 2006 to July 2009.
They used US NASDAQ (National Association of Securities Dealers Automated Quotation) opening values to identify dates associated with a decrease in stock market levels.
In all, 2465 of the 11,590 patients included in the study cohort suffered an AMI. Time-series analysis showed that there was a significant increase in AMI rates during the period directly associated with a steep stock market decrease, from September 2008 to March 2009 (p=0.01).
There was also a strong correlation between this period and increased AMI rates using a 1-month lag period from October 2008 to April 2009 (p=0.003).
By contrast, further analysis showed no significant correlation between stock market returns and AMI rates over the whole 3-year period, discounting periods of volatility.
When adjusted for seasons, known to impact on cardiovascular event rates, the period directly linked to the stock market decrease was associated with only a trend towards increased AMI rates, whereas the association with the 1-month lag period remained statistically significant (p=0.02).
The team cautions that their findings should be interpreted in the context of several limitations, including that the sample was modest in number and limited to one regional center, may not reflect true events in a broad population, and did not account for fatal AMIs.
But they say the results suggest that, like acute stressors, persistent mental stress may be a trigger for AMI.
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