The holiday season is a time of merriment for families around the world, but amid the excitement comes a sobering result from a Swedish study: The incidence of heart attacks spikes around the holidays, particularly on Christmas Eve.
Published online Dec. 12 in The BMJ, the analysis included more than 283,000 cases of myocardial infarction reported to the SWEDEHEART nationwide registry between 1998 and 2013. Events were documented to the nearest minute, and the incidence of MI was calculated two weeks before and after each holiday as a reference standard.
The Swedish population averaged 50.3 heart attacks on those reference dates, but the incidence increased to 69.1 per day on Christmas Eve, 64.9 on Christmas Day and 60.4 on New Year’s Day.
The relative increase was highest (37 percent) for Christmas Eve and was between 20 and 30 percent for Christmas Day, Boxing Day (Dec. 26) and New Year’s Day. There weren’t significant increases in MI associated with New Year’s Eve or Easter, but the Midsummer holiday—which the authors said is the biggest holiday in Sweden outside of Christmas, with lots of drinking, eating and dancing—was linked to a 12 percent spike in heart attacks.
People older than 75 and those with diabetes and/or coronary artery disease had the strongest associations with heightened risk around Christmastime, suggesting those individuals might be especially vulnerable to holiday-related triggers and stressors.
“Previous meta-analyses have shown that acute experience of anger, anxiety, sadness, grief, and stress increases the risk of myocardial infarction and thus possibly explains the higher risk observed in our study,” wrote the authors, led by Moman A. Mohammad of Lund University’s Department of Cardiology. “Understanding what factors, activities, and emotions precede these myocardial infarctions and how they differ from myocardial infarctions experienced on other days could help develop a strategy to manage and reduce the number of these events.”
The researchers noted the study was observational, so it couldn’t prove causation. But the heightened risk of MI associated with specific holidays was consistent for men and women, with the exception of men having a more marked jump in events on Midsummer. Mohammad et al. suggested men may be more likely than women to smoke and consume excessive amounts of food and alcohol on that particular holiday.
Other notable findings included 8 a.m. being the most likely time for an MI and heart attacks being most likely to occur on Mondays, with about a 10 percent increased incidence when compared to Sundays. There was no association for heart attacks during major soccer tournaments or the Olympics, which the researchers found surprising given previous studies that linked sporting events to peaks in MI rates.