Hospital admissions for acute aortic dissection were highest during peak flu season November-March, according to research presented at the American Heart Association's Scientific Sessions 2014.
Acute aortic dissection (AAD) is a life-threatening condition in which blood leaks from the aorta, the major artery that carries blood from the heart to the body. The leak is often caused by a tear in the inside wall of the aorta. The most common symptom of aortic dissection is sudden and severe chest or upper back pain.
Researchers at the University of Texas Health Science Center at Houston compared national flu activity from the U.S. Centers for Disease Control to monthly admissions for AAD at their center for 2001-13. They found:
- Doctors treated 869 AAD patients at UT-Houston during the period.
- Admissions for AAD were highest in November-March (3.1 per month during this period compared to 2.1 per month for the remaining months).
- Flu activity (percent of office visits for flu-like illness) averaged 2.6 percent during the peak AAD period (November-March) compared to 1.1 percent in the remaining months.
- A mathematical model showed statistically significant seasonality and showed type A dissection and flu activity moving cyclically and generally in synchrony throughout the period.
- Type A dissection was significantly linked with peak flu activity.
Type A dissection, the most devastating type of AAD dissection, involves the ascending aorta and/or aortic arch and possibly the descending aorta. Type A generally requires surgery.
"We suspect that flu creates an inflammatory reaction that could theoretically increase chances of dissection in susceptible individuals," said Harleen K. Sandhu, M.D., M.P.H., study senior researcher. "While more research is needed to further explore this association, we suggest at-risk patients, such as older Americans, should get seasonal flu shots."