Surgical Removal of the Tonsils and Appendix Linked to Early Heart Attack

The surgical removal of the appendix and tonsils before the age of 20 is associated with an increased risk of premature acute myocardial infarction (AMI), according to a new study.

Researchers at the Karolinska Institute (Stockholm, Sweden) conducted a prospective matched cohort study among all Swedish residents born between 1955 and 1970, using a national register to identify all appendectomies and tonsillectomies. For each patient undergoing appendectomy or tonsillectomy, the researchers randomly selected five controls without a history of the respective operation, matched on sex, age, and county of residence. Participants were followed for fatal and non-fatal AMI for an average of 23.5 years. Because appendiceal and tonsillar tissues have reduced function after adolescence, primary analyses were restricted to individuals below age 20 at the time of surgery (54,449 appendectomies and 27,284 tonsillectomies).

The researchers found that operations before 20 years of age were associated with an increased risk for AMI (417 and 216 events in the appendectomy and tonsillectomy datasets, respectively), with adjusted HRs of 1.33 for appendectomy and 1.44 for tonsillectomy. This association was graded, with the highest risk among those undergoing both procedures, and generally similar among both males and females. Appendectomy and tonsillectomy performed at or above 20 years of age were not associated with the risk of AMI. The study was published early online on June 1, 2011, in the European Heart Journal.

"Given the strong biological and epidemiological evidence linking inflammation with coronary heart disease, one might anticipate that surgical removal of the tonsils and appendix, with their consequent effects on immunity, might also have a long-term effect on CHD," said lead author Imre Janszky, MD, PhD, of the department of public health science. "However, we were aware of no studies evaluating the potential effects of appendectomy or tonsillectomy on atherosclerosis or CHD risk."

Both the appendix and tonsils are secondary lymphoid organs whose removal can affect several aspects of immune activity, including decreased production of immunoglobulins. Recurrent tonsillitis and appendicitis, caused by infection, are the usual reasons for their removal. Studies have shown that removal was associated with moderate long-term effects on the immune system and alterations in risk for some autoimmune disorders. The researchers also noted that atherosclerosis, the underlying pathophysiology of AMI, is widely considered to be an inflammatory process.

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