Radiation Therapy for Cancer may Lower Survival Rates Post Major Heart Surgery

According to a new study, the chances of dying early post heart surgery are higher for patients who've undergone chest radiation for cancer.

These chest radiations kill cancerous cells, but their effect on survival rates post-heart surgery remains after many years of the initial exposure. Researchers say that the risk of dying early after a heart surgery is two times higher for people who've undergone radiation therapy for cancer.

"While radiation treatments done on children and adults in the late 1960s, '70s and '80s played an important role in cancer survival, the treatment often takes a toll on the heart. Survivors are at greater risk than people who do not have radiation to develop progressive coronary artery disease, aggressive valvular disease, as well as pericardial diseases, which affect the heart's surrounding structures. These conditions often require major cardiac surgery," said Milind Desai, M.D., associate professor of medicine at the Cleveland Clinic in Ohio, and one of the study authors.

The study included 173 patients who had undergone radiation treatment for cancer some 18 years before their heart surgery. Researchers followed these patients for about 7.6 years on an average and then compared their survival rates with 305 patients undergoing similar surgeries who had received any such radiation treatment.

Researchers said that initially, all patients, regardless of their radiation history, had similar pre-surgical risk scores. These pre-surgical scores help doctors assess how a patient will respond to a particular treatment.

The study results showed that after about 7.6 years, more than 50 percent of the radiation group patients died compared with about 28 percent of the non-radiation group.

"These findings tell us that if you had radiation, your likelihood of dying after major cardiac surgery is high. That's despite going into the surgery with a relatively low risk score. In patients who have had prior thoracic radiation, we need to develop better strategies of identifying appropriate patients that would benefit from surgical intervention. Alternatively, some patients might be better suited for percutaneous procedures,' said Desai in a news release from the American Heart Association.

The study is published in the journal Circulation.

Recently, a study published in the New England Journal of Medicine associated radiation treatment for breast cancer with increased risk of heart disease in some patients.