Heart surgery increases mortality risk for cancer survivors who had radiation

Cancer survivors who had chest radiation are at increased risk for substantial cardiac morbidity and mortality, even decades after radiation therapy, according to new research in Circulation.

Researchers conducted an observational cohort study to measure long-term survival in radiation-associated heart disease patients undergoing cardiothoracic surgery. The analysis included 478 consecutive patients undergoing cardiothoracic surgery (75% women; mean age, 63 years). Of those, 173 had chest irradiation treatment for cancer an average 18 years before needing cardiac surgery and 305 were comparison patients who did not have chest irradiation. Radiation-associated heart disease was diagnosed with clinical and echocardiographic evaluation.

Milind Desai

During a mean follow-up of 7.6 years, more patients with radiation-associated heart disease died compared with patients in the comparison group (55% vs. 28%; P<.001). The long-term survival of radiation-associated heart disease patients was worse than that of a similar, age-matched patient population who did not undergo cardiac surgery (86% at 10 years).

“This finding was consistent across various subgroups, including the ones where the expected mortality is lower (e.g. younger age and low perioperative risk),” researchers wrote.

In addition, patients with radiation-associated heart disease fared worse than comparison patients undergoing cardiothoracic surgery. Proximal CAD was higher in patients with radiation-associated heart disease (45% vs. 38%; P=.09).

Repeat cardiothoracic surgery was less common in the radiation-associated heart disease patients compared with the comparison group (20% vs. 29%; P=.02). Approximately two-thirds of patients in both groups underwent combination surgical procedures.

Pre-surgical risk scores were similar between the two groups (7.8 vs. 7.4; P=.1).

Multivariable Cox proportional hazard analysis revealed that an association between radiation-associated heart disease (HR=2.47; 95% CI, 1.82-3.36), increasing EuroSCORE (HR=1.22; 95% CI, 1.16-1.29) and lack of beta-blockers (HR=0.66; 95% CI, 0.47-0.93) with increased mortality (P<.01 for all).

“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,” Milind Desai, MD, associate professor of medicine at Cleveland Clinic, said in a press release.

“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.”

For more information:

Desai M. Circulation. 2013;doi:CIRCULATIONAHA/2013/001435.

Disclosure: The researchers report no relevant financial disclosures.