Fighting prostate cancer by lowering the levels of androgens—male sex hormones—has proven successful in saving lives, but a new study shows that this therapy may increase the risk of heart disease. Of the 3,262 patients in the study who underwent prostate surgery, the 266 men who also received androgen deprivation therapy had about a 2.5 higher chance of dying from heart disease. A majority of the deaths occurred in patients who were 65 or older.

Although there are no concrete explanations for these findings, lead researcher Henry Tsai, MD, suggests that all doctors should evaluate a patient’s risk of heart disease before recommending androgen deprivation therapy.