New research, published in "Circulation: Cardiovascular Quality and Outcomes", finds women who have endometriosis, the abnormal growth of uterine tissue outside the uterus, may face a 60 percent higher risk of developing heart disease than women without the disorder. The potential risk was especially high for women 40 or younger. At least 10 percent of women of reproductive age suffer from endometriosis (endo) says Dr. Stacey Missmer of Brigham and Women's Hospital, who co-authored the study.