A study published Sept. 28 in the Annals of Thoracic Surgery is debunking the myth that women receive less surgical revascularization for coronary artery disease than men due to gender bias.

Senior study author Fraser D. Rubens, MD, and colleagues analyzed data from more than 1,200 heart disease patients between 1990 and 2015 and found that age and delayed diagnoses, rather than a sex bias, is what prevents more women from being referred for revascularization.

“It appears that by the time women present with heart disease, they are slightly older and may be facing more comorbidities such as obesity and diabetes,” Rubens said in a release from the Society of Thoracic Surgeons. “As a consequence, these higher operative risks may preclude women from undergoing the more complex multiple arterial revascularization procedures that men receive.”

An initial cohort of nearly 20,000 individuals was narrowed to 1,254—627 men and 627 women, matched in characteristics—before Rubens and colleagues evaluated all patients’ percentages of bilateral internal thoracic artery use and radial artery use during previous coronary artery bypass grafting surgeries. The team found that use of the bilateral internal thoracic artery was 31.9 percent in men and 30.1 percent in women. Figures for the radial artery were 44.5 percent and 414.1 percent for each gender, respectively.

In short, Rubens and co-authors found little difference between the sexes when it came to the actual surgeries. The scientists did, however, discover a significant gap in the number of arterial grafts received: Just 7.3 percent of women received three arterial grafts, while 10.5 percent of men underwent the treatment.

Rubens said in the release this is likely attributed to late diagnoses of heart disease in women. While men are receiving intensive care and invasive treatments, as well as gaining more access to cardiovascular medications and therapies, woman remain undiagnosed for years. Since women are diagnosed later in life, their age and elevated risk factors like obesity and diabetes prevent them from receiving the same quality of care as younger men, who can be referred for invasive surgeries due to better health.

“Higher operative risks may preclude women from undergoing the more complex multiple arterial revascularization procedures that men receive,” Rubens said.

The researchers noted in their study that newer diagnostic techniques, like coronary computed tomography and myocardial perfusion imaging, could aid in the process of diagnosing women with cardiovascular disease earlier in life, preventing complications further down the road.

“With earlier diagnoses, women could be referred for revascularization as healthier surgical candidates, affording them the opportunity of complete arterial revascularization strategies with better postoperative outcomes,” Rubens said. “This study has given us the confidence to continue educating surgeons on the feasibility of multiple arterial revascularization and to ensure that this choice of surgical strategy be based on patient risk profiles and not solely on gender.”