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Women with heart disease tend to receive fewer surgical coronary artery bypass graft (CABG) procedures than men, but gender bias in selecting patients for surgery is not to blame, new research suggests.
Rather, when delayed coronary artery disease (CAD) is diagnosed in women, they are frequently older and sicker than men when presenting for treatment and, therefore, poorer candidates for aggressive surgical revascularization, said Fraser Rubens, MD, of the University of Ottawa Heart Institute, who led a study published Thursday.
Action Points
- Note that this study of a single, albeit large, Canadian health system found that fewer women with heart disease undergo CABG than men.
- However this discrepancy was largely due to later diagnosis, leading to a greater burden of comorbidity among these women.
That later diagnosis does reflect a gender inequity, Rubens told 51˶, one that urgently needs to be addressed.
"We need to try to get them to surgery at an earlier stage before they develop comorbidities such as diabetes or obesity," he said. "If more women had (CABG) surgeries at earlier stages when they are better able to tolerate it, outcomes would be better."
Cardiologist Nieca Goldberg, MD, of NYU Langone Health Medical Center in New York City, told 51˶ she agreed.
"It is somewhat disheartening that after all these years, we are still talking about this," said Goldberg, who was not involved with the study. "We have known for some time that women with heart disease are less likely to have these surgical procedures and that, compared to men, they do not get as complete a relief from symptoms when they do have them."
Goldberg said clinicians still tend to be less aggressive in controlling risk factors for heart disease in women than in men.
"This needs to be addressed," she said. "We need to get better at targeting women of all ages and get aggressive about reducing their cardiovascular risk."
The researchers assessed gender differences in surgical procedures for coronary artery disease using the Ottawa Heart Institute database of patients who have undergone CABG at the institution since 1990. The Ottawa Heart Institute is the largest cardiovascular health center in Canada and the sole provider of cardiac surgical services in the region.
A total of 19,557 CABG procedures were included in the larger analysis and the researchers conducted propensity-balanced analysis using a subset of 1,254 patients based on 45 pretreatment covariates (627 male and 627 female patients).
In the entire cohort, male gender was associated with increased use of bilateral internal thoracic artery or BITA (OR 1.667; 95% CI 1.166-2.386; P<0.005).
Multiple-arterial grafting increased annually in both genders, but the rate of increase in BITA use was greater in men (1.59% per year, 95% CI 1.56%-1.63%, versus 1.37% per year, 95% CI 1.30%-1.45%; P<0.001).
The use of three arteries was also greater in men (1.16% per year, 95% CI 1.13%-1.20%, vs 0.73% per year, 95% CI 0.67%-0.80%; P<0.001) as was the use of any two arteries (2.34% per year, 95% CI 2.32% to 2.35%, versus 1.92% per year, 95% CI 1.90%-1.95%; P<0.001).
In the propensity-matched patients, however, there was no difference in BITA use (male: 31.9%, female: 30.1%; P=0.502), BITA use in low-risk patients (male: 46.4%, female: 38.0%; P=0.126), or radial artery use (male: 44.5%, female: 44.1%; P=0.994).
Use of three arteries was greater in men (10.5% versus 7.3%, P=0.048).
Women in the overall cohort experienced higher rates of non-ST segment myocardial infarction, recent MI peripheral vascular disease, pulmonary edema, cerebral vascular accident, anemia, hypertension, diabetes, COPD, heart failure and carotid disease. They also tended to be older with higher BMIs.
Rubens said one reason for the delayed diagnosis of heart disease in women may be that common testing strategies, such as exercise treadmills, are not as sensitive and specific in women. He said newer diagnostic tests including coronary computed tomography and myocardial perfusion imaging may do better.
The researchers concluded that studies examining surgical revascularization rates in women versus men "remain outdated and have yet to examine the differences in rates of multiarterial revascularization between genders."
"As women are increasingly being included in CAD trials, data are emerging that CAD perhaps should be managed differently in women," they wrote. "Continued statements that all women have worse outcomes with CABG than men are counterproductive and will possibly perpetuate a gender bias and a sub par approach to arterial CABG revascularization in women."
Disclosures
The researchers declared no relevant relationships with industry related to this study.
Primary Source
Annals of Thoracic Surgery
Jabagi H, et al "Impact of gender on arterial revascularization strategies for coronary artery bypass grafting" Ann Thor Surg 2017; DOI: 10.1016/j.athoracsur.2017.06.054.