SCAI: Female cardiac treatment disparities rooted in lack of knowledge

SAN DIEGO—The risk factor profile in women presenting with acute coronary syndrome (ACS) and acute MI is distinctive compared to men, and cardiologists need to tailor their management of women with these differences in mind, noted Kimberly A. Skelding, MD, during a Wednesday presentation at the 33rd annual scientific sessions for the Society for Cardiovascular Angiography and Interventions (SCAI).

“There are definitely differences, and the FDA and NIH are getting involved with how we can address these differences,” said Skelding, who is an interventional cardiologist at Geisinger Health System in Danville, Pa.

Slideshow | ACS & AMI Update WIN Program - SCAI 2010

Kimberly A. Skelding MD FSCAI FACC FAHA Associate Interventional Cardiology Geisinger Health System Danville, Pennsylvania

She reviewed some of the gender differences in treatment, including later referrals, which equates to more advanced coronary artery disease, more urgent or emergency procedures and longer door-to-balloon times for women. Female patients who undergo bypass surgery have lower rates of internal mammary artery grafts, even after adjustment for age, extent of disease and urgent surgery. Some similarities between men and women include similar benefits from GP IIb/IIIa agents and stents, as well as improved PCI mortality over time.

“Although we’re improving mortality overall in both groups, we’re not doing it as well in women,” said Skelding, who encouraged practitioners to examine these potential treatment disparities at their own institutions.

Only 33 percent of PCI procedures are performed in women annually, and delayed treatment for women is common—often more than 24 hours after presentation. “It’s hard to say if this delay is a result of the disease state not being as well recognized or due to a lack of aggressive treatment,” she said.

Skelding stressed that women continue to be underrepresented in clinical trials for PCI, as they don’t meet the inclusionary criteria. “Even in the best trials, the enrollment barely reaches 25 percent,” she added. “However, the exception will be the percutaneous aortic valve trials, which will have a lot in women."

She said that women have less multi-vessel disease than their male counterparts, but "we don’t know why.”

For outcomes following PCI, contemporary subacute or late thrombosis rates are similar between genders (1.3 vs. 1.2 percent). Women are 61 percent more likely to present with in-stent restenosis following drug-eluting stent implantation, particularly diffuse in-stent restenosis. Also, almost two-times more women will return to the ER within 30 days of their intervention, even after successful interventions.

“Women have a higher rate of vascular complications after PCI,” said Skelding, which has spawned the consideration of using the transradial approach for women. However, the radial approach is still associated with more bleeding in women.

For anticoagulants, among drug applications submitted to the FDA between 1994 and 2000, 20 percent had gender differences in pharmacokinetics, including more hepatic cytochrome CYP3A in women; more dietary supplements taken by women; more accumulation in fat; and less renal excretion.

For treatment of women with acute coronary syndrome, Skelding pointed out that they are less likely to have an ECG done within 10 minutes of presentation; less likely to be cared for by a cardiologist during their inpatient admission; and less likely to acutely be given appropriate pharmacotherapy such as heparin, aspirin, statins and ACE inhibitors.

Skedling said that “while women less often receive guideline recommended therapy, they would significantly benefit from an early aggressive invasive strategy.”

She reviewed the outcome following treatment of ACS:

• Young women, at least 55 years old, have at least twice the risk of having a dissection or artery occlusion during their procedure.
• All women have increased bleeding and vascular access site complications, those at least 55 years old have more than five-times the risk compared to men.
• Following PCI, women with ACS have a 37 percent higher risk of death, MI or rehospitalization than men with ACS.
• Women who are less than 65 years old have a 46 percent higher risk of death, MI or rehospitalization.

There also are gender differences in atherosclerosis, including plaque erosion, as the etiology of coronary thrombosis and acute MI occurs at a higher frequency in women than in men. Skelding referenced an autopsy study of 291 patients who died of AMI and had coronary thrombosis. The prevalence of plaque erosion was 37 percent in women and 18 percent in men.

For the treatment of acute MI in clinical practice, women have longer door-to-balloon times and are less likely to undergo invasive evaluation on the index admission regardless of age. However, Skelding pointed out that contemporary in-hospital and late mortality rates are similar across genders when treated in randomized controlled trials.

Based on all the clinical data, Skelding encouraged cardiologists to “treat with parity. Examine your local data to see how your female patients are being diagnosed and treated in order to improve outcomes, improve practice and improve enrollment in clinical trials.”