STEMI Protocol Bridges Gender Gap in Care and Outcomes

A systems-based approach to minimize care variability in the management of ST elevation myocardial infarction (STEMI) can significantly shrink the long-standing gender gap in STEMI care processes and clinical outcomes, according to a new Cleveland Clinic study.

“Despite important differences in biology and risk profiles between men and women with STEMI, we have shown that a standardized, systems-based approach to care can reduce entrenched gender disparities and significantly improve STEMI care and outcomes in women,” says Umesh Khot, MD, Vice Chair of Cardiovascular Medicine at Cleveland Clinic and senior author of the study.

“After we implemented a comprehensive four-step STEMI care protocol, we saw improved clinical outcomes in all patients,” says co-author Samir Kapadia, MD, Director of Cleveland Clinic’s Sones Cardiac Catheterization Laboratory. “Importantly, similar reductions in 30-day mortality were noted among men and women, as were similar rates of in-hospital adverse events,” adds co-author Chetan Huded, MD, MSc, who presented the study March 10 in a Young Investigator Finalist presentation at the American College of Cardiology’s 2018 scientific session. The study was simultaneously published online by the Journal of the American College of Cardiology.

What prompted the study

“It’s well established that STEMI care provided to women lags behind the care provided to men,” says Dr. Khot. He notes that women with STEMI generally are treated less rapidly compared with their male counterparts and receive guideline-directed medical therapy at lower rates. These realities underlie the fact that in-hospital mortality from STEMI was twice as high in women versus men in a major American Heart Association registry study. “This gender disparity has been identified as a public health priority, yet data on strategies to close this gender gap have been scarce.”

When Cleveland Clinic implemented a new care process for STEMI across its 10 hospitals and three freestanding emergency departments in Northeast Ohio in July 2014, the health system had an ideal opportunity to obtain some much-needed prospective data to address these issues. The aim of the new care process was to minimize variability in STEMI care through introduction of a comprehensive STEMI protocol featuring four key process changes:

• Standardization of criteria by which emergency department physicians can activate the cath lab
• Use of a “STEMI safe handoff checklist” delineating distinct roles for all caregivers involved
• Institution of a policy of immediate patient transfer to an immediately available cath lab at all times to avoid patient delays
• Transition to a “radial artery first” approach for vascular access in primary percutaneous coronary intervention (PCI) for all suitable candidates

To assess the new protocol’s effect on care processes and clinical outcomes, the researchers conducted a study of 1,272 consecutive patients with STEMI treated with primary PCI at Cleveland Clinic from 2011 through 2016. Of those 1,272 patients, 549 were treated after implementation of the STEMI protocol in July 2014 and constituted the protocol group. The other 723 patients were treated prior to the protocol and served as a control group.

Results: Protocol brings particularly large gains for women

The overall study population was 68 percent male and 32 percent female. In both the protocol and control groups, women were older than men (4-year difference in mean age) and had significantly higher rates of diabetes, cerebrovascular disease and chronic lung disease.

In the control group (before the protocol), women received guideline-directed medical therapy prior to sheath insertion significantly less often than men did (69 percent vs. 77 percent of the time; P = .019), and women had a longer door-to-balloon time (D2BT) (112 min [85, 147] vs. 104 min [79, 133]; P = .023).

Consistent with those process measure results, women in the control group had significantly higher rates of in-hospital death and cardiovascular death, stroke, vascular complications, bleeding and transfusion requirements compared with men in the control group. In contrast, no adverse events occurred significantly more often in men than in women.

“The finding of worse outcomes in women compared with men during the study’s control period is consistent with the prior literature,” observes Dr. Huded.

After implementation of the STEMI protocol in July 2014, both process measures and clinical outcomes improved overall relative to those in the control period, with the biggest gains achieved among women. The result was that gender disparities in process measures ceased to be significant, as follows:

• Use of guideline-directed medical therapy was 84 percent in men versus 80 percent in women (P = .320).
• D2BT was 89 minutes in men versus 91 minutes in women (P = .150).

In keeping with those process measures, rates of in-hospital death and cardiovascular death within the protocol group were statistically similar between men and women, as were rates of stroke, vascular complications, bleeding and all other monitored adverse events.

The absolute gender difference in 30-day mortality declined from the control period, when it was 6.1 percent higher in women (P = .002), to the period under the STEMI protocol, when it was 3.2 percent higher in women (P = .090).

More-equal care may be at hand

“These findings clearly and convincingly show that this new STEMI care process has led to substantial improvements in the care of women,” says Dr. Khot. He cites improvements in the rate of appropriate medication use, time to reperfusion and use of radial artery catheterization as specific care enhancements under the protocol. “These improvements reduced the higher risk of serious complications in women compared with men.”

While noting that these findings warrant validation at other centers, Dr. Khot points out that no patients were excluded from this large prospective analysis and that the study sample should reflect the STEMI population of any large U.S. urban STEMI referral center. “This strategy offers the promise of providing equal STEMI care to patients regardless of gender,” he concludes.