Elsevier

Gender Medicine

Volume 9, Issue 5, October 2012, Pages 329-334
Gender Medicine

Original research
Analysis of Sex Differences in Preadmission Management of ST-Segment Elevation (STEMI) Myocardial Infarction

https://doi.org/10.1016/j.genm.2012.07.002Get rights and content

Abstract

Background

Many reports suggest gender disparity in cardiac care as a contributor to the increased mortality among women with heart disease.

Objective

We sought to identify gender differences in the management of Myocardial Infarction (MI) Alert–activated ST-segment elevation myocardial infarction (STEMI) patients that may have resulted from prehospital initiation.

Methods

A retrospective database was created for MI Alert STEMI patients who presented to the emergency department (ED) of an academic community hospital with 74,000 annual visits from April 2000 through December 2008. Included were patients meeting criteria for an MI Alert (an institutional clinical practice guideline designed to expedite cardiac catheterization for STEMI patients). Data points (before and after initiation of a prehospital alert protocol) were compared and used as markers of therapy: time to ECG, receiving β-blockers, and time to the catheterization laboratory (cath lab). Differences in categorical variables by patient sex were assessed using the χ2 test. Medians were estimated as the measure of central tendency. Quantile regression models were used to assess differences in median times between subgroups.

Results

A total of 1231 MI Alert charts were identified and analyzed. The majority of the study population were male (70%), arrived at the ED via ambulance (60.1%), and were taking a β-blocker (67.8%) or aspirin (91.6%) at the time of the ED admission. Female patients were more likely than male patients to arrive at the ED via ambulance (65.9% vs 57.6%, respectively; P = 0.014). The median age of female patients was 68 years, whereas male patients were significantly younger (median age, 59 years; P < 0.001). The proportion of patients currently taking a β-blocker or low-dose aspirin did not vary by gender. Overall, 78.2% of the MI Alert patients arriving at the ED were MI2 (alert initiated by ED physician), and this did not vary by gender (P = 0.33). A total of 1064 MI Alert patients went to the cath lab: 766 male patients (88.9%) and 298 female patients (80.8%). Overall, the median time to cath lab arrival was 79 minutes for men and 81 minutes for women (P = 0.38). Overall, the median time to cath lab arrival significantly decreased from MI1 to MI3, (Ptrend < 0.001). For prehospital-initiated alerts (MI3), the median time to cath lab arrival was the same for men and women (64 minutes; P = 1.0). For hospital-initiated alerts, time to cath lab arrival was 82 minutes for male patients and 84 minutes for female patients (P = 0.38). Prehospital activation of the process decreased the time to the cath lab by 19 minutes (P < 0.001; 95% CI, 13.2–24.8).

Conclusion

No significant gender differences were apparent in the STEMI patients analyzed, whether the MI Alert was initiated in the ED or prehospital initiated. Initiating prehospital-based alerts significantly decreased the time to the cath lab.

Introduction

In the United States each year, >5.3 million individuals present to emergency departments with chest discomfort and related symptoms, and ultimately >1.4 million of them are hospitalized for acute coronary syndrome (ACS).1 Potential sex differences in ACS management have been of particular interest. Although sex is the most accurate term in describing these biological differences, in this manuscript we have used the term “gender”–the socially assigned characteristics of an individual–as it is frequently the term used by health care providers.

Several studies performed outside the United States show no major influence of gender on coronary artery disease management.2, 3, 4, 5 Yet it is perceived that women in the United States with ACS receive more conservative care than men, specifically fewer hospitalizations, fewer established pharmacological therapies, and fewer percutaneous coronary interventions (PCIs).6, 7, 8, 9, 10, 11, 12, 13 Studies have looked at this from many angles. Recent interest in the provision of care in the out-of-hospital setting has illustrated significant gender disparity in treatment as well as delays in emergency medical services transport for women.14, 15 These delays could affect delivery time of services, particularly PCI. If gender differences could be specifically and consistently defined, it might allow us to better focus our strategies to eliminate their existence.

At our institution, a 988-bed academic, tertiary care, community medical center accredited by the Society of Chest Pain Centers (which has an annual census of 74,000 patients), “Heart Help for Women” (HHW) is an initiative that was developed to address the issue of gender disparity in cardiac care in our institution and community. This center also has 24-hour access to the cardiac catheterization laboratory (cath lab) (staff are on call nights and weekends). As a part of the HHW initiative, a network team of investigators set out to define and resolve any gender differences in the care of our emergency department (ED) cardiac patients. Simultaneously, in the year 2000, the network initiated an early recognition management program (Myocardial Infarction [MI] Alert) to improve door-to-balloon time for patients with ST-segment elevation myocardial infarction (STEMI). In a quality improvement assessment of the process, it was already established that there were no gender differences in MI Alert STEMI patients in the time to ECG, β-blocker administration, or time to the cath lab. This program was upgraded in 2007 to include prehospital activation (MI3). It has been shown that field triage programs like ours decrease the revascularization time for STEMI patients.16 It is recognized that non-STEMIs are the more prevalent form of MI, and although STEMI is the minority type of MI, it is the type on which the authors chose to focus their attention. In this retrospective review of a cohort of STEMI patients, we sought to identify and evaluate any gender gaps in the management of MI Alert–activated STEMI patients that may have resulted from the initiation of the prehospital MI Alert (MI3) protocol.

Section snippets

Methods

After obtaining expedited approval from our hospital's Institutional Review Board, a retrospective database review of a cohort of STEMI patients was performed. This database was populated by an automated abstraction of the electronic medical record that was supplemented by manual abstraction performed by the institution's MI Alert coordinator. The database was maintained for patients who had presented to the ED with an MI Alert STEMI from April 2000 through December 2008.

MI patients included

Results

A total of 1231 MI Alert charts were identified and analyzed. Characteristics of the study population and patient visits to the ED are presented in Table I. The majority of the study population was male (70.0%), arrived at the ED via ambulance (60.1%), and were taking β-blockers (67.8%) or aspirin (91.6%) at the time of ED admission. Female patients were more likely than male patients to arrive at the ED via ambulance (65.9% vs 57.6%, respectively; P = 0.014). The median age of female patients

Discussion

To our knowledge, the addition of a prehospital component to protocol-driven STEMI management has not been assessed for its impact on provision of care for women. These results suggest that there are no statistically significant gender differences in the management of STEMI patients and specifically by the addition of field activation. Based on our findings, we suggest that future resources devoted to teasing out the cause of gender disparities in ACS patient outcomes not be devoted to the area

Conclusions

In this retrospective cohort study, protocol-driven STEMI management had no statistically significant gender differences in the outcomes evaluated. No conclusions can be made for other types of MI. However, the addition of field activation of a STEMI protocol does not appear to negatively affect the care provided to female STEMI patients, and it benefits both genders by significantly decreasing door-to-balloon times.

Conflicts of Interest

The authors have indicated that they have no conflicts of interest regarding the content of this article.

Acknowledgments

Drs. Greenberg, Miller, MacKenzie, Richardson, Annert, Scalfani, Jozefick, and Ms. Rupp conceived the study, designed the trial, and obtained research funding. Drs. Greenberg, Miller, MacKenzie, Richardson, Burmeister, and Ms. Rupp supervised the conduct of the study and data collection. Drs. Greenberg, Miller, MacKenzie, Richardson, Scalfani, Jozefick, Goyke, Burmeister, and Ms. Rupp managed the data. Stephen W. Dusza, DrPH, provided statistical advice and analyzed the data. Dr. Greenberg

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