Ethnic Minorities Exhibit Reduction in Door-to-Balloon Time Comparable to Whites with a Newly-Implemented Emergency Physician Activation Protocol (Code-STEMI)
ABSTRACT: Background. Studies have shown significant differences in door-to-balloon times (D2B) for ethnic minority patients (minorities) undergoing angioplasty for ST-elevation myocardial infarction (STEMI) compared to white patients (white). In this study, we evaluated the D2B for these groups before and after modification of the emergency protocol for STEMI. Methods. We compared D2B for 51 consecutive STEMIs during 2006, (serial activation protocol, SAP) with D2B times for 72 consecutive STEMI patients during 2007 when a “Code STEMI” (concurrent activation) protocol was instituted. Outcomes were D2B times in whites versus minorities, pre- and post-Code-STEMI, length of stay (LOS) and peak troponin I levels. Results. The median D2B time in the SAP group was 113 (whites) vs. 122 (minorities) minutes (p = 0.324), as compared to 74 (whites) vs. 78 (minorities) minutes (p = 0.324) in the Code STEMI group. The D2B for both groups was significantly reduced (p 50%) of ethnic minority patients with STEMI come to St. Joseph’s Regional Medical Center. Therefore, we conducted a retrospective observational study to evaluate ethnic and racial differences in D2B for primary coronary angioplasty for the treatment of STEMIs. We also assessed the effectiveness of the newly implemented Code-STEMI protocol, beginning in January 2007, compared with the usual-care SAP in 2006 for all ethnic groups. We also proposed that either protocol would show no racial disparity in receiving timely reperfusion treatment for STEMI using PCI and that any benefit in the reduction of D2B for STEMI with utilization of the Code-STEMI protocol would be similar for both whites and ethnic minority patients. To our knowledge, this is the first study comparing an emergency physician-activated process (SAP) to assess the reduction of D2B time for ethnic minority versus non-ethnic minority patients.
Methods
Study design. We conducted a retrospective observational study over two sequential 12-month periods for each of two cohorts with STEMI treated with primary PCI: ethnic minority (African-Americans/Blacks, Hispanics, Asian/Pacific Islanders and other non-whites) and whites in our 660-bed, inner-city teaching hospital (St. Joseph’s Regional Medical Center). We compared primary PCI D2B times for patients presenting with STEMI treated in 2006 with our usual-care SAP, consisting of sequential telephone calls from the ER physician to the primary care physician, to the interventional cardiologist and the CCL. Fifty-one sequential patients in the SAP cohort presented from January 1, 2006 through December 31, 2006. These patients were compared with 72 sequential patients in the Code STEMI protocol implemented at our institution starting on January 1, 2007 with patients enrolled through December 31, 2007. Overseen by two physicians, data from primary documents were collected in a standardized form. Two independent observers cross-checked source documentation using ER computerized medical records and the patient’s medical record. The data were compiled in an Excel 2003 spreadsheet (Excel 2003; Microsoft, Redmond, Washington). Our study received formal institutional review board exemption because it was an observational study judged to present no risk to the subjects included.
Setting and selection of participants. This study was conducted at St. Joseph’s Regional Medical Center, a 660-bed, inner-city, acute-care, teaching, tertiary medical center located in Paterson, New Jersey. During the time period studied (January 2006 through December 2007), a clinical cardiology fellow was available in the hospital 24 hours a day, 7 days a week, while an attending interventional cardiologist and a non-interventional cardiologist took call from home. Additionally, 15 cardiac catheterization technical and nursing staff members took rotating call from home during off-hours (Monday–Friday 5:00 pm to 8:00 am) and weekend hours (from 5:00 pm Friday to 8:00 am Monday). When emergently called, both the interventional cardiologist and the CCL staff members were required to arrive to the CCL within 30 minutes. Only patients believed to have suffered a STEMI based on electrocardiographic (ECG) criteria and who were taken emergently to the CCL were included in our study. The ECG criteria used to define a STEMI were: ST elevation > 1 mm in two contiguous limb leads and > 2 mm in precordial leads, or new-onset of left bundle branch block. Patients transferred for urgent revascularization from another facility were excluded from analysis. None of the patients who presented with STEMI were excluded from this analysis. No other changes were made in the standard operating procedure for the care of a STEMI patient including pharmacotherapy and standard medical care.
Data collection and processing. Protocol during cardiology activation serial activation protocol (SAP): January 1, 2006 through December 31, 2006. All patients suspected of having symptoms consistent with myocardial ischemia received an ECG upon arrival to the ER. The ER physician evaluated these ECGs to identify patients with acute STEMI. Once a patient with a STEMI was identified, the ER physician paged the in-house cardiology fellow. The fellow would then contact the patient’s primary-care physician who would indicate which interventional cardiologist to contact — who may or may not have been available at the time. If the patient was under the care of a primary care physician and a cardiologist, the cardiology fellow would try to contact the cardiologist who may or may not have been available, and may or may not have been an interventionalist. If the cardiologist was available and was a non-interventionalist, he/she would try to contact an interventionalist in their group or ask the cardiology fellow to call the interventionalist on call. If the interventional cardiologist agreed with the diagnosis of STEMI, the CCL was activated by the cardiology fellow directly through the CCL patient coordinator or the hospital page operator during off-hours and weekend. Once the CCL team was on site and the CCL coordinator was available, the laboratory coordinator called ER to have the patient transferred to the CCL. Based on national standard STEMI guidelines and the recommendation of the interventionist, appropriate medical therapy was initiated in the ER.
Protocol during ER physician activation “Code-STEMI”: January 1 2007, through September 31, 2007. The Code-STEMI protocol was implemented at our institution starting on January 1, 2007. This protocol bypassed private primary care physicians and private cardiologists and authorized the ER physician to simultaneously activate the interventional cardiologist on call, the cardiology fellow on call and the CCL. This was accomplished by a single call placed by the ER physician to the page operator. The page operator in turn notified the in-house cardiology fellow, the interventional cardiologist on call, and the CCL coordinator and staff during normal working hours, evening and night hours and during weekend. As in the SAP, the patient was transferred to the CCL once the team and laboratory were available.
Patient demographic and historical information. We obtained patient race, age, sex, time of initial presentation, and history of coronary artery disease (CAD), diabetes mellitus, coronary artery bypass graft surgery (CABG), hypertension, dyslipidemia, family history of premature CAD, smoking and cerebral vascular accident. The D2B during the serial activation protocol and Code-STEMI protocol was categorized based on the race of the patient.
Study objectives. The primary endpoint for this study was the D2B. The primary objective was to compare D2B for the 12-month period of SAP to the Code-STEMI protocol as it relates to the care of minority and non-ethnic minority patients presenting with STEMI. The secondary endpoints were:
• To compare ethnic minorities’ D2Bs to that of whites pre- and post-Code-STEMI;
• Length of hospital stay for both ethnic minorities and whites;
• Peak troponin I serum levels from the SAP compared to the Code-STEMI protocol for ethnic minorities and whites.
Statistical analysis. All categorical data were analyzed by either Fisher’s exact test (for 2 x 2 cross tabulation) or the chi-square test (for 2 x n cross tabulation). Continuous data were tested for fit-to-normality by the D’Agostino-Pearson omnibus normality test. Data, which were normally distributed, were compared by a parametric method (unpaired t-test); non-normally distributed data were compared by the Mann-Whitney test. The reduction in D2B for both groups was analyzed by the two-way ANOVA test using pre- and post-Code STEMI and whites/minority as the independent variables. For normally distributed data, mean ± 1 standard deviation (SD), 95% confidence intervals (CI) are given; for non-normally distributed data, we used median and interquartile ranges (IQR). All calculations were made with Prism™ software (GraphPad Corp., San Diego).
Results
Baseline characteristics of patients. Baseline characteristics of subjects in the SAP and Code-STEMI groups are presented in Table 1. Both groups were compared in reference to age, gender, race, history of CAD, dyslipidemia, diabetes, CABG, hypertension, peripheral vascular disease, blood pressure and heart rate. No statistically significant difference was found between these characteristics at baseline between the two groups. Furthermore, the number of patients (n = 51) in the SAP group was similar to that in the Code-STEMI group (n = 72, p = 0.72).
Door-to-balloon time. Median D2B in the SAP group was 113 minutes (interquartile ranges) for whites as compared to 122 minutes (p = 0.324) for ethnic minority patients. Median D2B in the Code-STEMI group was 74 minutes for whites, which was not significantly different from the minority D2B of 78 minutes (p = 0.324). For whites, the D2B decreased from a median 113 minutes for the SAP group to a median of 74 minutes after implementing the Code-STEMI protocol. This represents a reduction of 39 minutes. A similar result was observed for minorities, where the D2B decreased from a median 122 minutes in the SAP group to 78 minutes for the Code-STEMI group. This represents a total reduction of 44 minutes. The reduction of D2B for both groups was significant (p Discussion
The AHA3 outlined several guiding principles at the March 2006 conference: Development of System of Care for STEMI Patients. In addition to principles aimed at reducing disparities based on ethnic/racial, socioeconomic and regional variation in health-care delivery regarding the care of a STEMI patient, and implementing evidence-based research in improving the quality of care. Several studies have discussed race and ethnicity with regard to cardiovascular care.14–19 Kressin et al15 showed that despite adjusting for clinical indication, African-American, Hispanic and Asian patients are less likely to receive percutaneous transluminal coronary angioplasty (PTCA) than white patients. Schneider et al18 provided evidence that significant variation by geographic region as a possible reason for overuse of PTCA in white males. Furthermore, Bradley et al14 illustrated that the hospital of admission was responsible for disparities in time-to-treatment based on race and ethnicity. On the contrary, independent of hospital, insurance and clinical characteristics, African-American and lower-income patients exhibited significant disparities in receiving primary PCI after STEMI as reported by Casale et al.17 However, the D2B time was not documented for ethnic minorities versus whites.
To our knowledge, our study is the first to show a significant reduction in D2Bs for minorities using the Code-STEMI process of care versus the SAP, where 78% of minorities and 87% of whites achieved a D2B of 90 minutes are associated with higher mortality rates, irrespective of risk factors and symptom onset-to-door times. Therefore, lowering the D2B will translate into a mortality benefit for our patients. The D2B data reported here for the SAP group set were similar to the data reported by McNamara et al16 from the National Registry of Myocardial Infarction (NRMI) 3 and 4. Moreover, our newly implemented Code-STEMI protocol achieved D2Bs of 74 minutes for whites and 78 minutes for minorities. Khot et al8 and Barbagelata et al20 reported similar D2Bs of 75.5 and 78 minutes, respectively, for their population. However, there were no separate data reported for ethnic minorities based on a new protocol to decrease D2B.
In addition to decreasing the length of stay, we were also able to achieve lower 24-hour peak troponin levels using the Code-STEMI process of care as compared to the SAP (p = 0.0005). An elevated troponin I level is associated with a poorer prognosis. The GUSTO IIa study group demonstrated the relationship between the degree of troponin elevation and 30-day mortality rates.21,22 Therefore, achieving a lower peak troponin level with the newly implemented Code-STEMI protocol is associated with a significant mortality benefit. We also noticed that minorities had lower peak troponin I levels in both the SAP and Code-STEMI groups. This suggests that minorities will experience a 30-day mortality benefit.
Cultural sensitivity, diversity awareness from training provided by the institution or state, in addition to the experience gained on the job, we believe, contributed to the success of our staff in overcoming some of the cultural barriers encountered during the process of delivering health care to diverse population of different ethnicities. Furthermore, strict adherence to a protocol can eliminate some of the subjectivity that might lead to ethnic disparities such as access to care, knowledge of disease, socioeconomic status, patient/physician relationship and the willingness to undergo a procedure. In fact, it has been publicized that racial differences in the use of cardiac catheterization were independent of the race of the physician treating the patient.19 This provides further evidence for the need of established protocols when possible to reduce racial disparities, ensuring appropriate treatment for all patients admitted with STEMI. An established protocol can enhance more timely and effective treatment and reperfusion regardless of race, ethnicity, gender or socioeconomic status. This hypothesis should be further examined in future studies.
Study limitations. First, ours is a single-center study with data collected specific to our institution and may not reflect the regional performance of other community hospitals in achieving similar D2B times. Second, our two cohorts are relatively small to demonstrate improvement in mortality for the newly implemented Code-STEMI protocol as compared to the SAP. However with the reduction in D2Bs, peak troponin I and LOS, and given the greater percentage of patients achieving D2Bs of Conclusion
In conclusion, we have demonstrated that a Code-STEMI protocol activated in the ER successfully reduced D2Bs for both whites and minorities to an equal degree. This translated into a similar reduction in the significant cardiac marker troponin I. Furthermore, LOS was lower for both groups. This suggests that both whites and minorities derive an equal benefit from the institution of a protocol such as that described herein. Our study is the first, to our knowledge, to demonstrate this reduction.
From the Department of Cardiology, Seton Hall University, St. Joseph’s Regional Medical Center, Paterson, New Jersey, and †Seton Hall University, South Orange, New Jersey.
The authors report no conflicts of interest regarding the content herein.
Manuscript submitted April 15, 2009, provisional acceptance given May 4, 2009, final version accepted May 27, 2009.
Address for correspondence: Mahesh Bikkina, MD, MPH, FACC, FSCAI, Director, Catheterization Lab & Cardiovascular Research, Seton Hall University, Division of Cardiovascular Diseases, St. Joseph’s Regional Medical Center, 703 Main Street, Paterson, NJ 07503. E-mail: bikkinam@sjhmc.org
1. Heart disease and stroke statistics — 2007 Update, at americanheart.org/statistics. Accessed September 28, 2008.
2. Antman, EM, Anbe, DT, Armstrong, PW, et al. ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction. Available at: www.acc.org/qualityandscience/clinical/statements.htm (accessed December, 2007).
3. Berger BP, Ellis GS, Holmes RD, et al. Relationship between delay in performing direct coronary angioplasty and early clinical outcome in patients with acute myocardial infarction. Circulation 1999;100:14–20.
4. Jacobs AK, Antman EM, Faxon DP, et al. Development of systems of care for ST-elevation myocardial infarction patients: Executive summary Circulation 2007;116:217–230.
5. Hospital compare — A quality tool for adults, including people with Medicare. Washington, DC: Department of Health and Human Services. http://www.hospitalcompare. hhs.gov/. Accessed December 20, 2008.
6. A comprehensive review of development and testing for national implementation of hospital core measures, AMI-8 time to PTCA. http://www.jointcommission.org. Accessed January 28, 2008.
7. McNamara RL, Herrin J, Bradley EH, et al. Hospital improvement in time to reperfusion in patients with acute myocardial infarction, 1999 to 2002. J Am Coll Cardiol 2006;47:45–51.
8. Khot UN, Johnson ML, Ramsey C, et al. Emergency department physician activation of the catheterization laboratory and immediate transfer to an immediately available catheterization laboratory reduce door-to-balloon time in ST-elevation myocardial infarction. Circulation 2007;116;67–76.
9. Bradley EH, Roumanis SA, Radford JM et al. Achieving door-to-balloon times that meet quality guidelines. J Am Coll Cardiol 2005;46:1236–1241.
10. Nissen SE, Brush JE Jr, Krumholz HM. President’s page: GAP-D2B: An alliance for quality. J Am Coll Cardiol 2006;48:1911–1912.
11. Bradley EH, Herrin J, Wang Y, et al. Strategies for reducing the door-to-balloon time in acute myocardial infarction. N Engl J Med 2006;355:2308–2320.
12. Kruz CM, Babcock C, Sinha S, et al. The impact of emergency physician-initiated primary percutaneous coronary intervention on mean door-to-balloon time in patients with ST- segment –elevation myocardial infarction. Ann Emerg Med 2007;50:527–534.
13. Zarich SW, Sachdeva R, Fishman R, et al. Effectiveness of a multidisciplinary quality improvement initiative in reducing door-to-balloon times in primary angioplasty. J Interv Cardiol 2004;17:191–195.
14. Bradley EH, Herrin J, Krumholz HM, et al. Racial and ethnic differences in time to acute reperfusion therapy for patients hospitalized with myocardial infarction. JAMA 2004;292:1563–1572.
15. Kressin NR, Petersen LA. Racial differences in the use of invasive cardiovascular procedures: Review of the literature and prescription for future research. Ann Intern Med 2001;135:352–366.
16. McNamara RL, Wang Y, Krumholz HM, et al. Effect of door-to-balloon time on mortality in patient with ST-segment elevation myocardial infarction. J Am Coll Cardiol 2006;47:2180–2186.
17. Casale SN, Auster CJ, Devereux RB, et al. Ethnicity and socioeconomic status influences use of primary angioplasty in patients presentation with acute myocardial infarction. Am Heart J 2007;154:989–993.
18. Schneider EC, Leape LL, Epstein AM, et al. Racial differences in cardiac revascularization rates: Does “overuse” explain higher rates among white patients, Ann Intern Med 2001;135:328–337.
19. Chen J, Rathore SS, Radford MJ, et al. Racial differences in the use of cardiac catheterization after acute myocardial infraction. N Engl J Med 2001;344:1443–1449.
20. Barabagelata A, Perna ER, Clemmensen P, et al. Time to reperfusion in acute myocardial infarction. It is time to reduce it! J Electrocardiol 2007;40:257–264.
21. Newby LK, Christenson RH, Ohman EM, et al. Value of serial troponin T measures for early and late risk stratification in patients with acute coronary syndromes. The GUSTO IIA Investigators. Circulation 1998;98:1853–1859.
22. Ohman EM, Armstrong PW, Christenson RH, et al. Cardiac troponin T levels for the risk stratification in acute myocardial ischemia GUSTO IIA Investigators. N Engl J Med 1996;335:1333.
