Impact of Community Intervention to Reduce ... - Wiley Online Library

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Hedges et al. • REACT TRIAL AND REPERFUSION THERAPY

Impact of Community Intervention to Reduce Patient Delay Time on Use of Reperfusion Therapy for Acute Myocardial Infarction: Rapid Early Action for Coronary Treatment (REACT) Trial JERRIS R. HEDGES, MD, MS, HENRY A. FELDMAN, PHD, VERA BITTNER, MD, ROBERT J. GOLDBERG, PHD, JANE ZAPKA, SCD, STAVROULA K. OSGANIAN, MD, MPH, DAVID M. MURRAY, PHD, DENISE G. SIMONS-MORTON, MD, PHD, ADRIANA LINARES, MD, MPH, JANET WILLIAMS, MPH, RUSSELL V. LUEPKER, MD, MICKEY S. EISENBERG, MD, PHD, FOR THE REACT STUDY GROUP*

Abstract. Background: Reperfusion therapy for acute myocardial infarction (AMI) is a time-dependent intervention that can reduce infarct-related morbidity and mortality. Out-of-hospital patient delay from symptom onset until emergency department (ED) presentation may reduce the expected benefit of reperfusion therapy. Objective: To determine the impact of a community educational intervention to reduce patient delay time on the use of reperfusion therapy for AMI. Methods: This was a randomized, controlled community-based trial to enhance patient recognition of AMI symptoms and encourage early ED presentation with resultant increased reperfusion therapy rates for AMI. The study took place in 44 hospitals in 20 pair-matched communities in five U.S. geographic regions. Eligible study subjects were noninstitutionalized patients without chest injury (aged ⱖ30 years) who were admitted to participating hospitals and who received a hospital discharge diagnosis of AMI (ICD 410); n = 4,885. For outcome assessment, patients were excluded if they were without survival data (n = 402), enrolled in thrombolytic trials (n = 61), receiving reperfusion therapy >12 hours after ED arrival (n = 628), or missing symptom onset or reperfusion times (n = 781). The applied intervention was an educational program targeting community organizations and the general public, high-risk patients, and health professionals in target communities. The primary outcome was a change in the pro-

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CUTE coronary ischemia is a disease spectrum with significant morbidity and mortality. However, even in the context of an acute myocardial infarction (AMI), rapid early action can lead to the salvage of viable myocardium and a reduction in hospital-associated mortality.1,2 Indeed, current therapies for AMI incorporate timely reperfusion of the myocardium within hours of the onset of ischemia. If therapy is delayed, the benefits of reperfusion therapy diminish. Therefore, a

portion of AMI patients receiving early reperfusion therapy (i.e., within one hour of ED arrival or within six hours of symptom onset). Trends in reperfusion therapy rates were determined after adjustment for patient demographics, presenting blood pressure, cardiac history, and insurance status. Four-month baseline was compared with the 18-month intervention period. Results: Of 3,013 selected AMI patients, 40% received reperfusion therapy. Eighteen percent received therapy within one hour of ED arrival (46% of treated patients), and 32% within six hours of symptom onset (80% of treated patients). No significant difference in the trends in reperfusion therapy rates was attributable to the intervention, although increases in early reperfusion therapy rates were noted during the first six months of the intervention. A significant association of early reperfusion therapy use with ambulance use was identified. Conclusions: Community-wide educational efforts to enhance patient response to AMI symptoms may not translate into sustained changes in reperfusion practices. However, an increased odds for early reperfusion therapy use during the initiation of the intervention and the association of early therapy with ambulance use suggest that reperfusion therapy rates can be enhanced. Key words: acute myocardial infarction; reperfusion therapy; thrombolysis; angioplasty; public health; community education. ACADEMIC EMERGENCY MEDICINE 2000; 7:862–872

major factor affecting the success of modern therapy for AMI is the rapidity with which patients present to the emergency department (ED) following the onset of acute coronary symptoms. Because of a complex interaction between recognition of symptoms, cognitive acceptance of disease, social barriers, and the psychology of responding to these factors, patients with symptoms of AMI may wait for prolonged periods of time before presenting to an ED.3,4 Preliminary, uncon-

ACADEMIC EMERGENCY MEDICINE • August 2000, Volume 7, Number 8

trolled, single-community investigations have suggested that educational programs can reduce the duration of out-of-hospital delay.5 Such programs hold the potential to hasten patient presentation for timely medical care, thereby increasing the early delivery of reperfusion therapy for AMI patients. The Rapid Early Action for Coronary Treatment (REACT) study was designed to evaluate a community-based intervention program for reducing out-of-hospital delay in patients with symptoms of acute coronary syndromes.5 The REACT study is a prospective, controlled community and provider education trial using randomization within ten community pairs distributed within five regions of the United States. This paper reports the effects of the REACT intervention on the rates of reperfusion therapy and mortality following AMI in the study communities. We hypothesized that the intervention would result in earlier patient presentation, which would lead to a greater number of AMI patients receiving reperfusion therapy. Were this to occur, we also anticipated that patient mortality from AMI would be reduced in intervention as compared with control communities.

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paired communities. The trial evaluated an intervention specifically designed to enhance patient recognition of AMI symptoms and to encourage early ED presentation in the intervention as compared with control communities.5,6 This report focuses on how the intervention affected reperfusion therapy rates for AMI and patient survival. A National Heart, Lung, and Blood Institute–appointed Data and Safety Monitoring Board approved the study protocol and regularly monitored study progress and data quality. Local institutional review board approval was obtained from the 44 participating hospitals. The requirement for written informed consent was waived for this portion of the REACT investigation.

Study Design. The REACT study was a prospective, controlled trial with randomization within

Study Setting and Population. Patients admitted to 44 participating hospitals in 20 pairmatched communities, each of approximately 100,000 population, in five U.S. geographic regions5 who received a hospital diagnosis of AMI (ICD-9-CM: 410) were eligible for the current analysis. Patients transferred from a study hospital for further evaluation or treatment were included when data abstraction could be completed at the second hospital. Patients were excluded if they had sustained an acute injury, were 12 hours after ED arrival were excluded from the primary analyses. These excluded AMI patients may represent patients with a stuttering symptom onset, those with an in-hospital or post-angioplasty infarct onset, or those with recurrent AMI not initially meeting reperfusion therapy criteria. Patients missing symptom onset or reperfusion therapy times (if receiving reperfusion therapy) were excluded to permit determination of reperfusion therapy rates at specific delay intervals. Because greater delayed use of reperfusion therapy may occur in the setting of a changing disease spectrum if relatively more patients present with pre-infarction angina rather than evolving AMI, we also analyzed overall reperfusion therapy rates among all AMI patients with key outcome information. This secondary analysis of reperfusion therapy evaluated the use of reperfusion therapy at any time during the patient’s hospitalization and included those patients who were excluded from our primary analyses because of enrollment in a thrombolytic trial, receiving reperfusion >12 hours after ED arrival, or incomplete time data. Study Protocol. An educational program emphasizing patient, family, and provider recognition of AMI symptoms and desired actions was developed.6 The intervention targeted community organizations and the general public, high-risk patients, and health professionals.5 The primary objective of the intervention was to reduce delay in seeking care among patients with signs and symptoms of acute cardiac ischemia. The intervention messages and target groups were based on review of the published literature and focus-group analyses performed prior to baseline data collection. The primary educational message emphasized recognition of chest pain and other ischemic symptoms, with action if symptoms persisted for 15 minutes or more. Multiple media channels were used to deliver the message to the general public.6 Physicians, nurses, paramedics, and other health care providers helped deliver the message to high-risk groups. After a four-month baseline period, the intervention was implemented in one randomly chosen community from each matched pair. The public education component of the intervention sequentially emphasized different themes (i.e., general awareness of AMI symptoms and the need for


rapid action, development of a Heart Attack Survival Plan, AMI in women, variability of AMI symptoms, bystander response to heart attacks, and use of 9-1-1) to reinforce the primary message. These themes were sequentially introduced over an 18-month period by community interventionists to help sustain awareness of the campaign and primary message. Outcomes. Reperfusion therapy was defined as either the use of an intravenous thrombolytic agent (e.g., alteplase, streptokinase) or percutaneous transluminal coronary angioplasty with or without intracoronary thrombolytic therapy. The primary study outcome was a change in the proportion of selected AMI patients receiving early reperfusion therapy (i.e., within 1 hour of ED arrival or within six hours of symptom onset) from baseline throughout the 18-month intervention period. We hypothesized that the increase in reperfusion therapy rates would be significantly greater in the intervention than control communities. Another outcome of interest was a change in the proportion of patients receiving angioplasty as their reperfusion therapy within 12 hours of ED arrival. A change in this proportion might represent a confounder influencing early reperfusion therapy rates. We also examined changes in inhospital death rates over time in the intervention vs control communities. As noted above, we also examined the reperfusion therapy rate among all patients with an AMI diagnosis and available survival information. For this secondary analysis, patients enrolled in thrombolytic trials, receiving reperfusion therapy >12 hours after ED arrival, or having missing time data were included. We also evaluated the association of patient transport by emergency medical services personnel (i.e., EMS use) with receipt of reperfusion therapy. Because an increase in EMS use was a secondary goal of the REACT study, the association of this covariate with reperfusion therapy was evaluated separately. Similarly, since community trends in interhospital transfer patterns might alter the approach to evaluation and management of acute cardiac ischemia, we looked for associations of interhospital transfer with the point of AMI diagnosis and with reperfusion therapy use during hospitalization. Data Collection. Patient demographic and outcome data were collected by trained medical record abstractors. Charts of patients presenting to the ED with chest pain (or other synonyms, such as chest pressure, tightness, or discomfort) were reviewed. Emergency nurses and physicians were instructed to ask all ED patients with chest pain

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about the onset of their acute symptoms using a standardized query.7 Demographic data, history of coronary disease or prior AMI, EMS use, and specific times (ED arrival, reperfusion therapy, and symptom onset) were obtained from the patient’s medical record. A hierarchical method for data abstraction was used.5 That is, the primary source of data was the ED nurse notes; secondary sources, in priority of order, were the emergency physician note, the inpatient nurse note, and the inpatient physician note. A secondary source was used only if the primary source was unavailable. Time of reperfusion therapy was defined as either the time infusion of a thrombolytic agent was initiated or the time an angioplasty-associated reperfusion procedure was reported to have begun. No otherwise eligible patient received coronary artery bypass during the 12 hours following ED presentation. Efforts to characterize success of the reperfusion therapy were not made, nor were electrocardiographic (ECG) data at presentation collected. Data Analysis. Trends for each dichotomous outcome in the intervention and control community groups over the 1.5-year period of the trial were estimated and compared by multiple mixedmodel logistic regression.8 In the primary analyses, calendar time was treated as a continuous variable, with baseline data assigned to time zero. Trends from the primary analyses are reported below as the increase in odds of the outcome over the 1.5-year intervention period, expressed as the ratio of end-trial odds to baseline odds. The null hypothesis in the primary analyses was that the intervention and control trends were equal. In a secondary analysis (not specified by the study protocol), the trial was divided into baseline (4 months) and six 3-month intervention periods, and the relative odds of each outcome (intervention period divided by control) estimated for each period. Results are reported as the odds ratio (intervention:control) for reperfusion therapy at each time point relative to the baseline odds ratio. Both primary and secondary analyses were adjusted for patient factors believed to affect reperfusion therapy use (Simons-Morton, DG, personal communication, August 1999, based on preliminary review of REACT baseline data). The covariates controlled for patient demographics (age, sex, ethnicity, co-inhabitant status, insurance status), medical findings (presenting blood pressure [hypertensive: systolic >180 mm Hg or diastolic >110 mm Hg, hypotensive: systolic 12 hours after ED presentation. §Either onset of symptoms or time of therapy missing.

trends, as well as for residual error. The analytic model also included random effects, accounting for community-level variation in the frequency and trend of each outcome variable. The type I error rate was set at 5% per pairing of dependent and independent variables.9 No datadependent comparisons were made among the levels of multilevel covariates. Covariate frequencies between groups were compared using chi-square analysis.

RESULTS Patient Characteristics. During the REACT trial, there were 4,885 study patients diagnosed as having AMI (ICD-9-CM: 410) during their hospital stays (Table 1). An additional 402 AMI patients were excluded for the lack of key outcome information (399 were transfer patients with no data available from the second hospital and three patients had no survival information at the first hospital). We also excluded 61 patients who had been enrolled in a thrombolytic therapy trial, 628 patients who received reperfusion therapy >12 hours after ED arrival, and 781 patients with missing out-of-hospital or in-hospital delay data. Characteristics of the remaining 3,013 patients selected for the primary analyses are shown in Table 2 for intervention vs control community groups. Although patients in the intervention community group were more often documented as being white, there were more patients without a recorded ethnic background in the control community group. Those hospitals where ethnic status was often not recorded primarily served predominately white populations. The proportions of patients documented as being either African American or Hispanic were similar for the two populations. Pro-

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portionately fewer patients in the intervention community group were transferred to a second hospital, although the transfer rate was less than 6% for both groups. The characteristics of the 3,013 patients selected for our primary analyses were compared with those of the 1,470 AMI patients who had been excluded because of participation in a thrombolytic therapy trial, receipt of reperfusion therapy >12 hours after ED arrival, or missing time data (data not shown). The groups were similar in terms of age, gender, ethnicity, cohabitation status, history of AMI or other coronary heart disease, presence of insurance coverage, ED blood pressure, and treatment community group assignment (all p >

0.08; data not shown). The rate of transfer to a second hospital was significantly lower in the patients selected for our primary analyses (3.7% vs 9.8%; p < 0.001). Rates of Reperfusion Therapy. Of the 3,013 selected study AMI patients, 40% underwent reperfusion therapy within 12 hours of ED arrival (unadjusted rate). Specifically, 18% received therapy within one hour of ED arrival (46% of treated patients) and 32% within six hours of symptom onset (80% of treated patients). Trends in adjusted reperfusion therapy rates and other clinical endpoints discussed below are summarized in Table 3. Inclusion of patients involved in thrombolytic tri-

TABLE 2. Characteristics of Intervention and Control Community Groups for All Time Periods Intervention (%) (n = 1,689)

Control (%) (n = 1,324)

Age group 30–49 years 50–64 years 65–74 years 75⫹ years

12.9 29.1 25.2 32.9

13.4 30.6 26.4 29.5

Gender Male Female

65.4 34.6

61.5 38.5

Ethnicity White African American Hispanic Other/not reported

82.2 4.5 5.6 7.6

68.7 6.0 6.6 18.7

Cohabitation status Single Cohabiting Not reported

35.9 61.6 2.5

34.4 62.8 2.8

History of heart disease Prior myocardial infarction Coronary heart disease Neither/not reported

28.3 19.5 52.2

27.2 18.7 54.1

Insured Yes No/not reported

91.5 8.5

91.7 8.3

Initial blood pressure (see text) High Low Normal/not reported

15.7 6.9 77.4

18.1 6.3 75.6

Transfer case Yes No

2.5 97.5

5.2 94.8

Out-of-hospital delay time 0–1 hours >1–2 hours >2–6 hours >6 hours

20.7 28.6 30.3 20.5

24.2 28.9 28.2 18.8

Category

p-value* 0.28

0.025

0.001

0.65

0.58

0.83

0.21

0.001

0.10

*Chi-square test of equal proportions, unadjusted for other covariates.

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TABLE 3. Trends in Clinical Endpoints in Intervention (I) and Control (C) Communities of REACT, 1995–97*

Endpoint

Group

Baseline Rate (%)†

Reperfusion ⱕ1 hr from ED arrival (n = 3,013) Reperfusion ⱕ6 hr from symptom onset (n = 3,013) Angioplasty, those reperfused (n = 1,207) Survival (n = 3,013)

I C I C I C I C I C

13.8 19.3 28.3 27.9 53.1 19.3 94.9 95.0 49.6 45.5

Reperfusion, no exclusions (n = 4,483)

OR Trend/1.5 Year (95% CI)‡ 0.90 0.78 0.92 1.11 3.09 1.86 1.06 1.06 0.96 0.83

(0.55, (0.47, (0.61, (0.70, (1.45, (0.81, (0.54, (0.49, (0.69, (0.57,

1.47) 1.30) 1.40) 1.76) 6.57) 4.30) 2.08) 2.29) 1.34) 1.21)

OR Trend Ratio (I:C) (95% CI)‡

p-value§

1.15 (0.57, 2.33)

0.69

0.83 (0.45, 1.55)

0.54

1.66 (0.54, 5.09)

0.36

1.00 (0.36, 2.76)

0.99

1.16 (0.70, 1.91)

0.55

*Patients presenting to ED with chest pain, admitted for MI or to rule out MI, and discharged with ICD-9 code 410. Except as noted, sample limited to 3,013 patients with recorded out-of-hospital delay and ED-reperfusion interval (if reperfused), and not enrolled in clinical trial or reperfused >12 hours after arrival. †Adjusted by multiple logistic regression for age, sex, ethnicity, cohabitation status, coronary heart disease history, insurance status, presenting blood pressure, and transfer status. ‡Odds in favor of endpoint at end of 1.5-year trial divided by odds at baseline, with 95% confidence interval. Estimates from multiple logistic regression model. §Testing Ho: I trend = C trend.

als (n = 61) did not significantly affect these results. Of the patients included in the primary analyses, 13.8% received reperfusion therapy within one hour of ED arrival in the intervention community group during the baseline period, compared with 19.3% in the control community group. The odds of reperfusion therapy use within one hour of ED arrival declined slightly during the follow-up period in both community groups, though more so in the control group (ORtrend = 0.78) than in the intervention group (ORtrend = 0.90). As a result, the net change in reperfusion therapy use favored the intervention group (OR = 1.15, 95% CI = 0.57 to

2.33), though this net difference was not significant. The odds of receiving reperfusion therapy within one hour of ED arrival as a function of time period showed an increase in the odds ratio over baseline for all time periods, with the largest observed effect during the first three months of the intervention (Fig. 1). Similarly, of the patients included in the primary analyses, 28.3% received reperfusion therapy within six hours of symptom onset in the intervention community group during the baseline period, compared with 27.9% in the control community group. The odds of reperfusion therapy use during the first six hours of symptom onset declined

Figure 1. Reperfusion therapy within one hour of ED arrival in the sample for primary analyses (n = 3,013). Top: Reperfusion rates in intervention and control community groups, adjusted for covariates. Bars indicate ⫾1 standard error. Bottom: Odds ratio for reperfusion therapy at each time point relative to baseline [OR (I:C) ⫼ OR (I:C)Base ]. Bars indicate 95% confidence intervals.

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Figure 2. Reperfusion therapy within six hours of symptom onset in the sample for primary analyses (n = 3,013). Top: Reperfusion rates in intervention and control community groups, adjusted for covariates. Bars indicate ⫾1 standard error. Bottom: Odds ratio for reperfusion therapy at each time point relative to baseline [OR (I:C) ⫼ OR (I:C)Base ]. Bars indicate 95% confidence intervals.

slightly during the follow-up period in the intervention community group (ORtrend = 0.92), but not in the control group (ORtrend = 1.11). As a result, the net change favored the control group (OR 0.83; 95% CI = 0.45 to 1.55). As a function of time period, the odds ratio for receiving reperfusion therapy within six hours of symptom onset was most favorable during the first six months of the intervention (Fig. 2). Of the covariates included in the multiple logistic regression analysis for the receipt of reperfusion therapy within six hours of symptom onset, younger age, low presenting systolic blood pressure, not being transferred to a second facility, and no prior history of AMI or coronary disease were associated with reperfusion therapy use (all p < 0.0001). Similar findings were found for administration of reperfusion therapy within one hour of ED arrival. Angioplasty as Initial Reperfusion Therapy. Of the selected study patients, 1,207 (40%) received reperfusion therapy within 12 hours of ED arrival. Among these patients, the adjusted probability of receiving angioplasty reperfusion therapy during the intervention time period ranged from 43% to 72% in the intervention group vs from 12% to 31% in the control group. Although there was a significant trend for greater use of angioplasty as the initial reperfusion therapy in the intervention community group (ORtrend = 3.09; 95% CI = 1.45 to 6.57), the net difference between intervention and control trends for angioplasty as initial reperfusion therapy was not significant (OR 1.66; 95% CI = 0.54 to 5.09).

In-hospital Mortality. Of the 3,013 patients selected for our primary analyses, 202 died (6.7%) during the hospital course. The adjusted death rate for different time periods ranged from 2.9% to 6.0% in the intervention group vs from 3.2% to 5.2% in the control group. The difference between adjusted intervention and control trends for inhospital death rate was not significant (OR 1.00; 95% CI = 0.36 to 2.77). Reperfusion Therapy Rates for All AMI Patients during Hospitalization. Of the 4,483 REACT AMI patients with key outcome information, 2,135 (48%) received reperfusion therapy during their hospitalizations. The adjusted reperfusion therapy rate during the intervention period ranged from 54% to 59% in the intervention group vs from 46% to 57% in the control group. The difference between intervention and control trends for receipt of reperfusion therapy during the hospital admission was not statistically significant (OR 1.16; 95% CI = 0.70 to 1.91). However, the odds ratio as a function of time period was increased over baseline throughout the study and was largest during the first six months of the intervention (Fig. 3). Effect of EMS Use on Reperfusion Therapy. Of the 3,013 selected study patients, 1,195 (40%) were transported via EMS personnel. The adjusted rate of reperfusion within six hours of symptom onset was significantly greater for AMI patients transported via EMS personnel (36% vs 24%; p < 0.0001). Although EMS use was a predictor of early reperfusion therapy, it was not found to be a confounder in the multivariate model. That is, other


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Figure 3. Reperfusion therapy at any time during the hospital course in all patients with acute myocardial infarction (n = 4,483). Top: Reperfusion rates in intervention and control community groups, adjusted for covariates. Bars indicate ⫾1 standard error. Bottom: Odds ratio for reperfusion therapy at each time point relative to baseline [OR (I:C) ⫼ OR (I:C)Base ]. Bars indicate 95% confidence intervals.

predictor and covariate effects were virtually unchanged in magnitude and significance by the addition of this variable. A similar effect of EMS use on adjusted rates for reperfusion therapy use any time within the first 12 hours after ED presentation was seen for the selected study population (44% vs 33%; p < 0.0001). The associations between EMS use and reperfusion therapy use were similar for intervention and control communities. The effect of the intervention on EMS use by patients with cardiac diagnoses (including those with AMI) will be the subject of another REACT report. Transfers and AMI Diagnosis/Reperfusion Therapy. Of the 3,013 selected study patients, only 111 (3.7%) were transferred to a second hospital. Of these, only five (4.5%) were first diagnosed as having an AMI at the second hospital. The reperfusion therapy rate was 8.1% for those transferred (covariate-adjusted rate 4.5%) vs 41.3% (covariate-adjusted rate 39.7%) for nontransferred patients (p < 0.0001). Among the 1,470 AMI patients with key outcome information who were excluded from the primary analyses, 144 (9.8%) were transferred. Of these, 20 (13.9%) were first diagnosed as having an AMI at the second hospital. Although the overall reperfusion therapy rate was 91% (131/144) for these excluded transfer patients, the rate of reperfusion therapy within 12 hours of initial ED presentation was only 13.2% (19/144).

DISCUSSION The REACT intervention was intended to increase

community awareness of acute cardiac ischemia symptoms and knowledge of the appropriate actions to be taken when these symptoms occur, with the primary goal of reducing patient-associated out-of-hospital delay times. The REACT community educational program was successfully implemented as evidenced by significant increases in the community recognition of the REACT name (spontaneously and when presented as an option) and AMI symptoms, more correct answers to appropriate actions in the setting of an AMI, an increase in the perceived ability to recognize a heart attack, and the certainty of calling 9-1-1 for others.10 The REACT intervention also was associated with increases in the number of patients evaluated for chest pain and EMS use by patients with cardiacrelated diagnoses, but not in the subgroup with AMI. The REACT intervention was not associated with a reduction in the mean out-of-hospital delay time for patients with cardiac-related diagnoses.10 However, the baseline geometric mean delay time was relatively low (134 minutes) and decreased during the study for both community groups. The present study evaluates the effect of the REACT intervention on early coronary reperfusion therapy use. We hypothesized that the intervention would increase the proportion of AMI patients receiving early reperfusion therapy. Early coronary reperfusion therapy has been associated with better coronary patency rates, lower mortality,1,2 and lower recurrent AMI rates.11 We found no significant trend in reperfusion therapy outcomes when analyzed over the entire intervention. However, our secondary analyses (Figs. 1–3) suggest a favorable early intervention effect. Efforts to involve

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EMS personnel and hospital providers in the REACT program were greatest during the first half of the intervention. We also found that EMS use was significantly associated with reperfusion therapy use in both community groups. A number of factors may have influenced our findings: 1. The REACT study was primarily designed to reduce out-of-hospital delay time. The study did not achieve a greater reduction in delay time within the intervention community group.10 However, the baseline mean delay time for the REACT population was shorter than reported previously.12,13 Perhaps in communities with relatively short delay times, the impact of a community educational intervention on time-dependent cardiac therapy will be limited. Interestingly, the odds for reperfusion therapy use consistently increased during the early months of the intervention. This may represent enhanced efforts by the EMS personnel and other providers in the intervention communities as the study was initiated. 2. The current study of reperfusion therapy rates was insufficiently powered to determine clinically significant differences with confidence. Although the REACT study was adequately powered to demonstrate a 30-minute reduction in out-of-hospital delay time in patients with cardiac-related diagnoses, a post-hoc power analysis suggests that the current study had a power of only 33% to demonstrate an absolute 10% increase in the rate of reperfusion therapy use within six hours of symptom onset. 3. Despite greater community awareness of the symptoms of a heart attack and the value of EMS use, persistent barriers to timely ED presentation remain. For example, early patient attribution of their own symptoms to a ‘‘heart attack’’ event remains a major issue.14 Baseline REACT data suggest that people lack confidence in their ability to interpret symptoms, and this is particularly true among elders.15 REACT focus groups suggest that for some people, the embarrassment of a ‘‘false alarm’’ was a barrier to fast action.16 Similar to Meischke et al.,17 we found that older patients were less likely to receive reperfusion therapy, even after adjustment for presenting blood pressure and prior coronary heart disease. Similarly, economic and psychological barriers to EMS use may exist for patients with AMI symptoms.18 Since EMS use in both community groups was associated with early reperfusion therapy, future community efforts may benefit from strategies to remove perceived barriers to EMS use. 4. If the mean in-hospital delay to arrange angioplasty reperfusion therapy exceeded the analogous delay in the initiation of intravenous thrombolytic therapy, an increase in angioplasty use would be


associated with a reduction in the proportion of AMI patients receiving early reperfusion therapy. For our selected population, there was an increase in angioplasty as the initial reperfusion treatment over time. This trend favored the intervention community group, although the difference between intervention and control trends did not reach statistical significance. Despite our efforts to select a population less likely to be affected by this trend in therapy, the increased use of angioplasty for reperfusion therapy may have masked the desired effect on early reperfusion. 5. A successful intervention might increase the absolute number of patients presenting to the ED with a small AMI not meeting reperfusion therapy criteria. In such a scenario, the proportion of AMI patients eligible for reperfusion therapy may decrease while the absolute number of AMI cases evaluated would increase. Interestingly, the monthly rate of AMI case presentation increased by 7.2% in the intervention communities vs 2.7% in the control communities, but the difference was not statistically significant (data not shown). 6. A successful intervention also might change the spectrum of acute coronary ischemia presenting to the ED. That is, rapid response by patients with pre-infarction angina might result in more cases of coronary ischemia presenting to the ED prior to progression to an AMI. While these patients would not receive ‘‘early’’ reperfusion therapy based on our study criteria, reperfusion therapy should be increased among all AMI patients. Our secondary analysis of reperfusion therapy use at any time during hospitalization among all AMI patients with key outcome information (Fig. 3) favored the intervention community group, but the effect size was not statistically significant. 7. Our mortality rate for AMIs was not affected by the intervention, but the mortality rate was relatively low at baseline. If the intervention shifted the coronary ischemia spectrum from AMI to unstable angina, overall community benefit in terms of fewer in-hospital complications and better overall cardiac function might occur without a reduction in the mortality rate. Indeed, earlier recognition of the acute coronary syndrome may lead to increased timely medical management for acute coronary ischemia exclusive of reperfusion therapy.

LIMITATIONS AND FUTURE QUESTIONS Our study is limited by the absence of data reflecting specific exclusions and contraindications to the use of reperfusion therapy. In particular, thrombolytic therapy is largely guided by the patient’s ECG findings. Given our paired-community design with randomization of one community from each pair to the intervention, we suspect that the dis-


tributions of reperfusion therapy exclusions were similar in community groups at baseline. However, without ECG data, we are unable to determine whether the spectrum of presenting ECG findings for these AMI patients was changed by the intervention. It is important to note that ECG criteria for thrombolysis may develop after ED presentation. Silber et al found that 10% of AMI patients developed ECG criteria within 12 hours after ED presentation and another 10% developed ECG criteria more than 12 hours after presentation.19 Similarly, Fesmire et al. noted that repeating the ECG every 20 minutes while the patient was in the ED could raise the sensitivity of the ECG for AMI from 55% to 68%.20 Hence, even if we were able to reduce the out-of-hospital delay time in many patients with AMI, the evolution of appropriate ECG findings (i.e., ST-segment elevation or new bundle branch block) may lag a patient’s ED presentation. Indeed, the proportion of AMI patients eligible for reperfusion therapy within an hour of ED presentation may be negatively influenced by reducing delay time. Overall, we found a 40% rate of reperfusion therapy for our primary population and a 48% rate for all AMI patients. This compares well with the rates for other populations reported in the literature. The UK Heart Attack Study Investigators reported a 52% rate of thrombolytic therapy in 2,439 patients under the age of 76 years.21 A Norwegian multihospital study reported a 32% thrombolytic rate for AMI patients of all ages, despite 50% being eligible for thrombolytic therapy.22 The National Registry of Myocardial Infarction (NRMI) investigators reported that in participating U.S. hospitals from 1990 to 1993, 35% of AMI patients received thrombolytic therapy.23 Of our primary selected population, 32% received reperfusion therapy within six hours of symptom onset. The Myocardial Infarction Triage and Intervention (MITI) Project in Seattle, WA, reported a 28% rate of reperfusion therapy within six hours of symptom onset.24 The MITI investigators also reported a 10% in-hospital death rate. There was a 6.7% death rate in our primary population. Hence, although we cannot directly compare our study population with other groups stratified by ECG criteria, our similar reperfusion therapy and death rates suggest we have identified a fairly typical AMI population. Future studies evaluating the effect of interventions on reperfusion therapy rates should monitor relative and absolute exclusion criteria for these procedures.

CONCLUSIONS Community-wide educational efforts to enhance

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patient response to AMI symptoms may not translate into sustained changes in reperfusion practices. However, evidence for an increase in early reperfusion therapy during the initiation of the intervention suggests that reperfusion practices can be enhanced. The association of EMS use and early reperfusion therapy suggests that removing barriers to EMS use by patients with symptoms of AMI may represent a valuable strategy for increasing early reperfusion therapy use. The investigators express appreciation to the REACT Data and Safety Monitoring Board: Charles Francis, MD (Chair), Genell Knatterud, PhD, Amelie Ramirez, DrPH, Terence Valenzuela, MD, and Thomas Vogt, MD.

References 1. Weaver WD, Cerqueira M, Hallstrom AP, et al. Prehospitalinitiated vs hospital-initiated thrombolytic therapy. The Myocardial Infarction Triage and Intervention Trial. JAMA. 1993; 270:1211–6. 2. Newby LK, Rutsch WR, Califf RM, et al. Time from symptom onset to treatment and outcomes after thrombolytic therapy. GUSTO-1 Investigators. J Am Coll Cardiol. 1996; 27: 1646–55. 3. Goff DC, Feldman HA, McGovern PG, et al., for the REACT Study Group. Prehospital delay in patients hospitalized with heart attack symptoms in the United States: the REACT trial. Am Heart J. 1999; 138:1046–57. 4. Meischke H, Sellers D, Robbins ML, et al. Factors that influence risk perceptions of an acute myocardial infarction. Behav Med. Spring 2000 (in press). 5. Simons-Morton DG, Goff DC, Osganian S, et al. Rapid early action for coronary treatment: rationale, design, and baseline characteristics. Acad Emerg Med. 1998; 5:726–38. 6. Raczynski JM, Finnegan JR, Zapka JG, et al. REACT theory-based intervention to reduce treatment-seeking delay for acute MI. Am J Prev Med. 1999; 16:325–34. 7. Hedges JR, Mann NC, Meischke H, Robbins M, Goldberg R, Zapka J, for the REACT Study Group. Assessment of chest pain onset and out-of-hospital delay using standardized interview questions: the REACT pilot study. Acad Emerg Med. 1998; 5:773–80. 8. Feldman HA, Proschan MA, Murray DM, et al. Statistical design of REACT (Rapid Early Action for Coronary Treatment), a multisite community trial with continual data collection. Controlled Clin Trials. 1998; 19:391–403. 9. Glantz SA, Slinker BK. Primer of Applied Regression and Analysis of Variance. New York: McGraw-Hill, 1990, pp 302– 3. 10. Luepker RV, Raczynski JM, Cornell CE, et al. Rapid early action for coronary treatment: the REACT community trial. Dallas, TX: Presented at the American Heart Association’s 71st Scientific Session, Nov 1998. 11. van’t Hof AW, Zijlstra F, de Boer MJ, Liem AL, Hoorntje JC, Suryapranata H. Patency and reinfarction in late-entry myocardial infarct patients treated with reperfusion therapy. Angiology. 1997; 48:215–22. 12. Blohm M, Herlitz J, Schroder U, et al. Reaction to a media campaign focusing on delay in acute myocardial infarction. Heart Lung. 1991; 20:661–1. 13. Gaspoz JM, Unger PF, Urgan P, et al. Impact of a public campaign on pre-hospital delay in patients reporting chest pain. Heart. 1996; 76:150–5. 14. Meischke H, Ho M, Eisenberg M, Schaeffer S, Larson M. Reasons patients with chest pain delay or do not call 911. Ann Intern Med. 1995; 25:193–7. 15. Zapka JG, Simons-Morton DG, Oakes MJ, et al. Missed opportunities to impact fast response to AMI symptoms. Patient Educ Couns. 2000; 40:67–82.

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16. Finnegan JR, Meischke H, Zapka J, et al. Delay in seeking care for heart attack symptoms: findings from national focus groups. Health Commun. 2000 (in press). 17. Meischke H, Eisenberg MS, Larsen MP. Prehospital delay interval for patients who use emergency medical services: the effect of heart-related medical conditions and demographic variables. Ann Emerg Med. 1993; 22:1597–601. 18. Siepmann DB, Mann NC, Daya MR, Hedges JR. Effect of payment system on emergency medical services utilization for chest discomfort syndrome [abstract]. Acad Emerg Med. 1998; 5:423–4. 19. Silber SH, Leo PJ, Katapadi M. Serial electrocardiograms for chest pain patients with initial nondiagnostic electrocardiograms: implications for thrombolytic therapy. Acad Emerg Med. 1996; 3:147–52. 20. Fesmire FM, Percy RF, Bardoner JB, Wharton DR, Calhoun FB. Usefulness of automated serial 12-lead ECG moni-

toring during the initial emergency department evaluation of patients with chest pain. Ann Emerg Med. 1998; 31:3–11. 21. el Gaylani N, Weston CF, Griffith K, Wong PS, Norris RM, Penny WJ. Acute myocardial infarction: are there missed opportunities for reperfusion? UK Heart Attack Study Investigators. Coron Artery Dis. 1998; 9:753–8. 22. Reikvam A, Ketley D. Thrombolytic eligibility in acute myocardial infarction patients admitted to Norwegian hospitals. Int J Cardiol. 1997; 61:79–83. 23. Rogers WJ, Bowlby LJ, Chandra NC, et al. Treatment of myocardial infarction in the United States (1990 to 1993). Observations from the National Registry of Myocardial Infarction. Circulation. 1994; 90:2103–14. 24. Maynard C, Weaver WD, Litwin PE, et al. Hospital mortality in acute myocardial infarction in the era of reperfusion therapy (the Myocardial Infarction Triage and Intervention Project). Am J Cardiol. 1993; 72:877–82.

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Instructions for Contributors to Clinical Pearls Clinical Pearls is a section of Academic Emergency Medicine that uses photographic images to provide visual clues for a case study presented as an unknown. Visual clinical findings make up a large part of the practice of emergency medicine (EM). ‘‘Capturing’’ these findings allows clinicians to share their experience and knowledge with others, making clinical photographs an excellent teaching tool. This section intends to stimulate academic emergency physicans to use clinical photography for augmenting their teaching of EM. Clinical Pearls manuscripts should be presented as case study ‘‘unknowns’’ and must be accompanied by a clinical photograph. Radiographs and other supporting data (ECGs, pathology specimens, Gram stains, etc.) are acceptable if they accompany a clinical photograph. A series of clinical photographs to demonstrate a progressive disease process is acceptable. Cases with a radiograph or ECG alone should be discussed with the section editor before submission. Manuscript preparation should follow the general Instructions for Authors found in AEM. Format of the section follows this general scheme: Title (usually the chief complaint of the patient), Chief Complaint, History of Present Illness, Physical Examination and Laboratory, Diagnosis, Discussion, Clinical Pearls (3 – 5 ‘‘take-home’’ points of the case), and References. The most original image available (slide, negative, or photograph) and two 5 ⫻ 7-inch color prints should accompany

the manuscript. The original image will be returned. Arrows, symbols, or labels identifying structures should be marked on the second print if necessary. Each print and slide should be labeled with the last name(s) of the contributors and an arrow indicating the top of the image. Contributors must provide the names, highest academic degrees, addresses, and phone and fax numbers of the photographer and all contributors. Acknowledgment of manuscript and photograph acceptance will be made in writing to the contributor. The section editor will have the photograph critiqued by a professional medical photographer to provide suggestions for improving photographic technique. The critique will become part of the published article. By submitting to the Clinical Pearls, the contributor allows the section editor to distribute the case and image to all EM residency programs in the United States as part of a prejournal mail-out. This activity allows programs to preview the case in didactic situations to enhance the learning from the case. It is the responsibility of the contributor to obtain patient consent for use of the photograph in a publication if the patient is in any way identifiable. Send manuscripts and images to AEM, 901 North Washington Avenue, Lansing, MI 48906. For additional information or questions, contact Larry Stack, phone: 615-936-0093; fax: 615-936-1316; e-mail: [email protected]