Racial differences in the management of unstable angina: Results from the multicenter GUARANTEE registry

Racial differences in the management of unstable angina: Results from the multicenter GUARANTEE registry Benjamin M. Scirica, MD,a David J. Moliterno, MD,b Nathan R. Every, MD, MPH,c H. Vernon Anderson, MD,d Frank V. Aguirre, MD,e Christopher B. Granger, MD,f Costas T. Lambrew, MD,g LeRoy E. Rabbani, MD,h Shelly K. Sapp, MS,b Joan E. Booth, RN,b James J. Ferguson, MD,i Christopher P. Cannon, MD,a and the GUARANTEE Investigators Boston, Mass; Cleveland, Ohio; Seattle, Wash; Houston, Tex; St Louis, Mo; Durham, NC; Portland, Me; and New York, NY

Background Prior studies, usually conducted with the use of insurance databases, have shown differences in the use of cardiac procedures between black patients and white patients hospitalized with various types of coronary artery disease. However, few data are available in prospectively collected cohorts of patients with unstable angina or on the use of appropriate medications or interventions.

Methods and Results We evaluated 2948 consecutive patients with unstable angina admitted to 35 hospitals across the United States in 1996, comparing nonwhite and white patients. Seventy-seven percent of patients were white, 14% were black, 4% were Hispanic, 1% were Asian, and 3% were other or unknown race. Differences were seen in coronary risk profile, with a higher incidence of hypertension and diabetes mellitus in nonwhites. Cardiac catheterization was performed less often in nonwhites compared with whites (36% vs 53%, P = .001). Even in patients meeting the criteria for appropriate catheterization in the Agency for Health Care Policy Research unstable angina guidelines, fewer nonwhites underwent catheterization (44% vs 61%, P = .001), but among these, fewer nonwhites had significant coronary stenosis (72% vs 90%, P = .001). However, among patients catheterized who had indications for revascularization, angioplasty and coronary artery bypass grafting were performed equally often in nonwhites and whites. Conclusions Current guidelines would recommend more aggressive use of cardiac catheterization for nonwhite patients. However, our findings suggest that racial differences may need to be included in the diagnostic and interventional algorithms. (Am Heart J 1999;138:1065-72.) Previous studies have shown differences in the treatment of coronary artery disease between black patients and white patients hospitalized with various types of coronary artery disease, with lower use of cardiac catheterization and coronary artery bypass surgery in black patients.1-17 However, most of these studies focused only on black patients and relied on administrative databases that do not document the clinical severity and specific hospital treatment of individual patients.1-5,7,8,12,13,16,17 Further, it is not clear whether nonwhites receive the appropriate intervention when indicated and how this compares with whites. From aHarvard Medical School and Brigham and Women’s Hospital, the bCleveland Clinic Foundation, the cUniversity of Washington, the dUniversity of Texas Houston Health Sciences Center, eSt Louis University Health Sciences Center, fDuke University Medical Center, gMaine Medical Center, hColumbia Presbyterian Medical Center, and the iTexas Heart Institute. Supported by an unrestricted grant from Eli Lilly, Co. Submitted February 1, 1999; accepted May 5, 1999. Reprint requests: Christopher P. Cannon, MD, Cardiovascular Division, Brigham and Women’s Hospital, 75 Francis St, Boston, MA. E-mail: [email protected] Copyright © 1999 by Mosby, Inc. 0002-8703/99/$8.00 + 0 4/1/99845

To better understand the differences in initial examination and subsequent management of unstable angina between different racial populations, we compared white and nonwhite patients enrolled in the Global Unstable Angina Registry and Treatment Evaluation (GUARANTEE). This registry was a prospective, observational study designed to assess the demographic features, current medical treatment, and clinical outcomes of patients admitted with unstable angina to a group of hospitals in the United States.

Methods Study population The GUARANTEE registry study group consisted of 35 hospitals in 6 geographic regions of the United States, including the Northeast, Mideast, Midwest, Southeast, Southwest, and Northwest regions. Selected hospitals within each region were identified to provide a representative assessment of local practice patterns among academic and nonacademic institutions. Patients entered the GUARANTEE registry between September 22, 1995, and August 23, 1996. To avoid selection bias, all consecutive patients admitted with a diagnosis consistent with unstable angina pectoris were enrolled, with a goal of enrolling approximately 3000 patients. Inclusion criteria were an admission diagnosis consistent with unstable

American Heart Journal December 1999

1066 Scirica et al

Figure 1

Racial distribution of GUARANTEE registry.

angina pectoris, including suspected myocardial infarction, acute coronary syndrome, chest pain, unstable angina, and coronary artery disease. Patients were excluded if they had acute ST-segment elevation on initial electrocardiography, received thrombolysis or primary percutaneous transluminal coronary angioplasty, were admitted with a diagnosis of chest pain of noncardiac origin, or were transferred for planned coronary revascularization. There were no exclusion criteria regarding age, sex, race, prior medical history, or demographic characteristics. Medical records were reviewed at each center, and a 3-page questionnaire was completed for each patient.

Statistical analysis In addition to comparing baseline characteristics and treatments between white and nonwhite patients, we evaluated subgroups of patients who met the Agency for Health Care Policy Research (AHCPR) Unstable Angina Guideline criteria for cardiac catheterization and bypass surgery.18 In the AHCPR guidelines, cardiac catheterization was recommended for patients who had (1) recurrent or persistent ischemia, (2) recurrent myocardial infarction, (3) prior percutaneous transluminal coronary angioplasty or bypass surgery, (4) associated congestive heart failure or left ventricular ejection fraction <50%, (5) positive exercise test, (6) malignant ventricular arrhythmia, or (7) a transient defect on an imaging test.18 Bypass surgery was recommended if the patient had (1) significant left main coronary artery disease (≥50% stenosis) or (2) significant 3-vessel coronary artery disease (≥70%) with depressed left ventricular function (ejection fraction <50%).18 We also evaluated subgroups of patients who met the Thrombolysis in Myocardial Ischemia (TIMI) IIIB criteria19 for catheterization, which recommended catheterization if patients had (1) recurrent ischemia with electrocardiographic changes, (2) recurrent myocardial infarction, (3) positive exercise test, or (4) positive imaging test.

Table I. Baseline characteristics

No. of patients, n (%) Age (y, mean ± SD) Age ≥65 y (%) Female (%) Hypertension Diabetes Current smoker Hypercholesteremia Family history Menopausal (women) Prior stroke Previous angina Prior myocardial infarction Congestive heart failure Prior angioplasty Prior bypass surgery Managed care feefor-service insurance

Nonwhite (%)

White (%)

P value

666 (23) 59 ± 13 35 46 74 33 29 36 36 81 11 62 32 17 14 13

2274 (77) 63 ± 13 47 38 57 24 24 46 44 87 8 67 37 14 25 24

.001 .001 .001 .001 .001 .01 .001 .001 .02 .04 .014 .02 .09 .001 .001

52

74

.001

Univariate analyses of the continuous variables were performed with the use of a t test or a Wilcoxon 2-sample test if the assumption of normality was not met. Chi-square tests or exact tests for cases in which the expected cell frequencies were small (<5) were used in the univariable comparisons of the categorical variables.20 A multiple logistic model was developed to assess the independent contribution of factors in distinguishing nonwhites from whites. This model was used as the foundation for evaluating the effect of race on each outcome that was not attributable to the factors associated with race. Demographics, insurance status, and clinical factors were univariably tested to access their relation with race. Factors found to have some association with race (P < .10) were included in a stepwise logistic model to determine their multivariable significance (P < .05). With the exception of the comparisons of the baseline characteristics (Table I) and extent of disease within criteria for catheterization (Table III), the probability values reported in the text and tables are based on multiple logistic models, adjusting for the factors multivariably associated with race. The effect of the interaction between race and sex was also investigated in the models of in-hospital procedures and outcomes and found to be not significant.

Results Study population Of the 2948 patients enrolled in the GUARANTEE Study, 666 (23%) were nonwhite and 2274 (77%) were white (Figure 1). Of the nonwhite cohort, 420 (63%) were black, 129 (19%) were Hispanic, 39 (6%) were Asian, 78 (12%) were of other ethnic origin, and there was no identified race for 8 patients. Nonwhite patients were younger (59 vs 63 years, P = .001), with a greater percentage younger than 65 years old (65% vs 53%, P = .001). A greater percentage of nonwhite patients were female (46% vs 38%, P = .001) (Table I). There were

American Heart Journal Volume 138, Number 6, Part 1

Scirica et al 1067

Table II. Clinical examination

Figure 2

Nonwhite White Adjusted (n = 666) (n = 2274) P value Braunwald classification “severity” of pain (%) New/accelerated (I) Subacute rest (II) Acute rest (III) Clinical circumstances (%) Secondary (A) Primary (B) Postinfarction (C) Electrocardiographic changes at initial examination (%) ST changes T-wave changes Left bundle branch block None

29 20 52

34 13 53

.09 <.001 .29

8.3 91 1

5 94 1

<.001 .004 .35

28 45 3 40

34 33 4 47

.001 .001 .49 .01

more nonwhites enrolled in the southern region (60% vs 35%, P = .001). On-site catheterization at the admission hospital was available for 85% and 83% (P = NS) of nonwhite and white patients, respectively.

Catheterization by race. Differences between nonwhite races were not significant.

whereas history of prior angina (58% vs 69%, P = .005) was less common.

Preadmission characteristics Nonwhites were more likely to have hypertension or diabetes mellitus but less likely to have hypercholesterolemia or a family history of premature coronary artery disease (Table I). Nonwhites were less likely to have prior angina or myocardial infarction and to have undergone percutaneous transluminal coronary angioplasty or bypass surgery. Nonwhites were less likely to be taking β-blockers (22% vs 30%, P = .025), but there was no difference in preadmission therapy with aspirin, nitrates, or calcium channel blockers.

Clinical examination At hospital admission, nonwhites were more likely to have subacute (>48 hours) symptoms at rest, that is, Braunwald class II, and secondary angina (precipitated by other causes, eg, hypertension or anemia).21 Admission electrocardiograms revealed nonwhites had more T-wave changes (P = .001) but fewer STsegment changes than whites (P = .001) (Table II). Nonetheless, nonwhites were equally likely to “rulein” for a myocardial infarction on admission (10% vs 12%, P = .65). Comparing blacks with Hispanics, Asians, and other nonwhite races, there was no difference in age or history of diabetes mellitus, hypercholesterolemia, prior myocardial infarction, prior congestive heart failure, or previous cardiac procedures. There were also no differences in admission electrocardiography between different nonwhite races. Among blacks, female sex (49% vs 40%, P = .03), hypertension (77% vs 68%, P = .02), and smoking (33% vs 22%, P = .003) were more common,

In-hospital treatment and evaluation Heparin was more often given to whites (68% vs 60%, P = .05), but there was no significant difference in the use of aspirin (P = .47), β-blockers (P = .88), calcium channel blockers (P = .07), or nitrates (P = .13). There was no difference in medications used at discharge between the 2 groups. Nonwhites were more likely to undergo exercise tests (21% vs 16%, P = .03) and nuclear imaging stress tests or stress echocardiography (23% vs 16%, P = .001) than whites. Although there was no difference in exercise test results, nonwhites were more likely to have normal nuclear scans or stress echocardiograms (65% vs 45%, P = .02). Left ventricular function was similar in both groups.

Catheterization Fewer nonwhites underwent coronary catheterization (36% vs 53%, P = .001). There were no significant differences in the rate of catheterization between nonwhites (Figures 2 and 3). Among all patients, fewer nonwhites fulfilled the AHCPR unstable angina guidelines for cardiac catheterization (51% vs 63%, P = .001) However, among patients meeting the AHCPR Unstable Angina Guideline criteria for catheterization, nonwhites were less likely than whites to undergo catheterization (44% vs 61%, P = .001) (Figure 4). This discrepancy persisted when applying the stricter TIMI IIIB criteria for catheterization (44% vs 61%, P = .02) (Figure 4). At catheterization, nonwhites more commonly had no significant coronary artery disease compared with whites (31% vs 15%, P = .004) and a trend toward less multives-

American Heart Journal December 1999

1068 Scirica et al

Figure 3

Interventional procedures performed on white and nonwhite patients.

Table III. Extent of angiographically determined coronary artery disease in patients with positive and negative clinical criteria for catheterization AHCPR criteria Extent of disease Positive 0 Vessels 1 Vessel 2 to 3 Vessels Negative 0 Vessels 1 Vessel 2 to 3 Vessels

TIMI criteria

Nonwhite (%)

White (%)

P value

Nonwhite (%)

28 22 50

10 30 60

.001

23 14 63

6 30 64

.004

40 33 27

29 32 39

.06

34 28 38

17 31 52

.001

sel coronary disease (42% vs 54%, P = .21). Table III shows the extent of atherosclerotic disease in patients meeting AHCPR and TIMI criteria for catheterization. Those with positive criteria had a higher prevalence of coronary artery disease. Interestingly, despite meeting guideline criteria for catheterization, nonwhites had an approximately 3 times higher rate of no significant coronary artery disease.

Revascularization Nonwhites underwent coronary angioplasty less frequently (9% vs 18%, P = .001) (Figure 3). However, among patients with coronary artery disease documented at catheterization, the percentage who underwent angioplasty was similar in the 2 groups (37% vs 39%, P = .76). Nonwhites similarly underwent fewer bypass surgeries (4% vs 10%, P = .001) (Figure 3). There was no difference between the 2 patient groups in the rate of bypass surgery among patients who ful-

White(%)

P value

filled the AHCPR unstable angina guidelines for bypass surgery (46% vs 43%, P = .56).

Outcomes In-hospital mortality and postadmission myocardial infarction rates were equally low in both groups (Table IV). Recurrent ischemia was common in both groups, although only a minority of those had associated electrocardiographic changes. Nonwhites were less likely to be transferred to another hospital (2.9% vs 5.9%, P = .09). They were also less likely to have a discharge diagnosis of unstable angina (24% vs 33%, P = .02) or coronary artery disease (34% vs 43%, P = .06).

Discussion This registry has identified significant racial differences in the underlying causes and in the medical and interventional management of unstable angina. The major goal of the multicenter GUARANTEE registry was

American Heart Journal Volume 138, Number 6, Part 1

Scirica et al 1069

Figure 4

Percentages of white and nonwhite patients who received “appropriate” catheterization according to clinical guidelines.

Table IV. Outcomes

Death Postadmission myocardial infarction Death or myocardial infarction Recurrent angina With electrocardiographic changes Without electrocardiographic changes

to characterize the demographics and treatment strategies of patients with unstable angina in diverse clinical settings among various geographic regions of the United States. Unlike clinical trials, our data provide a real-life assessment of consecutive hospitalized patients with unstable angina. We observed differences in the coronary risk factors, clinical histories, admission electrocardiograms, and the extent of coronary artery disease in nonwhite patients compared with whites, which suggests there may be differences both in the clinical expression and pathobiology of unstable angina in different racial groups.

Causes and initial examination This study confirmed several differences in the causes of coronary artery disease between whites and nonwhites noted in other studies. Nonwhites were more likely to be younger and female than whites.3,11,16 In our registry, nonwhites have a higher prevalence of diabetes mellitus and hypertension,8,10,11,14-17,22 both

Nonwhite (%)

White (%)

Adjusted P value

0.6 0.8 1.2

1.0 0.9 1.8

.25 .97 .45

5.3 16.0

7.0 18.0

.88 .44

treatable risk factors, but a lower incidence of hypercholesteremia and family history of coronary artery disease.10,11 Nonwhites more often had subacute rest pain but with less ST-segment admission electrocardiography than whites. Nonwhites appeared to have less extensive coronary artery disease in this cohort of patients admitted with unstable angina. They had a larger percentage of normal stress imaging studies, and of those patients who underwent catheterization, nonwhites were twice as likely as whites to have no significant coronary lesions determined at angiography. However, although nonwhites may appear to have less significant disease, their in-hospital outcome is similar to that of whites and not better, as might be expected. This suggests that there may be a different pathobiology of unstable angina in different racial groups (or subgroups). Previous studies have found that blacks have a higher rate of hypertension and left ventricular hypertrophy.8,10,11,14-16,22 It has been postulated that blacks have more microvascu-

American Heart Journal December 1999

1070 Scirica et al

lar dysfunction causing angina with angiographically “normal” coronary arteries and that risk stratification may need to be differently tailored for black patients.23,24 Our findings in nonwhites suggest that further studies are needed to analyze any potential racial differences in the underlying plaque structure, coronary artery vessel wall, and the triggers for acute coronary syndromes.

Medical treatment In our study, initial medical treatment, with the exception of heparin, was similar in nonwhites compared with whites. This is different from the earlier TIMI III registry (conducted from 1990 to 1993), in which blacks admitted with unstable angina were less likely to receive heparin, β-blockers, and intravenous nitroglycerin.10 Although this suggests some overall improvement in care, it is noteworthy that a significant percentage of patients of all races were not prescribed aspirin, heparin, and β-blockers at initial examination, suggesting that patients in general may be undertreated for unstable angina.

Interventional treatment This study extends prior observations of underutilization of cardiac procedures in minorities. Although numerous studies demonstrated that nonwhites were still less likely to undergo catheterization,3,4,7,9,10,12-15,17 few have been able to control for differences in clinical examination and medical history. To better evaluate the clinical appropriateness of catheterization, we applied clinical guidelines to assess how many patients clinically warranted catheterization. Although fewer nonwhites fulfilled both the AHCPR and the TIMI IIIB criteria for catheterization, among patients who did meet the criteria, nonwhites were still less likely to actually undergo cardiac catheterization. This treatment discrepancy persisted when even more stringent TIMI IIIB criteria for catheterization were applied, suggesting that nonwhites receive less aggressive therapy compared with whites with similar clinical and diagnostic findings. The question of why fewer nonwhites undergo catheterization is not easily answered. Many studies that used administrative data speculated that the observed differences may be the result of different degrees of severity of illness between racial groups (ie, that nonwhites may not have needed those procedures).1-5,7,8,12,13,16,17 Several studies argue that nonwhites are more likely to refuse invasive procedures than whites.22,25 We did not assess patients’ wishes in our study and theoretically this could have led to the greater number of noninvasive diagnostic tests obtained in nonwhites in our registry. Comorbid disease would also change treatment strategies. Prior studies have shown that nonwhites underwent fewer bypass surgeries when compared with whites.1-9,11-17

It was previously shown that bypass surgery was underutilized in blacks.11 Although we observed that nonwhites were less likely to undergo bypass surgery, we observed that there was no difference in the percentage of patients for whom bypass surgery was appropriate according to AHCPR criteria. A similarly low percentage of white and nonwhite patients appropriate for bypass surgery actually underwent surgery, suggesting that clinical criteria fail to account for all the variables in the decision to undergo bypass surgery, and many people choose more conservative treatment.

Limitations There are several limitations of our study. First, the sample size of nonwhite patients was modest. Nonetheless, the data collected were extensive and thus allowed detailed characterization of this population. Second, we did not control for socioeconomic status, a potential confounding variable that may affect therapeutic decisions; however, we did control for insurance coverage. A more detailed analysis of the influence of insurance status in this registry has been published.26 Furthermore, other studies have found similar differences in the treatment of coronary disease by race in groups in which economic variables should not affect treatment,1,2,7,9,12,15-17 lending outside support to our findings. Finally, because in-hospital clinical outcomes were favorable in this cohort of patients (ie, low event rates), there is limited power for comparisons between subgroups.

Conclusions We observed that nonwhites have a different pathogenetic profile than whites, with more diabetes and hypertension yet similar outcome, suggesting a different pathobiology of unstable angina in nonwhite patients compared with whites. Even after controlling for differences in baseline characteristics and hospital course, nonwhites do not always undergo guideline-recommended cardiac catheterization as compared with whites. However, among patients shown at cardiac catheterization to have indications for revascularization, a similar percentage of nonwhites and whites underwent angioplasty and bypass surgery. Current guidelines would thus recommend aggressive use of cardiac catheterization for nonwhite patients. However, our findings suggest that when the unstable angina guidelines are updated, racial differences may need to be included in the diagnostic and interventional algorithms.

References 1. McBean AM, Warren JL, Babish JL. Continuing differences in the rates of percutaneous transluminal coronary angioplasty and coronary artery bypass graph surgery between elderly African-American and white Medicare patients. Am Heart J 1994; 127:287-95. 2. Goldberg KC, Hartz AJ, Jacobsen SJ, et al. Racial and community

American Heart Journal Volume 138, Number 6, Part 1

3.

4.

5. 6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

factors influencing coronary artery bypass surgery rates for all 1986 Medicare patients. JAMA 1992;267:1473-7. Wenneker MB, Epstein AM. Racial inequalities in the use of procedures for patients with ischemic heart disease in Massachusetts. JAMA 1989;261:253-7. Ford E, Cooper RS, Castaner A, et al. Coronary arteriography and coronary bypass surgery among whites and other racial groups relative to hospital based incidence rates for coronary disease: findings from NHDS. Am J Public Health 1989;79:437-40. Gittlesohn KG, Halpern J, Sanchez RL. Income, race, and surgery in Maryland. Am J Public Health 1991;81:1435-41. Johnson PA, Lee TH, Cook EF, et al. Effect of race on the presentation and management of patients with acute chest pain. Ann Intern Med 1993;18:593-601. Peterson ED, Wright SM, Daley J, et al. Racial variations in cardiac procedure use and survival following acute myocardial infarction in the Department of Veterans Affairs. JAMA 1994;271:1175-80. Maynard C, Litwin PE, Martin JS, et al. Characteristics of black patients admitted to coronary care units in metropolitan Seattle: results from the Myocardial Infarction Triage and Intervention registry (MITI). Am J Cardiol 1991;67:18-23. Whittle J, Conigliaro J, Good CB, et al. Racial differences in the use of invasive cardiovascular procedures in the Department of Veteran Affairs. N Engl J Med 1993;329:621-7. Stone PH, Thompson B, Anderson HV, et al. Influence of race, sex, and age on management of unstable angina and non-Q-wave myocardial infarction: the TIMI III registry. JAMA 1996;275:1104-12. Peterson ED, Shaw LK, DeLong ER, et al. Racial variation in the use of coronary revascularization procedures: are the differences real? Do they matter? N Engl J Med 1997;336:480-6. Udvarhelyi SM, Gastonis C, Epstein AM, et al. Acute myocardial infarction in the Medicare population: process of care and clinical outcomes. JAMA 1992;268:2530-6. Giles WH, Anda RF, Casper ML, et al. Race and sex differences in rates of invasive cardiac procedures in US hospitals. Arch Intern Med 1995;155:318-24. Maynard C, Every NR, Martin JS, et al. Long-term implications of racial differences in the use of revascularization procedures (the Myocardial Infarction Triage and Intervention Registry). Am Heart J 1997;134:656-62. Mirvis DM, Burns R, Gaschen L, et al. Variation in utilization of cardiac procedures in the Department of Veterans Affairs health care system: effect of race. J Am Coll Cardiol 1994;24:297-304. Ayanian J, Udvarhelyi I, Gatsonis C, et al. Racial differences in the use of revascularization procedures after coronary angiography. JAMA 1993;269:2642-6. Ferguson JA, Tierney WM, Westmoreland GR, et al. Examination of racial differences in management of cardiovascular disease. J Am Coll Cardiol 1998;30:1707-13. Braunwald E, Mark DB, Jones RH, et al. Unstable angina: diagnosis and management. Clinical practice guideline No. 10. Rockville, Md: Agency for Health Care Policy and Research and the National Heart, Lung, and Blood Institute, Public Health Service, US Department of Health and Human Services, 1994:154. TIMI IIIB Investigators. Effects of tissue plasminogen activator and a comparison of early invasive and conservative strategies in unstable angina and non-Q-wave myocardial infarction: results of the TIMI IIIB Trial. Circulation 1994;89:1545-56. Mehta CR, Patel NR. A network algorithm for performing Fisher’s Exact Test in r x c Contingency tables. J Am Stat Assoc 1983;78:427-34.

Scirica et al 1071

21. Braunwald E. Unstable angina: a classification. Circulation 1989; 80:410-4. 22. Maynard C, Fisher LD, Passamani EG. Survival of black persons compared with white persons in the Coronary Artery Surgery Study (CASS). Am J Cardiol 1987;60:513-8. 23. Houghton J, Prisant L, Carr A, et al. Racial differences in myocardial ischemia and coronary flow reserve in hypertension. J Am Coll Cardiol 1994;23:1123-9. 24. Liao Y, Cooper R, McGee D, et al. The relative effects of left ventricular hypertrophy, coronary artery disease, and ventricular dysfunction on survival among black adults. JAMA 1995;273:1592-7. 25. Schecter AD, Goldschmidt-Clermont PJ, McKee G, et al. Influence of gender, race, and education on patient preferences and receipt of cardiac catheterizations among coronary care patients. Am J Cardiol 1996;78:996-1001. 26. Every NR, Cannon CP, Granger C, et al, for the GUARANTEE Investigators. Influence of insurance type on the use of procedures, medications and hospital outcome in patients with unstable angina: results from the GUARANTEE registry. J Am Coll Cardiol 1998;32:387-92.

Appendix Steering Committee David J. Moliterno, MD (Study Chairman), Frank V. Aguirre, MD, Christopher P. Cannon, MD, Nathan R. Every, MD, MPH, James J. Ferguson, MD, Christopher B. Granger, MD.

Data Coordinating Center The Cleveland Clinic Coordinating Center, Cleveland, Ohio; David J. Moliterno, MD, Joan Booth, RN (Study Coordinator), Shelly Sapp, Cynthia Ashley, Todd Knuth, Dawn Dykstra.

Study centers, enrollment, principal investigators, and study coordinators The Cleveland Clinic Foundation, Cleveland, Ohio, 186 patients (David Moliterno, MD, Lisa Korcuska, RN); Texas Heart Institute, Houston, 153 patients (James Ferguson, MD, Mary Harlan, RN); Duke University Medical Center, Durham, NC, 131 patients (Chris Granger, MD, Cresha Crancido); Harbor UCLA Medical Center, Los Angeles, Calif, 127 patients (William J. French, MD, Debbie Terrell, RN); Kernodle Medical Center, Burlington, NC, 123 patients (Alexander Paraschos, MD, Kenneth Fath, MD, Leslie Paraschos, RN, MSN); St Louis University Hospital, St Louis, Mo, 118 patients (Frank Aguirre, MD, Michael Marshall); Harborview Medical Center, Seattle, Wash, 100 patients (Nathan Every, MD, Kathleen Allmaras); St Vincent Hospital, Worcester, Mass, 100 patients (Richard Bishop, MD, Tammy Brunelle, RN, Patricia Arsenault, RN); University of Washington Medical Center, Seattle, 100 patients (Nathan Every, MD, Jenny Martin, RN); Veteran’s Hospital, Seattle, Wash, 100 patients (Nathan Every, MD, Peg Hanrahan, RN); Highline Community Hospital, Seattle, Wash, 99 patients (Kent Kreisman, MD, Carol Krueger-Schaaf, RN); Lancaster General Hos-

1072 Scirica et al

pital, Lancaster, Pa, 98 patients (Paul Casale, MD, Kay M. Knepper, RN, Lou Anne Frey, RN); University of Michigan Medical Center, Ann Arbor, 98 patients (Eric Bates, MD, Tina Alexandris, Laurie Quain, Maurene Stock, RN); Maine Medical Center, Portland, 98 patients (Costas T. Lambrew, MD, Jane Conner Kane, RN); Valley Medical Center, Renton, Wash, 97 patients (Gerald Lorch, MD, Carol Kreuger Schaff, RN); McKay-Dee Hospital, Ogden, Utah, 96 patients (Rick Converse, MD, Sally Whitehead, RN); John Sealy Hospital Annex, Galveston, Tex, 95 patients (Barry Uretsky, MD, Dana Strott); Brigham and Women’s Hospital, Boston, Mass, 93 patients (Christopher Cannon, MD, Benjamin Scirica, MD); Alta Bates Medical Center, Berkeley, Calif, 90 patients (Robert M. Greene, MD, Eileen Healy, RN); Lake Forest Hospital, Lake Forest, Ill, 88 patients (Jay Alexander, MD, Lynn Steckel, RN); Lynchburg General Hospital, Lynchburg, Va, 84 patients (Thomas Nygaard, MD, Joyce White, RN); University of South Carolina, Columbia, 81 patients (Christine B. Hopkins, MD, Brandon Fosterm, RN); University of Tennessee College of Medicine, Chattanooga, 79 patients (Calvin Bell, MD,

American Heart Journal December 1999

Tami Ridge, RN); Carle Clinic Heart Center, Urbana, Ill, 75 patients (Leslie Fleicher, MD, Sylvia Lofrano, RN); Ochsner Medical Institutions, New Orleans, La, 72 patients (Stephen R. Ramee, MD, Kelly Landry, RN); University of Texas Medical School, Houston, 70 patients (H. Vernon Anderson, MD, Julie Manning, RN); University of Missouri, Columbia, 66 patients (H.K. Reddy, MD); Asheville Cardiology Associates PA, Asheville, NC, 50 patients (William T. Maddox, MD, Susan Allen); Cleveland Clinic Florida, Ft Lauderdale, 50 patients (Vincente E. Font, MD, Mary Scully Morales, RN); University of Arkansas, Little Rock, 40 patients (J. David Talley, MD, Sherri Ashcraft, RN, Millie Rawert, RN); Columbia Presbyterian Medical Center, New York, NY, 31 patients (LeRoy E. Rabbani, MD, Edith Escala, RN); Morton Plant Hospital, Clearwater, Fla, 29 patients (Douglas J. Spriggs, MD, Sally A. Wahl, RN); Danville Regional Medical Center, Danville, Va, 27 patients (Gary P. Miller, MD, Cathy Marlow, RN); Whitefish Bay, Wis, 13 patients (Anita M. Arnold, DO, Timothy Sommers, RN); Twin County Medical Associates, Galax, Va, 9 patients (Joseph A. Puma, Laurie Jones, RN).