Diabetes status and racial differences in post–myocardial infarction mortality

Diabetes status and racial differences in post–myocardial infarction mortality Masoor Kamalesh, MD,a Usha Subramanian, MD,a Anahita Ariana, MD, PhD,b Stephen Sawada, MD,a and Eric Peterson, MD, MPH c Indianapolis, Ind, Urbana-Champaign, Ill, and Durham, NC

Background Prior studies regarding the effect of racial status on post–myocardial infarction (MI) in subjects with diabetes have yielded conflicting results. We evaluated the effect of diabetes status on racial differences in post - MI mortality and morbidity for a 7- year period, from 1990 through 1997. Methods

All patients discharged with the primary diagnosis of acute MI from any Veterans Affairs Medical Center in the country between October 1990 and September 1997 were identified. Demographic, comorbid conditions, inpatient, outpatient, mortality, and readmission data were extracted. Mortality, revascularization, readmissions, and length of hospital stay for MI were compared for the group with diabetes and that without diabetes. Comparison was made between black and white patients. Independent predictors of survival using a Cox regression model were examined.

Results We identified 67 889 patients with MI of whom 17 756 (26%) had diabetes. Race status was known for 66 506 subjects of whom 55 731 (84%) were white and 8437 (13%) were black. Regardless of the race, the diabetic patients tended to have higher mortality than nondiabetic patients. The post - MI mortality during the entire follow-up period tended to be similar between blacks and whites for the nondiabetic patients, whereas the mortality tended to be lower in blacks than in whites in diabetic patients. Conclusions Mortality from post-MI is significantly lower in blacks with diabetes than in whites with diabetes. In contrast, no racial difference in long-term mortality was seen among subjects without diabetes. Thus, it appears that diabetes status determines racial variation in post-MI mortality. The reasons for better survival post-MI of blacks in general and among subjects with diabetes in particular need to be further investigated. (Am Heart J 2005;150:912-9.) Mortality from ischemic heart disease has generally been reported to be higher among blacks than whites.1 - 5 Limited data suggest that this may be especially true in subjects with diabetes.2,6 The prevalence of diabetes in these studies has consistently been higher among blacks compared with whites. In addition, black patients have been reported to be less likely to be referred for coronary angiography7,8 and receive revascularization.5,9 However, data from health care systems where there are no financial barriers to access to health care, such as the

From the aKrannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, Ind, bVA Medical Center, University of Illinois College of Medicine at Urbana/Champaign, Urbana-Champaign, Ill, and cDuke University Medical Center, Durham, NC. This study was supported in part by grants CPG-970001 and REA 01-098 from the Health Services Research and Development Service of the Department of Veterans Affairs, Washington, DC. The opinions herein do not necessarily represent those of the authors’ institutions or the Department of Veterans Affairs. Submitted April 30, 2004; accepted February 23, 2005. Reprint requests: Masoor Kamalesh, MD, (111C), 1481 W 10th Street, VAMC, Indianapolis, IN 46202. E-mail: [email protected] 0002-8703/$ - see front matter n 2005, Mosby, Inc. All rights reserved. doi:10.1016/j.ahj.2005.02.042

Veterans Affairs ( VA) Health Care System and the Military Health Services System, suggest that survival outcomes in blacks are not worse than whites.7,10 -12 The Veterans Affairs Medical Center ( VAMC) health system is the largest health care system in the country and offers uniform care without regard to a patient’s ability to pay. In addition, most veteran patients share similar socioeconomic backgrounds irrespective of race and, hence, form a homogenous group to study. The results of the above-mentioned studies have been derived from data in the 1980s or before. Major changes have occurred in the management of ischemic heart disease in the 1990s.13 Diabetes is a major determinant of morbidity and mortality and is associated with greater concomitant hypertension and dyslipidemia, both of which are major risk factors for coronary disease. Given the fact that blacks with ischemic heart disease have a higher prevalence of diabetes, we hypothesized that the presence or absence of diabetes could be a major determinant of mortality difference between blacks and whites. The objectives of this study were to determine the influence of diabetes on racial differences in the use of cardiac catheterization and revascularization procedures, and in short- and

American Heart Journal Volume 150, Number 5

Kamalesh et al 913

Table I. Baseline characteristics

Age Male sex Diabetes No. of diagnoses Hypertension Hyperlipidemia History of AF History of stroke COPD CHF CAD

Table II. Baseline characteristics for diabetic patients

Black*

White* (n = 55 731)

P

63.9 F 11.9 8332 (98.8) 2480 (29.4) 5.59 F 2.5 4986 (59.1) 953 (11.3) 439 (5.2) 12 (1.5) 1146 (13.6) 1744 (20.7) 3261 (42.9)

65.2 F 10.7 54958 (98.6) 14088 (25.3) 5.64 F 2.6 23588 (42.3) 8307 (14.9) 5384 (9.7) 579 (1.0) 11560 (20.7) 12241 (22.0) 27589 (49.5)

b.001 .2937 b.001 .0735 b.001 b.001 b.001 b.001 b.001 .0073 b.001

Age Male sex No. of diagnoses Hypertension Hyperlipidemia History of atrial fibrillation History of stroke COPD CHF CAD history

BlackT

WhiteT (n = 14 088)

P

65.4 F 10.0 2448 (98.7) 6.5 F 2.2 1716 (69.2) 312 (12.6) 112 (4.5)

66.4 F 9.2 13862 (98.4) 6.7 F 2.3 7488 (53.2) 2215 (15.7) 1461 (10.4)

b.001 .2444 .0244 b.001 b.001 b.001

38 (1.5) 308 (12.4) 677 (27.3) 1174 (47.3)

173 2568 4176 7290

(1.2) (18.9) (29.6) (51.8)

.2127 b.001 .0180 b.001

Values are expressed as means F SD or number (percentage). AF, Atrial fibrillation. Tt Tests were performed for these variables, as opposed to m2.

Values are expressed as means F SD or number (percentage). Tt Tests were performed for these variables, as opposed to m2.

long-term survival among patients admitted to the VAMC after an acute myocardial infarction (MI ). Data were analyzed for the overall cohort as well as for the subgroups with and without diabetes.

extracted from patients’ paper medical charts.16 Demographic, inhospital, and follow-up data were recorded for each patient. Each hospitalization record in the PTF contained up to 10 discharge diagnosis. We used the discharge diagnoses 2 through 10 from the index admission to identify comorbid conditions. The severity of the patients’ acute MI and medication profile were not available in the PTF. All readmissions and readmissions due to cardiac causes (first listed diagnosis of acute MI, angina, and congestive heart failure [CHF]) to any VAMC were assessed at 60 days and 1 year after discharge from the index hospitalization. Patients who died before 30 days were excluded from readmission analysis. For outpatient services, utilization data were extracted from the VA outpatient clinic file identifying visits to primary care, cardiology clinic, emergency units, and cardiac surgery clinics. Data regarding diagnostic tests and procedures were also extracted for cardiac catheterization, coronary bypass surgery, percutaneous coronary revascularization, and pacemaker or defibrillator implantation. To determine mortality, the beneficiary information and resource locator was used.17,18 This contains date of death but not cause of death. Hence, all- cause mortality was used as an end point.

Methods Study population The patient treatment file (PTF) portion of the medical record was used to identify all patients discharged from any VAMC in the United States between October 1990 and September 1997, with a diagnosis of acute MI (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD -9 -CM] code 410) listed as the primary discharge diagnosis. The validity of this strategy to identify patients with acute MI has been previously established.14,15 For veterans with N1 admission with an eligible ICD - 9 - CM code during the study period, the first admission was considered the index admission. Patients who were discharged and readmitted the same day were assumed to have been transferred from one medical center to another (a common practice in the VA medical system), and their admissions were considered to represent a single hospitalization. Patients whose length of stay exceeded 1 year were excluded from the analyses. These patients had comorbid conditions causing long-term disability or were mental health care patients who had a different postinfarction course and health care utilization than those without these conditions. The patients were grouped as black or white. Other races, or those patients for whom race was unknown, were excluded from the analysis. Veterans with diabetes were studied as a separate group comparing blacks and whites. The study was approved by the Institutional Review Board of the Indiana University School of Medicine.

Data on hospitalization, follow-up, and mortality Data were extracted from the central VA administrative data center in Austin, Tex. Data regarding VA inpatient utilization throughout the index hospitalization was extracted from PTFs. There was a high agreement between PTF data and data

Statistics Baseline characteristics were compared between whites and blacks. For discrete variables, m2 tests were used, whereas t tests were used for continuous variables. Because the distributions of number of readmissions, either for general reason or for cardiovascular reason, were extremely skewed, the median number of admissions was reported, and comparisons were made using the Kruskal-Wallis nonparametric test. Similar tests were also used to assess the time to cardiac procedures at 60 days and 1 year post-MI. The number of patients requiring readmission (for general or cardiovascular reasons) was compared between black versus white patients using logistic regression models with and without adjusting for the comorbid conditions age, length of stay in hospital, number of diagnosis, hypertension, hyperlipidemia, CAD, CHF, and stroke. The likelihood of outpatient service utilization for black patients was compared with that of white patients using

American Heart Journal November 2005

914 Kamalesh et al

Table III. One year post-MI follow-up end points in diabetic patients Black (n = 2480)

White (n = 14 088)

Odds*

n (%)

n (%)

Adj. odds ratio* (95% CI)yy

CABG

121 (4.9)

992 (7.0)

PTCA

96 (3.9)

593 (4.2)

275 (11.1)

1949 (13.8)

1285 (59.6)

7446 (61.0)

929 (43.1)

5678 (46.5)

Median

Median

41 40 48 48

37 49 39 41

Catheterization Patients readmitted Patients readmitted for CV reason

Days to CABG Day to PTCA Time to first readmission Time to first CV readmission

1.48 1.56 1.09 1.19 1.29 1.40 1.07 1.07 1.15 1.17

(1.22-1.79) (1.28-1.90) (0.88-1.36) (0.95-1.48) (1.13-1.47) (1.22-1.60) (0.97-1.17) (0.98-1.18) (1.05-1.26) (1.06-1.28)

Between-groups P z .75 .43 b.001 b.02

CABG, Coronary artery bypass graft surgery; PTCA, percutaneous transluminal coronary angioplasty. TOdds ratio for comparing white versus black. y Adjusted for age, length of stay in hospital, number of diagnosis, hypertension, hyperlipidemia, CAD, CHF, and stroke. z P values are from Kruskal-Wallis test.

Table IV. Post-MI end points during the entire follow-up in diabetic patients Black (n = 2480)

White (n = 14 088)

Odds ratio*

n (%)

n (%)

Adj. odds ratio* (95% CI)yy

CABG

199 (8.0)

1732 (12.3)

PTCA

168 (6.8)

1141 (8.1)

CC

504 (20.3)

3806 (27.0)

Median

Median

81 96

65 115

Days to CABG Day to PTCA

1.61 1.73 1.21 1.31 1.45 1.58

(1.38-1.87) (1.48-2.03) (1.03-1.43) (1.10-1.56) (1.31-1.61) (1.41-1.76)

Between-groups Pzz 0.40 0.43

TOdds ratio for comparing white versus black. y Adjusted for age, length of stay in hospital, number of diagnosis, hypertension, hyperlipidemia, CAD, CHF, and stroke. z P values are from Kruskal-Wallis test.

logistic regressions models. These comparisons were further assessed after adjusting for the aforementioned comorbid conditions. Mortality comparisons between white versus black patients were made using the time-to-event Cox proportional hazards models. First, the unadjusted mortality comparisons were made for 60 - day, 1-year, and for the entire follow-up postMI, then the adjusted comparisons were made using the same comorbid conditions mentioned earlier. In general, when covariate adjustments were made (for either logistic regression or Cox proportional hazards models), the final model was chosen using a backward selection procedure. In cases when the unadjusted final model did not include the term race (implying that there was no significant difference between black and white patients), no further comparisons were performed. Kaplan-Meier curves were plotted for comparing

the survival curves between black and white patients with and without diabetes.

Results Between October 1990 and September 1997, a total of 67 889 patients were discharged from any VAMC with a primary discharge diagnosis of acute MI. Race status was known for 66 506 subjects of whom 55 731 (84%) were white and 8437 (13%) were black. Of subjects for whom race status was known, there were 16 568 (25%) with diabetes. Baseline characteristics of the 2 groups ( black and white) are shown in Table I. White subjects were slightly ( but significantly) older than blacks. The

American Heart Journal Volume 150, Number 5

Kamalesh et al 915

Table V. Post-MI mortality using the Cox proportional hazards model in diabetic patients Black (n = 2480)

White (n = 14 088)

Hazard ratio*

n (%)

n (%)

Adj. hazard ratio* (95% CI)yy

84 (3.9)

676 (5.5)

1-y mortality

288 (13.4)

2057 (16.9)

Entire follow-up mortality

741 (34.3)

4619 (37.9)

60-d mortality

1.44 1.29 1.31 1.22 1.17 1.09

(1.15-1.81) (1.03-1.63) (1.16-1.48) (1.08-1.39) (1.08-1.26) (1.01-1.18)

THazard ratio comparing the mortality of white versus black. yAdjusted for age, length of stay in hospital, number of diagnosis, hypertension, hyperlipidemia, CAD, CHF, stroke.

incidence of diabetes was much higher in blacks. Among other baseline characteristics, hypertension and stroke were more common in blacks, whereas hyperlipidemia, atrial fibrillation, chronic obstructive pulmonary disease (COPD), history of CHF, and history of coronary artery disease (CAD) were more common in whites. For short-term (60 days) post-MI mortality, interaction between race and diabetes was not significant ( P = .58). Whereas, for post-MI mortality, there was a significant interaction ( P b .02) between diabetes status and race for both the 1-year follow-up and the entire follow-up, indicating that the effect of diabetes on the rate of mortality depended on the race of origin. Therefore, results are provided separately for subjects with and without diabetes.

Diabetic subjects Baseline characteristics of black and white subjects with diabetes are shown in Table II. Black subjects were significantly younger and had more hypertension. White subjects carried a greater number of diagnoses and had more COPD, more CHF, and more CAD history. Post-MI rates of cardiac catheterization and coronary bypass surgery were significantly higher among whites at 1 year and for the entire follow-up period ( Tables III and IV ). Percutaneous coronary revascularization rate was significantly higher among whites for the entire follow-up period. The 1-year post-MI rates of readmission for cardiovascular reason were higher for whites with significantly shorter median days to readmission. Post-MI mortality was significantly higher among whites at 60 days (adjusted hazard ratio [HR] 1.29, 95% CI 1.03-1.63) and at 1 year (adjusted HR 1.22, 95% CI 1.08-1.39) (Table V). The rate of mortality during the entire post-MI follow-up period was also significantly higher in whites (37.9%) than in blacks (34.3%) (adjusted HR 1.09, 95% CI 1.01-1.18). Nondiabetic patients At baseline, most of the characteristics comparisons between blacks and whites followed a similar trend as in

Figure 1

Kaplan-Meier survival curves for the 4 groups. There was no significant difference between white and black nondiabetic patients. On the other hand, white diabetic patients had significantly higher mortality than black diabetic patients (log-rank P b .001).

the diabetic population (data not shown). In addition, the follow-up procedure comparison results, comparing race differences, were consistent with those in the diabetic subjects (data not shown). The 60 - day post-MI mortality was significantly higher in whites (4.2%) than in blacks (3.2%) (adjusted HR 1.24, 95% CI 1.05-1.46). However, the mortality from the 1-year post-MI or the entire follow-up rates were not significantly different ( P N .05) between blacks (11.3% and 29.5%, respectively) and whites (12.3% and 29.0%, respectively). The Kaplan-Meier survival curve ( Figure 1) revealed that regardless of the race, the diabetic patients tended to have higher mortality than nondiabetic patients. The post-MI mortality during the entire follow-up period tended to be similar between blacks and whites for the

916 Kamalesh et al

nondiabetic patients, whereas the mortality tended to be lower in blacks than in whites in diabetic patients.

Discussion Our study investigated the racial differences in short-term and long-term mortality, morbidity, and use of post-MI cardiac procedures in a large cohort of veteran population in the 1990s. Furthermore, it looked at the influence of diabetes on racial variation in postMI mortality. Our study reveals that in general, whites have higher comorbidities than blacks. However, the prevalence of diabetes was 16% higher among blacks (29.4%) compared with whites (25.3%). Despite receiving a significantly higher number of interventional post-MI cardiac procedures, white diabetic patients have higher shortterm and long-term mortality compared with black diabetic patients. This remains true even after adjustment for comorbidities. Diabetes, despite being significantly more common in blacks, was associated with a lower long-term mortality among blacks. In contrast, among nondiabetic patients, although the short-term (60 days post-MI) mortality was slightly but significantly higher in whites (4.2% vs 3.2%), long-term mortality was not different among the 2 groups. Our findings that incidence of coronary risk factors of hypertension and diabetes are more common in blacks are consistent with prior reports both in the VA and non-VA settings,19-24 although COPD is more common among white veterans,25 indicating higher incidence of smoking. Our finding that overall invasive coronary procedures are used less frequently in blacks is also consistent with previous reports, again both in the VA and non-VA sectors.5 - 8,25 -38 In 1994, Peterson and coworkers examined the racial variation in cardiac procedure use and in survival after acute MI in 33 641 veterans from January 1988 to December 1990. They found that blacks with acute MI were 33% less likely to undergo cardiac catheterization, 44% less likely to receive percutaneous revascularization, and 54% less likely to receive coronary bypass surgery. In 1997, they reported on racial variation in the use of cardiac revascularization procedures in the non-VA setting in 12 402 patients (10.3% were black) at Duke University from the years 1984 to 1992. They found that blacks were 13% less likely to undergo angioplasty and 32% less likely to undergo coronary bypass surgery. In that study, the indication for catheterization was suspected ischemic heart disease as opposed to after an acute MI in our study, which is a sign of confirmed CAD. Thus, although the criteria for including patients in the study may differ, it appears that despite numerous reports documenting the underuse of cardiac procedures in blacks, this persisted through the mid to late 1990s.

American Heart Journal November 2005

The reasons for this are not entirely clear although several explanations have been put forth including one of access to medical care. However, given equality of access to medical care in the VA health system, this explanation appears less likely. Furthermore, our findings are from a national database thus ruling out confounding effects of regional variations. It has been previously reported that black patients more frequently refuse physicians’ advise to undergo catheterization39 or coronary bypass surgery.40 However, our data show that in the baseline characteristics, the total number of diagnosis was slightly (but significantly) lower for blacks regardless of diabetes status, thus making the white population more sick overall. This may have influenced the physician to be more aggressive in managing a white patient, or on the contrary, the black patient may feel more healthy and be less inclined for aggressive cardiac procedures. These criteria are influenced by complex patient-physician relationships in which individual perceptions of risks and benefits of medical interventions may vary. Previous data suggesting poorer outcomes after coronary bypass among blacks41 have not borne out in later studies.42,43 The effect of cultural factors, social factors, and perceptions of the health care system on the decision to undergo procedures has also been implicated.44,45 In contrast to the consistency in reported data on baseline characteristics and coronary procedures between blacks and whites, data on racial differences in mortality from ischemic coronary disease are much less consistent. In general, it appears that blacks do better after acute MI in hospitals that provide equal access to medical care irrespective of socioeconomic status,7,10 -12 whereas in other settings, they do worse.1-5 Califf and coworkers1 reporting on the 1-year survival postthrombolysis for acute MI showed that the black race was an independent predictor of post-MI mortality even without the confounding factors of cardiac interventional procedures as part of the GUSTO-1 trial. Udvarhelyi et al38 in the Medicare patients and Peterson et al7 in the VA setting reported that blacks had better short-term survival but there was no difference in survival at 2 years. Our study with a much larger database and longer followup shows that despite having lower number procedures, blacks have lower unadjusted and adjusted mortality 60 days post-MI regardless of the diabetes status.

Mortality In the diabetic population, blacks had lower unadjusted and adjusted mortality although the 1-year and entire follow-up mortality rates were similar between blacks and whites in the nondiabetic subjects. Several explanations have been put forward to explain this phenomenon. It has been postulated that inhospital-treated blacks for acute MI may represent a skewed population of less sick patients (and hence have better outcomes), because

American Heart Journal Volume 150, Number 5

it has been shown that out - of-hospital death rates are higher in blacks.46,47 However, these studies were done in the non-VA setting. Other possibilities include decreased survival caused by complications of interventions themselves which are clearly more frequent in whites. However, this possibility is discounted by the analysis done by Peterson and coworkers7 in their report. In our study, the possibilities for improved survival among blacks could be partly due to the baseline characteristics. Blacks were slightly (but significantly) younger and had a fewer number of diagnoses than whites. Our most significant finding in this study was the highly significant long-term lower post-MI mortality among blacks with diabetes. It is interesting that among the nondiabetic population, there appears to be no longterm racial difference in post-MI survival (Figure 1). To our knowledge, these findings have not been reported before and are in contrast to prior smaller studies.2 According to the National Vital Statistics Report of 2002, diabetes is ranked as the fifth leading cause of death in the United States for blacks and the seventh for whites.48 A recent study found that in the VA setting, 30 - day mortality was nonsignificantly lower among blacks admitted for diabetes.25 The reasons for lower post-MI mortality in blacks with diabetes are not readily explainable. It is possible that certain cardioprotective mechanisms may be more prevalent in the black population. For example, blacks have higher levels of high-density lipoproteins49 which, in general, are especially lower in subjects with diabetes. On the other hand, it is possible that diabetes has a particularly noxious effect in white subjects. Subjects with diabetes and coronary disease have a much higher mortality than subjects who have one of these conditions only.50 Our study has several strengths. It is one of the largest studies to date to investigate long-term post-MI mortality in the 1990s, the period when substantial changes occurred in the management of acute MI.13 The data were collected all over the country as opposed to certain regions or medical centers, thus, giving a homogenous and unbiased population. Hospitals treating the patients included both community hospitals and tertiary care referral centers. There is a good mix of white and black population with 13% of the population being black. We used all-cause mortality as an end point, which has been used and accepted in such investigations previously.7,13 Certain methodological considerations merit discussion. The diagnosis of diabetes and MI was based on ICD -9 - CM codes and validation of the diagnosis in a random sample was not done. However, prior data reveal N 88% correlation of database coding information for acute MI with actual review of medical records in VA patients.7 Previous administrative database studies have shown good validity using ICD-9 codes for MI14,15 and diabetes mellitus. Because medication history was not

Kamalesh et al 917

available, treatment with hypoglycemic agents could not be confirmed. Data on duration of diabetes, HbA1c levels, and classification of diabetes as type 1 or type 2 were not available. However, because both diabetes and MI are diagnosed based on objective tests (blood tests), the possibility of misclassification would be lower than some other clinical situations such as CHF diagnosis.15 It needs to be mentioned that many of the studies we have referred to have used similar administrative data bases.7,14,15 The absolute number of patients with diabetes may be higher as a recent report shows that undiagnosed diabetes is common in patients admitted with acute MI.51 Moreover, we used the index admission to classify patients as with or without diabetes. Therefore, patients who have been diagnosed subsequent to their index admission may be misclassified. Our study population consisted of predominantly male subjects as it was a VAMC study. These patients, in general, have more comorbid conditions than Medicare patients. Thus, its applicability to female patients is limited. It is possible that during the period of the study, some patients in the group without diabetes may have developed diabetes. This could potentially narrow the mortality difference between the 2 groups.

Conclusions Despite undergoing fewer invasive cardiac procedures, mortality from post-MI is significantly lower in blacks with diabetes than in whites with diabetes. In contrast, no racial difference in long-term mortality was seen among subjects without diabetes. Thus, it appears that diabetes status determines racial variation in post-MI mortality. The reasons for better survival post-MI of blacks in general and among subjects with diabetes in particular need to be further investigated.

References 1. Califf RM, Pieper KS, Lee KL, et al. Prediction of 1-year survival after thrombolysis for acute myocardial infarction in the global utilization of streptokinase and TPA for occluded coronary arteries trial. Circulation 2000;101:2231 - 8. 2. Will JC, Casper M. The contribution of diabetes to early deaths from ischemic heart disease: US gender and racial comparisons. Am J Public Health 1996;86:576 - 9. 3. Castaner A, Simmons BE, Mar M, et al. Myocardial infarction among black patients: poor prognosis after hospital discharge. Ann Intern Med 1988;109:33 - 5. 4. Strong JP, Oalmann MC, Newman WP, et al. Coronary heart disease in young black and white males in New Orleans: community pathology study. Am Heart J 1984;108:747 - 59. 5. 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. 6. Keil JE, Sutherland SE, Knapp RG, et al. Mortality rates and risk factors for coronary disease in black as compared with white men and women. N Engl J Med 1993;329:73 - 8.

918 Kamalesh et al

7. Peterson ED, Wright SM, Daley J, et al. Racial variation in cardiac procedure use and survival following acute myocardial infarction in the Department of Veterans Affairs. JAMA 1994; 271:1175 - 80. 8. Whittle J, Conigliaro J, Good CB, et al. Racial differences in the use of invasive cardiovascular procedures in the Department of Veterans Affairs medical system. N Engl J Med 1993;329:621 - 7. 9. Taylor HA, Canto JG, Sanderson B, et al. Management and outcomes for black patients with acute myocardial infarction in the reperfusion era. Am J Cardiol 1998;82:1019 - 23. 10. Akereley WL, Moritz TE, Ryan LS, et al. Racial comparison of outcomes of male Department of Veterans Affairs patients with lung and colon cancer. Arch Intern Med 1993;153:1681 - 8. 11. Ferguson JA, Tierney WM, Westmoreland GR, et al. Examination of racial differences in management of cardiovascular disease. J Am Coll Cardiol 1997;30:1707 - 13. 12. Taylor AJ, Meyer GS, Morse RW, et al. Can characteristics of a health care system mitigate ethnic bias in access to cardiovascular procedures? Experience from the Military Health Services System. J Am Coll Cardiol 1997;30:901 - 7. 13. McGovern PG, Pankow JS, Shahar E, et al. Recent trends in acute coronary heart disease — mortality, morbidity, medical care and risk factors. N Engl J Med 1996;334:884 - 90. 14. Pladevall M, Goff DC, Nichaman MZ, et al. An assessment of the validity of ICD code 410 to identify hospital admissions for myocardial infarction: the Corpus Christi Heart Project. Int J Epidemiol 1996;25:948 - 52. 15. Petersen LA, Normand ST, Daley J, et al. Outcome of myocardial infarction in veterans health administration patients as compared with medicare patients. N Engl J Med 2000;343:1934 - 41. 16. Wright SM, Petersen LA, Lamkin RP, et al. Increasing use of medicare services by veterans with acute myocardial infarction. Med Care 1999;37:529 - 37. 17. Fisher SG, Weber L, Goldberg J, et al. Mortality ascertainment in veteran population: alternatives to national death index. Am J Epidemiol 1995;141:242 - 50. 18. Fleming C, Fisher ES, Chang CH, et al. Studying outcomes and hospital utilization in the elderly: the advantages of a merged database for medicare and veterans affairs hospitals. Med Care 1992;30:377 - 91. 19. Arozullah AM, Ferreira MR, Bennett RL, et al. Racial variation in the use of laparascopic cholecystectomy in the Department of Veteran’s Affairs Medical Center. J Am Coll Surg 1999;188: 604 - 22. 20. Cushman WC, Reda DJ, Perry HM, et al. Regional and racial differences in response to antihypertensive medication use in a randomized controlled trial of men with hypertension in the United States. Arch Intern Med 2000;160:825 - 31. 21. Gottdiener JS, Reda DJ, Williams DW, et al. Left atrial size in hypertensive men: influence of obesity, race and age. J Am Coll Cardiol 1997;29:651 - 8. 22. Conigliaro J, Whittle J, Good CB, et al. Understanding racial variations in the use of coronary revascularization procedures: the role of clinical factors. Arch Intern Med 2000;160:1329 - 35. 23. Mickelson JK, Blum CM, Geraci JM. Acute myocardial infarction: clinical characteristics, management and outcome in a metropolitan Veterans Affairs Medical Center Teaching Hospital. J Am Coll Cardiol 1997;29:915 - 25. 24. Wilt TJ, Rubins HB, Collins D, et al. Correlates and consequences of diffuse atherosclerosis in men with coronary heart disease. Arch Intern Med 1996;156:1181 - 8.

American Heart Journal November 2005

25. Jha AK, Shlipak MG, Hosmer W, et al. Racial differences in mortality among men hospitalized in the veterans affairs health system. JAMA 2001;285:297 - 303. 26. 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. 27. Giles WH, Anda RF, Casper ML, et al. Race and sex differences in rates of invasive cardiac procedures in US hospitals: data from the National Hospital Discharge Survey. Arch Intern Med 1995;155: 318 - 24. 28. 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;24:1297 - 304. 29. 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. 30. 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;118:593 - 601. 31. Gillum RF. Coronary artery bypass surgery and coronary angiography in the United States, 1979-1983. Am Heart J 1987;113:1255 - 60. 32. Mc Bean AM, Warren JL, Babish JD. Continuing differences in the rates of percutaneous transluminal coronary angioplasty and coronary artery bypass graft surgery between elderly black and white Medicare beneficiaries. Am Heart J 1994;127:287 - 95. 33. Goldberg KC, Hartz AJ, Jacobsen SJ, et al. Racial and community factors influencing coronary artery bypass surgery rates for all 1986 Medicare patients. JAMA 1992;2671:1473 - 7. 34. Wenneker MB, Epstein AM. Racial inequalities in the use of procedures for patients with ischemic heart disease in Massachusetts. JAMA 1989;261:253 - 7. 35. Ford E, Cooper RS, Castaner A, et al. Coronary arteriography and coronary bypass surgery survey among whites and other racial groups relative to hospital based incidence rates for coronary artery disease: findings from NHDS. Am J Public Health 1989;79: 437 - 40. 36. Hannan EL, Kilburn Jr H, O’Donnell JF, et al. Interracial access to selected cardiac procedures for patients hospitalized with coronary artery disease in New York State. Med Care 1991;29:430 - 41. 37. Gittelsohn KG, Halpern J, Sanchez RL. Income, race, and surgery in Maryland. Am J Public Health 1991;81:435 - 41. 38. Udvarhelyi S, Gatsonis C, Epstein AM, et al. Acute myocardial infarction in the Medicare population: process of care and clinical outcomes. JAMA 1992;268:2530 - 6. 39. Schecter AD, Goldschmidt-Clermont PJ, McKee G, et al. Influence of gender, race, and education on patient preferences and receipt of cardiac catheterization among coronary care unit patients. Am J Cardiol 1996;78:996 - 1001. 40. Maynard C, Fisher LD, Passamani ER, et al. Blacks in Coronary Artery Surgery Study (CASS): race and clinical decision making. Am J Pub Health 1986;76:1446 - 8. 41. Watkins Jr L, Gardner K, Gott V, et al. Coronary heart disease and surgery in black males. Am Heart J 1984;108:695 - 9. 42. Liao Y, Cooper RS, Ghali JK, et al. Survival rates with coronary artery disease for black women compared with black men. JAMA 1992;268:1867 - 71. 43. Simmons BE, Castaner A, Santhanam V, et al. Outcome of coronary artery bypass grafting in black persons. Am J Cardiol 1987;59: 547 - 51.

American Heart Journal Volume 150, Number 5

Kamalesh et al 919

44. Blendon RJ, Aiken LH, Freeman HE, et al. Access to medical care for black and white Americans: a matter of continuing concern. JAMA 1989;261:278 - 81. 45. Ferguson JA, Wienberger M, Westmoreland GL, et al. Racial disparity in cardiac decision making. Results from patient focus group. Arch Intern Med 1998;158:1450 - 3. 46. Keil JE, Saunders DE, Lackland DT, et al. Acute myocardial infarction: period prevalence, case fatality and comparisons of black and white cases in urban and rural areas of South Carolina. Am Heart J 1985;109:776 - 84. 47. Weisse AB, Abiuso PD, Thind IS. Acute myocardial infarction in Newark, NJ. Arch Intern Med 1977;137:1402 - 95.

48. Anderson RN. Deaths: leading causes for 2000. National Vital Statistics Report 2002. p 1-85. 49. Glueck CJ, Gartside P, Laskarzewski PM, et al. High density lipoprotein cholesterol in blacks and whites: potential ramification for coronary heart disease. Am Heart J 1984;108:815 - 23. 50. Haffner SM, Lehto S, Ronnemaa T, et al. Mortality from coronary heart disease in subjects with type 2 diabetes and in non diabetic subjects with and without prior myocardial infarction. N Engl J Med 1998;338:229 - 34. 51. Norhammar A, Tenerz A, Nilsson G, et al. Glucose metabolism in patients with acute myocardial infarction and no previous diagnosis of diabetes mellitus: a prospective study. Lancet 2002;359:2140 - 4.

The following article is a AHJ Online Exclusive. Full text of this article is available at no charge at our website: www.mosby.com/ahj

Effects of canrenoate plus angiotensin-converting enzyme inhibitors versus angiotensin-converting enzyme inhibitors alone on systolic and diastolic function in patients with acute anterior myocardial infarction Pietro Di Pasquale, MD,a Sergio Cannizzaro, MD,a Sebastiano Scalzo, MD,a Gaspare Parrinello, MD,b Sergio Fasullo, MD,a Francesco Giambanco, MD,a Antonio Fatta, MD,a and Salvatore Paterna, MDc Palermo, Italy

Background

Aldosterone (ALDO) exerts profibrotic effects,

Results

Clinical and demographic aspects were similar in

acting via the mineralocorticoid receptors in cardiovascular

both groups. In addition, baseline cardiac enzyme levels, left ventricular

tissues. Aldosterone antagonism in combination with

function, and incidence of surgical interventions and angioplasty

angiotensin-converting enzyme inhibition may better protect against

were comparable. Overall, creatinine, blood urea, and serum potassium

the untoward effects of ALDO than angiotensin-converting enzyme

levels did not show significant differences between groups. However,

inhibition alone.

in 18 patients in group A, increases in serum potassium levels to N5.5 mEq/L

Methods

In a double-blind randomized study, the tolerability

and efficacy of canrenoate (25 mg/d) plus captopril versus captopril alone were evaluated in 510 patients with an acute anterior myocardial infarction (MI), a serum creatinine concentration b2.0 mg/dL, and a serum potassium level b5.0 mmol/L. Three hundred forty-one patients

and creatinine levels to N2.0 mg/L after 10 days of treatment were observed. At 180 days, the mitral E-wave–A-wave ratio was higher ( P = .0001) and left ventricular end-systolic volume was smaller ( P = .0001) in patients treated with canrenoate than in those receiving placebo. No further side effects were observed during the study period.

received captopril and 25-mg canrenoate (group A). Group B

Conclusions

(346 patients) received captopril and placebo. At baseline and at 10, 90,

captopril plus canrenoate is well tolerated after an acute

and 180 days after admission, Doppler echocardiography

MI and has beneficial effect on systolic and diastolic parameters and may

was performed.

decrease post-MI remodeling. (Am Heart J 2005;150:919.e1-919.e8.)

Our data suggest that the combination of