Coronary artery disease in blacks of lower socioeconomic status: angiographic findings from the Cook County Hospital Heart Disease Registry

Issues in minority health: atherosclerosis and coronary heart disease in African Americans

Cardiovascular disease (in particular, CHD) is the leading cause of death in the United States for Americans of both sexes and of all racial and ethnic backgrounds. African Americans have the highest overall CHD mortality rate and the highest out-of-hospital coronary death rate of any ethnic group in the United States, particularly at younger ages. Contributors to the earlier onset of CHD and excess CHD deaths among African Americans include a high prevalence of coronary risk factors, patient delays in seeking medical care, and disparities in health care. The clinical spectrum of acute and chronic CHD in African Americans is the same as in whites; however, African Americans have a higher risk of sudden cardiac death and present clinically more often with unstable angina and non-ST-segment elevation myocardial infarction than whites. Although generally not difficult, the accurate diagnosis and risk assessment for CHD in African Americans may at times present special challenges. The high prevalence of hypertension and type 2 diabetes mellitus may contribute to discordance between symptomatology and the severity of coronary artery disease, and some noninvasive tests appear to have a lower predictive value for disease. The high prevalence of modifiable risk factors provides great opportunities for the prevention of CHD in African Americans. Patients at high risk should be targeted for intensive risk reduction measures, early recognition/diagnosis of ischemic syndromes, and appropriate referral for coronary interventions and cardiac surgical procedures. African Americans who have ACSs receive less aggressive treatment than their white counterparts but they should not. Use of evidence-based therapies for management of patients who have ACSs and better understanding of various available treatment strategies are of utmost importance. Reducing and ultimately eliminating disparities in cardiovascular care and outcomes require comprehensive programs of education and advocacy(Box 4) with the goals of (1) increasing provider and public awareness of the disparities in treatment; (2) decreasing patient delays in seeking medical care for acute myocardial infarction and other cardiac disorders; (3) more timely and appropriate therapy for ACSs; (4) improved access to preventive, diagnostic, and interventional cardiovascular therapies; (5) more effective implementation of evidence-based treatment guidelines; and (6) improved physician-patient communications.

Cardiac surgery in African Americans

Retrospective and prospective randomized studies that provide information on the influence of race on the morbidity and mortality of cardiac surgical procedures are reviewed. We intentionally focus our attention on the specific outcomes of these procedures in African Americans because African Americans have a high incidence of all-cause cardiovascular mortality and a high prevalence of a number of risk factors associated with cardiovascular mortality. Furthermore, numerous studies have confirmed that blacks, as a function of race, lack equal access to diagnostic and therapeutic invasive cardiac procedures. Here we use the terms "black" and "African American" interchangeably. In this context we interpret both terms to refer to Americans of African descent. Similarly, we use the term "white" or "Caucasian" interchangeably to refer to Americans of European descent.

Black-white differences in severity of coronary artery disease among individuals with acute coronary syndromes

OBJECTIVE

To determine whether the extent of coronary obstructive disease is similar among black and white patients with acute coronary syndromes.

DESIGN

Retrospective chart review.

PATIENTS

We used administrative discharge data to identify white and black male patients, 30 years of age or older, who were discharged between October 1, 1989 and September 30, 1995 from 1 of 6 Department of Veterans Affairs (VA) hospitals with a primary diagnosis of acute myocardial infarction (AMI) or unstable angina (UnA) and who underwent coronary angiography during the admission. We excluded patients if they did not meet standard clinical criteria for AMI or UnA or if they had had prior percutaneous transluminal coronary angioplasty or coronary artery bypass grafting.

MEASUREMENTS AND MAIN RESULTS

Physician reviewers classified the degree of coronary obstruction from blinded coronary angiography reports. Obstruction was considered significant if there was at least 50% obstruction of the left main coronary artery, or if there was 70% obstruction in 1 of the 3 major epicardial vessels or their main branches. Of the 628 eligible patients, 300 (48%) had AMI. Among patients with AMI, blacks were more likely than whites to have no significant coronary obstructions (28/145, or 19%, vs 10/155 or 7%, P =.001). Similarly, among patients with UnA, 33% (56/168) of blacks but just 17% (27/160) of whites had no significant stenoses (P =.012). There were no racial differences in severity of coronary disease among veterans with at least 1 significant obstruction. Racial differences in coronary obstructions remained after correcting for coronary disease risk factors and characteristics of the AMI.

CONCLUSIONS

Black veterans who present with acute coronary insufficiency are less likely than whites to have significant coronary obstruction. Current understanding of coronary disease does not provide an explanation for these differences.

Delay in presentation for cardiac care by race, age, and site of care

BACKGROUND

Racial differences exist in the management of coronary artery disease. One hypothesis is that black patients delay seeking care and that this delay may influence the management of coronary artery disease.

OBJECTIVES

To assess delay in seeking care for heart disease.

RESEARCH DESIGN

Cross-sectional survey.

SUBJECTS

One thousand six hundred and fifty-two patients awaiting coronary angiography at three VA and one non-VA Medical Center.

MEASURES

Patients were asked to retrospectively report the time between symptom onset and presentation for medical care and what if any were the reasons for delay.

RESULTS

One thousand five hundred eleven patients (12% VA & 43% non-VA) answered questions regarding delay in treatment. Overall, 73% reported delaying 1 month or more and 16% reported delaying more than 6 months. Black patients and white patients were equally likely to delay as were older persons (> or = 65) compared with younger. Patients at the VA hospitals reported longer delays and patients with prior revascularization were less likely to report delays. We used ordinal logistic regression to predict delay using site type and prior revascularization as covariates. VA site of care independently predicted longer delays whereas prior revascularization predicted less delay. Among patients who reported at least a 1 month delay, patients at the non-VA hospital were more likely to cite ignoring symptoms as their reason for delay (72% vs. 61%; P = 0.03) as were those with at least a high school education 69% versus 50%; P = 0.003). Black patients reported that they ignored their symptom more often but this was marginally significant (77% vs. 63%; P = 0.053).

CONCLUSIONS

Race was not associated with delay in seeking care among patients awaiting coronary angiography. Non-VA patients, and those with past revascularization, were less likely to delay. Ignoring symptoms was the most common reason for delays greater than 1 month. Further study of the sequence of patient and provider decisions that ultimately lead to revascularization is needed.

Coronary heart disease in African Americans

African Americans have the highest overall mortality rate from coronary heart disease (CHD) of any ethnic group in the United States, particularly out-of-hospital deaths, and especially at younger ages. Although all of the reasons for the excess CHD mortality among African Americans have not been elucidated, it is clear that there is a high prevalence of certain coronary risk factors, delay in the recognition and treatment of high-risk individuals, and limited access to cardiovascular care. The clinical spectrum of acute and chronic CHD in African Americans is similar to that in whites. However, African Americans have a higher risk of sudden cardiac death and present more often with unstable angina and non-Q-wave myocardial infarction than whites. African Americans have less obstructive coronary artery disease on angiography, but may have a similar or greater total burden of coronary atherosclerosis. Ethnic differences in the clinical manifestations of CHD may be explained largely by the inherent heterogeneity of the coronary syndromes, and the disproportionately high prevalence and severity of hypertension and type 2 diabetes in African Americans. Identification of high-risk individuals for vigorous risk factor modification-especially control of hypertension, regression of left ventricular hypertrophy, control of diabetes, treatment of dyslipidemia, and smoking cessation--is key for successful risk reduction.

The effect of race on coronary bypass operative mortality

OBJECTIVES

The study was done to determine whether race is an independent predictor of operative mortality after coronary artery bypass graft (CABG) surgery.

BACKGROUND

Blacks are less frequently referred for cardiac catheterization and CABG than are whites. Few reports have investigated the relative fate of patients who undergo CABG as a function of race.

METHODS

The Society of Thoracic Surgeons National Database was used to retrospectively review 25,850 black and 555,939 white patients who underwent CABG-alone from 1994 through 1997. A multivariate logistic regression model was developed to determine whether race affected risk-adjusted operative mortality.

RESULTS

Operative mortality was 3.83% for blacks versus 3.14% for whites (unadjusted black/white odds ratio [OR] 1.23 [1.15-1.31]). Blacks were younger, more likely female, hypertensive, diabetic and in heart failure. Nonetheless, the influence of these and other preoperative risk factors on procedural mortality was quite similar in black and white patients. After controlling for all risk factors, race remained a significant independent predictor of mortality in the multivariate logistic model (adjusted black/white OR 1.29 [1.21, 1.38]). Proportionately, these differences were greatest among lower-risk patients. The race-by-gender interaction was significant (p<0.05). The unadjusted mortality for black men, 3.30% and white men, 2.64% differed significantly (p<0.05), whereas for women there was no difference (black, 4.49%; white 4.41%).

CONCLUSIONS

Black race is an independent predictor of operative mortality after CABG except for very high-risk patients. The difference in mortality is greatest for male patients and, though statistically significant, is small in absolute terms. Therefore, patients should be referred for CABG based on clinical characteristics irrespective of race.

Insights into the pathophysiology of atherosclerosis and prognosis of black Americans with acute coronary syndromes

BACKGROUND

Disparities in prognosis for black and white patients with coronary heart disease have been widely reported. For several reasons it is unclear to what extent biologic factors contribute to these differences.

METHODS

The current medical literature regarding the pathophysiologic characteristics of cardiovascular disease is reviewed with emphasis on how racially mediated biologic differences may affect the manifestation, treatment, and prognosis of patients with coronary heart disease, particularly patients with acute coronary syndromes.

RESULTS

Black patients with coronary heart disease have a higher prevalence of ischemic heart disease risk factors, including hypertension, left ventricular hypertrophy, diabetes, and tobacco use. Other factors related to atherosclerosis, vascular reactivity, and thrombolysis that quantitatively and functionally differ among racial groups are identified. Prospective, randomized trials comparing outcomes among patients with acute coronary syndromes have included only a fraction of the available black population, although they reveal a similar short-term mortality rate for black and white patients. Several factors, including enhanced fibrinolysis among black patients with acute myocardial infarction, may in part counterbalance better understood and more prevalent comorbidities to equalize short-term (30-day) survival. All-cause, long-term (1-year) mortality appears worse for black patients compared with white patients with similar cardiovascular risk profiles.

CONCLUSION

As racially mediated biologic differences between black and white patients become better understood, targeted interventions to prevent coronary heart disease and treat acute coronary syndromes in black patients can be developed.

Baseline serum total cholesterol and coronary heart disease incidence in African-American women (the NHANES I epidemiologic follow-up study). National Health and Nutrition Examination Survey

Proportional-hazards analyses for African-American women aged 25 to 74 revealed a variable association of coronary heart disease risk with baseline serum total cholesterol (after adjusting for age fifth vs first quintile: RR = 1.62, 95% confidence interval [CI] 0.89 to 2.98, p = 0.12; after adjusting for age, systolic blood pressure, body mass index, smoking, history of diabetes, low education, and low family income: RR = 1.88, 95% CI 1.02 to 3.45, p = 0.04). Perhaps due to the relatively small number of events, the association of serum total cholesterol with coronary heart disease incidence in African-American women was not consistently significant.

Clinical and angiographic findings in black patients with suspected coronary artery disease

To determine the clinical variables and coronary angiographic findings in black patients with suspected coronary artery disease, we analyzed the data on consecutive black patients undergoing their first coronary angiogram over a three year period at the Cook County Hospital, Chicago, Illinois. We compared these findings to those of black and white patients from previous studies. There were 654 patients with a mean age+/-standard deviation of 56+/-10 years; 309 (47%) were men. Two hundred nineteen patients (33%) presented with unstable angina, 75 patients (12%) with acute myocardial infarction and 338 patients (52%) with chronic stable angina. Three hundred forty-six patients (53%) had 50% or greater stenosis in at least one of the major vessels. Among the patients with coronary artery disease, 128 patients (37%) had one vessel disease, 102 patients (29%) had two-vessel disease, and 116 patients (34%) had three-vessel disease. Black patients who undergo coronary angiography for suspected coronary artery disease have a high frequency of normal coronary angiogram or non-obstructive coronary artery disease. The frequency of 1-, 2- and 3-vessel disease in blacks with coronary artery disease is comparable to those observed in whites in previous reports.

Variation in utilization of cardiac procedures in the Department of Veterans Affairs health care system: effect of race

OBJECTIVES

Utilization rates for cardiac catheterization and cardiac surgery in the Department of Veterans Affairs (VA) health care system were studied to determine whether racial differences existed in a delivery plan in which access is not determined by patient finances.

BACKGROUND

Prior studies have demonstrated significant differences in utilization of cardiac diagnostic and therapeutic resources by white and black patients. Reasons for the reduced utilization by black patients include socioeconomic, biologic and sociocultural effects.

METHODS

Computerized discharge records of 30,300 patients with coronary artery disease and 1,335 patients with valvular heart disease who were discharged from any of 172 VA Medical Centers between October 1, 1990 and September 30, 1991 were studied.

RESULTS

For patients with coronary artery disease, utilization rates of cardiac catheterization were significantly greater for white patients (503.4 procedures/1,000 patients) than for black patients (433.2/1,000 patients), with a relative odds ratio of 1.33. Rates for surgery (179.0 vs. 124.5/1,000 patients) were also greater for whites than for blacks, with a relative odds ratio of 1.53. For the subset with valve disease, the catheterization rate was significantly greater for whites than for blacks (575.4 vs. 432.6 procedures/1,000 patients), with a relative odds ratio of 1.78. Surgical rates were not significantly different (423.8 vs. 354.6 operations/1,000 patients). Racial differences for both catheterization and surgery varied widely as a function of geographic region and the level of complexity of the local VA facility.

CONCLUSIONS

Racial differences in resource utilization exist in a health care system in which economic influences are minimized. The pattern of these differences depends on numerous variables and suggests both biologic and sociocultural factors as underlying causes.

Racial differences in myocardial ischemia and coronary flow reserve in hypertension

OBJECTIVES

Using invasive measurements of endothelium-independent coronary flow reserve and stress thallium testing with or without dipyridamole, this study investigated racial differences in ischemia and coronary reserve in hypertensive left ventricular hypertrophy.

BACKGROUND

African Americans compared with Caucasian Americans appear to have a higher case fatality from coronary heart disease but lesser amounts of atherosclerotic coronary artery disease. This paradox may be explainable by intrinsic or acquired racial differences in coronary arteriolar autoregulation and vasoreactivity.

METHODS

The study enrolled 91 African and 81 Caucasian Americans referred for cardiac catheterization because of suspected myocardial ischemia but found to have no significant coronary stenosis. Patients were stratified by degree of left ventricular hypertrophy for comparison purposes after calculation of indexed left ventricular mass by means of echocardiographic M-mode measurements. Coronary flow reserve measurements were made using the intracoronary Doppler catheter and hyperemic doses of intravenous dipyridamole in 100 patients and intracoronary papaverine and adenosine in 72 patients. Seventy-seven percent of patients underwent adequate stress thallium testing with or without dipyridamole.

RESULTS

In African Americans, mean (+/- SD) coronary flow reserve decreased from 4.4 +/- 2.3 for 38 without mass hypertrophy to 3.2 +/- 1.3 for 53 with hypertrophy (p = 0.005) to 2.7 +/- 1.1 for 12 with severe hypertrophy (p = 0.02). Thallium testing was abnormal in 31% of those without mass hypertrophy and 59% of those with hypertrophy. In Caucasian Americans, coronary flow reserve decreased from 4.1 +/- 2 for 58 without hypertrophy to 3.6 +/- 1.5 for 23 with hypertrophy (p = NS) to 3 +/- 1.5 for 6 with severe hypertrophy (p = NS). Thallium testing was abnormal in 36% without mass hypertrophy and in 39% with hypertrophy.

CONCLUSIONS

This study establishes that development of left ventricular hypertrophy in hypertension carries greater physiologic morbidity for African compared with Caucasian Americans, typified by marked reduction in endothelium-independent coronary flow reserve and increased frequency of abnormal thallium tests.

Coronary arteriographic findings in black patients and risk markers for coronary artery disease

Coronary arteriographic results are reported in 1535 black patients: 751 men (mean age 57 +/- 11) and 784 women (mean age 59 +/- 11). Among the black men 19%, 15%, 21%, and 4% had single-, double-, and triple-vessel and left main disease, respectively. Among the black women there were 12%, 10%, 15%, and 3% with similar involvement. Logistic regression models showed that most of the recognized risk factors were positively correlated with significant (at least one artery with > or = 50% stenosis) coronary disease, but a history of hypertension was not a significant independent predictor in either sex. ECG evidence of previous infarction increased the odds of detecting significant coronary disease by the greatest amount when controlling for other significant risk markers in women. In men both previous infarction and atypical pain (negative) were equally important. This study confirms but does not explain previous reports that have revealed less than expected angiographic evidence of significant coronary artery disease in black compared with white persons.

Out-of-hospital cardiac arrest: racial differences in outcome in Seattle

OBJECTIVES

Out-of-hospital sudden cardiac arrest is a key area in which to study the dual problem of the poorer health status of minority populations and their poorer access to the health care system. We proposed to examine the relationship between race (Black/White) and survival.

METHODS

We determined the incidence and outcome of cardiac arrests in Seattle for which medical assistance was requested.

RESULTS

Over a 26-month period, the age-adjusted incidence of out-of-hospital cardiac arrest was twice as great in Blacks than in Whites (3.4 vs 1.6 per 1000 aged 20 and over). The initial resuscitation rate was markedly poorer in the Black victims (17.1% vs 40.7%), and rates of survival to hospital discharge were also lower in Blacks (9.4% vs 17.1%). Both effective initial resuscitation and survival were significantly related to White race following adjustment for other covariates.

CONCLUSION

The differences in outcomes were not fully explained by features of the collapse or relevant service factors. Possible explanations include delays in instituting therapy, less bystander-initiated cardiopulmonary resuscitation, poorer levels of health, and differences in the underlying cardiac disorders.

Atherogenesis and thrombosis: mechanisms, pathogenesis, and therapeutic implications

Although the mortality rate from coronary heart disease (CHD) has declined by almost 50% during the past 25 years, CHD remains the leading cause of death in the United States and is responsible for more than 500,000 deaths annually. The underlying cause of CHD is coronary atherosclerosis. Although the intact intima is highly resistant to thrombus formation, when injury occurs, even superficial, a sequence of reactions is initiated--platelet aggregation, macrophage accumulation, intimal smooth muscle proliferation, fibrous tissue proliferation, and lipid accumulation--that result in the development of obstructive atheroma. Repeat intimal injury and cycling of this process lead to continued progression of the atheroma and coronary artery occlusion. Unstable angina and acute myocardial infarction appear to result from rupture of an atherosclerotic plaque, hemorrhage into the plaque, and luminal thrombosis. The cause of plaque rupture is unknown and may result from normal hemodynamic forces when the fibrous cap of an atheroma has become severely attenuated and fragile. Based on the pathogenesis of chronic atherosclerosis and acute rapid atheroma progression, several therapeutic options become evident. These include antiplatelet, anticoagulant, and thrombolytic therapies, as well as the possibility of arrest and reversal of atherosclerosis in some patients.

Characteristics of black patients admitted to coronary care units in metropolitan Seattle: results from the Myocardial Infarction Triage and Intervention Registry (MITI)

Since 1988, 641 black and 11,892 white patients with chest pain of presumed cardiac origin have been admitted to coronary care units in 19 hospitals in metropolitan Seattle. Black men and women were younger (58 vs 66, p less than 0.0001), more often admitted to central city hospitals (p less than 0.0001), and developed evidence of acute myocardial infarction (AMI) less often (19 vs 23%, p = 0.01). In the subset of 2,870 AMI patients, blacks (n = 121) were younger (59 vs 67, p less than 0.0001) and had less prior coronary artery bypass graft surgery (2 vs 10%, p = 0.005) and more prior hypertension (67 vs 46%, p less than 0.0001). During hospitalization, whites (n = 2,749) had higher rates of coronary angioplasty (18 vs 10%, p = 0.03) and coronary artery bypass graft surgery (10 vs 4%, p = 0.04), although thrombolytic therapy and cardiac catheterization were used equally in the 2 groups. Hospital mortality was 7.4% for black and 13.1% for white patients (p = 0.07). However, after adjustment for key demographic and clinical variables by logistic regression, this difference was not as apparent (p = 0.38). Questions about the premature onset of coronary artery disease, excess systemic hypertension, and the differential use of interventions in black persons have been raised by other investigators. Despite differences in age, referral patterns and the use of coronary angioplasty and bypass surgery, black and white patients with AMI in metropolitan Seattle had similar outcomes.

Survival determinants in black patients with angiographically defined coronary artery disease

Long-term survival of blacks with angiographically defined coronary artery disease was examined in a series of 1233 consecutive patients who underwent cardiac catheterization at a large urban municipal hospital. Vital status information was available at a mean of 86 weeks for the cohort as a whole, and 94 deaths were recorded. As noted in other angiographic series that included blacks, a high proportion of patients in this study had unobstructed coronary arteries (41%), and there was a preponderance of women (56%). Hypertension was present in 82% of the cases, whereas 68% of the sample had left ventricular hypertrophy as revealed by echocardiogram. The cumulative proportion of patients who were surviving at 5 years was 90 +/- 1 (+/- SEM), 79 +/- 4, and 70 +/- 4 for patients with no obstructive lesions, one-vessel disease, and multivessel disease, respectively. The survival rate at 3 years for patients who had undergone bypass surgery (N = 152) was only 82% (+/- 5%). Noninvasive univariate predictors of mortality included male sex, history of myocardial infarction, Q waves on electrocardiogram, exercise duration on treadmill stress testing, and left ventricular hypertrophy. Angiographic predictors included left ventricular end-diastolic pressure, the number of diseased coronary vessels, ejection fraction, and mean pulmonary artery pressure. Regression analysis showed an independent association for all the angiographic variables noted previously as well as for echocardiographically determined left ventricular hypertrophy. Survival rates for blacks with coronary artery disease in this series were considerably lower than those currently reported for whites, particularly for patients who underwent coronary bypass grafting.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular hypertrophy is associated with worse survival independent of ventricular function and number of coronary arteries severely narrowed

Left ventricular (LV) hypertrophy has been repeatedly shown to be associated with a marked increase in mortality risk. Available data, however, do not provide evidence that the risk associated with the increase in cardiac muscle mass is independent of the severity of preexistent coronary artery disease. In a cohort of predominantly black patients with a high prevalence of hypertension and LV hypertrophy, LV mass as estimated by echocardiography was found to be a powerful prognostic factor independent of ejection fraction and obstructive coronary disease. After excluding patients with either a dilated LV cavity (diastolic internal diameter greater than 5.8 cm) or asymmetric septal hypertrophy (septal:posterior wall ratio greater than 1.5) LV mass/height remained significantly increased in decedents compared to survivors (116 +/- 38 vs 131 +/- 47 g/m, p = 0.014), while the thickness of the ventricular septum and the posterior wall were even more highly predictive of a fatal outcome (p = 0.003 and 0.001, respectively). After exclusion of patients with eccentric LV hypertrophy, differences in LV muscle mass in survivors and decedents were due entirely to increased thickness of the ventricular wall, and no differences in cavity dimensions or LV ejection fraction were noted. Stepwise regression analysis was used to demonstrate that measures of LV hypertrophy were the most important predictors of survival and eliminated the contribution of all other prognostic factors to the model except the number of stenotic vessels. The relative risk associated with a 100-g increase in mass was 2.1, while a 0.1-cm increase in posterior wall thickness was associated with approximately a 7-fold increase in the risk of dying.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum lipids, lipoproteins and apolipoproteins in black patients with angiographically defined coronary artery disease

The association between angiographically defined coronary artery disease (CAD) and serum lipids, lipoproteins, and apolipoproteins was evaluated in 151 black men and 245 black women. Patients with 70% or greater narrowing of at least one coronary artery or greater than or equal to 50% stenosis of the left main coronary artery (n = 179) were compared to those with lesions of less than 50% stenosis (n = 217) for total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), LDL-C/HDL-C, triglycerides, apolipoprotein A-I, apolipoprotein B, and apolipoprotein A-I/B. A consistently more atherogenic pattern of lipids, lipoproteins, and apolipoproteins occurred only among the women. Using stepwise selection multiple logistic regression analysis, the ratio of apolipoprotein A-I/B (odds ratio = 0.38, 95% confidence limits 0.24-0.61) was the only statistically significant association of CAD in women, after adjusting for the effects of age, body mass index, and histories of smoking, hypercholesterolemia, hypertension, and diabetes. When stratified by median of total cholesterol, the ratio of apolipoprotein A-I/B was the most strongly associated with the presence of CAD in the lower half of the total cholesterol distribution (less than 208 mg/dl), whereas in the upper half of the total cholesterol distribution the total cholesterol/HDL-C ratio was more strongly associated with CAD. None of the variables studied was associated with CAD in men. These results support other studies suggesting that apolipoproteins may be better predictors of CAD.

Severity of coronary artery disease among blacks with acute myocardial infarction

A growing body of evidence suggests that survival after acute myocardial infarction (AMI) is considerably worse among blacks than whites. The severity of coronary artery disease (CAD), as measured by the number of diseased vessels and the degree of left ventricular dysfunction, is the major determinant of survival after AMI. To determine whether or not the severity of CAD could explain the poor prognosis in a cohort of blacks followed at this institution, cardiac catheterization was performed in a consecutive series of 51 patients less than 70 years of age. All patients were studied within 2 weeks after AMI. The mean age of the patients was 56 +/- 8 (mean +/- standard deviation) and 71% were men. A greater than or equal to 50 narrowing in 0, 1, 2 or 3 coronary arteries was noted in 5, 24, 40 and 31%, respectively. Left main stenosis was present in 3 patients (6%) and the mean left ventricular ejection fraction was 55%. In a subgroup of 20 patients echocardiographic estimates of left ventricular mass/height yielded a mean of 196 g/m, and left ventricular hypertrophy on echocardiogram was present in 74%. These data indicate that among blacks with AMI in this series CAD was only modestly more severe than expected and suggest that other factors most likely explain the high mortality in blacks after hospital discharge.

Coronary arteriography and coronary bypass survey among whites and other racial groups relative to hospital-based incidence rates for coronary artery disease: findings from NHDS

To assess racial differences in health care utilization for coronary artery disease (CAD) the data of the National Hospital Discharge Survey (NHDS) from 1979-84 were examined. Discharge rates for acute myocardial infarction (AMI) were utilized as a measure of hospital-based incidence and relative need for the designated cardiac procedures. Although 35-74 year old Black men had discharge rates of AMI that were 77 per cent of those observed for White men, they underwent coronary arteriography half as often and were only a third as likely to have coronary artery bypass graft (CABG) surgery. Black women in this age range were hospitalized at a slightly higher rate than White women for AMI, yet experienced a 19 per cent lower rate of coronary arteriography and a 52 per cent lower rate of CABG surgery. These data suggest a racial bias in the pattern of care delivered for CAD in US hospitals at the present time.