Outcome of coronary artery bypass grafting in black persons

Diabetes status and racial differences in post-myocardial infarction mortality

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.

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.

Acute myocardial infarction: clinical characteristics, management and outcome in a metropolitan Veterans Affairs Medical Center teaching hospital

OBJECTIVES

The influence of race and age on thrombolytic therapy, invasive cardiac procedures and outcomes was assessed in a Veterans Affairs teaching hospital. The influence of Q wave evolution on the use of invasive cardiac procedures and outcome was also assessed.

BACKGROUND

It is not well known how early revascularization procedures for acute myocardial infarction are delivered or influence survival in a Veterans Affairs patient population.

METHODS

From October 1993 to October 1995, all patients with myocardial infarction were identified by elevated creatine kinase, MB fraction (CK-MB) and one of the following: chest pain or shortness of breath during the preceding 24 h or electrocardiographic (ECG) abnormalities.

RESULTS

Racial groups were similar in terms of age, time to ECG, peak CK and length of hospital stay. Mortality increased with age (odds ratio [OR] 1.93, 95% confidence interval [CI] 1.33 to 2.81). A trend toward increased mortality occurred for race other than Caucasian. Patients meeting ECG criteria were given thrombolytic agents in 49% of cases, but age, comorbidity count and Hispanic race decreased the probability of thrombolytic use. Cardiac catheterization was performed more often after thrombolytic agents (OR 1.85, 95% CI 0.97 to 3.54), but less often in African-Americans (OR 0.59, 95% CI 0.35 to 1.02), older patients (OR 0.39, 95% CI 0.24 to 0.64) or patients with heart failure (OR 0.30, 95% CI 0.17 to 0.52). Patients evolving non-Q wave infarctions were older and had increased comorbidity counts and trends toward increased mortality. Angioplasty was chosen less for patients > or = 65 years old (p = 0.02); angioplasty and coronary artery bypass graft surgery were performed less in patients > or = 70 years old (p = 0.02). Patients treated invasively had lower mortality rates than those treated medically (p < 0.02).

CONCLUSIONS

The use of thrombolytic agents and invasive treatment plans declined with age, and mortality increased with age. Trends toward increased mortality occurred with non-Q wave infarctions and race other than Caucasian.

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)

Survival in patients with heart failure and normal basal systolic wall motion

To assess the prognostic effect of preserved systolic function in patients with congestive heart failure (CHF), the authors analyzed survival curves in 91 nonselected adult patients with CHF. Patients were assigned to one of two groups on the basis of fractional shortening. The first group consisted of 44 patients with a normal fractional shortening (greater than 0.17), and the second group, of 47 patients with a fractional shortening of 0.17 or less. The two groups were similar in respect to all historical and physical findings. Median survival was eleven months for patients with a decreased fractional shortening and twenty-six months for patients with a normal fractional shortening. Patients with a decreased fractional shortening had a significantly shorter survival (p = 0.01). The authors conclude that congestive heart failure with preserved systolic function is common and is associated with a better prognosis, and the literature suggests it may require nonstandard therapy. Their data also suggest, however, that CHF patients with preserved systolic function cannot be reliably distinguished at the bedside. Rather, echocardiography or other tests of systolic wall motion are needed to make the diagnosis.

Survival of black persons compared with white persons in the Coronary Artery Surgery Study (CASS)

From July 1974 to May 1979, 573 black persons in the Coronary Artery Surgery Study (CASS) underwent coronary angiography. Compared with 23,008 white persons, larger percentages of black men and women were current smokers and reported a history of systemic hypertension. Despite the presence of chest pain, larger percentages of blacks had normal coronary arteries by angiography than did whites. The 5-year age- and sex-adjusted survival rate was 88% for whites and 82% for blacks (p less than 0.0001). Cox analysis indicated that black race was related to poorer survival in the medical group (p = 0.0006) but not in the surgical group (p = 0.28). For blacks, surgical therapy was related to a better survival rate (p = 0.009). These results raise questions concerning the effects of excess cigarette smoking and systemic hypertension and the role of coronary artery bypass surgery on survival of black persons.