CHICAGO—Receiving a blood transfusion is associated with a greater risk of death for patients with acute coronary syndromes, such as a myocardial infarction (heart attack), according to a study in the October 6 issue of JAMA.

The use of invasive procedures for treatment of ischemic heart disease has more than tripled in the past 2 decades and is likely to increase in high-risk patients, according to background information in the article. This, coupled with the widespread use of antithrombotic drugs, has increased the potential for bleeding and blood transfusion among patients with cardiovascular disease. Approximately 12 million units of blood are transfused to 3.5 million patients each year in the United States, and although transfusing blood to anemic patients with ischemic heart disease may theoretically increase oxygen delivery and improve outcomes, there is no definitive evidence to support such a practice, according to the article.

Patients hospitalized for an acute coronary syndrome (ACS) are at risk of developing anemia acutely as a consequence of bleeding. For clinical practice, a crucial issue is whether blood transfusion is beneficial or harmful for patients with ischemic heart disease who have developed anemia acutely during their hospitalization. Clinical studies have had differing results.

Sunil V. Rao, M.D., of the Duke Clinical Research Institute, Durham, N.C., and colleagues used clinical data from three large international trials of patients with ACS to determine the association between blood transfusion and outcomes among patients who developed moderate to severe bleeding, anemia, or both during their hospitalization. The study included 24,111 participants in the GUSTO IIb, PURSUIT, and PARAGON B trials. Patients were grouped according to whether they received a blood transfusion during hospitalization.

Of the patients included, 2,401 (10.0 percent) underwent at least 1 blood transfusion during their hospitalization. The researchers found that the rates for three outcomes (30-day death, heart attack, and composite death/heart attack) were significantly higher among patients who received a transfusion (30-day death, 8.00 percent for patients who received a transfusion vs. 3.08 percent for patients who did not; 30-day heart attack, 25.16 percent vs. 8.16 percent; 30-day composite death/heart attack, 29.24 percent vs. 10.02 percent). Blood transfusion was associated with a nearly four times increased risk for 30-day death and nearly three times increased risk for 30-day death/heart attack. In further analysis that included procedures and bleeding events, transfusion was associated with a trend toward increased risk of death.

CHICAGO—Differences between racial/ethnic groups for times to treatment for a heart attack may be largely attributable to the differences between hospitals to which the patients are admitted, according to a study in the October 6 issue of JAMA.

According to background information in the article, recent reports have indicated that patients identified as African American/black or as nonwhite minority experience significantly longer times to fibrinolytic (dissolving blood clots) therapy ("door-to-drug" times) and percutaneous coronary intervention ("door-to-balloon" times) than patients identified as white, raising concerns of health care disparities. However, existing studies have not comprehensively investigated the factors that explain the observed racial and ethnic differences in time to reperfusion therapy (the restoration of blood flow to an organ or tissue). Understanding the sources of racial and ethnic differences in cardiovascular care is important to designing effective interventions to eliminate disparities.

Elizabeth H. Bradley, Ph.D., of the Yale University School of Medicine, New Haven, Conn., and colleagues estimated racial and ethnic differences in time between hospital arrival and receipt of reperfusion therapy, and examined the role of sociodemographic factors, insurance status, clinical characteristics, and health system factors in explaining these differences. The researchers used admission and treatment data from the National Registry of Myocardial Infarction (NRMI) for a large U.S. cohort of patients with ST-segment elevation (a certain measurement from an electrocardiograph) heart attack or left bundle branch block and receiving reperfusion therapy. Patients (73,032 receiving fibrinolytic therapy; 37,143 receiving primary percutaneous coronary intervention) were admitted to hospitals from January 1, 1999, through December 31, 2002.

The researchers found that door-to-drug times were significantly longer for patients identified as African American/black (41.1 minutes), Hispanic (36.1 minutes), and Asian/Pacific Islander (37.4 minutes), compared with patients identified as white (33.8 minutes). Door-to-balloon times for patients identified as African American/black (122.3 minutes) or Hispanic (114.8 minutes) also were significantly longer than for patients identified as white (103.4 minutes). Racial/ethnic differences were still significant but were substantially reduced after accounting for differences in average times to treatment for the hospitals in which patients were treated; significant racial/ethnic differences persisted after further adjustment for sociodemographic characteristics, insurance status, and clinical and hospital characteristics.

"...crude difference in door-to-balloon time between African American/black and white patients was reduced by 33 percent after accounting for differences between the hospitals in which patients were treated. More striking, the crude difference in door-to-balloon times between Hispanic patients and white patients was reduced by nearly 75 percent after accounting for differences between the hospitals in which they were treated," the authors write.

CHICAGO—Women who take the hormone therapy estrogen plus progestin have double the risk for venous thrombosis, a type of blood clot, according to an article in the October 6 issue of JAMA.

Venous thrombosis (VT) is a common disorder, according to background information in the article.

Mary Cushman, M.D., M.Sc., of the University of Vermont, Colchester, Vt., and colleagues examined the effects of postmenopausal hormone therapy on VT in the presence of other thrombosis risk factors, such as age and obesity. The researchers analyzed final data from the Women's Health Initiative Estrogen Plus Progestin clinical trial, a double-blind randomized controlled trial of 16,608 postmenopausal women between the ages of 50 and 79 years, who were enrolled in 1993 through 1998 at 40 U.S. clinical centers, with 5.6 years of follow up. Baseline gene variants related to thrombosis risk were measured in the first 147 women who developed thrombosis and in 513 controls. Participants were randomly assigned to 0.625 mg/d of conjugated equine estrogen plus 2.5 mg/d of medroxyprogesterone acetate, or placebo.

Venous thrombosis occurred in 167 women taking estrogen plus progestin and in 76 taking placebo (twice the risk for venous thrombosis for women taking hormone therapy). Compared with women between the ages of 50 and 59 years who were taking placebo, the risk associated with hormone therapy was higher with age: 4.3 times the risk for women aged 60 to 69 years and 7.5 times the risk for women aged 70 to 79 years. Compared with women who were of normal weight and taking placebo, the risk associated with taking estrogen plus progestin was increased among overweight (3.8 times the risk) and obese women (5.6 times the risk). Participants with the hereditary blood coagulation disorder Factor V Leiden had a 6.7 times increased risk of thrombosis compared with women in the placebo group without the genetic mutation.

"Based on projections for 10 years for 1,000 women taking estrogen plus progestin, the estimated excess number of events is 18 for VT, 6 for coronary heart disease, 8 for invasive breast cancer, and 8 for stroke," the authors write.

CHICAGO—Young women at low risk for coronary heart disease and cardiovascular diseases have a lower long-term death rate from these diseases and all other causes compared with others with higher risk factor levels, according to an article in the October 6 issue of JAMA.

Background information in the article states: "Young adult men and middle-aged men and women with favorable levels of all major cardiovascular risk factors, i.e., low-risk status, have much lower age-specific risks for cardiovascular disease (CVD) and all-cause mortality than those with adverse levels of one or more risk factors." However, this relationship has not yet been studied in young women.

Martha L. Daviglus, M.D., Ph.D., of the Feinberg School of Medicine, Northwestern University, Chicago, and colleagues examined the relationship between the presence of low levels of risk factors for coronary heart disease (CHD) and cardiovascular disease (CVD) in young adulthood and long-term incidence and cause of death in women. The Chicago Heart Association (CHA) Detection Project in Industry Study screened approximately 40,000 people 18 years and older from 1967 to 1973. Those at risk for CHD and/or CVD were classified using national guidelines for values of blood pressure, cholesterol, body mass index, diabetes, and smoking status.

Of the 7,302 women, 20.1 percent were classified as at a low risk for CHD and CVD. A majority of the cohort (58.5 percent) had high levels of one or more risk factors. In general, women at low-risk were younger, white, and better educated. During an average 31 years of follow-up, there were 47 CHD deaths, 94 CVD deaths, and 469 all-cause deaths. "The age-adjusted CVD death rate per 10,000 person-years was lowest for low-risk women and increased with the number of risk factors...," the authors write.

ESTROGEN PLUS PROGESTIN HORMONE THERAPY DOUBLES RISK OF BLOOD CLOTS IN THE LEG