Treating Chlamydia pneumoniae in Patients With Early Atherosclerosis
Treating patients for Chlamydia pneumoniae infections appeared to reduce the progression of early atherosclerosis, according to a study in this week’s issue of Circulation (Circulation. 2002;106:2428–2433). In this study led by Dirk Sander, MD, from the Department of Neurology at the Technical University of Munich, Germany, researchers evaluated the use of roxithromycin therapy in the treatment of patients aged ≥55 years with ischemic stroke by measuring the progression of intima-media thickness of the common carotid in a prospective, randomized trial.
Researchers found Chlamydia pneumoniae antibodies in 123 patients and IgA antibodies in 119. In the 3 years before they received antibiotic therapy, patients who were considered to have evidence of Chlamydia pneumoniae infection were more likely to show a progression of the intima-media thickness measurement even after adjustment for other cardiovascular risk factors. However, the 62 patients who received the antibiotic therapy demonstrated a decreased intima-media thickness after two years when compared with patients with evidence of Chlamydia pneumoniae infection who did not receive antibiotics. In patients who had no evidence of infection, the antibiotic had no effect.
The authors concluded: “Treatment with roxithromycin seems effective in reducing the bacterial burden of Cp [Chlamydia pneumoniae] within carotid atherosclerotic plaques and prevents the progression of peripheral arterial occlusive disease in Cp-positive men.”
Low Ejection Fraction and Inducible Tachyarrhythmias as MUSTT
An ejection fraction <30% and inducible ventricular tachyarrhythmias appeared to identify patients with coronary disease at an increased risk of dying, according to researchers involved in the Multicenter Unsustained Tachycardia Trial (MUSTT) in a report in this week’s issue of Circulation (Circulation. 2002;106:2466–2472).
The researchers noted that 50% of deaths in patients with coronary disease occur suddenly, but there is little confirmed information about the factors that predispose patients to die this way. Because such patients might benefit from implantable defibrillators, it would be advisable to find the factors involved in these sudden deaths.
In this study, the researchers analyzed the relation of ejection fraction and inducible ventricular tachyarrhythmias to mode of death in 1791 patients enrolled in MUSTT who had not already received antiarrhythmia therapy. They found that total mortality and deaths from arrhythmia as well as sudden deaths occurred more frequently in patients with an ejection fraction <30% when compared to those whose ejection fractions were 30% to 40%. Patients with inducible tachyarrhythmias were more likely to suffer arrhythmic mortality, and even more likely to die of arrhythmias, if their ejection fraction was also <30%.
The authors concluded that their analysis suggests a way to determine who needs implantable defibrillators by stratifying the risk among patients with coronary disease. “Our analysis suggests that the major utility of electrophysiological testing may be restricted to patients having an ejection fraction between 30% and 40%. The results of the present study and MADIT-II [the Multicenter Automatic Defibrillator Implantation Trial II] demonstrate the need for better methods of risk stratification. On the other hand, mortality was significant even in patients with ejection fractions ≥30% without inducible tachyarrhythmia. If one assumes that implantable defibrillators reduce mortality primarily by preventing arrhythmic events, our observations suggest that such devices have the potential to reduce mortality significantly not only in patients with coronary disease and left ventricular ejection fraction <30% but also in patients whose ejection fraction is ≥30%. The latter hypothesis suggests the basis for future trials.”
Heart Failure: A Worldwide Epidemic of Immediate Importance
According to a report in the New England Journal of Medicine (New Engl J Med. 2002;347:1397–1402), a review of heart failure among subjects in the more than 50 years of the Framingham Heart Failure Study shows that the rates of the disorder remained unchanged for men but declined in women. Survival from heart failure has improved in both sexes.
In this study, researchers identified 1075 people who had heart failure, 51% of whom were women. The rate of heart failure among men in the period from 1950 through 1969 remained the same from 1970 through 1979, from 1980 through 1989, and from 1990 through 1999. However, it declined 31 to 40% among women when the rate for 1950 through 1969 was compared with the subsequent relevant time periods.
The 30-day, 1-year, and 5-year age-adjusted mortality figures declined from 12%, 30%, and 70%, respectively, in the period from 1950 through 1969 to 11%, 28%, and 59% from 1990 through 1999. The corresponding rates in women were 18%, 28%, and 57% from 1950 through 1969 and 10%, 24%, and 45% from 1990 to 1999. They noted: “Despite the favorable trends in survival, heart failure remains highly fatal; among subjects who were given a diagnosis of heart failure in the 1990s, more than 50% were dead at 5 years.”
Women Don’t DIG Digitalis
Digoxin therapy was associated with increased mortality risk among women with heart failure, but not among men, according to Yale University researchers in a report in the October 29, 2002 issue of the New England Journal of Medicine (N Engl J Med. 2002;347:1403–1411).
In this analysis of data from the Digoxin Investigation trial (DIG), Yale University researchers, led by Harlan Krumholz, MD, sought to determine if there was a sex-based difference among the 6800 patients in the study. They found that there was an absolute difference of 5.8% between men and women in the effect of digoxin on the rate of death from any cause. “Specifically, women who were randomly assigned to digoxin had a higher rate of death than women who were randomly assigned to placebo,” the researchers noted. The rate of death was similar among men who received digoxin and those who received placebo. In a multivariate analysis, digoxin was associated with a significantly higher risk of death in women but not in men, they noted. In earlier results, the DIG investigators had reported that digoxin did not decrease overall mortality among patients with heart failure and depressed left ventricular systolic function.
The researchers noted: “Our study underscores the importance of investigations of sex-based variations in treatment efficacy. However, few randomized, controlled trials are designed to test for sex-specific effects, and relatively few women have been enrolled in trials of heart-failure therapies. The interaction between sex and digoxin therapy can be confirmed only by a sex-stratified, randomized, controlled trial of digoxin therapy. However, such a study may not be considered ethical, since it would be designed to confirm risk and not benefit.”