Investigational Drug Is Effective in the Treatment of Atrial Fibrillation
(48th Annual Scientific Session of the American College of Cardiology) Azimilide, an investigational anti-arrhythmic drug, shows promise in significantly prolonging the arrhythmia-free period in patients with atrial fibrillation, according to the results of three randomized, placebo-controlled trials that included over 1,000 patients (the Azimilide Supraventricular Arrhythmia Program). In one of the three trials, the patients were randomized to receive either 50 mg, 100 mg or 125 mg of azimilide daily, or placebo. These patients were representative of the population who have atrial fibrillation, with 70 percent having some form of structural coronary disease, ischemic heart disease or congestive heart failure. The patients carried portable electrocardiographic monitors to record their heart rhythms when they experienced symptoms of an arrhythmia. In the patients receiving 125 mg of azimilide daily, the median time to first symptomatic recurrence of atrial fibrillation was 130 days, compared with 17 days in the patients receiving placebo. The 100-mg dose of azimilide prolonged the median time to first symptomatic recurrence to 41 days, more than twice that of the patients receiving placebo. In the trials, the most common side effect was headache. The investigators note that additional research is ongoing.—edward l. c. pritchett, m.d., et al., Duke University, Durham, North Carolina.
Gender Is a Predictor of Increased Mortality in Myocardial Infarction
(American College of Cardiology) Results of a study of 856 consecutive patients who had myocardial infarctions between 1988 and 1997 show that women are at increased risk of morbidity and mortality following acute myocardial infarction, compared with men. The study included 531 men and 325 women. Following admission to a coronary care unit, 14.5 percent of the women and 7.2 percent of the men died. Overall, the women had higher rates of hypertension (58.2 percent versus 35.8 percent) and diabetes mellitus (21.2 percent versus 13.0 percent) but lower prevalence of smoking (21.2 percent versus 33.2 percent) and family history of coronary artery disease (14.8 percent versus 20.3 percent). Women were less likely to present with Killip Class I (72.3 percent versus 82.7 percent). In particular, women 75 years of age or younger had much higher mortality rates than men of the same age. The risk of increased mortality was independent of other risk factors. The investigators believe that gender is an important and independent predictor of mortality associated with acute myocardial infarction in patients under age 75 years.—john h. haley, m.d., et al., Mayo Clinic, Rochester, Minnesota.
Treatment Delay Increases Mortality After Myocardial Infarction
(American College of Cardiology) Thrombolytic therapy (clot-busting drugs or percutaneous transluminal coronary angioplasty) is delayed in a substantial number of elderly patients who have acute myocardial infarction, and this delay is an independent predictor of mortality, according to a retrospective chart review of 16,670 Medicare patients 65 years of age or older who presented with ST elevation or left bundle branch block (LBBB) and received thrombolytic therapy within six hours of presentation to the hospital. Of the patients, 61.5 percent were treated in the first hour after arrival and 39.5 percent were treated during the subsequent five hours. Significant and independent factors associated with treatment delay included age, female gender, diabetes, prior heart failure, nonanterior myocardial infarction location and LBBB. Both 30-day mortality rates (24.2 percent versus 17.2 percent) and one-year mortality rates (16.7 percent versus 11.9 percent) were higher in patients whose thrombolytic therapy was delayed by more than one hour. The investigators believe that earlier recognition of acute myocardial infarction and more rapid administration of thrombolytic therapy may decrease mortality rates among elderly patients.—alan k. berger, m.d., et al., Yale University, New Haven, Connecticut.
Extent of Coronary Calcification May Predict Heart Problems
(American College of Cardiology) Results of a study of persons who died suddenly of a first coronary event demonstrate that identification of calcification and atherosclerosis in persons under age 50 by electronic beam computed tomography (EBCT) may help predict which younger persons will benefit most from targeted primary prevention. The researchers examined arteries obtained at autopsy from 28 persons under 50 years of age who died suddenly of a coronary event and from 16 age-matched subjects who died of noncardiac causes. Although there was little coronary calcification relative to the extent of plaque formation in the persons who died of sudden coronary events, the extent of both atherosclerosis and calcification was substantially greater than in the age-matched control group. The investigators believe that EBCT, by quantifying coronary calcium, may be able to define the extent of coronary atherosclerosis and identify those persons who will likely benefit most from targeted primary prevention.—axel schmermund, m.d., et al., University Clinic Essen, Essen, Germany.
Elevated Fibrinogen Levels Increase Risk of Heart Disease in Women
(American College of Cardiology) Fibrinogin levels are a more powerful predictor in women than they are in men of the risk to develop coronary artery disease and to have a myocardial infarction, according to a study of 781 persons identified at being at risk of coronary disease. There were 286 women and 495 men in the study. Self reported and clinically confirmed coronary artery disease were calculated for each 50 mg per dL (5.0 g per L) increase in fibrinogen using logistic regression techniques. Separate logistic regression models were developed for patients with fibrinogen levels at or above 395 mg per dL (3.95 g per L) and those with fibrinogen levels less than 395 mg per dL (3.95 g per L). In the 180 persons with complete data and fibrinogen levels of at least 395, only age was a significant predictor of coronary artery disease. However, in those with fibrinogen levels less than 395 mg per dL (3.95 g per L), age, gender, smoking status and diabetes were significantly related to risk of developing coronary artery disease. The investigators conclude that elevated fibrinogen levels in women are an “ominous risk factor” that negates a women's typical gender advantage.—joanne micale foody, m.d., et al., The Cleveland Clinic Foundation, Cleveland, Ohio.