Predicting Stroke After Myocardial Infarction in the Elderly
Although the elderly (those over age 65) are considered at increased risk for stroke, they usually are excluded from studies that examine the relationship between acute myocardial infarction and stroke—a mistake, according to a report by researchers from the Yale–New Haven Hospital and the Yale University School of Medicine. In this week’s issue of the journal Circulation, a retrospective review by these researchers of the charts of 111 023 Medicare patients who were discharged with the diagnosis of stroke showed that there was a 2.5% rate of readmission for ischemic stroke within 6 months (Circulation. 2002;105:1082–1087).
Assessment of risk factors revealed several independent predictors of ischemic stroke in this group, including age >75 years, black race, no aspirin at discharge, frailty, prior stroke, atrial fibrillation, diabetes, hypertension, and history of peripheral vascular disease. When the authors, including Judith H. Lichtman, PhD, Harlan M. Krumholz, MD, Yun Wang, MS, Martha J. Radford, MD, and Lawrence M. Brass, MD, created a risk stratification strategy and assigned points to risk, they found that 4% of patients with a score of 4 or more were admitted to the hospital within 6 months of their heart attack admission.
The authors conclude: “The risk of stroke after myocardial infarction is substantial, with about 1 in 40 patients suffering an ischemic stroke within 6 months of discharge. Simple clinical factors can predict the risk of stroke and, based on these factors, we identified 20% of older patients who have a 1 in 25 chance of being hospitalized for a stroke within 6 months of discharge.”
They also added a note that advised the use of a representative cohort when estimating stroke risk because the condition is strongly associated with age. “It is highest for patients 75 years of age or older, who are underrepresented in many clinical studies but account for half of all strokes. Studies that do not account for age and comorbid disease not only underestimate the risk of stroke in the individual; they also shift attention away from the public health importance of cerebrovascular diseases and opportunity for enhancing preventive strategies.”
Most Boomers at Risk for Hypertension
Americans between the ages of 55 and 65 are at a 90% risk of developing at least mild hypertension (<140/90 mm Hg) at some point in their lives. However, their lifetime probability of receiving medication to control their blood pressure is 60%, said researchers led by Ramachandran S. Vasan, MD, of the Framingham Heart Study, in the February 27, 2002, issue of the Journal of the American Medical Association (JAMA. 2002;287:1003–1010).
The study, supported in part by the National Heart, Lung and Blood Institute as well as the National Institute of Neurological Disorders and Stroke, was carried out by researchers at the Framingham Heart Study, Boston University School of Medicine (Departments of Epidemiology and Biostatistics), and Beth Israel Deaconess Medical Center, as well as the National Heart, Lung and Blood Institute. The researchers found, however, that the risk of developing severe high blood pressure had decreased over the past quarter decade, in part because of improved treatment.
“Ninety percent is a staggering statistic and cause for concern,” said US Department of Health and Human Services Secretary Tommy G. Thompson in a released statement. “This finding should energize Americans to take steps to protect themselves against high blood pressure. By adopting some simple healthy behaviors, most people can reduce their risk of high blood pressure. Prevention gives people the power to protect their health.”
The study was based on the data from the Framingham Heart Study. “We chose to calculate estimates for ages 55 and 65 because that’s when the risk of developing hypertension dramatically increases,” said Dr Vasan, who is also an Associate Professor of Medicine at Boston University School of Medicine.
He and his colleagues determined that half of the participants aged 55 and two thirds of those aged 65 developed high blood pressure within 10 years. “Americans don’t necessarily have to develop high blood pressure as they get older. What they have to do is take preventive action,” said Dr Vasan.
Clozaril (Clozapine) Warnings Include Myocarditis Risk
The US Food and Drug Administration and the pharmaceutical firm Novartis have strengthened warnings about the drug Clozaril and have added information about the risk of patients on the medication developing myocarditis. Clozapine is used to treat patients with severe schizophrenia. In a letter to healthcare providers, officials of Novartis said they had moved all their warnings to the beginning of information provided about the drug and that those warnings had been revised to warn healthcare providers about the association of the drug with myocarditis.
Specifically, the drug company officials noted that post-market surveillance in 4 countries in which there is hematological monitoring of patients on clozapine had revealed 30 reports of myocarditis, with 17 deaths, in 205 493 US patients (August 2001); 7 reports of myocarditis, with 1 death, in 15 600 Canadian patients (August 2001); 30 reports of myocarditis, with 8 deaths, in 24 108 United Kingdom patients (August 2001), and 15 reports of myocarditis, with 5 deaths, in 8000 Australian patients (March 1999).
The letter cautioned, “The possibility of myocarditis should be considered in patients receiving clozapine who present with unexplained fatigue, dyspnea, tachypnea, fever, chest pain, palpitations, other signs or symptoms of heart failure, or electrocardiographic findings such as ST-T wave abnormalities or arrhythmias. It is not known whether eosinophilia is a reliable predictor of myocarditis. Tachycardia, which has been associated with clozapine treatment, has also been noted as a presenting sign in patients with myocarditis. Therefore, tachycardia during the first month of therapy warrants close monitoring for other signs of myocarditis. The prompt discontinuation of clozapine therapy is warranted upon suspicion of myocarditis.”
Novartis also said that “healthcare professionals should report all serious adverse events suspected to be associated with use of Clozaril (clozapine) to Novartis Pharmaceuticals Corporation, One Health Plaza, East Hanover, New Jersey 07936, or by phone at (800) 448-5938 or the internet at http://www.novartis.com. Alternatively, this information may be reported to the FDA’s MedWatch Reporting System by phone at 1-800-FDA-1088, by fax 1-800-FDA-0178, by mail using the Form 3500 at MedWatch, HF-2, 5600 Fishers Lane, Rockville, MD 20857; or the Internet at http://www.accessdata.FDA.gov/scripts/medwatch.”