Intracoronary β-Blocker Before Percutaneous Intervention Protects Myocardium
Intracoronary administration of the β-blocker propanolol before percutaneous intervention protected myocardium during the procedure, said researchers from The University of Texas Medical Branch at Galveston in this week’s issue of the journal Circulation (Circulation. 2003;107:2914–2919OpenUrlCrossRefPubMed).
Researchers led by Fen Wei Wang, MD, of UTMB, randomly assigned 150 patients scheduled for percutaneous intervention to receive intracoronary percutaneous intervention or placebo. Propanolol was delivered before the inflation of the angioplasty balloon using an intracoronary catheter. The scientists monitored creatine kinase–MB and troponin T in the patients during the first 24 hours after the procedure. Patients were monitored for 30 days for short-term adverse events.
They found that 36% of patients in the placebo group and 17% of those in the propanolol group showed evidence of myocardial infarction as measured by elevations of creatine kinase–MB. Higher levels of troponin T were seen in 33% of the placebo patients and only 13% of the patients who received β-blocker.
After 30 days, 40% of the patients in the placebo group had either died, suffered a myocardial infarction right after the procedure, suffered a non–Q-wave myocardial infarction after hospitalization for the procedure, or undergone an urgently required revascularization of the lesion that required treatment in the first procedure. By comparison, only 18% of the patients who received the propanolol fell into the above group.
The researchers concluded: “If one assumes that IC [intracoronary] β-blocker is used routinely and is applicable to 80% of patients (on the basis of inclusion criteria from the present study), there will be 10 000 more PCI [percutaneous coronary intervention] patients alive at 6 months in the United States alone if this therapy is used. It is important to emphasize that IC β-blocker in the dose used in the present study is extremely safe and without any adverse effects, even in patients with moderate left ventricular dysfunction and chronic lung disease.”
Aspirin Preferable in Preventing Stroke in Black Patients
A blinded portion of a study comparing ticlopidine and aspirin as a preventive measure for second stroke in black subjects who had already suffered at least one event was halted after 6.5 years when statisticians determined there was less than 1% chance that ticlopidine would be shown superior in preventing recurrent stroke, heart attack, or vascular death, according to researchers in the June 11, 2003, issue of The Journal of the American Medical Association (JAMA. 2003;289:2947–2957OpenUrlCrossRefPubMed).
Researchers led by Philip B. Gorelick of the Division of Neurologic Sciences at Rush Medical College in Chicago, Ill, randomly assigned 902 black men and women to receive 500 mg per day of ticlopidine and 907 to receive 650 mg per day of aspirin. All subjects had previously suffered an ischemic stroke. They were recruited from 62 academic and community hospitals in the United States and monitored for as long as 2 years.
Of the 902 ticlopidine patients, 133 either suffered another stroke or myocardial infarction or died of vascular causes. Of the 907 aspirin patients, 112 suffered one of the conditions listed above—the primary end points of the study.
The researchers wrote: “During a 2-year follow-up, we found no statistically significant difference between ticlopidine and aspirin in the prevention of recurrent stroke, myocardial infarction, or vascular death. However, there was a nonsignificant trend for reduction of fatal or nonfatal stroke among those in the aspirin group. Based on these data and the risk of serious adverse events with ticlopidine, we regard aspirin as a better treatment for aspirin-tolerant black patients with noncardioembolic ischemic stroke.”
In an accompanying editorial, Ralph I. Sacco, MS, MD, of the Departments of Neurology and Epidemiology at the Columbia University College of Physicians and Surgeons and the Mailman School of Public Health, New York, NY, noted: “Stroke continues to have a disproportionate public health impact on blacks compared with whites in the United States” (JAMA. 2003;289:3005–3006OpenUrlCrossRefPubMed).
“At present, control of stroke risk factors is still less than adequate, particularly in communities of lower socioeconomic status, who are less educated about the importance of these conditions and also have decreased access to health care for proper detection and management of these risk factors.. . .Effective stroke prevention continues to be elusive and patients at highest risk present the biggest challenges.”
Ambulatory Blood Pressure— Another Predictor
Monitoring ambulatory blood pressure can give clinicians a method of predicting cardiovascular events—even after adjustment for other risk factors, including measuring blood pressure in the office, said researchers from the Office Versus Ambulatory pressure study (OvA) in the June 12, 2003, issue of The New England Journal of Medicine (N Engl J Med. 2003;348:2407–2415OpenUrlCrossRefPubMed).
Led by Denis L. Clement, MD, of the Department of Cardiovascular Diseases at Ghent University in Belgium, the researchers in the multicenter trial monitored 1963 patients for an average of 5 years. Patients underwent baseline ambulatory blood pressure readings. A total of 157 patients suffered documented cardiovascular events during the stated time.
Statistical analysis of all risk factors found that higher mean values for 24-hour ambulatory systolic and diastolic pressure were found to be independent risk factors for new heart-related problems or events. The researchers found that the adjusted relative risk of cardiovascular events associated with a 1–standard deviation increase in blood pressure was 1.34 for 24-hour ambulatory systolic blood pressure, 1.3 for ambulatory systolic blood pressure during the day, and 1.27 for ambulatory systolic blood pressure during the night. For ambulatory diastolic blood pressure, the researchers found that the relative risks of such events associated with a 1–standard deviation increase were 1.21 for 24-hour ambulatory diastolic blood pressure, 1.24 for the day, and 1.18 for the night.
In an accompanying editorial (N Engl J Med. 2003;348:2377–2378), William B. White of the Division of Hypertension and Clinical Pharmacology at the University of Connecticut School of Medicine in Farmington, wrote that the practice of ambulatory monitoring is an old one. However, he said, its use has been well accepted.
“Gaining acceptance of this technique in clinical practice has been quite difficult, however, since experts in cardiovascular medicine have been uncomfortable with the relegation of the office-based measurement of blood pressure to secondary importance,” he wrote. “However, office blood-pressure measurements also have clinically relevant shortcomings. In today’s often-rushed practice of ambulatory medicine, repeated measurements over a period of several minutes in the examination room are the exception rather than the rule. Thus, a ‘white-coat effect’ (an increase in blood pressure only in the medical care environment) is reported often—in as many as 20 to 35 percent of patients in whom hypertension is diagnosed.”
“Questions remain regarding the optimal use of ambulatory blood-pressure monitoring in the diagnosis and management of hypertension. Research is needed to assess whether ambulatory monitoring can reduce the overprescribing of drugs to patients who seem, in the office setting, to be resistant to therapy,” he wrote.