doi: 10.1161/01.CIR.0000096420.63518.72
(Circulation. 2003;108:e9027.)
© 2003 American Heart Association, Inc.
Cardiovascular News
Circulation Newswriter
Percutaneous Intervention a Winner—Even in Patients With Stable, Single-Vessel Disease
Even though the question had never been answered in a clinical trial, most cardiologists have recommended that patients who have survived acute myocardial infarction without residual symptoms or ischemia undergo percutaneous transluminal angioplasty of the affected artery. In this small trial, Uwe Zeymer, MD, of the Klinikum Ludwigshafen, Medizinische Klinik B, Ludwigshafen, Germany, and his colleagues demonstrated that there is clinical benefit to the procedure in this group of patients. They urge that larger studies be carried out to confirm their results (Circulation. 2003;108:1324–1328.)
The physicians randomly assigned 300 patients with single-vessel disease of the infarct vessel and no or minor angina after an acute myocardial infarction to receive either angioplasty (n=149) or medical therapy (n=151). After one year, 82% of patients in the medically treated group and 90% in the angioplasty group were alive and had suffered no related events. The difference was mainly in the need for intervention. There were 20 interventions in the medically treated patients versus 8 in those who had undergone primary percutaneous intervention. After a follow-up that averaged 56 months, 89% of patients in the medically treated group were alive versus 96% in the percutaneous intervention group. The percentage of those who survived without another myocardial infarction, (re)intervention, or coronary artery bypass graft surgery was 66% in the medically treated group and 80% in the percutaneous intervention group. The angioplasty group was less likely to use nitrates, as well.
The authors concluded, "Percutaneous revascularization of the infarct-related coronary artery in stable patients with single-vessel disease improves clinical outcome at long-term follow-up and reduced the use of nitrates." They urged that a confirmatory study be considered with a larger sample before the recommendation to use percutaneous intervention in this group of patients be made standard.
More News From the European Society of Cardiology Congress 2003
VIENNA, Austria—Cardiologists meeting here for the European Society of Cardiology Congress 2000, August 31, 2003, through September 3, 2003, brought more than the findings of new large-scale clinical trials. Many studies answered questions that plague physicians in everyday practice.
Not in Your Breast Pocket
VIENNA, Austria—Patients with pacemakers need not fear that their mobile or cellular telephones will interfere with the action of their pacemakers, said Massimo Santini, MD, of San Filippo Neri Hospital in Rome, Italy. However, he advises them not to keep the phone anywhere within 10 centimeters of their pacemakers. That means they probably should not keep them in the breast pockets of their shirts or jackets, he said.
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When he tested GSM mobile phones—those most commonly used in Europe and becoming more common in the United States, he said he found that the telephones could cause some changes in pacemaker function in about 26% of patients. The interference occurred mainly when the telephones were ringing or being turned on or off, he said, and it is usually of very short duration.
The phone either increased the rate of pacing or simply stopped the pacing function. He said the duration of the problem was approximately 3 seconds.
"This may not be important in patients with spontaneous heart activity," he said. However, it could cause concern in patients who depend on the pacemakers to keep their hearts beating.
On the positive side, he said, there has been no indication that the interference causes permanent malfunction of the pacemaker or reprograms its activities.
He tested the use of the phones in more than 100 patients implanted with pacemakers made by 43 manufacturers. A major question is who is responsible for eliminating the interference, he said. Is it the pacemaker or the mobile telephone manufacturer?
In the Airport
VIENNA, Austria—The risk of problems with implanted defibrillator or pacemaker-dependent patients going through metal detectors or being near anti-theft screening systems is only minimal, said Hugo Ector, MD, of the University Hospital Gasthuisberg, Leuven, Belgium.
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He said there have been some reports of problems suffered by patients who are exposed to anti-theft systems. Two case reports have demonstrated the problems that occur when patients with implanted defibrillators come into long-term contact with such a device. In one, said Dr Ector, a 61-year-old man chatted with a cashier as he leaned against an electronic anti-theft device. After 10 to 15 minutes, the implanted cardiac defibrillator fired without physical cause. Another man, aged 72, suffered 2 episodes of inappropriate shocks that were triggered by a nearby electronic anti-theft device.
"A normal routine exposure is not a problem," said Ector. "Extreme exposure, however, could have caused inappropriate shock in 7 patients."
He advised that patients should avoid a search with a handheld metal detector and should request a personal search instead.
Christof Kolb, MD, of the German Heart Center in Munich, said he had tested 200 pacemaker patients and 150 implanted cardiac defibrillator patients by asking them to stay 20 seconds in a metal detector gate. Each was asked to place the side of his or her body on which the device was implanted as close as possible to the transmitter. The medical devices were made by 7 different manufacturers and represented 75 different models.
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"No interaction was seen in the 350 patients," he said. Currently, he said, patients with pacemakers or implanted defibrillators are not required to pass through metal detectors, but he does not believe that it would affect their health. Handheld detectors are usually considered safe, he said. "But I would not advise putting it directly over the pacemaker."
Stay out of the MRI
VIENNA, Austria—Having a pacemaker or an implanted cardiac defibrillator remains a major contraindication for undergoing magnetic resonance imaging (MRI), said Firat Duru, MD, of the Cardiovascular Center at the University Hospital in Zurich.
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However, he said, in recent years, that contraindication has become controversial because some patients with the devices have successfully undergone the diagnostic test. There are actually different magnetic fields associated with MRIs, he said. The one of most concern now is the heating that has been associated with the radiofrequency field of the MRI, he said. In the MRI, the tip of the pacemaker lead can go from 24°C to 90°C (about 194°F).
"I don’t want to say it is an absolute," said Dr Duru, but he emphasized that it should be avoided in all but the most extreme conditions. He advises contacting an expert, using low field strengths and low energy values, avoiding a full body scan, and insuring that a cardiologist is present during the scan.
"While some patients and physicians have been fortunate in the past, that does not mean it is now considered safe," said Dr Duru.
A Cough Start?
VIENNA, Austria—A Polish physician wants to add a new dimension to the battle against sudden cardiac death—cough cardiopulmonary resuscitation (CPR).
Tadeusz K. Petelenz, MD, of the Silesian Medical School in Katowice, Poland, said that if the public could be taught to recognize the early symptoms of sudden cardiac arrest and how to cough themselves out of it, lives might be saved. "Most sudden cardiac deaths are caused by ventricular fibrillation that may be transient," said Dr Petelenz. "The victims are often 50 to 60 years old, which are often the most productive years of life. Two of five victims are alone during sudden cardiac arrest."
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Frequently, he said, patients in the catheter lab are asked to cough if their hearts start to beat erratically. The coughing can restore normal heart rhythm, he said, because it increases the pressure in the chest and abdomen, much the same as occurs with external CPR.
Dr Petelenz and fellow researchers identified 115 patients at high risk of sudden cardiac arrest and taught them to recognize early warning signs of the condition, including shortness of breath, sudden nausea, and sweating. They were also taught the resuscitative cough technique and encouraged to practice it.
Patients used resuscitative cough in 365 instances when they felt faint, and symptoms disappeared in 292 cases. Dr Petelenz said only 73 cases required further medical assistance. All survived to receive follow-up therapy, which included 45 pacemaker implantations, 55 heart surgeries, and 15 pharmacological interventions.
Leo L. Bossaert, MD, Executive Director of the European Resuscitation Council from Antwerp, Belgium, was less enthusiastic about the prospect of cough CPR than Dr Petelenz. Teaching the technique might muddy the message that one should call for help as soon as possible. He worried that patients might make the call too late for emergency medical services to provide help. He was skeptical of the ability of the lay public to recognize symptoms of sudden cardiac arrest in time to act.
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The American Heart Association does not endorse the concept of cough CPR, reports of which have been widely spread on the Internet. The Association states: "‘Cough CPR’ should not be routinely taught in lay-rescuer CPR courses, because it would complicate the teaching of traditional CPR. It would add information that is not generally useful in the prehospital setting. In virtually all lay-rescuer CPR courses, the finding that signals an emergency is the victim’s unresponsiveness. This signals the rescuer to begin the ‘A,B,C’s’ of CPR. Unresponsive victims will not be able to perform ‘cough CPR’. . . .This coughing technique to maintain blood flow during brief arrhythmias has been useful in the hospital, particularly during cardiac catheterization. In such cases the patient’s ECG is monitored continuously, and a physician is present. During cardiac catheterization, patients may develop sudden arrhythmias. If a life-threatening arrhythmia is detected within the first 10 to 15 seconds and before the patient loses consciousness, a physician or nurse may instruct the patient to cough. Repeated, forceful coughing can help the person remain conscious until the arrhythmia disappears or is treated."
"The best strategy is to be aware of the early warning signs for heart attack and cardiac arrest and respond to them by calling 9-1-1. If you’re driving alone and you start having severe chest pain or discomfort that starts to spread into your arm and up into your jaw, you should pull over and flag down another motorist for help or phone 9-1-1 on a cellular telephone."
Cooling It!
VIENNA, Austria—Cooling the brains and bodies of unconscious adult survivors of out-of-hospital cardiac arrest to 32° to 34°C can save precious brain and heart cells, said Fritz Sterz, MD, of the Department of Emergency Medicine at Vienna General Hospital in Vienna, Austria.
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Already a recommendation of the American Heart Association and the American College of Cardiology as well as the European Resuscitation Council, such cooling is honored more in concept than practice, said Dr Sterz. "I looked around the hospitals in Vienna, and I wondered where it was really being done."
He has convinced 10 European centers to join him in a registry of cooling practice. "We want to see who is cooling in Europe, how is it done and what is the outcome," he said. The online registry is located at www.coolheart.com, and Dr Sterz hopes to have it go worldwide eventually.
He said he began the cooling practice 5 to 6 years ago by blowing cool air on his patients. Today, he said, he circulates cold liquid through balloons inserted with intravascular catheters. In Australia, he said, researchers are giving patients as much as 3 liters of cool saline intravenously during transport.
"There are many methods on the horizon," he said. "Having all ambulances equipped with small fridges that carry cool fluids would be a start. The sooner the cooling, the more efficient the procedure."
Thrombolytics for Sudden Cardiac Arrest?
VIENNA, Austria—With the value of thrombolytics in myocardial infarction pretty well understood, Bernd W. Bottinger, MD, of the Department of Anesthesiology at the University of Heidelberg, wants to try them in sudden cardiac death to mitigate the activation of coagulation that occurs during cardiac arrest and reperfusion.
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"If blood vessels are clotted, it is hard to establish circulation," he said. In animal studies, he said, administering a thrombolytic agent with heparin results in adequate reperfusion of many areas of the brain after cardiac arrest.
"The hypothesis is that hemostatic actuation plays an important role after reperfusion in the wake of cardiac arrest," said Dr Bottinger. In a pilot study in 90 patients drawn from in and around Heidelberg, he said the number of patients who could be stabilized in the field improved from 50% to 70% with the use of a thrombolytic and heparin. About 10% of control patients survived to be discharged from the hospital. That figure, he said, nearly doubled with the addition of the thrombolytic agent and heparin. He expects a large-scale European trial of the technique to begin next year.
Resisting Aspirin
VIENNA, Austria—Treating 1000 high-risk patients with aspirin for 2 years will prevent 36 cardiovascular events, said Tina Poulsen, MD, PhD, of Odense University Hospital in Denmark. Why some patients are protected and others are not is a dilemma that might be explained by "aspirin resistance," she said.
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Or, they may suffer the event because of the natural progression of their atherosclerotic disease, she said. To find out, she measured platelet aggregation times in 298 patients who appeared at her hospital and who were taking 150 mg of aspirin daily. Seventy of the patients had an acute myocardial infarction and 228 did not.
She could not detect the aspirin effect in 36% of the patients who had the myocardial infarction and in 19% of those who did not have the heart attack. From this, she said, "If you are admitted to the hospital on suspicion of acute myocardial infarction and you are taking 150 mg of aspirin daily and demonstrate aspirin resistance, your risk of having an acute MI [myocardial infarction] is increased more than twofold. We have not shown that the myocardial infarction was caused by the absence of aspirin effect," she said. "We need to clarify if aspirin resistance is a predictor of effects."
She would not recommend testing patients for aspirin resistance at this time and prescribing something else. Much more work in the field must be done before that is decided, she said.
The Economics of Drug-Eluting Stents in Europe
VIENNA, Austria—The decision as to which patient gets a drug-eluting stent is economic, not clinical, said European cardiologists who discussed the newest form of stent as a "panacea" during the Congress.
Marie-Claude Morice, MD, of the Institut Cardiovasculaire Paris Sud in Massy, France, said, "Why are we not giving the stents to our older patients? Because they are three time more expensive than bare metal stents."
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She predicted that in the next year, 80% of stents in the United States will be drug eluting, while only 50% in Europe will be. "We will have to select a few patients who will have this major benefit."
The problem, she said, is that there is currently no approved reimbursement for drug-eluting stent in countries like France. When such payments are approved, they will probably cover only a few of the highest-risk patients, such as diabetics.
Bernard DeBruyne, MD, PhD, of the Cardiovascular Center, OLV Hospital in Aalst, Belgium, agreed that the price of the drug-eluting stent will remain a problem in coming years. "Most countries will have to deal with no reimbursement at all for 3 to 5 years," he said, a paradox because the pioneering studies in such stents were carried out in Europe.
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He said that drug-eluting stents promise to increase the numbers of patients who can receive stents instead of surgery. Yet because of the price, the increase in numbers may not occur.
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