Chest pain duration can signal heart attack . . . Patients with longer-lasting chest pain are more likely having a heart attack than those with pain of a shorter duration, according to a study by researchers at Henry Ford Hospital (Detroit). The study is published in the September issue of Critical Pathways in Cardiology. Every year, eight to 10 million people in the U.S. go to emergency departments for chest pain. But only 15% to 30% of them are having a heart attack. The characteristics of chest pain are important to diagnosing the cause. Researchers studied the relationship between the length of time that a patient experienced chest pain and a diagnosis of heart attack in patients evaluated in the emergency department. "Patients can experience varying strength, location, and duration of chest pain," says James McCord, MD, a cardiologist at Henry Ford Hospital on the research team. "The variety of symptoms any one patient may experience during a heart attack is a challenge to the physician who is trying to distinguish between patients who are having a heart attack and those who are not." He added that although an electrocardiogram and cardiac markers in the blood are important in the evaluation of patients with a possible heart attack, they are not 100% accurate. Records of patients who were evaluated for possible heart attack in the emergency department at Henry Ford Hospital between January and May of 1999 were studied. Only patients for whom chest pain duration and 30-day follow-up data was available were selected. Of 426 patients included in the study, 38 (less than 9%) had a final diagnosis of heart attack, with average chest pain duration of 120 minutes, compared with 40 minutes in patients without heart attack. In patients with chest pain lasting less than five minutes, there were no heart attacks and no deaths at 30 days. "These findings suggest that patients with chest pain lasting less than five minutes may be evaluated as an out-patient in their doctor's office; while patients with chest pain greater than five minutes, without a clear cause, should seek prompt medical evaluation in an emergency department," McCord said. Patients were interviewed during the study to determine medical history and demographics. Those with a diagnosis of heart attack were significantly older. The researchers concluded that patients with heart attack have longer duration of chest pain than those not experiencing a heart attack; patients with chest pain of short duration, less than five minutes, are unlikely to have a heart attack and have a good prognosis at 30 days. He added that, since this study was done at one hospital with a relatively small number of patients, further study is needed.

MRI may predict heart attack or stroke in diabetics . . . Whole-body MRI may serve as a valuable noninvasive tool for assessing the risk of heart attack and stroke in diabetic patients, according to a new study published online in the journal Radiology. Diabetes is a metabolic disease characterized by an increased concentration of glucose in the blood. Patients with diabetes are known to develop atherosclerosis, or thickening of the arterial walls, at an accelerated rate, resulting in a higher incidence of major adverse cardiac and cerebrovascular events (MACCE), such as a heart attack or stroke. However, there are wide variations in the degree of risk for adverse events among diabetic patients. In recent years, whole-body MRI has emerged as a promising means to assess the cardiovascular systems of people with diabetes. "One of the major advantages of whole-body MRI in this population is that the technique itself is not associated with radiation exposure, and larger body areas can be covered without increased risk, especially in younger patients," said Fabian Bamberg, MD, from the Department of Radiology at Ludwig-Maximilians University (Munich, Germany). "As such, MRI can be used to evaluate the whole-body degree of disease burden that is not clinically apparent yet." Bamberg and colleagues studied the predictive value of whole-body MRI for the occurrence of MACCE in 65 patients with diabetes. The patients underwent a contrast-enhanced whole-body MRI protocol, including brain, cardiac and vascular sequences. The researchers then conducted follow-up inquiries to assess the rate of MACCE in the study group. Follow-up information was available for 61 patients. After a median of 5.8 years, 14 patients had experienced MACCE. Patients who had detectable vascular changes on whole-body MRI faced a cumulative MACCE risk rate of 20% at three years, and 35% at six years. None of the patients with a normal whole-body MRI went on to experience MACCE. The findings point to a role for whole-body MRI as an accurate prognostic tool for diabetic patients that could speed effective treatments to those at risk, Bamberg said. "Whole-body MRI may help in identifying patients who are at very high risk for future events and require intensified treatment or observation," he said. "Conversely, the absence of any changes on whole-body MRI may reassure diabetic patients that their risk for a heart attack, stroke or other major cardiac or cerebrovascular event is low." Along with its prognostic accuracy, whole-body MRI has other advantages over existing methods of determining heart attack risk, according to Bamberg. "Other established and valuable tools, such as myocardial perfusion imaging or computed tomography (CT) for quantification of coronary calcification, are generally limited to cardiac evaluation due to their associated risk profiles," he said. "Also, MRI provides unique insights into soft tissue pathology, including cerebral and vascular changes, such as restriction of blood flow to the brain." Bamberg said that while whole-body MRI is a relatively recent development that needs more study, the results so far are promising. "Our study provides preliminary evidence that the technique may be beneficial for risk stratification in patients with diabetes," he said. "We anticipate that emerging study findings in different diabetic cohorts will provide additional scientific basis to establish whole-body MRI as a screening modality."

Scientists discover gene variant that predisposes people to special type of heart attack . . . Scientists at The University of Manchester (Manchester, UK) and medical institutes in Italy have identified a gene variant that predisposes people to a special type of heart attack. Their research, published in the International Journal of Cardiology could lead to the development of new drugs to treat the problem. The researchers say that in some people with perfectly clean arteries, the coronary artery suddenly constricts, shutting off the blood supply to the heart. They have discovered that this process, known as vasospasm, can be associated with a rare variant of a particular gene. This type of heart attack is known to occur in about 6% of patients but until know, scientists did not know which gene was responsible. Once that is identified, they say, it will be possible to predict who is at risk and treat them accordingly. The gene identified by the team encodes a protein termed KATP channel. This protein forms microscopic gated pores that allow potassium ions to move into and out of the cells, in this way giving rise to electrical impulses. The researchers noted that these channels are abundant in the cells forming the wall of coronary arteries, and the electrical impulses they generate govern this artery's diameter. Due to the mutation identified during the research, the KATP channel in the coronary artery can no longer fulfill this delicate process, they noted.

Pediatric chest pains can often be evaluated in ambulatory setting . . . Employing a unique quality improvement methodology, called Standardized Clinical Assessment and Management Plans (SCAMPs), physicians have demonstrated that chest pain in children, rarely caused by heart disease, can be effectively evaluated in the ambulatory setting using minimal resources, even across a diverse patient population. So found a multi-institutional study, led by cardiologists throughout New England and published Sept. 9 in Pediatrics. "Previous research has shown that children referred for chest pain infrequently leads to a diagnosis of a cardiac condition, and yet, we continue to see referrals at a very high rate," says the study's senior author David Fulton, MD, chief of outpatient cardiac services at Boston Children's Hospital. In fact, one study found that among 3,700 children and young adults, ages 7 to 22, who were evaluated for chest pain in the outpatient clinics at Boston Children's from 2000 to 2009, only 1% were found to have a cardiac cause. The researchers also found that the patient testing involved with those visits was quite disparate, from extensive to minimal. "Based on these findings, we recognized the opportunity to decrease practice variation through the design of a SCAMP," Fulton says. "At the inception of this process, we thought it important to include other pediatric cardiologists from the New England region to see if the SCAMP was scalable and exportable enough to be successfully deployed across clinical groups of varied sizes." In this study, the physicians assessed 1,016 ambulatory patients, ages 7 to 21 years, initially seen for chest pain at Boston Children's Hospital or a practice within the New England Congenital Cardiology Association (NECCA). They developed a SCAMP algorithm for pediatric chest pain using history, physical exam and electrocardiogram to suggest when further diagnostic testing was indicated. Without the use of the SCAMP algorithm, practices frequently ordered expensive tests, such as echocardiograms, exercise stress tests, Holter monitors and event monitors - with disparate utilization depending on the unique practice or physician. This algorithm was designed to identify cardiac causes of chest pain while effectively using resources in the outpatient cardiology clinic setting. The algorithm was used to analyze the combined patient population and to compare outcomes of those seen at BCH and NECCA sites. The overall goal of SCAMPs is to analyze the data collected every six months and improve the SCAMP based on these analyses, the researchers noted. The SCAMP has been updated once with an additional review of the most current data in progress. Among the 1,016 patients in this study, only two had chest pain due to a cardiac etiology. Testing performed outside of guideline recommendations of the SCAMP demonstrated only incidental findings, and the few patients who returned for persistent symptoms did not have cardiac disease. In addition, though not part of this review, Fulton reports a 15% to 20% drop in costs after implementing the SCAMP relative to a pre-SCAMP population.

— Compiled by Amanda Pedersen, MDD Senior Staff Writer

No Comments