The Proinsulin Story Also Gets Stronger
For 27 years, Swedish and British researchers followed 874 men to determine the relationship between various molecules of proinsulin and the development of coronary heart disease. The study, led by Bjorn Zethelius, MD, of the Departments of Public Health Care Sciences/Geriatrics at Uppsala University, Sweden, appears in this week’s issue of Circulation (Circulation. 2002;105:2153–2158). According to Zethelius and colleagues, “It has been suggested that increased concentrations of insulin precursor molecules, rather than plasma insulin per se, constitute the association with coronary heart disease.”
The researchers evaluated increased plasma immunoreactive insulin, intact proinsulin, 32-33 split proinsulin, and specific insulin, and their relationship to death from cardiovascular causes in this male population comprised of members who were at least 50 years old when the study began. Researchers from the Department of Clinical Biochemistry, Addenbrooke’s Hospital in Cambridge, United Kingdom, were coauthors and contributed to the study analysis.
They found that the relationship between intact proinsulin and death from myocardial infarction was strongest. They determined that proinsulin itself is a strong and highly significant predictor of coronary heart disease, independent of other known risk factors.
Pregnancy Problematic for Women With Heart Disease
The infants of women with heart disease are more likely to suffer newborn problems compared with infants born to healthy women, according to a group of researchers from the University of Toronto, in a report appearing in this week’s issue of Circulation (Circulation. 2002;105:2179–2184). In the study, led by Samuel C. Siu, MD, SM, and others from the University, researchers concluded that when women with heart disease had other obstetric or cardiac risk factors, such as smoking, multiple gestation, or history of anticoagulant use, the risk for neonatal problems was even greater.
In their study, the researchers compared the frequency of neonatal and cardiovascular complications in pregnancies in 302 women with heart disease with 572 pregnancies in women without heart disease. Overall, 18% of the women with heart disease had infants with neonatal or cardiac complications, compared with 7% of women without heart disease.
As would be expected, the rate of complications was lowest in women aged 20 to 35 years who did not smoke during pregnancy, did not receive anticoagulants, and had no obstetric risk factors: 4% in the control group and 5% in the heart disease group who did not have cardiac complications for left heart obstruction, poor function class (or cyanosis), and 7% in women with one or more such risk factors. The complication rate was 11% among women in the control group who were <20 or >35 years of age with obstetric risk factors, multiple gestation, or a history of smoking during pregnancy.
Women with heart disease who were <20 or >35 years of age and had obstetric risk factors, multiple gestation, history of smoking during pregnancy, or who received anticoagulants, had a higher rate of neonatal complications. They had a complication rate of 27% with no cardiac risks for neonatal events and 33% when one or more cardiac risk factors were present.
The authors concluded that, “The increased risk of neonatal complications in pregnant women with heart disease is amplified by the presence of obstetric risk factors. . ..These women will likely benefit from referral to a regional center for care during their pregnancies. Conversely, women with heart disease without cardiac or obstetric risk factors are at minimally increased risk compared to pregnant women without heart disease and likely do not require increased intensity of antepartum surveillance.”
Calling for a Confluence of Talents
In an unusual joint editorial, two cardiologists and two emergency physicians called for more cooperation among the specialties of cardiology and emergency medicine. W. Brian Gibler, MD, Chairman of Emergency Medicine at the University of Cincinnati School of Medicine, Eric J. Topol, MD, Chairman of the Department of Cardiovascular Medicine at The Cleveland Clinic Foundation, Paul W. Armstrong, MD, Professor in the Division of Cardiology at the University of Alberta, and Brian Holroyd, MD, Director of the Division of Emergency Medicine at the University of Alberta, coauthored the editorial titled, “Cardiology and Emergency Medicine: United We Stand, Divided We Fall,” which appeared in the February issue of the Annals of Emergency Medicine (Ann Emerg Med. 2002;39:164–167).
“We had been chatting about this for a number of years,” said Dr Armstrong. “As times and situations change, it became clear that we needed to call for change. This is a manifesto and a call to action.”
“Note that this was written by a cardiologist and an emergency physician each from the United States and Canada,” said Dr Gibler. “We have developed a game plan. The next step is to actually get some momentum in our specialty for the formalization of a fellowship in emergency cardiac care.” He said one such emergency care cardiac fellowship already exists under the direction of Joseph Ornato, MD, Chairman of Emergency Medicine at the Medical College of Virginia.
According to Dr Ornato, he and Dr Armstrong had met frequently at meetings and commented on the “waning of collaboration between cardiology and emergency medicine. What would it take to collaborate more?”
“Without that kind of collaboration between emergency medicine and cardiology, we can’t bring optimal care to patients or perform studies to improve the future care of patients,” he said.
Until the two specialties begin to collaborate, he said, “We won’t be able to bring care up to the next level.”
In their editorial, the four noted, “The explosive growth of cardiovascular medicine in the past quarter century and the burgeoning number of patients presenting with acute chest pain and possible acute coronary syndromes (ACS) have focused the issue of delivery of high-quality patient care squarely on the interface between cardiology and emergency medicine. Hence, it is our intention in this paper to explore the relationship between these 2 disciplines, especially regarding patients with ACS, and to suggest a template for enhancing future collaborations in education, research, and patient care.”
They pointed out that collaboration between the two disciplines has resulted in better coordination of care for patients with ACS. Effective communication between the two disciplines has made the development of protocols possible, the authors wrote. “It is most desirable to see this model develop in an atmosphere of mutual respect and cordiality, in which the differing perspectives and knowledge base of the 2 specialties become aligned toward the common goal of optimal patient care.”
They described the transition of the use of fibrinolytic therapy for patients with acute myocardial infarction from cardiologists to emergency physicians in the early 1990s. They noted, “The ED [emergency department] in most hospitals in North America now serves as a major diagnostic and treatment center that focuses on the timely, effective triage of patients with ACS. This consists of rapid hospital admission of patients with severe or critical illness, discharge of patients at low risk with appropriate follow-up, and the release of still other patients after extensive diagnostic evaluations and treatment that prevents hospital admission. In the current environment of managed care, increasing patient visits to the ED, fewer in-patient beds for those requiring admission, and more time-consuming and sophisticated workups for all patients, caring for the patient with possible ACS is an even greater challenge.”
The development of chest pain units was based on the design of the trauma unit, said Dr Armstrong. In the beginning, he said, there were often the questions of, “Who is in charge here? What are the rules?”
The development of consensus and guidelines is key to making sure that the two specialties work well together, he said. He believes that leaders in both specialties have attempted to accomplish that.
With the complications of severe overcrowding in most emergency departments along with an increasing amount of information on diagnosis and treatment of ACS making such treatment difficult, the authors recommend use of new information technologies and guidelines as the basis for caring for patients.
In their editorial, the four proposed:
• Education of healthcare providers, including emergency and critical care nurses, as well as out-of-hospital providers who are frequently overlooked in continuing education.
• Clinical investigations that involve both emergency medicine physicians and cardiologists, as well as nursing and out-of-hospital care providers to search for the best ways to ensure accurate and prompt treatment of acute coronary syndromes. Improvement of routine care to ensure early integration of new findings into care. “Sophisticated monitoring by well-trained personnel with appropriate response devices should also be seamless, beginning at the patient’s home and continuing to the ED, chest pain unit, catheterization laboratory, or coronary care unit. Without true collaboration between these health care providers, these advances cannot be realized.”
• Creation of site-specific and multicenter databases that will make use of evidence-based medicine in patient care and allow continuous quality improvement to remove impediments to the best care.
• Subspecialization within emergency medicine and cardiology that would include fellowship training within both cardiology and emergency medicine “to develop specialists who have the expertise to design and implement future trials that can provide important new information for this dynamic field.”
“Fellowship-trained physicians in ACS from cardiology and emergency medicine could then collaborate to ensure that research and clinical care reflect the input of the 2 disciplines. It is clear to us that future progress in the care, teaching, and investigation of ACS is best achieved through enlightened partnerships. Cardiology and emergency medicine must surely stand united to advance our common goals and to continue progress in patient care,” the four concluded.