Impact of Revised Criteria for Myocardial Infarction
At this year’s European Society of Cardiology (ESC) Congress, it was clear that the revised criteria for myocardial infarction (MI), proposed in 2000 by the ESC and the American College of Cardiology, have yet to gain general approval. The criteria depend on troponin and creatine kinase-MB (especially troponin) as markers of myocardial necrosis, and any such necrosis as a result of ischemia, however small, signifies MI. The proponents, or “troponites,” declare that the new laboratory-dependent criteria offer more sensitive diagnosis and stronger prognostic information, and allow for more aggressive management. The “antitroponites” question the clinical relevance of small increases in troponin and worry about the clinical and social implications of labeling numerous extra people as having MI. Several speakers at the Congress had retrospectively assessed the diagnostic impact of the new definition. For example, Dr S. Wilson, from the Cardiology Department, Newham Healthcare Trust, London, UK, reported on 964 patients with acute coronary syndromes. Of these, 297 fulfilled the old criteria for MI and 481 fulfilled the new. In percentage terms, the ratio of unstable angina to MI fell from 69/31 to 42/58, and the in-hospital fatality rate for MI (new definition) fell by more than one-third. Dr G.A. Large, from the Department of Cardiovascular Medicine, University Hospital Nottingham, Nottingham, UK, analyzed data on 1348 patients seen in a teaching hospital. Of these, 385 met the old criteria for MI and an additional 240 the new. These extra MI patients spent less time in the hospital and had a lower case fatality rate. Dr F. Macor, from the Cardiology Department, A.O. S. Maria degli Angeli, Pordenone, Italy, found that, in 760 patients admitted with acute coronary syndromes, the new criteria would have increased the diagnosis of MI by 43%, but that the use of diagnostic and therapeutic techniques did not differ between the extra patients with MI and those with classic non–ST-elevation MI. At a session on the clinical and prognostic implications of troponin release, Dr A. Jaffe, from the Department of Cardiovascular Diseases, Mayo Medical School, Rochester, Minn, dismissed criticisms of the new definition, declaring that over the years, clinicians have been required to adapt to a whole series of diagnostic advances, of which troponins are merely the latest. Even a small increase in these markers, he said, has prognostic implications. But he did express concern about the accuracy of some of the assays now in use. He strongly advised clinicians to verify that their local laboratory uses a reliable assay. These words will not have appeased the clinicians who spoke anxiously about the effects of an MI diagnosis on self-perception and the ability to work and play. If the new criteria are applied, clinicians will have to make clear that some MI are more equal than others.
A European Model for Collaborative Research
An ESC silver medal was awarded to Professor L. Tavazzi, from the Division of Cardiology, S. Matteo University, Pavia, Italy, who then delivered the ESC Lecture on Population Sciences. At a time when we enjoy a golden age of medical science, Tavazzi declared, we are entering a dark age of healthcare delivery. He spoke of a growing gulf between physicians and patients, reflected in mistrust, litigation, and defensive medicine. One reason for the rift, in his view, is that research is too often driven by commercial pressures rather than perceived medical need. The public suspects conflicts of interest. The answer, in Tavazzi’s opinion, is to conduct more research on real-world issues, and he cited the studies of GISSI as a model—undertaken by a national medical society (the Italian Society of Hospital Cardiologists), driven by clinical need, conducted by members without payment, incorporating input from every cardiology center, and yielding results with immediate implications for practice. The work, in which Tavazzi played a key part, began with the influential GISSI-1, which dealt with the effects of streptokinase in myocardial infarction, and subsequent studies have addressed other therapeutic strategies. In addition, GISSI has conducted short-term but comprehensive snapshots of practice in Italy, again involving most of the cardiology community, to identify clinical needs and possible ways to respond. One probable reason for the silver medal was that the ESC has lately been conducting surveys that have been called “embryo-GISSI.” These are the Euro Heart Surveys, 4 of which were presented at the Congress (on coronary revascularization, heart failure, valvular heart disease, and acute coronary syndromes). One thing they show is the difference between real-world medicine and the selected populations recruited in clinical trials. For example, in patients undergoing percutaneous coronary interventions, the prevalence of diabetes is 22% rather than the 11% in such trials. But these Euro surveys have a long way to go before reaching the GISSI level of clinician involvement.