ArticlesVariations between countries in invasive cardiac procedures and outcomes in patients with suspected unstable angina or myocardial infarction without initial ST elevation*
Introduction
Patients with unstable angina or suspected non-Q-wave myocardial infarction are at high risk of death, myocardial infarction, or severe ischaemia despite current pharmacological therapy.1 There is a growing trend for routine early coronary angiography in these patients, with the expectation that early revascularisation in appropriate patients will prevent adverse outcomes. Other physicians adopt a more conservative approach and refer patients for angiography only if symptoms are refractory or if there is clear evidence of provocable ischaemia. These differing practice patterns are influenced by such factors as the beliefs of physicians and availability of catheterisation facilities. Two randomised trials2, 3 in patients with acute myocardial infarction or unstable angina compared the strategy of an early aggressive invasive approach with a conservative approach and showed no significant difference in outcomes (although in one there was a non-significant 25% excess in death or myocardial infarction with the more aggressive approach). In these trials, however, even the conservatively treated groups had high rates of catheterisation, which could have decreased the power of the studies to show any difference in effect between the strategies.
Investigation of the impact of differing approaches to the management of patients with ischaemic syndromes can be approached in another way. This approach is to compare the outcomes of patients managed in centres or countries without readily available catheterisation facilities (where only a few selected patients are referred for the procedure) with outcomes in centres or countries where such facilities are readily available (where there is likely to be a greater and earlier use of procedures). Most previous studies (all of myocardial infarction) with this design have used administrative databases (many of which do not include detailed characteristics of patients) or have been carried out within a single country (thus a broad range of practice styles cannot be contrasted).4, 5
To overcome these limitations, we set up a large prospective study in six countries to examine variations in patterns of invasive strategies, their relation to the patient's risk, and clinical outcomes. The countries and hospitals included were expected to represent a broad range of practice patterns with respect to use of invasive procedures. This study had two main aims. The first was to compare outcomes for patients with acute ischaemic syndromes in countries with a more aggressive use of catheterisation and in those with a more conservative approach. The second aim was to compare outcomes for patients admitted initially to hospitals with cardiac-catheterisation facilities and for those admitted to hospitals without such facilities.
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Patients
95 hospitals in Australia, Brazil, Canada, the USA, Hungary, and Poland took part in the study. Each hospital enrolled consecutive eligible patients during their participation in the study (1995-96). Eligibility criteria were: admission to hospital (coronary-care unit, intermediate coronary-care unit, cardiology ward, or emergency department ward) with acute ischaemic cardiac chest pain within 48 h of onset; and, if there were no electrocardiographic (ECG) changes at presentation, a history of
Results
The study enrolled 7987 patients from 95 hospitals in six countries.
Discussion
Despite wide variations in the proportion of patients undergoing invasive procedures among the countries we studied, there was no evidence of better prognosis in countries with a more aggressive approach. Indeed, in the two countries with the highest intervention rates (Brazil and USA), there was a significant excess in stroke and major bleeding. However, these differences seemed to be largely related to the availability of cardiac-catheterisation facilities and easier access to invasive
References (11)
- et al.
The electrocardiogram predicts one-year outcome of patients with unstable angina and non-Q wave myocardial infarction: results of the TIMI III Registry ECG Ancillary Study: Thrombolysis in Myocardial Ischemia
J Am Coll Cardiol
(1997) - et al.
One-year results of the thrombolysis in myocardial (TIMI) IIIB clinical trial
J Am Coll Cardiol
(1995) - et al.
Effect of coronary aftery bypass graft surgery on survival: overview of 10-year results from randomised trials by the Coronary Artery Bypass Graft Surgery Trialists Collaboration
Lancet
(1994) - et al.
One-year results of the Thrombolysis in Myocardial Infarction Investigation (TIMI) phase II trial
Circulation
(1992) - et al.
A comparison of management patterns after acute myocardial infarction in Canada and the United States: the SAVE investigators
N Engl J Med
(1993)
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