Considerable debate surrounds the treatment of patients who show signs of being at risk of heart attack. Current guidelines suggest that, for such patients with unstable coronary syndromes who are at moderate risk of death from coronary-artery disease, either an interventional strategy (angiography followed by revascularisation [restoration of coronary artery bloodflow by angioplasty or coronary artery bypass surgery]) or a conservative 'wait and see' strategy is appropriate.
Keith Fox, lead investigator of the British Heart Foundation Randomised Intervention Trial of unstable Angina (RITA) and colleagues did a randomised multicentre trial of 1810 patients at moderate risk of heart attack. Patients were assigned to either an intervention or conservative treatment group. Patients assigned to intervention were given angiography and (if necessary) revascularisation. Conservative treatment was a 'wait and see' strategy with subsequent intervention if needed. The anti-clotting drug enoxaparin was used in both treatment groups.
At 4 months, 9.6% of patients in the intervention group had died, had a heart attack, or had angina, compared with 14.5% of patients in the conservative group-mainly due to a halving of angina in the intervention group. Rates of death and heart attack were similar between the two groups at one year follow-up. Around a quarter of patients given conservative treatment subsequently required surgery for coronary revascularisation within one year.
Keith Fox comments: "Our study has shown that, among patients with unstable coronary syndromes, the combined endpoint of death, non-fatal heart attack, or severe angina is significantly reduced in patients assigned intervention, and that the main effect was on severe angina. Conclusive evidence for the effect on prognosis (death or heart attack) will require completion of the planned 5 year follow-up. As in previous studies, the hazards of intervention seem to be more than counterbalanced by the subsequent reduction in risk of heart attack."
In an accompanying Commentary (p 738), Lars Wallentin from University Hospital Uppsala, Sweden, concludes: "Based on the [previously published] randomised trials, RITA 3, observational data, and clinical experience, an early invasive compared with a non-invasive strategy improves survival without recurrence of myocardial infarction and re-admission or urgent revascularisation for severe angina. The effects are greatest in intermediate-risk and high-risk patients based on non-invasive risk indicators on admission. In women the effects on prognosis are uncertain and might be unfavourable, necessitating a more cautious approach to invasive procedures. These conclusions accord with the guidelines from the ESC [European Society of Cardiology] and ACC/American Heart Association that will be published in 2002. Further studies are needed to improve methods to reduce the risks associated with invasive procedures, to explore new treatment alternatives in women, and to prevent recurrences of instability in the longer term."
Professor Keith Fox, c/o Ronald Kerr,
University of Edinburgh Press Office;
Professor Keith Fox (mobile)
Professor Lars Wallentin,
Uppsala Clinical Research Centre,
University Hospital, Uppsala,
S-751 85 Uppsala, Sweden;