5-year outcome of an interventional strategy in non-ST-elevation acute coronary syndrome: the British Heart Foundation RITA 3 randomised trial

The long-term outcome of an interventional strategy in patients with non-ST-elevation acute coronary syndrome is unknown. We tested whether an interventional strategy (routine angiography followed by revascularisation) was better than a conservative strategy (ischaemia-driven or symptom-driven angiography) over 5 years' follow-up. In a multicentre randomised trial, 1810 patients (from 45 hospitals in England and Scotland, UK) with non-ST-elevation acute coronary syndrome were randomly assigned to receive an early intervention (n=895) or a conservative strategy (n=915) within 48 h of the index episode of cardiac pain. In each group, the aim was to provide the best medical treatment, and also to undertake coronary arteriography within 72 h in the interventional strategy with subsequent management guided by the angiographic findings. Analysis was by intention to treat and the primary outcome (composite of death or non-fatal myocardial infarction) had masked independent adjudication. RITA 3 has been assigned the International Standard Randomised Control Trial Number ISRCTN07752711. At 1-year follow-up, rates of death or non-fatal myocardial infarction were similar. However, at a median of 5 years' follow-up (IQR 4·6–5·0), 142 (16·6%) patients with intervention treatment and 178 (20·0%) with conservative treatment died or had non-fatal myocardial infarction (odds ratio 0·78, 95% CI 0·61–0·99, p=0·044), with a similar benefit for cardiovascular death or myocardial infarction (0·74, 0·56–0·97, p=0·030). 234 (102 [12%] intervention, 132 [15%] conservative) patients died during follow-up (0·76, 0·58–1·00, p=0·054). The benefits of an intervention strategy were mainly seen in patients at high risk of death or myocardial infarction (p=0·004), and for the highest risk group, the odds ratio of death or non-fatal myocardial infarction was 0·44 (0·25–0·76). In patients with non-ST-elevation acute coronary syndrome, a routine invasive strategy leads to long-term reduction in risk of death or non-fatal myocardial infarction, and this benefit is mainly in high-risk patients. The findings provide support for national and international guidelines in the need for more robust risk stratification in acute coronary syndrome.