Background: The ICTUS trial was a study that compared an early invasive with a selective invasive treatment strategy in patients with non-ST-elevation acute coronary syndrome (nSTE-ACS). The study reported no difference between the strategies for frequency of death, myocardial infarction, or rehospitalisation after 1 year. We did a follow-up study to assess the effects of these treatment strategies after 4 years.

Methods: 1200 patients with nSTE-ACS and an elevated cardiac troponin were enrolled from 42 hospitals in the Netherlands. Patients were randomly assigned either to an early invasive strategy, including early routine catheterisation and revascularisation where appropriate, or to a more selective invasive strategy, where catheterisation was done if the patient had refractory angina or recurrent ischaemia. The main endpoints for the current follow-up study were death, recurrent myocardial infarction, or rehospitalisation for anginal symptoms within 3 years after randomisation, and cardiovascular mortality and all-cause mortality within 4 years. Analysis was by intention-to-treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN82153174.

Findings: The in-hospital revascularisation rate was 76% in the early invasive group and 40% in the selective invasive group. After 3 years, the cumulative rate for the combined endpoint was 30.0% in the early invasive group compared with 26.0% in the selective invasive group (hazard ratio 1.21; 95% CI 0.97-1.50; p=0.09). Myocardial infarction was more frequent in the early invasive strategy group (106 [18.3%] vs 69 [12.3%]; HR 1.61; 1.19-2.18; p=0.002). Rates of death or spontaneous myocardial infarction were not different (76 [14.3%] patients in the early invasive and 63 [11.2%] patients in the selective invasive strategy [HR 1.19; 0.86-1.67; p=0.30]). No difference in all-cause mortality (7.9%vs 7.7%; p=0.62) or cardiovascular mortality (4.5%vs 5.0%; p=0.97) was seen within 4 years.

Interpretation: Long-term follow-up of the ICTUS trial suggests that an early invasive strategy might not be better than a more selective invasive strategy in patients with nSTE-ACS and an elevated cardiac troponin, and implementation of either strategy might be acceptable in these patients.