Aims: To compare an early to a delayed invasive strategy in high-risk patients with NSTE-ACS.
Methods and results: In this prospective multicentre trial, 542 patients hospitalised with NSTE-ACS were randomised to either an immediate (angiography and revascularisation if appropriate <12 hr) or a delayed invasive strategy (>48 hr after randomisation). Patients were eligible if they had two of the following three high-risk characteristics: evidence of extensive myocardial ischaemia on ECG, elevated biomarkers for myocardial necrosis (TropT >0.10 μg/L), and an age above 65 years. Primary endpoint of the study was the combined incidence of death, reinfarction and/or recurrent ischaemia at 30-day follow-up. Secondary endpoints were enzymatic infarct size as assessed by a single cardiac troponin T, at 72-96 hours after admission or at discharge, and the percentage of patients without a rise in CKMB during admission. Median age was 71.9 (interquartile range [IQR] 64.5-78.4) years. Median time between randomisation and start of angiography was 2.6 (IQR 1.2-6.2) hours in the immediate and 54.9 (44.2-74.5) hours in the delayed intervention group. The composite of death, reinfarction and/or recurrent ischaemia at 30 days occurred in 12% of patients and was not significantly different between the two groups (9.9% and 14.2%, respectively, p=0.135). All secondary endpoints and bleeding complications were comparable. Hospital duration was two days shorter in the immediate intervention group (4 days [IQR 2-10] vs. 6 days [IQR 4-12]).
Conclusions: Although no definitive conclusion can be drawn due to a lower than expected prevalence of the primary endpoint, an immediate invasive strategy was safe and feasible but not superior to a delayed invasive strategy in terms of the combined primary endpoint of death, reinfarction and/or recurrent ischaemia at 30 days. These results are consistent with previous randomised trials which studied the effect of timing of angiography in patients with NSTE-ACS.
Trial registration: ISRCTN Register 9230163.