Early invasive strategy in high-risk acute coronary syndrome without ST-segment elevation. The Sisca randomized trial.

Background: The optimal therapeutic strategy for patients with high-risk acute coronary syndrome without ST-segment elevation (NSTE-ACS) remains unclear.

Objective: Our aim was to compare the effectiveness of an early invasive strategy and a delayed invasive strategy in the management of high-risk NSTE-ACS patients.

Methods: This randomized clinical trial in a primarily pre-hospital setting enrolled patients with chest pain, electrocardiographic criteria for an NSTE-ACS, and at least one criterion of severity (ESC criterion or TIMI score >5). Patients were randomized to either an early invasive strategy (tirofiban infusion and coronary angiography within 6h) or delayed invasive strategy (as per guidelines and physician discretion; coronary angiography within 6h was not advised). The primary endpoint was the cumulative incidence of deaths, myocardial infarctions, or urgent revascularizations at 30days of follow-up. Secondary endpoints were failure of delayed management, length of hospital stay and long-term mortality.

Results: Between January 2007 and February 2010, 170 patients were enrolled. The cumulative incidence of adverse outcomes was significantly lower for early invasive than delayed management (2% [95% CI 0-9] vs. 24% [95% CI 16-35], p<10(-4)). Delayed management failed in 24% of cases. The length of hospital stay was significantly shorter in patients undergoing angioplasty or treated with tirofiban within 6h (p=0.0003). Long-term mortality was 16% in both arms after a median follow-up of 4.1years.

Conclusion: An early invasive strategy reduced major adverse cardiac events in patients with high-risk NSTE-ACS. Early angiography or tirofiban (GP IIb/IIIa inhibitor) infusion proved necessary in a quarter of patients assigned to delayed management.