5-year outcomes in the FRISC-II randomised trial of an invasive versus a non-invasive strategy in non-ST-elevation acute coronary syndrome: a follow-up study

Abstract

Background: The FRISC-II invasive trial compared an early invasive with a non-invasive strategy in terms of death and myocardial infarction in non-ST-elevation acute coronary syndrome. We present 5-year follow-up results, overall and in subgroups based on recommended risk stratification criteria.

Methods: In the FRISC-II trial, 2457 patients with non-ST-elevation acute coronary syndrome were randomised to early invasive strategy (coronary angiography and, if appropriate, revascularisation, within 7 days from admission) or non-invasive primarily medical strategy. Risk stratification was done on the basis of risk indicators at randomisation: age older than 65 years, male sex, diabetes mellitus, previous myocardial infarction, ST-segment depression, raised troponin concentration (>0.03 mug/L), and raised C-reactive protein or interleukin 6. Information on events after 24 months was taken from national registries. Analyses were done on an intention-to-treat basis.

Findings: At 5 years the groups differed in terms of the primary composite endpoint of death, myocardial infarction, or both (invasive 217, 19.9 %; noninvasive 270, 24.5 %; risk ratio 0.81; 95% CI 0.69-0.95; p=0.009). 5-year mortality was 117 (9.7%) in the invasive group compared with 124 (10.1%) in the noninvasive group (0.95; 0.75 -1.21; p=0.693). Rates of myocardial infarction were 141 (12.9 %) in the invasive and 195 (17.7%) in the non-invasive group (0.73; 0.60-0.89; p=0.002). The benefit of the invasive strategy was confined to male patients, non-smokers, and patients with two or more risk indicators.

Interpretation: The 5-year outcome of this trial indicates sustained benefit of an early invasive strategy in patients with non-ST-elevation acute coronary syndrome at moderate to high risk.