Level 2: Mid-level evidence
A routine invasive strategy for non-ST-elevation acute coronary syndrome (ACS) may reduce rate of rehospitalization for ACS but not rate of death or MI, based on a systematic review of eight randomized trials with 10,412 patients (JAMA. 2008;300:71-80). The review lacked a quality assessment of included trials. The principal investigators for all eight trials provided sex-specific outcome data for a collaborative meta-analysis. Invasive strategy was defined as coronary angiography followed by revascularization if appropriate for all patients with non-ST-elevation ACS; conservative strategy was defined as pharmacologic management with coronary angiography for patients with recurrent unprovoked symptoms of angina or evidence of ischemia on noninvasive testing.
Data on incidence of death, MI, or rehospitalization for ACS within 12 months were available for 10,150 patients (3,075 women and 7,075 men). When comparing invasive vs. conservative strategies after 12 months, there were no significant differences in mortality (4.3% vs. 4.4%) or incidence of nonfatal MI (7.4% vs. 8.5%), but there was a significant reduction in rehospitalization rate for ACS (12.8% vs. 18%, P <.05, NNT 20). Results were similar in subgroup analyses in women and in men. Data were not suggestive of benefit in the subgroup of women with negative biomarkers.