OBJECTIVETo investigate the risk factors and the values of early invasive intervention in patients with acute coronary syndromes (ACS) without ST-segment elevation.

METHODSFive hundred and forty-five patients of ACS without ST-segment elevation were randomly assigned to an early conservative strategy or early invasive strategy who had been admitted to hospitals consecutively from Oct. 2001 to Oct. 2003. The combined cardiovascular events (a combination of cardiac death, nonfatal myocardial infarction, nonfatal heart failure and re-hospital admission due to recurrent ischemia angina) within 30 days and 6 months were analyzed and the primary high risk factors for combined cardiovascular events were evaluated by means of multivariate logistic regression analysis among baseline clinical characteristics and laboratory data, meanwhile, the effects of an early conservative strategy or early invasive strategy on outcomes were also investigated.

RESULTSThe incidences of combined cardiovascular events within 30 days and 6 months among 513 cases were 14.0% and 25.7% respectively. Multivariate logistic regression analysis implied ST-segment depression, elevation of troponin I level, increased C-reactive protein, lower ejection fraction of left ventricular and higher TIMI risk scores were all associated with an increases in cardiovascular events within 6 months, and they were respectively independent predictive factor for the increases of cardiovascular events. Early invasive strategy was associated with a lower rate of re-hospital admission due to recurrent ischemia angina within 30 days and a decreased incidences of combined cardiovascular events within 30 days and 6 months compared with early conservative strategy (all P < 0.05).

CONCLUSIONSST-segment depression, elevation of troponin I level, increased C-reactive protein, lower ejection fraction of left ventricular and higher TIMI risk scores are high risk factors for patients with ACS without ST-segment elevation, and early invasive strategy can have a substantial impact in reducing combined cardiovascular events.