Early invasive strategy and outcomes of non-ST-elevation acute coronary syndrome patients: is time really the major determinant?

In non-ST-elevation acute coronary syndromes (ACS), an early invasive strategy is recommended for middle/high-risk patients; however, the optimal timing for coronary angiography is still debated. The aim of this study was to evaluate the prognostic implications of the time of angiography in ACS patients treated in accord with an early invasive strategy. We analyzed the relationship between the time of angiography and outcomes at follow-up in 517 ACS patients, of whom 482 were revascularized with percutaneous coronary intervention (PCI) (86.9%) or coronary artery by-pass graft (13.1%). We also evaluated the influence of clinical, biohumoral and angiographic variables on the patients' outcomes at follow-up. Among patients submitted to angiography at different time intervals from both hospital admission and symptom onset, significant differences neither in mortality nor in cardiac ischemic events at follow-up were observed. At univariate analysis, complete versus partial revascularization, longer hospital stay, higher TIMI risk score, diabetes mellitus, higher discharge creatinine and admission anemia were associated with mortality and cardiac ischemic events at follow-up; a lower left ventricular ejection fraction was associated with mortality; higher peak troponin I and previous PCI were associated with cardiac ischemic events at follow-up. At multivariate analysis longer hospital stay, higher discharge creatinine levels, and previous PCI were independent predictors of cardiac ischemic events at follow-up. Our evaluation in ACS patients treated with an early invasive strategy does not support the concept that angiography should be performed as soon as possible after symptom onset or hospital admission. Rather, an unfavorable long-term outcome is influenced principally by the clinical complexity of patients.