Surgical Revascularization for Acute Coronary Insufficiency: Analysis of Risk Factors for Hospital Mortality

Background. A retrospective study of 444 patients undergoing urgent and emergent coronary artery bypass grafting for acute coronary insufficiency was performed to identify the risk factors for hospital death specifically associated with the clinical severity of the acute coronary insufficiency syndrome. Methods. The patients were divided into three groups—urgent, emergent A, and emergent B—on the basis of the evolution of the clinical pattern of the acute coronary insufficiency syndrome on full medical treatment. The three categories were defined as follows: urgent (257 patients), surgical revascularization could be delayed for 24 to 36 hours after surgical consultation because of adequate control of ischemia; emergent A (127 patients), prompt myocardial revascularization was required because medical treatment achieved only transient regression of an unrelenting ischemic pattern; and emergent B (60 patients), prompt myocardial revascularization was required because the acute coronary insufficiency was entirely refractory to medical treatment. Results. Mortality rates were 7.4% for the urgent group, 13.4% for the emergent A group, and 31.7% for the emergent B group. Multivariate analysis identified the following as risk factors for hospital mortality: ejection fraction (p = 0.023) and aortic cross-clamp time (p = 0.10) for the urgent group; aortic cross-clamp time (p = 0.017), ejection fraction (p = 0.03), and nonuse of blood cardioplegia (p = 0.04) for the emergent A group; and cardiogenic shock (p = 0.00), preoperative ischemic interval (p = 0.00), aortic cross-clamp time (p = 0.018), and nonuse of blood cardioplegia (p = 0.012) for the emergent B group. Conclusions. A more exact definition of patient risk can be achieved when predictive outcome models are constructed using the risk factors specifically related to each level of clinical severity of the ischemic syndrome.