Approximately 600,000 postoperative cardiac ischemic events occur annually in the United States, costing 20 billion dollars for in-hospital and long-term care. These ischemic events are attributed to the surgery- induced stress response, which can lead to both fixed and reversible myocardial oxygen supply-demand imbalance. Surveillance monitoring has revealed that prolonged, and therefore, potentially reversible myocardial ischemia precedes most postoperative ischemic events. These same studies have also demonstrated that postoperative myocardial ischemic events predict long-term risk for cardiovascular morbidity and mortality. Current management of patients with coronary artery disease does not aggressively detect or treat postoperative myocardial ischemia, which is usually silent. This has been due to lack of cost-effective, real-time monitoring to enable acute intervention during the postoperative period. This investigation explores the use of new technology, employed in an innovative fashion that allows real-time intervention of prolonged ischemia; and seeks to define the acute and chronic outcomes of this intervention. We are conducting a randomized clinical trial with a continued annual follow-up to answer the specific aims. 500 patients having vascular reconstruction will be randomized following surgery either to the intervention or control arm. Both arms are monitored continuously for 48 hours postoperatively by 12lead ECG, which is connected by a dedicated intranet to a central microprocessor ST analyzer. In addition to ECG monitoring, all patients are followed clinically until discharge and with cardiac enzymes (CPK-MB, troponin I) immediately post-op, days 1, 2, 3, and on discharge or Post-op day 7 (troponin I only). In addition all patients will have a sample collected to assess a specific platelet genotype that has been associated with increased frequency of acute coronary thrombosis in the non-operative setting (PlA2 polymorphism). Both arms receive routine postoperative care, which includes time in the ICU (usually 18-24 hours) followed by a transfer to a step-down unit or surgical ward. For patients in the intervention arm, the ST analyzer will alarm (through a beeper notification system) their caregiver when the patient develops 20 minutes of continuous ischemia (>1mm ST segment elevation or depression), in 2 adjacent leads. This initiates the protocol. Patients in the control arm will not alarm, and the same treatment protocol will be instituted only in response to clinical indicators. The treatment consists of standard therapy for ischemia including rate control, assessment of adequate oxygen saturation and hemoglobin and blood pressure management if indicated. All patients are followed-up annually to evaluate the effect of real-time intervention on long-term cardiovascular morbidity and mortality. Successful completion of this trial will help to define the pathogenesis of postoperative cardiac ischemic events, and reduce acute and long-term cardiovascular complications, resulting in improved care at substantial cost savings.""""""""
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