Advantageous Predictors of Acute Coronary Syndromes Evaluation (APACE) Study

Background: The triage of patients with suspected acute coronary syndrome in the emergency room is a time-consuming diagnostic challenge. Triage and management of patients with low probability of coronary artery disease often cause excessive hospital costs. Therefore high sensitive early markers for myocardial damage are needed for more rapidly rule out of acute myocardial infarction (AMI).

Cardiac troponins (T and I) are currently the gold standard for definitive AMI diagnosis due to their high sensitivity and specificity for detection of myocardial cell injury. Unfortunately, troponin is undetectable by current assays in peripheral blood within 3 to 4 hours after onset of chest pain in AMI ("troponin-blind" period).

New cardiac markers such as the novel high-sensitive troponin I/T, ischemia modified albumin and placental growth factor have demonstrated certain advantages compared to troponin such as high negative predictive value for AMI, earlier verifiability in peripheral blood and possible value as independent risk marker. However, clinical evaluation in a large cohort of unselected patients presenting to an emergency department is still lacking.

Aim: To test the hypothesis that the use meticulous patient history and novel cardiac markers (including high-sensitive troponin I/T, myeloperoxidase, ischemia modified albumin, placental growth factor) can provide a faster detection or exclusion of AMI in patients presenting with acute chest pain to the emergency department.

Patients and Methods: The prospective cohort study is designed to enrol unselected patients presenting with acute chest pain at rest within the last 12 hours to the emergency department. Several blood samples for detection of the new markers will be drawn (baseline, 1, 2, 3 and 6 hours) and compared with the gold standard for the diagnosis of AMI (high-sensitivity cardiac troponin T). Timing and treatment of patients are left to the discretion of the attending physician and will be performed according to the standard house routine of the hospital. All patients will be contacted by telephone at 6, 12, 24 and 60 months to determine functional status, major adverse cardiac events (death, myocardial infarction, coronary artery bypass grafting, percutaneous coronary intervention), and the results of cardiac examination (stress test, coronary angiography) if performed.

Expected results: It is our hypothesis that the use meticulous patient history and novel cardiac markers can improve the detection of AMI by providing an early diagnosis for AMI with a high negative predictive value within the "troponin-blind" period.

Significance: The earlier detection of myocardial necrosis in peripheral blood could help to rule out AMI more rapidly. In addition it will allow a more rapid diagnosis and appropriate therapy of AMI. This can lead to a significant improvement in patient management and a reduction of in-hospital costs.

Inclusion criteria

• Patients presenting to the emergency department
• Typical angina pectoris or other thoracic sensations that are suspected to be caused by myocardial ischemia
• Symptoms at rest or minor exertion
• Onset of symptoms within the last 12 hours prior to presentation
• Written informed consent

Exclusion criteria

• Age < 18 years
• Cardiogenic shock
• Terminal kidney disease requiring regular dialysis