MedicalResearch.com Interview with: PJ Devereaux MD PhD Professor of Medicine, and of Health Research Methods, Evidence and Impact McMaster University President of the Society of Perioperative Research and Care  MedicalResearch.com:  What is the background for this study?  Response: More than 1 million patients undergo cardiac surgery in the United States and Europe annually. Although cardiac surgery has the potential to improve and prolong a patient’s quality and duration of life, it is associated with complications. Prognostically important heart injury – detected by an elevated blood concentration of either cardiac troponin or creatine kinase myocardial MB isoform (CK-MB) – is one of the most common complications after cardiac surgery and is associated with increased mortality. Although elevated CK-MB was historically used to define heart injury after cardiac surgery, this assay is no longer available in many hospitals worldwide, and consensus statements have recommended high-sensitivity cardiac troponin assays as the preferred biomarker. Based on expert opinion, the Fourth Universal Definition of Myocardial Infarction suggested that a cardiac troponin concentration >10 times the upper reference limit, in patients with a normal baseline measurement, should be the threshold used in the diagnosis of heart attack along with evidence of ischemia (e.g., ischemic ST changes on an ECG) in the first 48 hours after coronary artery bypass grafting (CABG). Although the Academic Research Consortium-2 Consensus stated there was no evidence-based threshold for cardiac troponin after CABG, they endorsed a threshold for the diagnosis of heart attack of ≥35 times the upper reference limit together with new evidence of ischemia, based on expert opinion. They also defined a threshold of ≥70 times the upper reference limit as a stand-alone criterion for clinically important periprocedural myocardial injury. Globally, many hospitals now use high-sensitivity cardiac troponin assays; however, limited data are available to define a prognostically important degree of myocardial injury after cardiac surgery based on these assays. We undertook the Vascular Events in Surgery Patients Cohort Evaluation (VISION) Cardiac Surgery Study to examine clinical outcomes after cardiac surgery. A primary objective was to determine the relationship between postoperative levels of high-sensitivity cardiac troponin I and the risk of death 30 days after cardiac surgery.  (more…)