Grant: Operating Grant

More than 230 million people undergo major surgery worldwide every year. At least 5 million of them suffer major heart problems after these operations. People with poor physical fitness, or "functional capacity", may be at high risk for having these heart problems. They might also be at high risk for other important problems, such as infections or difficulty breathing after surgery. At present, doctors estimate fitness for surgery by asking patients about the general types of activities that they can perform. For example, patients will often be asked whether they can climb up 2 flights of stairs. However, this approach (called "subjective assessment") does not perform well at identifying patients at risk for having major heart problems after surgery. We will therefore conduct a large international study to compare the usual approach ("subjective assessment") against 3 other methods to measure fitness for surgery. These methods are an exercise test (called CPET), a questionnaire about physical activities (called DASI), and a simple blood test (called NT pro-BNP). Our study (called the METS study) will include 1312 patients undergoing major surgery at 8 hospitals in Ontario and the United Kingdom. Before surgery, each participant will undergo a "subjective assessment" of their fitness, complete a CPET exercise test, answer the DASI questionnaire, and undergo a NT pro-BNP blood test. We will then follow the participants for 1 year after surgery to determine which method does best at identifying people who have heart problems after surgery. By helping to better identify high-risk patients before their operations, our study will help improve their medical care, and therefore reduce their risk of major problems after surgery. It will also help make sure that specialized (and expensive) medical care is used in patients who most need it. Our study will thus significantly help millions of people who have major surgery every year, in Canada and around the world.