CTT: Cholesterol Treatment Trialists' Collaboration

The Cholesterol Treatment Trialists’ (CTT) Collaboration conducts meta-analyses of cholesterol intervention trials. It was originally established in 1994 with the aim of bringing together data for each participant in all of the large-scale, long-term randomised controlled trials of statin therapy in order to be able to assess - more reliably than was possible with any of the individual trials - the effects of such therapy in different types of people. The Collaboration currently holds data on heart attacks, strokes, revascularisation procedures, cause-specific mortality and cancers from about 30 such statin trials equating to approximately 175,000 individuals. The CTT Collaboration’s work is coordinated jointly by Clinical Trial Service Unit & Epidemiological Studies Unit in Oxford and the National Health and Medical Research Council Clinical Trials Centre in Sydney.

The CTT Collaboration has shown that lowering LDL cholesterol using statin therapy reduces the risk of major vascular events (heart attacks, stroke or coronary revascularisation procedures) by about one fifth for each 1 mmol/L reduction in LDL cholesterol achieved. These benefits are achieved in a wide range of people at risk of cardiovascular disease, irrespective of pre-existing cardiovascular disease or diabetes, and regardless of age, sex and other factors.

The results of the CTT’s work also indicate that statin therapy does not increase the risk of non-vascular causes of death or of cancer. The Collaboration is currently collecting new data from participating trials to examine the effects of statins on adverse events other than death and cancer.