And in the diabetic patients in the HOT Study, an achieved difference of systolic blood pressure of 4 mmHg was associated with a halving in the number of cardiovascular events. A finding of complete reversibility of risk would suggest that, whatever the mechanisms whereby vascular stiffness increases risk, it is the levels of pressure in the stiffened vessel which are responsible for the thrombotic risk in that vessel. Yet greater than full reversibility must suggest other mechanisms of benefit, and these remain to be explored.