Despite taking multiple tablets to lower blood pressure (BP), some people with high BP have no change in their BP. These people are at increased risk of developing health problems, such as a heart attack or a stroke. For some of these people, BP can be lowered simply by changing the type and dose of the tablets they are using. For others, a simple catheter procedure that removes excess nerve signals to and from the kidneys (""renal denervation""; RDN) can reduce BP. The proposed research aims to understand how best to manage resistant high BP in NZ. We plan to review existing datasets and conduct a randomised trial to compare the effects of RDN and intensive medical treatment on BP. The costs of both approaches will be assessed, as well as identification of the best way to introduce these services into the NZ health system.