Harry's guests this week are Frank Cheng, CEO of UK-based Caristo Diagnostics, and Keith Channon, Caristo's co-founder and chief medical officer. Under their leadership, Caristo has introduced an AI-based test called CariHeart that applies machine learning to the data in a three-dimensional CT scan of the heart. It looks for signs of inflammation in the fat tissue around the major coronary arteries—a risk factor that's often overlooked because it isn't always accompanied by plaque or narrowing of the arteries. Doctors can use that information to decide whether a patient needs to take a cholesterol-lowering drug like a statin or an anti-inflammatory drug like colchicine. Caristo’s test is being used on an experimental basis in the UK, and it hasn’t yet been approved for use in the US. But it’s a leading example of the way AI, put together with fundamental advances in our understanding of human biology, is really beginning to change the practice of medicine.