EP144: What About Imaging The Arteries - An Interview With Dr. Karam Kostner

Welcome to my podcast. I am Doctor Warrick Bishop, and I want to help you to live as well as possible for as long as possible. I’m a practising cardiologist, best-selling author, keynote speaker, and the creator of The Healthy Heart Network. I have over 20 years as a specialist cardiologist and a private practice of over 10,000 patients. Podcast Summary Introduction Dr. Warrick Bishop, a practicing cardiologist and patient education advocate, hosts this episode with Dr. Karam Kostner, a Brisbane-based cardiologist specializing in preventive cardiology and lipid management. In a unique reversal, Dr. Kostner interviews Dr. Bishop about cardiac imaging—specifically how and why clinicians use imaging technology to assess arterial health and guide treatment decisions in modern cardiology. Key Takeaways Arterial imaging is essential for clinicians to understand the extent of plaque buildup and tailor treatment intensity appropriately, and patients increasingly want direct knowledge about their own arterial health. CT imaging of the heart has only become reliable in the past decade due to technological advances that can "freeze" the heart's motion and capture clear, reproducible images. Calcium scoring (non-contrast CT) and CT coronary angiography (contrast-enhanced CT) serve different purposes: calcium scoring detects plaque markers, while CT angiography provides detailed information about plaque composition, narrowings, and artery size. Functional imaging (stress tests) is appropriate for symptomatic patients, while anatomical imaging (CT scans) is better suited for asymptomatic risk assessment in patients around age 50 for men and 60 for women. Imaging allows clinicians to move from population-level risk estimates to individual precision medicine, identifying which high-risk patients within a population will actually experience cardiac events. Cardiac CT carries minimal radiation exposure—approximately one millisievert per scan, equivalent to a mammogram—making it safer than many commonly accepted medical tests. Serial imaging protocols typically recommend repeat testing at five-year intervals for patients with zero calcium scores, though individual factors like age and risk profile modify this recommendation. CT coronary angiography carries a very small contrast allergy risk of approximately one in 200,000—three times safer than peanut butter's documented allergic reaction rate. In Australia, cardiac CT lacks formal guideline recommendations and Medicare rebates, making informed patient consent and shared decision-making particularly important for clinicians offering these tests. Imaging is generally not recommended for younger patients unless they have severe family history, very elevated cholesterol, or significant additional risk factors like elevated lipoprotein(a) or hypertension.