Episode 136. Coronary Calcium Score with Dr Alistair Fyfe
The corner stone of cardiovascular disease prevention is the identification of high-risk asymptomatic individuals. In this regard coronary artery calcium is a highly specific marker of atherosclerosis and can be quantified using non contrast CT scanning which provides an accurate measure of atherosclerotic burden. Coronary artery disease is the single leading cause of disease morbidity and mortality in Australia and is responsible for approximately one in 10 deaths furthermore half the individuals with coronary artery disease will present with a myocardial infarction or death.
The compelling reason for undertaking coronary artery calcium scoring is to identify asymptomatic at-risk individuals who are likely to benefit from early detection, risk factor intervention and treatment of coronary artery disease.
In Australia risk assessment is recommended using the National Vascular Disease Prevention Alliance tool based on the Framingham Risk Equation. This risk stratification is drawn upon to guide the decision for calcium scoring which according to the Cardiac Society of Australia and New Zealand is recommended for asymptomatic intermediate risk patients or where there may be other strong evidence supporting its ability to improve cardiovascular risk assessment. High risk individuals may be better assessed by means of stress testing.
The calcium score is determined by non-contrast CT scanning and is complete within about ten minutes delivering just a little over 1 mSv of radiation equivalent to the annual background radiation we are exposed to. Using the Agatston method the volume and density of calcium is calculated and computed as a score. Again drawing upon The Cardiac society of Australia and New Zealand calcium scores may be interpreted as follows: A measurement of 0 is very low risk of coronary disease, a score of 1-100 is low risk, a measure of 101-400 is considered moderate risk and a patient lying within the 75th percentile of this group is at moderately high risk. Measurement over 400 denotes a high risk.
Multiple studies including the Multiethnic Study of Atherosclerosis (MESA) have confirmed the long-term prognostic value of CT calcium scores with over ten years of prospective follow up.
The value of calcium scoring lies in its ability to improve the accuracy of risk prediction. It helps to identify individuals who may benefit from more aggressive primary prevention measures; including the use of low dose aspirin that may otherwise not be recommended for primary prevention, as well as aggressive lipid management with statin therapies.
Given the importance of detecting asymptomatic coronary heart disease I was interested in pursuing the conversation further with one of the US expert cardiologists Dr Alistair Fyfe who has been practicing cardiology for over 38 years after graduation from the University of Tasmania.
Alistair has worked in Canada as well as the United States and is in Dallas, Texas where he has affiliations with Medical City Dallas and White The Heart Hospital Baylor Plano and is Medical Director of Blue Cross and Blue Shield of Illinois, Montana, New Mexico Oklahoma, and Texas not bad for a home-grown lad.
He is currently busy writing a contributing chapter to a soon to be published book titled: "The Implementation of Personalised Precision Medicine”, which, if I know Alistair will be excellent and a must read.
Given his expertise I was curious to learn a little more about its application and how a measured coronary calcium score should influence our approach to patient management.
I know you will find this conversation with Alistair very interesting. Please welcome him to the podcast.
References:
Dr Alistair Fyfe - on google and LinkedIn Coronary artery calcium in primary prevention
Chuah.www1.racgp.org.au When not to use calcium scoring
www.ausdoc.com.au Polonsky et al.
Coronary artery calcium score and risk classification for coronary heart disease prediction.
Special Episode 16. Interventional Radiology with Dr Yen Chieng
Interventional radiology is an innovative and rapidly growing medical profession that enables radiologists to blend clinical interaction, procedural work, and imaging. It stands as an exciting domain within modern medicine, offering precise, targeted treatments for complex diseases and conditions throughout the body. Interventional radiologists seamlessly integrate various specialty interests, including gastroenterology, vascular surgery, neurosurgery, oncology, pain management, gynecology, and more. Moreover, they've pioneered treatment techniques using state-of-the-art technology like MRI, CT scans, fluoroscopy, ultrasound, and plain X-rays.
Their scope of practice encompasses a broad range of procedures such as biliary intervention, cholecystostomy, chemo and radioembolization of tumors, Radiofrequency ablation, Cryoablation and microwave ablation, balloon angioplasty, vascular stenting, aneurysm repair, embolization (e.g., of the uterine artery, fibroids, and pulmonary arteriovenous malformations), catheter-directed thrombolysis, placement of IVC filters, dialysis-related interventions, central venous catheter placement, percutaneous nephrostomy placement, ureteral stent placement, coeliac axis nerve blocks, spinal blocks, and more.
Interventional radiology is poised to play an increasingly significant role in the future of modern medicine. It offers cost-effective, minimally invasive treatments with shorter procedural and recovery times, sometimes yielding better patient-focused outcomes compared to many surgical alternatives.
In this podcast, my goal was to expand my knowledge about the remarkable world of IR. I am delighted to welcome interventional radiologist Dr. Yen Chieng to join us, covering many of the areas mentioned above. Yen has skillfully navigated challenging clinical scenarios, bailing many of us out more than once with his incredible yet measured skills and enthusiasm. Please welcome Yen to the podcast."
References:
Dr. Yen Chieng: i-med.com.au
Royal Australian and New Zealand College of Radiologists: www.ranzcr.com
Interventional Radiology Society of Australasia: www.irsa.com.au
Inside radiology: www.insideradiology.com.au
Episode 124. Lipids and Atherosclerotic Cardiovascular Disease with Dr Brett Forge (Part 3/3)
Lipids are essential for cell function and healthy metabolism however clinical analysis of a patient’s lipid profile also addresses one of the fundamental drivers of atherosclerotic cardiovascular disease responsible for 25 % of all deaths in Australia. Modification of abnormal serum lipid levels by lifestyle and pharmacologic intervention aims to achieve a healthy coronary circulation reducing new atheroma formation and stabilizing preexisting atheromatous plaques.
Lipids are essential for cell function and healthy metabolism however clinical analysis of a patient’s lipid profile also addresses one of the fundamental drivers of atherosclerotic cardiovascular disease responsible for 25 % of all deaths in Australia. Modification of abnormal serum lipid levels by lifestyle and pharmacologic intervention aims to achieve a healthy coronary circulation reducing new atheroma formation and stabilizing preexisting atheromatous plaques.
Atheroma develops when cholesterol esters and triglycerides enter the vascular intima inducing local inflammation. Macrophages recruited to the inflammation engulf the cholesterol esters by phagocytosis. Stuffed with cholesterol these cells are referred to as foam cells. The inflammatory cascade is accentuated and recruits more inflammatory cells some of whom perish over time and calcium deposition and fibrosis develops within a forming plaque. Plaque enlargement may distort vascular anatomy expanding into the vessel lumen impeding blood flow and inducing ischaemia however not all plaques impact in this way and even large developing plaques may form in a way that does not disrupt blood flow. Instability in a growing plaque however may lead to rupture and the initiation of an acute thrombotic event. Whilst hyperlipidemia underscores atheroma pathogenesis this complex and life-threatening process is also adversely influenced by cigarette smoking, hypertension, genetics, and poor glycaemic control.
Having a clear understanding of lipid physiology allows us to appreciate both atheroma formation and how cardiovascular risk may be modified. One of the key points is that as lipids are water insoluble and they must be transported in specialized vesicles. These are called lipoproteins when produced by the liver for entry into the circulation and micelles for entry into the biliary system and subsequently the gastrointestinal tract. Chylomicrons are the specialized vesicles produced by gut enterocytes to transport lipids from the digestive tract via lymphatics ultimately into the circulation.
Current Australian guidelines for lipid management recommend:
Total Cholesterol < 4 mmol/l if high risk, < 5 .5 mmol/l for general population
LDL < 1.8 mmol/l for high risk, < 2.0mmol/l general population
Triglycerides < 2 mmol/l
HDL > 1.0 mmol/l
Lowering LDL cholesterol by 1mmol/l reduces the incidence of major vascular events (non-fatal myocardial infarction, coronary death, coronary revascularization, or stroke) by about one fifth. With 11 fewer vascular events per 1000 treated over 5 years. Similarly, triglyceride reduction per 1 mmol/l is associated with about half this cardiovascular risk reduction.
Interventions that are utilized to modify the cardiac risk associated with lipids include:
Dietary manipulation
Pharmacologic modification of lipid synthesis or absorption
Multiple epidemiological studies have demonstrated a greater incidence of coronary artery disease linked to non-HDL cholesterol and elevated serum triglycerides as well as a protective benefit from high HDL levels which includes when triglycerides and LDL levels are high and a lowering of CVD risk even when optimal triglyceride and non HDL cholesterol levels are achieved.
Given the critical importance of cardiovascular risk modification it was a pleasure to invite cardiologist Dr Brett Forge to the following two episodes of this podcast to expand on this fascinating subject.
References:
Basic and Clinical Pharmacology 14th ed -Bertram G. Katzung, LANGE Books, Ch 35.
Principles of Medical Biochemistry, Eisenberg & Simmons,3Rd Ed, Elsevier Saunders, Ch 23
Ganong’s Review of Medical Physiology, Barrett et al,25 th Ed, LANGE Books, Ch 26
Dietary Fat and Risk of Cardiovascular Disease: Recent Controversies and Advances, Annual Review of Nutrition, Vol. 37:423-446, Wang & Hu
Dietary Cholesterol and the Lack of Evidence in Cardiovascular Disease, Nutrients 2018Jun;10(6):780 Ghada A. Soliman
To be a guest on the show or provide some feedback, I’d love to hear from you: manager@gihealth.com.au. Dr Luke Crantock MBBS, FRACP, is a gastroenterologist in practice for over 25 years. He is the founder of The Centre for GI Health, based in Melbourne, Australia, and is passionate about educating General Practitioners and patients on disease prevention and how to manage and improve their digestive health.
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Episode 41. Primary Prevention of Cardiovascular Disease with Dr John Counsell [Part 1]
Heart disease affects one in six Australians with an AMI occurring every 10 minutes and accounts for one in four of all deaths, so primary and secondary prevention are very important considerations in relation to any patient presenting with heart disease or at risk of heart disease. Risk factors including family history, lipid abnormalities, diabetes mellitus, hypertension, smoking or those with elevated BMI all need consideration. Whilst there have been significant controversies regarding lipids management and the use of statins, the evidence for their use, particularly in secondary prevention of heart disease is clear.
Heart disease affects one in six Australians with an AMI occurring every 10 minutes and accounts for one in four of all deaths, so primary and secondary prevention are very important considerations in relation to any patient presenting with heart disease or at risk of heart disease. Risk factors including family history, lipid abnormalities, diabetes mellitus, hypertension, smoking or those with elevated BMI all need consideration. Whilst there have been significant controversies regarding lipids management and the use of statins, the evidence for their use, particularly in secondary prevention of heart disease is clear.
To discuss this interesting subject in detail we are joined by the very experienced cardiologist and local mentor Dr John Counsell who covers:
· Primary prevention in cardiovascular disease [Part 1]
· Secondary prevention in cardiovascular disease [Part 2]
· Use of statins and ACE inhibitors
Please join me in this very interesting conversation with John Counsell.
Useful references include:
To be a guest on the show or provide some feedback, I’d love to hear from you: manager@gihealth.com.au
Dr Luke Crantock MBBS, FRACP, is a gastroenterologist in practice for over 25 years. He is the founder of The Centre for GI Health, based in Melbourne Australia and is passionate about educating General Practitioners and patients on disease prevention and how to manage and improve their digestive health.
Luke has been offering interventional endoscopy for over 22 years. He is passionate about patient care and managing digestive health. He is highly regarded for technical ability and his compassionate approach to patients.
Episode 40. Mole mapping and skin cancer surveillance with Dr Archie Xu
Non-melanotic skin cancers and melanoma are the most common cancers affecting humans. At least two in three Australians will be diagnosed with skin cancer before the age of 70 years and the risk is higher for men than women. Whilst basal cell carcinomas and squamous cell carcinomas are more common they are not as lethal as melanomas which are referred to as Australia’s “national cancer”. Indeed in 2020 it is estimated that 16,200 will be diagnosed with melanoma, that is one new case every half hour and a death every five hours.
Non-melanotic skin cancers and melanoma are the most common cancers affecting humans. At least two in three Australians will be diagnosed with skin cancer before the age of 70 years and the risk is higher for men than women. Whilst basal cell carcinomas and squamous cell carcinomas are more common they are not as lethal as melanomas which are referred to as Australia’s “national cancer”. Indeed in 2020 it is estimated that 16,200 will be diagnosed with melanoma, that is one new case every half hour and a death every five hours.
Skin clinics have emerged embracing mole mapping to assist in the diagnosis and management of melanotic skin cancers as well as non-melanotic skin cancers and we are grateful to have a conversation today with Dr Archie Xu who has been running a suburban skin cancer clinic for many years. He joins us to discuss:
· Mole mapping
· Dermoscopy
· Melanoma and non-melanotic skin cancer
I am most grateful to have had this discussion with Archie on a very important subject particularly relevant to our sun-drenched outdoor lifestyle. Please join me with Archie.
Useful references include:
To be a guest on the show or provide some feedback, I’d love to hear from you: manager@gihealth.com.au
Dr Luke Crantock MBBS, FRACP, is a gastroenterologist in practice for over 25 years. He is the founder of The Centre for GI Health, based in Melbourne Australia and is passionate about educating General Practitioners and patients on disease prevention and how to manage and improve their digestive health.
Episode 37. Why We Get Fat And What We Can Do About It with Professor Joseph Proietto
The western world faces a very significant obesity epidemic. In Australia, two-thirds of our population or 12.5 million are either overweight or obese and as a consequence may experience many medical sequelae including development of the metabolic syndrome, type 2 diabetes, cardiovascular disease, cerebrovascular disease, osteoarthritis and depression, contributing significantly to our health burden. In the first part of this series, we were joined by Joseph Proietto, Professor Emeritus at the University of Melbourne, the Department of Medicine at Austin Health and an endocrinologist specialising in diabetes and obesity to discuss why we become obese. Professor Proietto joins us again to guide us through a strategy of how to treat and manage obesity and direct our patients toward a healthy body mass index (BMI).
The western world faces a very significant obesity epidemic. In Australia, two-thirds of our population or 12.5 million are either overweight or obese and as a consequence may experience many medical sequelae including development of the metabolic syndrome, type 2 diabetes, cardiovascular disease, cerebrovascular disease, osteoarthritis and depression, contributing significantly to our health burden. In the first part of this series, we were joined by Joseph Proietto, Professor Emeritus at the University of Melbourne, the Department of Medicine at Austin Health and an endocrinologist specialising in diabetes and obesity to discuss why we become obese. Professor Proietto joins us again to guide us through a strategy of how to treat and manage obesity and direct our patients toward a healthy body mass index (BMI).
In this episode Professor Proietto discusses:
· The concept of energy balance
· The influence of exercise
· Dietary approaches including - Very low energy diets that induce a ketogenic state
· Medication used to suppress appetite and assist patients to establish an optimal BMI
Professor Proietto was extremely informative in this conversation navigating steadily and logically through a management strategy that may be applied to our patients experiencing obesity in primary practice. Thank you for joining me in this conversation.
Useful references include:
- www.darebinweightlosssurgery.com.au
- vermontsouthmedicalcentre.com.au
- Body Weight Regulation – Essential Knowledge to Lose Weight and Keep It Off by Joseph Proietto. ISBN 9781514497005. Published 12 August 2016, Publisher Xlibris.
- pubmed.ncbi.nlm.nih.gov
To be a guest on the show or provide some feedback, I’d love to hear from you: manager@gihealth.com.au
Dr Luke Crantock MBBS, FRACP, is a gastroenterologist in practice for over 25 years. He is the founder of The Centre for GI Health, based in Melbourne Australia and is passionate about educating General Practitioners and patients on disease prevention and how to manage and improve their digestive health.
Episode 36. Why We Get Fat with Professor Joseph Proietto
Up to two thirds of Australians are either overweight or obese as defined by body mass index (overweight: BMI 25-29.9, obese: BMI >30) with subsequent significant medical consequences including cardiovascular disease, type 2 diabetes, cerebrovascular disease (metabolic syndrome), osteoarthritis and depression. Becoming overweight and obese involves complex interactions between neurohormonal systems of the gut, neurobiology of the brain (particularly the hypothalamus) and leptin production from adipose sites coupled with an environment where there is an abundance of high glycaemic energy dense foods. Science demonstrates that the overarching controls of obesity are genetic (70%) rather than environmental (30%). Adoption studies relating to monozygotic twins demonstrate this. In view of the metabolic consequences of obesity, understanding why we get fat is extremely important to medical practitioners.
Up to two thirds of Australians are either overweight or obese as defined by body mass index (overweight: BMI 25-29.9, obese: BMI >30) with subsequent significant medical consequences including cardiovascular disease, type 2 diabetes, cerebrovascular disease (metabolic syndrome), osteoarthritis and depression. Becoming overweight and obese involves complex interactions between neurohormonal systems of the gut, neurobiology of the brain (particularly the hypothalamus) and leptin production from adipose sites coupled with an environment where there is an abundance of high glycaemic energy dense foods. Science demonstrates that the overarching controls of obesity are genetic (70%) rather than environmental (30%). Adoption studies relating to monozygotic twins demonstrate this. In view of the metabolic consequences of obesity, understanding why we get fat is extremely important to medical practitioners.
We are privileged to have a conversation in this podcast with Joseph Proietto, Professor Emeritus at the University of Melbourne in the Department of Medicine at Austin Health and an Endocrinologist who specialises in diabetes and obesity. Professor Proietto established the first Obesity Clinic in Victoria at the Royal Melbourne Hospital and is the head of Weight Control Clinic at Austin Health. He was the inaugural Sir Edward Dunlop medical research foundation Professor of Medicine and head of the Metabolic Disorders Research Group in the Department of Medicine, Austin Health, Joseph is on the executive of World Obesity and Chair of the Clinical Care Committee.
In this conversation he discusses:
· Why we become fat
· The role of genetic and epigenetic factors
· Some of the important hormones controlling satiety and hunger
Please enjoy this very interesting and informative conversation with Professor Joe Proietto.
Useful references include:
- www.darebinweightlosssurgery.com.au
- vermontsouthmedicalcentre.com.au
- Body Weight Regulation – Essential Knowledge to Lose Weight and Keep It Off by Joseph Proietto. ISBN 9781514497005. Published 12 August 2016, Publisher Xlibris.
- pubmed.ncbi.nlm.nih.gov
To be a guest on the show or provide some feedback, I’d love to hear from you: manager@gihealth.com.au
Dr Luke Crantock MBBS, FRACP, is a gastroenterologist in practice for over 25 years. He is the founder of The Centre for GI Health, based in Melbourne Australia and is passionate about educating General Practitioners and patients on disease prevention and how to manage and improve their digestive health.
Episode 35. The spleen and postsplenectomy syndrome with Dr Mohammed Al Souffi
The spleen performs a large number of important functions including processing and removal of opsonized pathogens, cellular maintenance, immunoglobulin production and the removal of effete worn out red blood cell. When removed either through trauma or for therapeutic indications the risk of overwhelming post splenectomy infection (OPSI) increases significantly; up to 58 times the general population in the setting of trauma and up to 1,100 times increased risk when for thalassaemia.
The spleen performs a large number of important functions including processing and removal of opsonized pathogens, cellular maintenance, immunoglobulin production and the removal of effete worn out red blood cell. When removed either through trauma or for therapeutic indications the risk of overwhelming post splenectomy infection (OPSI) increases significantly; up to 58 times the general population in the setting of trauma and up to 1,100 times increased risk when for thalassaemia.
The risk of OPSI is particularly high in the first 2-5 years for capsulated bacteria such as Strep pneumonia, Haemophilus influenzae and Neisseria meningitidis. To discuss the functions of the spleen and post splenectomy syndrome in more detail we are joined by expert and very affable general physician Dr Mohammed Al-Souffi, formally trained in Iraq and the United Kingdom before “walking free” to Victoria, where we are very fortunate to welcome him as a colleague and member of the Royal Australian College of Physicians. Mohammed joins us to talk about:
· Functions of the spleen
· OPSI
· Appropriate vaccination post splenectomy
· Management of thrombocytosis
· Spleen registry
I am most grateful to have Mohammed as part of this podcast series. I do hope you can join me in this conversation.
Useful references include:
Spleen.org.au
To be a guest on the show or provide some feedback, I’d love to hear from you: manager@gihealth.com.au
Dr Luke Crantock MBBS, FRACP, is a gastroenterologist in practice for over 25 years. He is the founder of The Centre for GI Health, based in Melbourne Australia and is passionate about educating General Practitioners and patients on disease prevention and how to manage and improve their digestive health.