AD Awareness Day UK Aortic Dissection

Music Music Clapping Thank you Gavin. It is a real honour for me to be here today. This is the second time I've been invited to this day to speak and of all the things I've been invited to, this is one of my favourite opportunities and it comes from the fact that actually this represents a journey for us and the journey in Bristol started in 2011 where we had three misdiagnosis of aortic dissection in 43 year old otherwise well men who we discharged and then we investigated. For radiologists, in that year we did 11 CT angiograms from the emergency department. Last year we did 458 and I put that down to the tenacity of the emergency department in Bristol who I'm lucky enough to work with and hopefully support from a radiological imaging point of view. So although I've been asked to talk about screening, it will come as no surprise to people that actually I'm going to talk a little bit about the acute situation because this This is what I'm really, really passionate about. Whatever you read, whatever you think, whatever you do, actually, what you need is a CT if you have thunderclap chest pain, full stop, okay? And people will say to me, well, actually, you have a chest radiograph first, and you were involved in the college, and you do the guidelines, and what do you think about that? And people would think that I would say, well, there are only a limited value in the diagnosis for acute aortic syndrome, but those are not my words. Those are the words from the consensus guideline from the European Journal of Cardiology in in 2014, so actually you ask yourself, why are we still doing chest radiographs? But that's fine, actually, because I'm going to ask you now to get involved. You are the audience, okay, and you are now a whole set of radiologists. These are two radiographs, and I'm pleased the lights are all on, because the lights are always on in the emergency department, so you can never see the films. And everyone will tell you imaging's easy, and everyone in this room will tell me imaging's easy, so you have not got your chance now. These are 43-year-old patients. One of these has an acute aorta. One of these is normal. Now, the worst type of radiologist, and I'll let you into a secret here, is the one that doesn't make his mind up. So you cannot abstain, all right, and I'm going to ask for a show of hands on which one requires a nine-hour operation and which one you're going to send home. So the film over here, who thinks this is acute aortic dissection? Hands up. Hands up. There's a lot of tentative, let me see what else is going on in my table, hands. They have to go up. Okay. Hands up. Who thinks this one is the acute aortic dissection? I can't believe Dr. Redfin's put her hand up to this one. Unbelievable. Right. Okay. So that is the aortic dissection. Who put their hands up? There's a minority. Who put their hands up? Brilliant. Keep your hand up. Who would be happy to send this man for a nine-hour operation on that examination alone? So you're all going to do something else. Not one of you in this room is happy enough to say that's an acute aortic dissection taken to theatre. So that's bad enough, but it gets worse. It gets much worse. I would have to say that it has to be a posterior anterior and absolutely proper chest radiograph to make the diagnosis because they are normal in four out of ten cases. Now most times you can only get a posterior anterior chest radiograph in the department and I challenge anyone here to get someone out of the ED, down to the radiographer, have a proper film and back within an hour. And Is that important? Well, of course it is, because actually this has a 1% per hour mortality rate associated with it. I do not believe, and I'm yet to see, someone confidently tell me that they've got an aortic dissection on a mobile or AP chest radiograph, so don't do them. Just don't do them. Now, these are CTs of acute aortic dissection, and I'm sure you can all see the abnormalities, areas in the aorta where there is a flap or something that's not right. How much easier is it to make that diagnosis? That's why we should go straight to CT in chest pain. The reason I tell you that is because this is the sensitivity. When we talk about screening, we want to know sensitivities and specificities, and you've got four imaging modalities. You've got echocardiogram, transthoracic echocardiography, you've got transesophageal echocardiography, you've got CT and you've got MRI. Everyone will tell you about the sensitivities of CT and MRI and they're good and they're specific so actually if you skip the diagnosis get the patient into the CT scanner but actually they can all see the aorta relatively well. So how do we take that forward, how do we move for that acute setting into the setting where we need to be thinking about screening because that's what we need to do and actually in Radiology, we're quite good at screening. We set up the breast screening program. We're involved in the colorectal cancer screening program. The questions are simple, because actually, radiology is not based on huge amounts of science. What do we need to see? What are you asking for the screening program to do? Who are we screening? Do we start at a very young population? Are we looking at people that we're going to screen throughout their lives? Because that's going to have an impact on how you, or what you want to do to deliver that screening program. And how often are you gonna subject that person to imaging throughout their lives? And these are key questions, and these are the questions that I think I would want to challenge you in the workshops this afternoon. But what about screening itself? Well, again, from the experience that we have in screening programs, we need to be safe with what we do. You can put people through a risk, but that risk has to be in proportion to the risk of the disease process itself. It has to be available, reproducible, easy to done, so that patients will comply with the screening process as it takes place going forward. And it actually has to answer a specific question so that you have a trigger point from your screening to know that you're going to do some action, because that is what you're looking for. What are we looking for? Well, we're looking for aortic size. And before, it used to be about screening for 55 millimeters. And now there's a consensus to say anything over 40 millimetres is defined as aortic dilatation. Now all of those imaging modalities will look at the aortic route. But we've already heard this morning that there's potential extra information, extra information that you need to think about. Are you looking for a bicuspid aortic valve? Do you want to look for coronary artery disease at the same time? Do you want to look for aortic disease? Are you looking at the descending aorta? You can't answer these questions once you've got a screening process in. you want to develop them and think about them before you get to that point. So what method? And I'm just going to run through a few and give you my thoughts as a radiologist on where we are to hopefully inform you for this afternoon. So trans-thoracic echo. Oh, it's playing brilliantly. I'm just going to go back. Bear with me. See if we can do that again. Now this is a trans-thoracic echo and you can see, if you look at the aortic route, which is just there, the flap that comes in, this is acute aortic dissection. I'll let you into a secret. Most clinicians don't like ultrasound. They don't like ultrasound because it's not as clear as cross-sexual imaging. Actually ultrasound is very good at what it does, but people don't tend to like it. That's the aortic route. That is the left atrium, that's the mitral valve, there's the aortic valve, and there's the left ventricle. So you can get very clear dimensions across here if that's what you're looking for. No information about the carotid arteries, not much information about the descending thoracic aorta which is going to be over here, but I'm just going to go back and run, if you can indulge me, and run that again and you can see that there is a flap that comes in and out. So you've made the diagnosis of aortic dissection. It's cheap, it's very cheap, it's very safe, it's widely available. I have seen an ultrasound probe that plugs into it like an iPhone. So this is the new stethoscope. will be how we look at people going forward. So ultrasound is out there. Do we want to do that? The negative, of course, is this only reviews the ascending aorta. If all you're interested in is that measurement, then this will reproduce it. What about CT? I've already said that CT is the mainstay of acute dissection imaging, and I absolutely believe that. But what about in screening? Well, these are two CTs taken from our institution this week. Actually, you can see this is the two of the 458. You can see the aortic view brilliantly here. You can see the aortic valve just in this region, the left ventricle. You can also get information about the coronary arteries. That's the right coronary artery coming off the sinus of Valsalva in that region there. There's the aortic root there, and there's the aortic valve. Very clear data that's absolutely there for taking. It's accurate, we know that. It detects calcification, we know that. It detects coronary artery disease. We also know that. It's available and it's reproducible. But what's the block? Now this is what I hear all the time and I'm about to explode myths again because actually, radiation. Oh my goodness, you can't put people through the CT scan app because it's radiation. Iodinated contrast, you've got to inject something. Oh my goodness, you're gonna radiate them and inject. Oh no. And clearly a lot of my colleagues read this. This is from the Daily Mail And I know that no one in this room reads the Daily Mail, but actually this is really important. CAT scan could trigger disease one in 80 patients. Nothing like a bit of responsible journalism to take it forward. So if I have four or five or six things, that's one in 10, eight scans of my life, one in 10, one in 10 chance of getting cancer. Oh my goodness. Is that accurate? Well, no, it's not. It's not accurate at all. If you look at the risks, and the FDA in the US, and you have to believe the FDA in the US, because this is where the litigation will go, will tell you the risk is 1 in 2,000 for a typical CT. 1 in 2,000. What does that mean? How do we quantify risk? Where do we go? And how can we put that into some degree of context? Because I don't understand what that means. Well, this patient with a paper... It wasn't 2005, that was a follow-up, but 1997, when it was first published, by Kenneth Kalman, ex-ex-chief medical officer, so very good author, right? Quantifies risk. I'll just bring your attention to the one at the bottom. One in 2,000 risk. Needing emergency treatment in the next year after being injured by a bed mattress or pillow. LAUGHTER Seriously? Dying from any cause in the next year is one in a hundred. That's a bit more sobering, actually, but it actually quantifies the risk that we're going to take. Now, I am not minimizing the effect or impact of radiation because, actually, that would be wrong of me to do that. What I'm saying is it needs to be risk-benefit quantification based on fact and understanding of what that risk is. What about MRI? MRI is a tremendous and expanding imaging modality. The two MRIs, again from last week in our institution, show on the left an MRI, and I'm sorry if you can't quite see it over here, of the ascending aorta with the aortic valve. This has been obtained by using flowing blood as the imaging modality, so there is no contrast in this. This is a contrast enhanced MRI, and you can see here are the origins of the great vessels, here's the ascending and descending aorta in the chest. So very good imaging modality. It's accurate. It's safe in pregnancy. No one can have an MRI in the first trimester of pregnancy. That's banned. But it's safe in pregnancy. You get the whole aorta and it's reproducible. The negative is it's a longer examination time. It will take you 30 to 40 minutes to have an MRI of your aorta. The availability in the UK still lags behind the majority of Europe in terms of the availability of scanning time. And as MR develops, it develops in every organ system and so there's pressure from every organ system to where you go. And actually there's claustrophobia. People talk about claustrophobia in MRI and it's recognised in 8% of patients and that's a genuine 8% and it's a genuine 8% who get to the machine and say I am not going inside that really tight tunnel. And I can sympathise with that very much actually because it is tight and it is a tunnel. So actually it is there, we have to think about that. but it's a very good and it's a very safe imaging modality. So in conclusion, and I want you to think about this to take it to the workshops this afternoon. In my mind, if you think you've got an aortic dissection, you need a CT and you need it now. But if you're screening, what do you do? Well, you need to know the question that you want to answer with the screening test. You need to know whether you're going to come back and want additional information, because that will be very helpful. then you need to balance safety and accuracy. And that's because all of these methods are reliable and they will all demonstrate to you very easily the aortic route. I would venture that cross-sexual imaging modalities add value. They will add something that you can't get from ultrasound alone. MRI is very safe and doesn't require contrast, but it comes back to the question that you're asking and what population you're asking that. Thank you very much for your attention. Thank you.