[MUSIC PLAYING]

JONATHAN GINNS: The presentation is obviously titled "Adult Congenital Heart Disease." And obviously, the reason for that is, I just started with Austin Heart a couple months ago, very excited to get the ACHD program up and running. And so we thought it'd be a good way to introduce things by going through the area. And, in particular, we'll cover a couple of cases that we've already seen here and then, at the beginning, also cover some of the general principles.

So as you're probably all aware, you've probably seen this slide ad nauseam, or similar slides, at various meetings. But now, we all know there's an increasing population of patients with congenital heart disease now who are surviving to adulthood, with over 90% of patients with repaired defects surviving beyond the age of 18 years. Now, this has led to a massively enlarging population so that now when you look at the overall population of children versus adults, what we think is there may be about a million children alive with congenital heart disease and 1-and-1/2 million-- and this was as of 2010, so the numbers have probably significantly increased from then. But there's definitely more adults alive with repaired congenital heart disease than children at this stage because of the enormous successes over the last half a century with surgical, interventional, medical, and other cares.

You may be aware that the adult congenital heart disease guidelines were recently updated in 2018. It'd been a long time coming. The last update to these guidelines was in 2010. And many of my colleagues contributed to this, and it's an important document. We will allude to it at various times during the presentation. And obviously, to get a fuller understanding of this area, reviewing the guidelines is worthwhile, and they go through lesion by lesion.

And certainly, there's been a significant improvement in the amount of data available to contribute to a really evidence-based practice in this area now given that very large population of patients. A couple of-- I thought we'd just cover a couple of the concepts that are novel in the newer guidelines. There's now a consideration of ACHD lesion complexity. And this has been divided into low-complexity, moderate-complexity, and high-complexity lesions. And this is meant to guide various things. But in particular, it's meant to guide referral to specialty clinics with low-complexity lesions, maybe once or even never at all seeing adult congenital specialists moderate-complexity lesions such as partial anomalous pulmonary venous repair, coronary anomalies, subaortic stenosis, coarctation, double-chambered right ventricle, Ebstein's, repair of tetralogy, Rastelli operations. Seeing adult congenital specialists intermittently and in the more high-complexity lesions, such as unrepaired cyanotic, congenital patients to transposition, Fontan patients, and truncus Eisenmenger patients, interrupted aortic arch patients more frequently seeing subspecialists.

Just a plug for the ACHD program, we are aware of data. This actually comes from Canada when they introduced the subsequently mandatory follow-up in adult congenital heart disease clinics, they did demonstrate an improvement in survival in these patients when they are a referral case. And you can see on the upper Kaplan-Meier plot, just the non-referral center care with improvements in mortality and outcomes in these patients.

And of course, an ACHD program doesn't involve just one person. As we say, it takes a village with cardiologists, surgeons, nurses, PAs, NPs, the involvement of other cardiac subspecialists, such as heart failure prevention, genetics pulmonary hypertension, and also noncardiac specialists, such as OB/GYN and hepatology. Obviously, the full suite of imaging modalities is important to have available with experienced readers and echo TEE, CTMR, and, obviously, excellent EP and cath services.

So I thought we'd just move on and do some interesting cases. In particular, there's a couple that I've seen while also being here, which I think were very interesting and illustrative of the area. So some of you may know this case. This is a gentleman that I met around about a month ago. And he had a history of repaired tetralogy of Fallot. At 2 years of age, he had a right, likely classic, BT shunt. And then at 5 years of age, he had a left classic BT shunt. And then at age of 11 years, he had a complete repair at the Mayo Clinic by McGoon.

He had no follow-up as a young adult, which is obviously common with these patients. He moved to Austin in the 1990s. He presented in 2010 with sustained one or more ventricular tachycardia and underwent a dual-chamber ICD placement out in Arizona. In 2018, he presented with CTI-dependent atrial flutter and underwent ablation. And more recently, he's been bothered by symptomatic paroxysmal a-fib that's been medically suppressed and considering ablation.

So just to cover what a BT shunt is, this is the type of shunt that this gentleman had, which is a classic BT shunt. And that's where the subclavian artery is actually detached and attached to the pulmonary artery. And this allows additional pulmonary blood flow in a patient who's got critical pulmonary stenosis with inadequate oxygenation.

In the last few decades, the classic BT shunt has gone out of favor, mostly because of inability-- its sort of unpredictable nature and also, obviously, that the fact that you lose blood supply to the upper limb. And it's been replaced by what's called a modified BT shunt, which is basically prespecified size Gore-Tex tube which is taken from the right subclavian or left subclavian artery down to the ipsilateral pulmonary artery and provides a predictable pulmonary blood flow. That operation is actually less done now, and most patients will just undergo a primary tetralogy repair. But the BT shunt is still used in other situations where the patient can't undergo a full repair.

So you'll probably recall, this is a tetralogy repair. You can see the overriding aorta over what was a ventricular septal defect, which is now closed with a VSD patch. And then across the stenotic pulmonary valve, most frequently a transannular incision is placed with a patch to enlarge the outflow tract. And these create some of the complications long term.

So this patch here can obviously damage the pulmonary valve and lead to pulmonary regurgitation. The VSD patch can lead to heart block. And both of these can lead to scar and atrial and ventricular arrhythmias.

So Mr. J.M. Has experienced worsening shortness of breath on exertion for the last six months. He's now short of breath with minimal activity. He gets intermittent palpitations, corresponding episodes of a-fib, he denies any edema, abdominal swelling, and has had no neurologic events. He's also overweight. We think he has hypertension, and he's anxious. He works as a radio consultant and lives in Austin with his two sons.

On examination, importantly to note here, he's comfortable at rest. Saturations are normal, so he doesn't have any evidence of right-to-left shunting. His blood pressure is diminished in both upper limbs because of the prior classic BT shunts, and he narrowed pulse pressure on both sides. So both of these blood pressures are completely unreliable. So if he turned up to the ER, you wouldn't know if he was in shock or not because the BT shunt basically precludes you from measuring the blood pressure, essentially. So his real blood pressure's most accurately represented by the blood pressures in his foot, which is 160 over 90.

He's had bilateral posterior thoracotomies and a midline sternotomy. His jugular veins pressure is elevated. And he has a short systolic murmur at the left upper sternal border, radiating to the back on the left. And that radiation to the back usually suggests that there may be pulmonary artery stenosis on that side. And he has a short, low-pitched diastolic murmur, which is consistent with pulmonary regurgitation.

His chest is clear, abdominal exam is normal, and he's got no edema. He's on sotalol, aspirin, and lisinopril. This is his ECG, and you can see he's in sinus rhythm with a prolonged AV delay. That may be due to the VSD patch.

And he's got the classic appearance post-tetralogy with a broad right bundle branch block. And this wide right bundle branch block probably predisposes to ventricular tachycardia and certainly, in most cases that I see with a BT, they have a wide QRS complex.

These labs are essentially normal with normal synthetic function of the liver. So this is his echocardiogram. And you can see his right ventricle is significantly dilated highlighted here, but the function appears relatively preserved. LV function appears pretty normal. And you can see a VSD patch here and his ICD lead.

This is an echo looking through his outflow tract. And you can see this is the blue forward flow. And then he's got a very broad regurgitation jet of pulmonary regurgitation. Obviously, this is consistent with basically wide-open PI. So you're looking for this broad jet. And if we had a PW Doppler through here, very short pressure half-time. And if you see this, this is obviously clearly consistent with severe pulmonary regurgitation.

We measured his pressure across the tricuspid valve, and his RVSP is at least 50 plus his right atrial pressure. So it's suggesting that he's got significant elevation of his RV systolic pressure. Now, this is abnormal. And if you've got this without any pulmonary stenosis, it suggests that there's some sort of obstruction at the level of the pulmonary vasculature.

And then last but not least, he has mild aortic regurgitation. And you can also see the VSD patch here. Aortic regurgitation is common as these patients get older due to aortic dilatation.

So we went ahead and did a cardiac catheterization. This is a nice picture showing the occluded right subclavian artery on the right-hand side with a tiny little bit of residual flow here. So this was closed off at the time of his tetralogy. This was the BT shunt, but then it was closed off at the time of his surgery.

And on the left side, he's got the same thing. So his subclavian artery here is occluded, and you can see some tiny little collaterals.

This is his main PA gram. And you can see there's a couple of things here, very vigorous contractions of the right ventricle, very pulsatile pulmonary artery here. And that's obviously consistent with his pulmonary regurgitation. You can see the right pulmonary artery lighting up quite well. But interestingly, you can't see the left pulmonary artery at all. And it's almost as if there's no flow going to the left lung.

And when you see this, it usually means something. So we went ahead and placed the catheter out in his left pulmonary artery. And lo and behold, he does have a left pulmonary artery, but he's got a very severe LPA stenosis. And you can actually see a little bit of retrograde filling of the old BT shunt.

So the location where the BT shunt was attached to the left pulmonary artery, he's developed a very severe LPA stenosis. And because of that and the way the pulmonary vasculature works, he probably is getting very minimal blood flow to the left lung. Most of his blood flow is going to the right lung. And that's at least part of the reason why his PA pressures are elevated.

And you can also see the remainder of the pulmonary vasculature looks quite abnormal here, with very ectatic vessels that look like he may have vascular disease. And this is a common appearance after someone's had a longstanding BT shunt. And remember, he had his BT shunt for almost 10 years, had at least his first one-- he had-- sorry, he had three years, and then he had the other one for about six years before he underwent his final surgery. And the flow associated with the BT shunt can obviously lead to pulmonary vascular disease as well.

So this is his cardiac cath numbers here. You can see his right atrial pressure is 20, so it's severely elevated. Filling pressure is on the right side. His cardiac output is normal. His RV pressure is 66 over 19. And his PA pressure is 65 over 22. So this is essentially a ventricularized pressure tracing in the PA. And this presentation is severe LPA stenosis, and he's got a 30-millimeter gradient from the main pulmonary artery to the left pulmonary artery. And he's got an elevated wedge pressure.

The cause of the elevated wedge pressure, it may be due to his longstanding hypertension. It may also be a secondary effect from his severe PI, eventually causing diastolic dysfunction on the left side. You can see he doesn't have any evidence of a significant shunt starting at the SVC 57 and going to the PA 59. And his aortic sat is a little bit low.

This is his CAT scan. And the reason this was done was actually to look at his pulmonary arteries. But we can also use this to look at the dimensions of the pulmonary outflow tract. You can also see his aortic root is severely dilated at 4.9 centimeters. You can see the LPA-- this is his main pulmonary artery, and this is his left pulmonary artery-- you can see this stenosis. But also, we take measurements of the outflow tract to see if he's suitable for a transcatheter pulmonary valve replacement. I'll show you why in a second.

So the management for this gentleman involves undergoing a pulmonary valve replacement. And he is also, prior to that, going to have an LPA stent. You can see this is what a PA stent looks like. And these are usually balloon-expandable stents, open-cell, that are placed in the pulmonary arteries. And the PAs are actually usually pretty compliant, and they'll dilate relatively straightforwardly, and it should be a relatively low-risk procedure.

And the reason we elected-- I'll just go back to the PA gram. The reason that he elected to do this in the cath lab rather than surgically was because of how far out this LPA stenosis is. It's almost all the way out of the hilum. And this is usually pretty difficult for the surgeons to actually attack.

So he's going to get an LPA stent followed by pulmonary valve replacement. And it's important to remember, pulmonary valve replacements are always going to be a bioprosthetic valve. We don't use mechanical valves in the pulmonary position because the very high rate of thrombosis. So they'll either get a tissue valve or a homograft pulmonary valve replacement. And obviously, more recently, transcatheter pulmonary valves, in particular for valve and valve situations, have become more popular.

So this brings us to some of the late sequelae after tetralogy repair, which I'm sure most of you are aware of. But certainly, pulmonary repaired is extremely common, with more than 2/3 having at least one pulmonary regurgitation. Tricuspid regurgitation, usually secondary to PI. Ventricular tachycardia, atrial flutter is the most common atrial arrhythmia.

Aortic dilatation-- this occurs in more than 50% will have an aorta greater than 4 centimeters. However, it turns out that aortic dissection is extremely rare in these patients. And then late-stage congestive heart failure-- though CHF is actually, whilst it's present to a mild degree, it actually forms a very small component of patients-- tetralogy patients are pretty small component of those requiring transplant with adult congenital heart disease.

So what do I do for the follow-up tetralogy patient? Most patients will get a yearly echo focused on a pulmonary valve-- like we said, the tricuspid valve. You look for residual VSDs. You want to try and see the pulmonary arteries from the suprasternal view and also look at the aortic ridge to see how dilated it is and to see if there's any associated aortic regurgitation.

I usually do an MRI every two to three years on these patients, mostly to document any change in right ventricular volumes. Obviously, if the patient's not appropriate for an MRI because they've got a device or because they're claustrophobic, a CT is a reasonable alternative.

Arrhythmia monitoring and risk stratification is very important in these patients. Particularly as they get older, VT seems to be more and more likely. When I first started about eight or nine years ago, I didn't think this was so common. But certainly, as time has gone by, we've seen more and more patients present with VT. Stress testing is important to get an idea of their exercise capacity, because most of them will underestimate-- will overestimate their exercise capacity. And genetic testing for 22q11 is an important thing to do.

In terms of pulmonary valve replacement, this is from our guidelines. This is obviously a very busy slide talking about the-- if you have any of these two criteria, which is a multitude of criteria, or other hemodynamic abnormalities. But we'll just kind of cut to the chase.

And the important things to take home from that slide are if the RV volume by MRI is greater than 160 mL per meter squared, with the normal volume being about 80 to 90 mL per meter squared, so roughly double that, or the systolic volume is greater than 80, where the RV is more than double the size of the LV, if there's evidence of systolic dysfunction of either ventricle, if there's a reduction in exercise tolerance, or if there are secondary effects, such as arrhythmias or tricuspid regurgitation, then you should think about pulmonary valve replacement.

I thought I'd just bring this up. There is a newer transcatheter valve that's become available. And actually, the trial rolled out pretty quickly, and they placed a couple of valves up at Columbia, where I worked before, about a month ago. Their first two, they placed about a month ago. This may become a new option for these patients. It's called the Alterra device. It's from Edwards. There's a competing device from Medtronic as well.

But this device, just to give you an idea, is designed to fill up that very large outflow tract because most of these patients have a very wide outflow tract. And even with a 29-millimeter Edwards SAPIEN valve, that's too big for that. And also, the outflow tract is usually too compliant. And so they've designed this basically kind of pre-stent that will be placed into the outflow tract that's self-expanding. And then after that's placed and is stabilized, inside that, an Edwards valve can be placed. And so this may be coming, obviously, if the trial is successful, and they have good outcomes, in order for a patient like this to potentially avoid surgery.

And this is how it's placed. You can see the pre-stent here. It's pretty faint. And then a valve, Edwards valve, is placed inside. And this is the appearance on echocardiography.

Obviously, VT risk is an important thing in these patients. And the main risk factors are older age, systolic dysfunction of the left ventricle, QRS with greater than 180 milliseconds, non-sustained VTE on Holter monitor, so these patients who get a Holter or event every one or two years, extensive RV fibrosis by MRI. And when one of these is present, it's now considered reasonable 2a by the recent guidelines to do an EP study to look for inducible VT. And if they have inducible VT, then to get a defibrillator.

So the next case we'll move on to is also a patient that I saw just a few weeks ago. He's a gentleman who's 50 years old. Sorry I didn't put his age in here-- who had a coarctation repair at age 4 at UCSF. Unfortunately, we didn't have his surgical reports, but it was complicated by LV perforation and paraplegia.

He moved to Austin about 10 years ago. He's had longstanding hypertension. And he also had a device ASD closure 15 years ago.

And this is just an MRI. This is not his MRI, but this just an MRI just to remind us all what a coarctation looks like. And this is an MRA with gadolinium. And you can see ascending aorta here, arch, descending aorta, and then a very severe coarctation here just distal to the left subclavian.

So this is a negative coarctation. This is not him, but just to remind us all. And then distal to that, there's often ectasia of the descending aorta. But these patients will frequently have a bicuspid valve and a dilated aorta, ascending aorta, as well.

There are different types of coarctation repair. I think this gentleman had an end-to-end anastomosis because of the appearance. And this is the most common procedure. So they resect out the coarctation and then bring the two ends back together like a sausage.

There's an interposition graft. This is infrequently done, though some adults will get this procedure because it's actually difficult to mobilize the aorta. A patch angioplasty-- again, this is infrequently done now but was more frequently done in the past. And this can be complicated by pseudoaneurysm formation.

And the subclavian turndown flap-- actually, we had a lot of these in Australia. I see this less in the US. With these patients, we're basically missing their left subclavian artery. So you can't check the blood pressure in the left arm. So there's multiple different types of coarctation repair.

So his hypertension has become more difficult to control. He's now short of breath with moderate activity. He had some atypical chest pain. And certainly, these patients, you must think about coronary disease because of the hypertension. He's got normal renal function and no neurological symptoms. Past medical history otherwise, apart from the paraplegia, is pretty unremarkable. He's a non-smoker, no alcohol.

So importantly, his examination, he's comfortable at rest, wheelchair-bound, saturations are normal. But what's the most important thing here is to check the blood pressure in all four limbs. So his blood pressure in his right arm is 140 over 80. His left arm is 140 over 85. So that makes that subclavian flap unlikely.

And then in his right foot, he's got a 20-millimeter gradient from arm to leg. As I'm sure you're all aware, the blood pressure in the foot should be higher than the arm. So if you've got a 20-millimeter gradient from arm to leg, that suggests significant coarctation.

He's got a left posterior thoracotomy scar. He's got a 1 on 6 systolic ejection murmur consistent with his bicuspid aortic valve. And he's got reduced lower limb pulses. He's on amlodipine and losartan.

His echocardiogram demonstrates normal LV size and systolic function. He's got moderate aortic incompetence and mean gradient through his coarct of 20 millimeters of mercury. So it's the mean gradient that we're most interested in because this correlates well with catheter-based measurements.

So this is his MRI. And so this gentleman actually was very, very anxious because of his previous complication of his catheter procedure that he didn't want to have any contrast. Actually, when he came to see me in the office, his blood pressure was more like 180 because he was so incredibly anxious because he thought he was about to go for a CAT scan.

So we reassured him, actually, that he can get an MRI without getting any contrast. And this is a study that can be done with very good resolution. And without any contrast, you can get beautiful images of ascending aorta arch and descending aorta, as [INAUDIBLE] can testify.

So this is the area of the recoarctation. And it's right here, just distal to his left subclavian. Importantly, as well, you can see his ascending aorta is a little bit dilated, about 3-and-1/2 centimeters. And his arch is pretty small. So this is really common in these patients to have a hypoplastic aortic arch. And they generally now try and deal with this at the time of surgery by sort of filleting open the arch when they're doing a repair. But this gentleman looks like they basically just cut the stenosis out and pulled the two ends back together, because he's still got pretty significant narrowing through his arch. And this can also contribute to hypertension because at about 1.5 centimeters, that's pretty small.

His coarctation is about 1 centimeter in diameter, and his descending aorta is about 2-and-1/2 centimeters, which is-- it's pretty normal. Some of these patients will get aneurysm multiplication of the descending aorta and can get dissection there. So he's got a hypoplastic arch and a significant recoarctation. This is just a cine image through the area. And you can see the jet of-- [INAUDIBLE] come up-- through this area, you can see a jet of stenosis here, which suggests he's got a significant recoarctation.

And then I actually just threw this one in as well. This is not him, but you can see this is what a subclavian turndown will look like. And basically, it looks like a big aneurysm at the area where the coarctation repair was. And he's missing-- and this patient is an old patient of mine. And they're missing the left subclavian artery.

So a big aneurysm and then a renarrowing and then a normal descending aorta in this particular patient. And this is what a subclavian flap turndown looks like. So each one of these repairs looks slightly different on imaging. And obviously, we prefer MRI in these patients because most of them are young. And repeated CT scans would involve a significant amount of radiation exposure.

So when do you intervene on a native or recurrent aortic coarctation? So obviously, when there's a native severe coarctation, it's pretty obvious. But the recurrent or recoarctation is the thing that we most typically see in these repaired adults. So if there's an upper to lower extremity resting peak-to-peak gradient of greater than 20 millimeters of mercury or a mean Doppler systolic gradient echo greater than 20, or if there's a gradient greater than 10, plus they've got decreased LV systolic function, significant AI, or evidence of collaterals.

So there's actually not that much of a gradient that needs to be had in order to think about reintervening in these patients. And part of the reason is obviously, this should be coupled with either a CT or an MRI that demonstrates recoarctation. If you haven't got a narrowing, then you need to find an alternative explanation for the gradient. But when there's a renarrowing and either a 20-millimeter gradient or a 10-millimeter gradient plus one of these other complications, you should think about fixing it.

So the best evidence to proceed includes patients that have got high blood pressure. They've got an upper-lower extremity blood pressure gradient echo evidence of a gradient, and anatomic evidence, which this gentleman all has. And then multiple factors to help you decide whether or not surgery or stenting is optimal, but in patients where there's recoarctation because they've had childhood surgery, stenting is performed in greater than 95% of situations because usually, it's actually very tricky to get back in there and operate because there's a lot of collaterals, and the surgery can be complicated by bleeding and neurologic complications, and stenting has become the absolute preferred way to fix recoarctation.

So this gentleman, because of the proximity of the recoarctation to his left subclavian, is actually, with the vascular surgeon, going to undergo a left subclavian to carotid bypass operation. And following that, he'll undergo a stent. And this is just showing you how this is done. Basically, a pigtail catheter takes some nice pictures, figure out where the coarctation is, and then place a stent across the recoarctation.

It, more frequently these days, is done with either a covered stent or some sort of endograft, mostly because of the feared complications of this procedure, which albeit are uncommon, are devastating when they occur and can be very difficult to recover from. So our biggest fear used to be that these patients would dissect during the procedure or, in particular, rupture during the procedure. It's actually pretty uncommon, but when it occurs, it's a very bad situation. And so often now, primarily a covered shunt is used rather than an open-cell stent. And as I said, occasionally, sometimes, and I think Dr. [INAUDIBLE] also does this with an endograft, that's obviously an extremely good way of doing this as well.

Obviously, the branch is going to be occluded at the time of doing a covered stent, and so thinking about revascularizing prior to that is an important thing to think about. And obviously, insufficient expansion with a residual coarctation of the procedure used to be more of a concern when using open-cell stents because sort of using very high pressures obviously was a risk factor for rupture, and so people were a little less aggressive than they are today in terms of reexpansion. But now with covered stents, these patients can usually be restored to a normal-caliber aorta, and so there shouldn't be any significant residual coarctation after the stent procedure is done. And as I said, surgery is not a great option generally for these patients.

So when I see a coarctation patient, I'm sure that I always measure both upper limb pressures and also lower limb pressures and see if there's a significant gradient. All of these patients, you get an echocardiogram to assess if they've got a bicuspid aortic valve, a VSD, and other associated issues, such as a dilated aorta. I prefer an MRI of the chest, an MRA, MRI, or a CT if they're unsuitable for an MRI, again, mostly for the radiation exposure.

We now suggest-- it's a 2A or a 2B recommendation-- all these patients that have an MRA of their brain to screen for perianeurysm, particularly if they're older, and if they are hypertensive. Consider exercise testing to see if their blood pressure responds. And obviously, aggressive management of their blood pressure, lipids, and other risk factors, because coronary disease and cerebrovascular disease are the biggest complications.

So this is obviously just from the guidelines. And that basically echoes what I said that I do, that recoarctation occurs in about 10% to 15% of these patients. Some can get aneurysms, pseudoaneurysm at the repair site. Upper body systemic hypertension is very common in these patients. More than a third of them will have hypertension, even in the presence of-- even in the absence of recoarctation. But if you see high blood pressure, you must look aggressively for recoarctation with multiple imaging modalities.

And they suggest that about 10% of patients can have evidence of perianeurysm. Actually, that has not been my experience. I've done lots and lots of MRA brains in these patients, and I haven't seen that. But this is what other centers have seen. And obviously, hypertension, hypertension, hypertension.

So on the next case, this is a patient of mine from New York. But it's an interesting case because it tells us a little bit about long-term complications in adult congenital heart disease. So Mr. J.T.-- and it's not who you think it is. It's not one of the cardiologists at Austin Heart, thankfully.

So I first met him, he presented with fevers and said that he'd had some sort of heart surgery in childhood. And he'd had ongoing swinging fevers for several months now. Otherwise, he was well, but he would get fevers, feel awful for a while, and then he would get some antibiotics and feel better, and then the fevers would come back. And he had a history of a D-TGA BSD PS and had a Rastelli operation and a redo RVPA conduit at age five years.

So this is his echocardiogram, looking at his right ventricle here. And you can see a little bit of a tricuspid regurgitation. And then we measured the gradient, how high his RVSP is. And that's at least 79 millimeters of mercury, plus his RA pressure.

Now, if you get this sort of pressure, this is obviously extremely abnormal. And these patients, again, should not have pulmonary hypertension. So if you've got this sort of gradient, it suggests that they've probably got significant obstruction across the RV to PA conduit.

And this is his short axis of his RV and LV. And you can see the systolic and diastolic flattening of the septum here, suggesting very high RV diastolic and systolic pressures. And this is the RV to PA conduit here. And you can see it appears thickened where the leaflets are moving. And there is turbulence here at the level of the valve, some mild pulmonary regurgitation, and then a peak gradient through the valve of 70 millimeters of mercury and a mean gradient of 42. And this is obviously consistent with severe obstruction.

So in this patient now, he's got a fever and severe obstruction across his pulmonary valve. It always makes you think that this is potentially endocarditis. And in my experience, pulmonary valve endocarditis frequently presents with severe obstruction, often because they certainly can have emboli. And you can see-- his plain CT chest here, you can see a couple little embolic lesions, in particular this kind of little necrotic one here in the left lower lobe.

And we also got a gated CT. And this is-- through the outflow tract here, you can see that he's got thickening of the pulmonary valve. And this was called pannus by the unsuspecting radiology, but this is actually all infected material.

And so CT can be very helpful in these patients, gated cardiac CT can be very helpful in these patients to look for vegetations, because MRI sometimes suffers a bit because of the fact that there will be a lot of artifact due to the valve. And so CT can be very helpful to see the vegetations and support the diagnosis of endocarditis.

So he was interesting. He had inflammatory markers that were not especially elevated. And his globulins, though, were extremely high. His blood cultures were all negative, AFBs were negative, HIV was negative, Bartonella was negative, histoplasma. And luckily, actually, it turned out that his blood was sent away for testing, and they did look for PCR for Q fever. And eventually, we did titers, and he had extremely elevated Q fever titers.

And so it turned out he'd been in Afghanistan a couple of years earlier and had a meal where they had been exposed to goat. And so we think that he probably got it from-- Q fever obviously comes from-- butchers will get it, abattoir workers, in particular in Australia, will get it. But it's a very low-grade organism that will sort of build up very early. And that's why he developed such severe obstruction.

So pulmonary valve endocarditis-- and in general, obviously, we've got to think of endocarditis in all these adult congenital patients. We think there's an increasing incidence of this. And certainly, when I first started, this is not something that we'd seen a lot of. But certainly now that we're doing so many pulmonary valve replacements, both surgical and transcatheter, I think the fact that these valves are on the right side of the heart means that they're much more likely to be exposed to skin organisms and oral organisms without being filtered out through the lungs.

And so if you do see someone with a fever, always think about whether on the pulmonary valve could be infected, even though I think 10 years ago, the incidence of-- if you'd asked any of my colleagues the incidence of pulmonary valve endocarditis, we would have told you it was vanishingly rare. We now see cases of this, like, two or three times per year. And certainly, we became aware of this after the Melody valve came onto the market that, with obviously very aggressive screening and follow-up with these patients, it turned out that a significant number of them were getting endocarditis.

There was a bit of a feeling from the surgeons maybe there was something wrong with the Melody valve. But I think that it's turned out that just any pulmonary valve bioprosthesis can get infected. And certainly, we see the rates seem to be equivalent in surgical pulmonary valves and transcatheter pulmonary valves. Wider range of organisms, obviously-- they frequently present with severe stenosis, embolic phenomenon, and obviously frequently need for surgical intervention. You don't want to put a transcatheter valve inside an infected pulmonary valve.

This is just one paper from one group just showing the incidence of pulmonary valve endocarditis over 30 years, follow-up after surgical pulmonary valve replacement. And it's not high. But we're talking sort of 10% to 15% of patients ended up with endocarditis. So it's not that infrequent.

This gentleman underwent surgery. And I think the most revealing bit about this was the fact that there's a phlegmon circumferentially around the most distal aspect of the RV to PA conduit in the area of the implanted pulmonary valve. And this was cultured. He had mediastinal adenopathy. And the whole thing had to be removed, and it was extremely infected. And then he got a pulmonary homograft inside where the old-- the Hancock valve had been taken out. And so this was the appearance afterwards. And this is obviously a normal appearance of a surgical pulmonary valve replacement.

So RV-PA conduit is obviously very common in our adult congenital population. Importantly-- I mean, I was guilty of this in the past as well, is I kind of would tell these patients they didn't need to be on any sort of anticoagulation. But now, again, since the advent of the transcatheter valves, everyone will get aspirin. And I now make sure I put all my patients on aspirin. I certainly feel personally that this decreases the incidence of thrombosis on the valves, obviously very much like in the aortic position, I think we're all aware of the issues with aortic bioprosthetic thrombosis. And I think the same probably occurs in the pulmonary valve. So all these patients should at least be on aspirin.

And I guess the other thing, while we're on the subject of right-sided valves, is to think about when someone does a bioprosthetic tricuspid valve, I always now think about giving patients with bioprosthetic tricuspid valves three to six months of Coumadin, if not longer, because the incidence of valve thrombosis is extremely high in bioprosthetic tricuspid valves, at least in the short term. In the long term, it's low. And obviously, we don't use mechanical valves in either of these positions generally. All these patients should get prophylactic antibiotics with dental procedures.

And then I guess the other slide that I wanted to bring up here was thinking about endocarditis prophylaxis guidelines in adult congenital heart disease. And it's a little bit different to everybody else. So those with previous endocarditis should get antibiotic prophylaxis with dental work, those with prosthetic valves, patients within the six months of placement of prosthetic material, such as even like an ASD closure device, patients with residual intracardiac cardiac shunt. So usually, it's like a VSD that's got a residual defect adjacent to the bioprosthetic material, like the VSD patch, and all those patients with uncorrected cyanotic heart disease. And I pretty much do it in all of the cyanotic patients. In particular, a lot of the Fontan patients, I still give antibiotic prophylaxis because they're high-risk for endocarditis.

So just one more case to talk about here. This is a 32-year-old married teacher who had a history of tricuspid atresia, underwent a BT shunt at age six months, a bidirectional Glenn operation at three years, and a lateral tunnel Fontan at age five years, had a epicardial permanent pacemaker for sinus node dysfunction, presented with one atrial flutter with one-to-one conduction and syncope and underwent successful radiofrequency ablation, is treated with warfarin and then transitioned to Xarelto, which we use in a lot of these patients now because of compliance issues, and now presents to establish care with recent onset of abdominal distention and fatigue.

So I thought we'd just briefly touch on the different sorts of Fontan operations that are done for patients with single ventricle. So this is the classic Fontan, where the right atrial appendage is attached directly to the pulmonary artery. And this is the bidirectional Glenn that we talked about, where the SVC is attached to the right pulmonary artery.

There was a classic Glenn with ASVC, just went to the RPA. We see that less commonly. It's a kind of very old procedure.

The bidirectional Glenn is what everyone gets these days. The lateral tunnel Fontan, you'll see a lot of these now in their 20s and 30s. And this is where a tube is attached from the inferior vena cava through the right atrium up to the inferior portion of the right pulmonary artery. And again, they get a bidirectional Glenn.

And the most common procedure these days, an external conduit Fontan-- and the reason for the transition from here to here is basically the thought that this might decrease the arrhythmia risk. And that's panned out to be true because of the fact that there's less operation and therefore less scar tissue in the right atrium. And these patients are much less likely to have atrial arrhythmias, though they're not completely free of them.

And most of them are now left with what's called a fenestration. So there'll be a little hole either made in the lateral tunnel or a little hole made in the conduit to allow some blue blood to not go through the lungs and go directly into the left side. That comes at the cost of low oxygen saturations. But it probably decreases your mean Fontan pressure, which probably helps the liver.

So just the physiology-- this is what we look like. So if you've got a right ventricle, it's going to be pumping from a low filling pressure, increasing the pressure, the PA pressure, which will go through the lungs and down into the left ventricle. In these Fontan patients, they don't have a right ventricle, so you need to reach that mean PA pressure through basically shear congestion on the right side.

This is probably the precursor of a lot of the complications in these patients, because their Fontan pressures will frequently be 15 or above. And certainly, a lot of the adults, you will see when you cath them, it can get up to 20, even 25. And that pressure is constantly what the liver is exposed to, leading to a lot of complications.

They also have preload failure because these low pressures, they can't particularly augment with exercise. They can go up to 20 or 30 or 40 with exercise, but they tend to underfill the left side of the heart. The other thing that's important to think about is these patients very infrequently get pulmonary edema. So if they ever present with lung infiltrates, pulmonary edema is uncommon.

This is his ECG showing an atrial paced rhythm. This is his echocardiogram. And you can see he's got a single ventricle here. And this round structure in the back of the RA here is the lateral tunnel. And he's got tricuspid atresia. He's got an atretic tricuspid valve but a normal mitral valve.

So labs were hemoglobin was a little elevated because of cyanosis. Platelet count was a little bit low. Electrolytes were normal. His alk phos, though, was significantly elevated. And unfortunately, his AFP was severely elevated.

So he underwent a CT scan of his liver. And this is one of the dreaded complications after the Fontan operation. This is hepatocellular carcinoma. And we first started-- I, personally, first seeing this five or six years ago. And certainly, the incidence of HCC, we've now realized, is actually pretty significant in these patients. And obviously, this is the worst outcome when you've got evidence of ascites and a very large mass with thrombosis of the hepatic portal vasculature.

So hepatocellular carcinoma appears to be associated with what's called Fontan-Associated Liver Disease, FALD. And Fontan-Associated Liver Disease is most likely due to what we just talked about in terms of the physiology, with congestion on the venous side backing up, which damages, basically, the hepatic parenchyma, and also the lack of forward flow. As we said, these patients have reduced cardiac output due to preload failure, and often they have systolic and diastolic function of the ventricles. So both lack of inflow, but I think most of us now think it's probably the outflow problem that's the issue.

And this can lead to cirrhosis. And like any form of cirrhosis, we then see regenerative nodules. And subsequently, these patients can develop hepatocellular carcinoma. And this tends to occur very late. So more than 15 years after the Fontan operation, you'll start seeing ascites, esophageal varices.

Some will eventually develop hepatic encephalopathy, increased RNR, low platelets, low albumin. Low albumin, you can also see in something called protein-losing enteropathy, and fibrosis on biopsy. And certainly, we now are extremely aware of this issue, and we pay close attention to these patients because 30 years out from the Fontan operation, at least half of these patients have evidence of advanced liver fibrosis.

So this is an array of ultrasound images across the top and MRI images across the bottom. And this is going from 5 years, 15 years, and then 25 years after the Fontan operation. So the ultrasound images aren't great, but that's often what you get with ultrasound. But five years after the Fontan operation, most times, the hepatic parenchyma looks pretty normal. Maybe 10, 15 years out, you start seeing some coarsening. And then more than 15 to 20 years out, you'll start seeing a regular profile of the liver consistent with cirrhosis.