Hello, and good afternoon. My name is Dr. Mark Anders. I'm one of the critical care physicians at Texas Children's Hospital Houston, Texas. I do work here in the adult and pediatric cardiac ICU units. I also do serve for the Extracorporeal Life Society Organization as Scientific Oversight Committee Chair, but I do not have any conflict of interests. And I would like to present to you today, during this talk, the use of mechanical circulatory support devices in patients with adult congenital heart disease. In this talk, I would like to present to you the increasing prevalence and incidence of ACHD population, the specifics and the etiology of heart failure, the use of extracorporeal membrane oxygenation, temporary ventricle assist devices or durable ventricle assist devices as mechanical circulatory support in those patients. There's definitely a strong need for more scientific research, more publication, more experience exchange for the use of mechanical circulatory support devices in adult patients with congenital heart disease. While preparation of this talk, I searched PubMed for keywords for ACHD, ECMO or VAD, or the combination of both. And while we have a constant influx of more than 3,000 publications each year about ACHD, an exponential rise for publications for ECMO and VAD, certainly sparked partially by the pandemic, we see really just a minimal output on those topics which combine ACHD and mechanical circulatory support with around 50 to 70 publications each year over recent years. While we do have, meanwhile, a pretty good understanding about the true incidence of congenital heart disease, affecting about 8 in 1,000 neonates, which approximates about 1% of all birth in Western countries, we still struggle up to date with the true prevalence of adult congenital heart disease in the population. Therefore, the first model was actually created by Morelli and colleagues who looked at an administrative database in Canada where he investigated the admission rate of adults with congenital heart disease from a timeframe from 1985 to 2000 and used these admission rates to create an estimate of the forthcoming 10 years from 2000 to 2010. He observed a general trend. First, the overall incidence of congenital heart disease among children remained relatively constant, ranging from 19,000 in 2000 up to 20,000 in 2010. However, over the same time period, he observed a significant and exponential increase of adult patients with congenital heart disease starting from 22,000 in 2000 up to 39,000 in 2010, which is, in fact, a 43% increase. Now, based on this model, Gilbora and colleagues transferred this into the US society, US population. And obviously, we're dealing here with different demographic structures in regards to race and ethnicity, so he had to use some correction factors. But even conservatives estimate he could show that up to 2010, around 2.4 million people in the US are living with congenital heart disease. And conservative estimates up to today, 2020, are ranging around 3.5 to 4.5 million people in the US are affected with congenital heart disease. As the survival to adult and individuals with congenital heart disease has significantly improved, adults with congenital heart disease are also increasingly facing now the risk of non-cardiac complication. The median age of adults with congenital heart disease is now up to 40 years, and the number of adults with congenital heart disease of age greater than 65 is steadily growing. As patients age, common adult comorbidities, such as endocrine problems with diabetes mellitus, coronary artery disease, arterial and pulmonary hypertension, may have and will have an impact on long-term outcomes. Potential residual hemodynamic and anatomically abnormalities or unrepaired congenital heart disease defects may place them at higher risk further for hematological, liver, and kidney disease. In one of the largest adult congenital heart disease centers, the Royal Brampton Hospital in London, UK, the authors could demonstrate in a long-term follow-up of their adult congenital heart disease patients over a 25-year time period from 1991 to 2016, where they identified more than 7,000 patients that cardiac mortality was and remained the predominant factor for mortality in all of these patients. However, especially with increasing age, and especially in the age group greater than 70-75 years, they saw a growing incidence of non-cardiac mortality in this population. In their study, the authors could identify that heart failure was the predominant factor and risk for mortality among all these patients included. Also not surprisingly, even on primary presentation, one-third of all patients with adult congenital heart disease presented with heart failure symptoms knew her class 2 and 3. The overall mortality in this patient cohort was 7.7 percent, which approximately around is 0.7 percent per patient year. To understand better the mechanism of heart failure, Mann and colleagues created this model. All heart failure, loss of myocytes, or loss of myocyte activity has a preceding precursor event. This event could be either acute, like myocardial infarction, subacute, with pressure volume overload, or congenital, perceived as congenital cardiomyopathies, but it leads to compensatory mechanisms of the body, of the heart, to overcome this reduced inotropic function. However, especially these compensatory mechanisms, together with the index event, lead to secondary damage for further destruction of myocytes and further impairment of the heart function. And this leads, over time, the patient who was asymptomatic to a symptomatic heart failure problem. Furthermore, in adult patients with congenital heart disease, heart failure can be more rapidly and more aggravated be presented than in patients with structurally normal heart. This could be due to potential volume overload from residual left-to-right shunts, valvular regurgitation, pressure overload resulting from valvular disease and other obstructive lesions, ventricular failure related to intrinsic myocardial dysfunction, pulmonary hypertension caused by the underlying congenital heart disease defect, arrhythmia burden, or more general disease processes in an aging population, like arteriosclerosis, coronary artery disease, kidney disease, or liver disease. The medical therapy for treatment of heart failure in adult patients with congenital heart disease was adapted from this adult population with structural normal heart and follows a staged approach. However, in patients with structural normal hearts, we have really good randomized controlled trial and large population studies showing the benefit of ACE inhibitors, ARBs, beta blocker, and antiarrhythmic therapy, aldosterone receptor, antagonist, digitalis, and so on. However, most of these medications are lacking or have not undergone any randomized controlled trial in adults with congenital heart disease. Furthermore, most of these medications, which have also been explored in the pediatric heart failure population, have shown no benefit. Now, in an ICU setting, it's getting even more complicated because, yes, we do know how to treat cardiogenic shock. We know how to treat acute on chronic heart failure with medications which have been proven beneficial in the short term. But most and all medications which we use in ICU show actually a potential harm for the patient on the mid- or long-term treatment for heart failure symptoms. Now, when we have exhausted all conventional medical treatment strategies to stabilize the cardiovascular and respiratory state of an individual patient and we are in an ongoing state of shock or acute heart failure symptomatic, we have to refer the patient for potential mechanical circulatory support like extracorporeal membrane oxygenation. However, all of these mechanical circulatory support strategies have one thing in common. They may not be feasible. They may be limited by the underlying anatomy, limited by resources, vascular access, and obviously have also to match the cardiovascular and respiratory need of the individual patient. Adult congenital heart disease intervention are generally high-risk procedures. This is not only due to the predisposing factors, but also the risk due to multiple stenotomies, adhesions, increased risk of wound infection make this peripost-operative management of these patients difficult for the surgeon, anesthetist, and intensive care physicians. In a study conducted at the Mayo Clinic from 2001 to 2013, the authors identified more than 2,200 patients with a median age of 39 with congenital heart disease. One percent of those patients required post-operative mechanical support in the form of extracorporeal membrane oxygenation, ECMO, and or the combination of ECMO and intraortic balloon pump. Although the authors couldn't identify certain risk factors, it is noteworthy to mention that 72 percent of those patients presented with heart failure symptoms of New Heart Class III and IV. The most common procedures performed which led to ECMO were valvular operations with or without mace procedure, fontanne conversions, CABG, and heart transplant. The overall survival in those patients who required ECMO was 46 percent. The overall survival rate of 46 percent for adults with congenital heart disease presented at Mayo Clinic is quite remarkable. In comparison, the Extracorporeal Life Support Organization, a non-profit consortium of healthcare institutions around the world, where regular data for all patients commenced on ECMO is provided to the registry, identifies more than 5,000 patients every year for cardiac disease commenced on ECMO. Less than one percent of these patients present with adult congenital heart disease. The overall outcome of these patients is 43 to 48 percent survival to hospital discharge. To further investigate predictors risk factors for the need of ECMO after adult congenital heart disease, Steve Toldner and colleagues investigated the public pediatric health information system FIS database, which includes administrative and billing data from 48 tertiary care centers among the United States. Among the investigated time period from 2004 to 2014, Steve identified 4,660 patients, adult patients with congenital heart disease surgeries. They identified increasing age, coronary artery disease, higher complexity during surgery, single ventricle physiology, and the pre-existence of complex chronic conditions as potential risk factors for the need for ECMO. The overall prevalence of this population was 1.1 percent for need for ECMO support. Once a patient required ECMO, the survival to hospital discharge was 33 percent. Dr. Toldner and his team further investigated the ALS registry for adult patients with congenital heart disease requiring ECMO support. He identified 368 patients from the time frame from 1994 to 2016. The overall mortality in the whole population was 61 percent, though numerically the mortality declined from 74 percent in the early years to 56 percent in the late years. However, this did not reach statistical significance. Most predominant factor for mortality was frontal physiology. Our own group further investigated the ALS registry for all adult patients with congenital heart disease who did not require ECMO support post-cardiopulmonary bypass as bridge to recovery, but were primarily commenced because of medical reasons. From 2009 to 2019, we identified 312 patients. The overall mortality was 58 percent, which was not significantly different in those patients who require eCPR, those patients who require further surgical or catheter-based intervention on ECMO or after ECMO. Most of us are quite familiar with the SAFE score developed by Matteo Schmidt and his colleagues in 2015. Matteo created the ALS registry for all adult patients with refractory cardiogenic shock requiring ECMO from 2003 to 2013. He used a multivariate logistic model to identify certain risk factors which are associated with survival. This derivation cohort he further compared with a validation cohort at his own hospital at the Alfred in Melbourne, Australia. Dr. Schmidt and colleagues identified certain predictors in the SAFE score contributing to mortality for adult patients commenced on ECMO support for cardiogenic shock. Those include age, weight, acute organ dysfunction, the duration of intubation prior ECMO, if the patient suffered a pre-ECMO arrest, the diastolic blood pressure prior ECMO, pulse pressure variation, but also the underlying diagnosis like myocarditis, arrhythmia burden like VT, VF, or post-heart or lung transplant. However, also the pre-existence of congenital heart disease already moves the potential survival curve for those patients to the left as demonstrated here in the colored column for the SAFE score. Allow me to demonstrate you some examples how do we utilize a Texas Children's Hospital ECMO support as bridge to decision or bridge to diagnostic. This is a 19-year-old female patient with an out-of-hospital cardiac arrest in the context of severe arrhythmia. She had no previous medical history. Her toxicology screen was negative, and she arrived from an outside hospital after return of spontaneous circulation, intubated, ventilated on high excessive doses of epinephrine and norepinephrine. On quick imaging, she showed severe depression of the LV function, was peripherally cold, blood pressure was marginally, so we decided to employ ECMO instantly in this patient. Peripheral renal arterial ECMO support was immediately initiated in this patient. Therefore, our surgical colleagues implanted a 29 French venous cannula and a 22 French arterial cannula with chimney graft into the femoral vessels. We generally use for the arterial approach a chimney graft to prevent distal lymph hyperperfusion without the need for a distal perfusion cannula. Subsequently, we floated a sworn-gans catheter, which revealed an LV EDP around 9 to 10. In peripheral renal arterial ECMO support, we generally aim to early evaluate for any signs of LA or LV hypertension, either echocardiographically or hemodynamically, as we want to prevent any secondary damage to the already stunned myocardium by minimizing wall stress to the LV and coronary perfusion. In cases of LA hypertension, we usually refer the patient to cath lab for early intervention via balloon atrial stertostomy. While patients with signs of LV hypertension, we either refer surgically to insert a direct LV vent, or also via cath lab initiated procedures, implementation of an impeller device. Further echocardiographic imaging of this patient showed no signs of congenital heart disease with a structural normal heart, normal coronary anatomy, and proximal flow pattern, which was later confirmed via a CTA. The patient ultimately made an excellent recovery over the next 48 hours and was weaned successfully from renal arterial ECMO support. The final diagnosis was a diagnosis of exclusion for us. However, because of the typical recovery pattern, we concluded this patient suffered from Takotsubo cardiomyopathy with malignant arrhythmia. Another case where we also used ECMO support as a bridge to decision making was this 42-year-old patient with the history of detransposition who underwent as a neonate a sending procedure. However, he suffered an out-of-hospital cardiac arrest, most likely due to arrhythmia and heart failure. He showed on initial echocardiographic assessment a chronic supraortic systemic RV failure, malignant ongoing atrial arrhythmia burden, and had a dual chamber ICDM placed. With ongoing severe systemic RV failure, need for inotropic support, ongoing arrhythmia burden, and unclear neurological state at this stage, we also employed peripheral re-ECMO cannulation in a similar setting like the previous patient with a 29 French venous cannula and a 22 French arterial cannula with chimney graft as a bridge to decision. Now, when these patients show an appropriate neurological recovery, an appropriate recovery of the end-organ dysfunction, but still minimal or not appropriate myocardial recovery, we have to go on the lookout for further other options what we can proceed further, not to only help their ventricular recovery, but also as further bridge to further decision making in the context of long-term ventricular assist device support or transplantation. In our patient, we decided after appropriate neurological recovery and appropriate recovery of other end-organ dysfunction, the implantation of an impeller 5.5 via the axillary. Generally, the axillary approach for us is advantageous because we can assure maximum mobilization of the patient in the recovery phase. ECMO was subsequently successfully weaned off. However, we also identified more indication for the impeller 5.5 device like demonstrated in this patient. This is a 20-year-old patient with heterotaxis syndrome, an unbalanced AV canal with double-outlet right ventricle who underwent as a toddler a gland procedure and subsequently an extracardiac fontane. He presented to us with severe AV valve regurgitation, which was replaced with a 33-millimeter sanctured valve. After weaning him of cardiopulmonary bypass, he showed significant ventricular dysfunction and also due to ongoing severe arrhythmia burden, the implementation of a cardiac pacemaker. So, despite these measures and despite optimization of the medical therapy to optimize his heart failure post-weaning of cardiopulmonary bypass, the patient was implanted with a 5.5 impeller again via the axillary approach. While fully supported with the impeller 5.5 for the initial two weeks, the patient was subsequently slowly weaned over the next coming two weeks with a total device placement for 28 days, but subsequently discharged and sent home with good ventricular function and recovery. To pick the right instrument to achieve the best myocardial recovery for the individual patient based on the underlying anatomy, physiology the patient presents primarily, we created this decision tree algorithm at our institution. Depending on the hemodynamic and respiratory needs, we decide either for the employment of ECMO support or primary ventricular assist device strategy, which can be temporarily, but then further adapted to more continuous ventricular assist device strategies or ultimately even leading to heart transplantation if necessary. Such individualized protocols should be certainly institutionalized and give a good practice guidelines for the individual provider. Now, what about those patients, however, who have still not shown an appropriate myocardial recovery with ECMO support or percutaneous ventricular assist device support and still are in further need as device implantation for further bridge to decision making or and bridge to recovery or and bridge to destination or bridge to transplant. Therefore, Wunderblum and her colleagues recently investigated the Intermax database for all adult patients implanted with durable ventricular assist devices. Over a 10-year time period, she identified more than 16,000 patients. Only 126 patients, which represents less than 1% of the whole patient cohort, were patients with congenital heart disease. Most of these patients with congenital heart disease showed still a systemic left ventricle, some a systemic right ventricle, and only 12% of these patients had single ventricle physiology. In an unmatched Kaplan-Meier analysis, Wunderblum and her group could demonstrate a significant lower survival rate for patients with adult congenital heart disease compared to patients without any congenital heart disease for the implementation of ventricle assist devices. The about three-year survival rate for patients with adult congenital heart disease was in this cohort around 60%. In a direct comparison, where their durable vent was implanted as a left ventricular assist device among ACHD and non-ACHD patients, there was no significant difference in survival. However, ACHD patients with LVAD showed higher rates of late arrhythmia, earlier hepatic dysfunction, early and late renal dysfunction, early and late respiratory failure, early and late renal dysfunction, early and late respiratory failure, and late infection in comparison to the non-ACHD population. Quite markedly, however, was the difference for patients implanted with bi-ventricle assist devices or total artificial hearts among the groups ACHD versus non-ACHD. ACHD patient showed significantly higher rates of early bleeding, late hepatic dysfunction, early and late infections, early and late neurological dysfunction, and early and late renal dysfunctions. In analyzing competing outcomes, CDOS et al. could demonstrate a trend towards increased transplantation in the non-ACHD group during the same hospitalization as mechanical circulatory support was deployed. Transplantation was presumably undertaken in this group to a suboptimal outcome early after the mechanical support placement. It is also possible that the ACHD patients with suboptimal but viable outcomes after mechanical support were less likely to receive a transplant, contributing to a higher earlier mortality rate. This falls into line with recent data demonstrating that ACHD patients are much more likely to die or to be delisted due to clinical worsening exclusively while listed as status 1A outcome. Let's return to one of our case examples. Here, our 42-year-old patient with detransposition who had an atrial switch operation outside hospital cardiac arrest subsequently as an adult with systemic RV failure and ongoing atrial arrhythmia burden requiring initial VA ECMO support, subsequently switched to an impeller 5-5 support. This patient showed appropriate neurological recovery, was fully mobilized, showed no signs of renal or hepatic failure, but still not appropriate myocardial recovery to remove the percutaneous VAT. So, after 43 days of impeller 5-5 support, we decided and swapped the patient to a durable ventricle assist devices with an HeartMate 3. After implantation of the HeartMate 3 into the systemic right ventricle, the patient had to spend a few more days in ICU, but was subsequently discharged. The HeartMate 3 as a durable ventricle assist device support currently serves the patient as a support to destination. My colleague, Dr. Chris Prodar, demonstrates here very well our own institutional experience at Texas Children's Hospital and Baylor St. Luke's. Over the last years, we supported several patients with impeller CP, impeller 5-0, and impeller 5-5, and durable support strategies like the HeartMate 2 and HeartMate 3, HeartWare, Jarvik 2000. For the durable VAT cohort, Dr. Prodar could demonstrate an excellent survival rate with a one-year survival around 84%, a three-year survival 72%, and a five-year survival around 36%. In summary, extracorporeal membrane oxygenation, temporary ventricle assist devices, and durable ventricle assist devices are feasible support strategies in ACHD patients. You should pay specific considerations to anatomy, muscular axis, potentially bleeding complications, which affect and may determine your decided support strategy. Always inform and pre-inform the patient, but also involve your colleagues about choosing the best support strategy. Consider the significant comorbidities which exist in this population, especially considering the higher age than the general pediatric population with congenital heart disease. Heart failure remains a major mortality factor where we have to focus on further medical research. But in general, durable mechanical support devices as destination therapy for adult congenital heart disease patients who are not transplant candidates should be considered, and in certain selected cases, can have similar outcomes like non-ACHD patients supported with ventricle assist devices. Thank you very much. And see you soon.

mechanical circulatory support devices

adult congenital heart disease

prevalence of ACHD

heart failure

mechanical support

extracorporeal membrane oxygenation

ventricular assist devices