Risk Factors for Increased Hospital Resource Utilization and In-Hospital Mortality in Adults With Single Ventricle Congenital Heart Disease

Five decades of Fontan palliation: What have we learned? What should we expect?

The Fontan procedure is the final palliative surgery in a series of staged surgeries to reroute the systemic venous blood flow directly to the lungs, with the ventricle(s) pumping oxygenated blood to the body. Advances in medical and surgical techniques have improved patients' overall survival after the Fontan procedure. However, Fontan-associated chronic comorbidities are common. In addition to chronic cardiac dysfunction and arrhythmias, complications involving other organs such as the liver, lungs, intestine, lymphatic system, brain, and blood frequently occur. This narrative review focuses on the immediate and late consequences in children, pregnant women, and other adults with Fontan circulation. In addition, we describe the technical advancements that might change the way single-ventricle patients are managed in future.

Acute vasodilator response testing in the adult Fontan circulation using non-invasive 4D Flow MRI: a proof-of-principle study

BACKGROUND

Pulmonary vasodilator therapy in Fontan patients can improve exercise tolerance. We aimed to assess the potential for non-invasive testing of acute vasodilator response using four-dimensional (D) flow MRI during oxygen inhalation.

MATERIALS AND METHODS

Six patients with well-functioning Fontan circulations were prospectively recruited and underwent cardiac MRI. Ventricular anatomical imaging and 4D Flow MRI were acquired at baseline and during inhalation of oxygen. Data were compared with six age-matched healthy volunteers with 4D Flow MRI scans acquired at baseline.

RESULTS

All six patients tolerated the MRI scan well. The dominant ventricle had a left ventricular morphology in all cases. On 4D Flow MRI assessment, two patients (Patients 2 and 6) showed improved cardiac filling with improved preload during oxygen administration, increased mitral inflow, increased maximum E-wave kinetic energy, and decreased systolic peak kinetic energy. Patient 1 showed improved preload only. Patient 5 showed no change, and patient 3 had equivocal results. Patient 4, however, showed a decrease in preload and cardiac filling/function with oxygen.

DISCUSSION

Using oxygen as a pulmonary vasodilator to assess increased pulmonary venous return as a marker for positive acute vasodilator response would provide pre-treatment assessment in a more physiological state - the awake patient. This proof-of-concept study showed that it is well tolerated and has shown changes in some stable patients with a Fontan circulation.

Hospital resource utilization in a national cohort of functionally single ventricle patients undergoing surgical treatment

Objective

The study objective was to provide a detailed overview of health resource use from birth to 18 years old for patients with functionally single ventricles and identify associated risk factors.

Methods

All patients with functionally single ventricles treated between 2000 and 2017 in England and Wales were linked to hospital and outpatient records using data from the Linking AUdit and National datasets in Congenital HEart Services project. Hospital stay was described in yearly age intervals, and associated risk factors were explored using quantile regression.

Results

A total of 3037 patients with functionally single ventricles were included, 1409 (46.3%) undergoing a Fontan procedure. During the first year of life, the median days spent in hospital was 60 (interquartile range, 37-102), mostly inpatient days, mirroring a mortality of 22.8%. This decreases to between 2 and 9 in-hospital days/year afterward. Between 2 and 18 years, most hospital days were outpatient, with a median of 1 to 5 days/year. Lower age at the first procedure, hypoplastic left heart syndrome/mitral atresia, unbalanced atrioventricular septal defect, preterm birth, congenital/acquired comorbidities, additional cardiac risk factors, and severity of illness markers were associated with fewer days at home and more intensive care unit days in the first year of life. Only markers of early severe illness were associated with fewer days at home in the first 6 months after the Fontan procedure.

Conclusions

Hospital resource use in functionally single ventricle cases is not uniform, decreasing 10-fold during adolescence compared with the first year of life. There are subsets of patients with worse outcomes during their first year of life or with persistently high hospital use throughout their childhood, which could be the target of future research.

Safety of gastrointestinal endoscopy in patients with acute coronary syndrome and concomitant gastrointestinal bleeding

BACKGROUND

Gastrointestinal bleeding (GIB) is a major concern in patients hospitalized with acute coronary syndrome (ACS) due to the common use of both antiplatelet medications and anticoagulants. Studies evaluating the safety of gastrointestinal endoscopy (GIE) in ACS patients with GIB are limited by their relatively small size, and the focus has generally been on upper GIB and esophago-gastroduod-enoscopy (EGD) only.

AIM

To evaluate the safety profile and the hospitalization outcomes of undergoing GIE in patients with ACS and concomitant GIB using the national database for hospitalized patients in the United States.

METHODS

The Nationwide Inpatient Sample database was queried to identify patients hospitalized with ACS and GIB during the same admission between 2005 and 2014. The International Classification of Diseases Code, 9^th Revision Clinical Modification was utilized for patient identification. Patients were further classified into two groups based on undergoing endoscopic procedures (EGD, small intestinal endoscopy, colonoscopy, or flexible sigmoidoscopy). Both groups were compared regarding demographic information, outcomes, and comorbi-dities. Multivariate analysis was conducted to identify factors associated with mortality and prolonged length of stay. Chi-square test was used to compare categorical variables, while Student’s t-test was used to compare continuous variables. All analyses were performed using SAS 9.4 (Cary, NC, United States).

RESULTS

A total of 35612318 patients with ACS were identified between January 2005 and December 2014. 269483 (0.75%) of the patients diagnosed with ACS developed concomitant GIB during the same admission. At least one endoscopic procedure was performed in 68% of the patients admitted with both ACS and GIB. Patients who underwent GIE during the index hospitalization with ACS and GIB had lower mortality (3.8%) compared to the group not undergoing endoscopy (8.6 %, P < 0.001). A shorter length of stay (LOS) was observed in patients who underwent GIE (mean 6.59 ± 7.81 d) compared to the group not undergoing endoscopy (mean 7.84 ± 9.73 d, P < 0.001). Multivariate analysis showed that performing GIE was associated with lower mortality (odds ratio: 0.58, P < 0.001) and shorter LOS (-0.36 factor, P < 0.001).

CONCLUSION

Performing GIE during the index hospitalization of patients with ACS and GIB was correlated with a better mortality rate and a shorter LOS. Approximately two-thirds of patients with both ACS and GIB undergo GIE during the same hospitalization.

Review on Mechanical Support and Cell-Based Therapies for the Prevention and Recovery of the Failed Fontan-Kreutzer Circulation

Though the current staged surgical strategy for palliation of single ventricle heart disease, culminating in a Fontan circulation, has increased short-term survival, mounting evidence has shown that the single ventricle, especially a morphologic right ventricle (RV), is inadequate for long-term circulatory support. In addition to high rates of ventricular failure, high central venous pressures (CVP) lead to liver fibrosis or cirrhosis, lymphatic dysfunction, kidney failure, and other comorbidities. In this review, we discuss the complications seen with Fontan physiology, including causes of ventricular and multi-organ failure. We then evaluate the clinical use, results, and limitations of long-term mechanical assist devices intended to reduce RV work and high CVP, as well as biological therapies for failed Fontan circulations. Finally, we discuss experimental tissue engineering solutions designed to prevent Fontan circulation failure and evaluate knowledge gaps and needed technology development to realize a more robust single ventricle therapy.

Modeling Physiological Flow Variation in Fontan Models with 4d Flow Mri, Particle Image Velocimetry, and Arterial Spin Labeling

The Fontan procedure is a successful palliation for single ventricle defect. Yet, a number of complications still occur in Fontan patients due to abnormal blood flow dynamics, necessitating improved flow analysis and treatment methods. Phase-contrast magnetic resonance imaging (MRI) has emerged as a suitable method for such flow analysis. However, limitations on altering physiological blood flow conditions in the patient while in the MRI bore inhibit experimental investigation of a variety of factors that contribute to impaired cardiovascular health in these patients. Furthermore, resolution and flow regime limitations in phase contrast MRI pose a challenge for accurate and consistent flow characterization. In this study, patient-specific physical models were created based on nine Fontan geometries and MRI experiments mimicking low and high flow conditions, as well as steady and pulsatile flow, were conducted. Additionally, an optically transparent Fontan model was created for flow analyses using a particle image velocimetry (PIV) system, arterial spin labeling (ASL), and four-dimensional (4D) flow MRI. Differences, though non-statistically significant, were observed between flow conditions and between patient-specific models. Large between-model variation supported the need for further improvement for patient-specific modeling on each unique Fontan anatomical configuration. Furthermore, high resolution PIV and flow tracking ASL data provided flow information that was not obtainable with 4D flow MRI alone.

Comparison of inhospital outcomes of pediatric heart transplantation between single ventricle congenital heart disease and cardiomyopathy

Data investigating the impact of household income and other factors on SV patient status-post-Fontan palliation after heart transplantation are lacking. We aim to evaluate factors affecting outcomes after OHT in this population. The PHIS database was interrogated for either SV or myocarditis/primary CM who were 4 years or older who underwent a single OHT. There were 1599 patients with a median age of 13.2 years (IQR: 9.3-16.1). Total hospital costs were significantly higher in the SV group ($408 000 vs $294 000, P < 0.0001), but as median household income increased, the risk of inhospital mortality, post-transplant LOS, and LOS-adjusted total hospital costs all decreased. The risk of inhospital mortality increased 6.5% per 1 year of age increase at the time of transplant. Patients in the SV group had significantly more diagnoses than those in the CM group (21 vs 15, P < 0.0001) and had longer total hospital LOSs as a result of longer post-transplant courses (25 days vs 15, P < 0.0001). Increased median household income and younger age are associated with decreased resource utilization and improved inhospital mortality in SV CHD patients who undergo OHT. In conclusion, earlier consideration of OHT in this population, coupled with improved selection criteria, may increase survival in this population.

Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals.

Real-world healthcare utilization in adult congenital heart disease: a systematic review of trends and ratios

BACKGROUND

As a result of medical advances, the adult congenital heart disease population is rapidly expanding. Nonetheless, most patients remain prone to increased morbidity and mortality. Therefore, long-term medical resource use is required. This systematic review aims to present the trends over the past decades of medical resource utilization in adult congenital heart disease as well as its current status, with a focus on hospitalizations, emergency department visits, outpatient cardiology visits, and visits to other healthcare professionals.

METHODS

MEDLINE (Pubmed), Embase, and Web of Science were searched for retrospective database research publications. The ISPOR checklist for retrospective database research was used for quality appraisal. Trends over time are explored.

RESULTS

Twenty-one articles met the inclusion criteria. All but one of the studies was conducted in Western Europe and North America. The absolute number of hospitalizations has been increasing over the last several decades. This increase is highest in patients with mild lesions, although these numbers are largely driven by hospitalizations of patients with an atrial septal defect or a patent foramen ovale. Meanwhile, outpatient cardiology visits are increasing at an even higher pace, and occur most often in geriatric patients and patients with severe lesions. Conversely, the number of hospitalizations per 100 patients is decreasing over time. Literature is scarce on other types of healthcare use.

CONCLUSION

A strong rise in healthcare utilization is noticed, despite the mitigating effect of improved efficiency levels. As the population continues to grow, innovative medical management strategies will be required to accommodate its increasing healthcare utilization.

Resource Utilization Among Adult Congenital Heart Failure Admissions in Pediatric Hospitals

We sought to analyze the trends and resource utilization of adult congenital heart disease (ACHD)-related heart failure admissions at children's hospitals. Heart failure admissions in patients with ACHD continue to rise at both pediatric and adult care facilities. Data from the Pediatric Health Information Systems database (2005 to 2015) were used to identify patients (≥18 years) admitted with congenital heart disease (745.xx-747.xx) and principal diagnosis of heart failure (428.xx). High resource use (HRU) admissions were defined as those over the 90th percentile. There were 562 admissions (55.9% male) across 39 pediatric hospitals. ACHD-related heart failure admissions increased from 4.1% in 2006 to 6.3% in 2015 (p = 0.015). Median hospital charge for ACHD-related heart failure admissions was $59,055 [IQR $26,633 to $156,846]. Total charges increased with more complex anatomic category (p = 0.049). Though HRU admissions represented 10% of ACHD-related heart failure admissions, they accounted for >66% of the total charges. The median total hospital charges for HRU admissions were $1,018,656 [IQR $722,574 to $1,784,743], compared with $58,890 [IQR $26,456 to $145,890] for non-HRU admissions (p < 0.001). Inpatient mortality rate (26.3% vs 4.0%) and the presence of ≥2 comorbidities (68% vs 31%) were higher for HRU admissions (p < 0.001). On multivariable analysis, technology dependence (aOR: 4.4, p < 0.001) and renal comorbidities (aOR: 3.0, p = 0.04) were associated with HRU. In conclusion, heart failure-related ACHD admissions in pediatric hospitals are increasing. Compared with non-HRU, HRU admissions had higher inhospital mortality and greater comorbidities. Additional care strategies to reduce resource use among these patients and improve overall quality of care merits further study.

Analysis of cavopulmonary and cardiac flow characteristics in fontan Patients: Comparison with healthy volunteers

BACKGROUND

Characterizing the flow of the Fontan circuit, and correlating flow characteristics with the development of complications, is an important clinical challenge. Past work has analyzed the flow characteristics of Fontan circulation on a component-by-component basis. 4D flow MRI with radial projections allows for large volumetric coverage, and therefore can be used to analyze the flow through many codependent cardiovascular components in a single imaging session.

PURPOSE

To describe flow characteristics across the entire Fontan circuit and to compare these with the flow characteristics in healthy volunteers.

STUDY TYPE

Prospective.

SUBJECTS

Eleven single ventricle patients with a Fontan connection and 15 healthy controls.

SEQUENCE

Phase contrast with vastly undersampled isotropic projection reconstruction (PC-VIPR) at a field strength of 3 T.

ASSESSMENT

Cavopulmonary and ventricular flow distributions, blood flow kinetic energy, vorticities, efficiency indices, and other flow parameters were analyzed using Ensight and MatLab.

STATISTICAL TESTS

The results were compared across Fontan subjects, between respiratory phases, and between Fontan subjects and healthy volunteers using a Student's t-test for unequal sample sizes and linear regression.

RESULTS

Cava-specific pulmonary flow distributions of Fontan patients varied significantly between respiratory phases (P < 0.05). Ventricular kinetic energy (KE) was significantly higher in Fontan patients than it was in healthy controls, leading to a lower cardiac efficiency metric in the Fontan group. A significant diastolic KE time-shift was also observed in the Fontan patient group. Peak diastolic KE was significantly higher in the single ventricle of patients with right ventricle morphology than it was in left ventricle morphology patients.

DATA CONCLUSION

Radial 4D flow MRI can be used for comprehensive analysis of single ventricle Fontan flow characteristics.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019.

Frontiers in Fontan failure: Innovation and improving outcomes: A conference summary

The initial "Frontiers in Fontan Failure" conference in 2015 in Atlanta, GA, provided an opportunity for experts in the field of pediatric cardiology and adult congenital heart disease to focus on the etiology, physiology, and potential interventions for patients with "Failing Fontan" physiology. Four types of "Fontan Failure" were described and then published by Dr Book et al. The acknowledgment that even Dr Fontan himself realized that the Fontan procedure "imposed a gradually declining functional capacity and premature late death after an initial period of often excellent palliation." The purpose of the second "Frontiers in Fontan Failure" was to further the discussion regarding new data and technologies as well as novel interventions. The 2017 "Frontiers in Fontan Failure: Innovation and Improving Outcomes" was sponsored by Children's Healthcare of Atlanta, Sibley Heart Center Cardiology, and Emory University School of Medicine. Future directions in the management of Fontan failure include further investigations into the risk of sudden cardiac death and how to properly prevent it, achievable interventions in modifying the Fontan physiology to treat or prevent late complications, and improved and refined algorithms in Fontan surveillance. Finally, further research into the interventional treatment of lymphatic-related complications hold the promise of marked improvement in the quality of life of advanced Fontan failure patients and as such should be encouraged and contributed to.

Hospital Inpatient Costs for Single Ventricle Patients Surviving the Fontan Procedure

We estimated the inpatient resource use for a Fontan patient from birth to adulthood and explored factors that might induce cost differences (2014 US dollar). Inpatient costing records from 4 hospitals with greatest numbers of Fontan patients in Australia and New Zealand were linked with the Fontan registry database. Inpatient records between July 1995 and September 2014 for 420 Fontan patients were linked, and the most frequent primary diagnoses were hypoplastic left heart syndrome (20.7%), tricuspid atresia (19.7%), and double inlet left ventricle (17.1%). The mean hospital cost for a Fontan patient from birth to 18 years of age was estimated to be $390,601 (95% confidence interval [CI] $264,703 to $516,499), corresponding to 164 (95% CI 98 to 231) inpatient days. The cost incurred from birth through to Fontan completion (the staged procedures period) was $219,482 (95% CI $202,410 to $236,553) and the cost thereafter over 15 years was $146,820 (95% CI $44,409 to $249,231), corresponding to 82 (95% CI 72 to 92) and 65 (95% CI 18 to 112) inpatient days, respectively. Costs were higher in male and hypoplastic left heart syndrome patients in the staged procedures period (p <0.001). Having fenestration was associated with higher costs in the staged procedures period (p <0.001) and lower cost after Fontan over 15 years (p = 0.66). In conclusion, patients with single ventricle congenital heart disease continue to demand considerable inpatient resources after the staged procedures period. Over 40% of the pediatric hospital costs for Fontan patients were estimated to occur after the last planned surgery.

National In-Hospital Outcomes of Pregnancy in Women With Single Ventricle Congenital Heart Disease

Most patients with single ventricle (SV) congenital heart disease are expected to survive to adulthood. Women with SV are often counseled against pregnancy; however, data on pregnancies in these women are lacking. We sought to evaluate in-hospital outcomes of pregnancy in women with SV. We used nationally representative data from the 1998 to 2012 National Inpatient Sample to identify women ≥18 years of age admitted to the hospital with International Classification of Diseases-9th Revision codes for an intrauterine pregnancy and a diagnosis of hypoplastic left heart syndrome, tricuspid atresia, or common ventricle. A matched comparison group without a diagnosis of congenital heart disease or pulmonary hypertension was identified from the database. National estimates of hospitalizations were calculated. Length of stay, hospital charges, and complications were analyzed and compared between groups. Charge data were adjusted to 2012 dollars. There were 282 admissions of pregnant women with SV (69% with deliveries) and 1,405 admissions in the control group (88% with deliveries). Vaginal delivery was more common in SV (74% vs 71%, p <0.001). Length of stay (4.1 ± 0.91 vs 2.8 ± 0.18 days, p <0.001) and charges ($30,787 ± 8,109 vs $15,536 ± 1,006, p <0.0001) were higher in the SV group. Complications occurred in most SV admissions and were more common in the SV group than in the control group. No deaths occurred. Cardiovascular complications occurred in 25% of pregnancy-related hospitalizations, although in-hospital pregnancy-related death is rare. Vaginal delivery is common in these patients. These data suggest that pregnancy and vaginal delivery can be tolerated in women with SV, although the risk for a cardiovascular event is significantly higher than in the general population.