Evaluation of dosing and safety outcomes of low-dose prophylactic warfarin in children after cardiothoracic surgery.

PURPOSE: Prophylactic warfarin with an International Normalized Ratio (INR) goal of 1.5 to 2.0 is one antithrombotic therapy utilized in children after cardiothoracic surgery (CTS); published sources suggest a dose of 0.1 mg/kg per day to achieve this goal. However, few studies have evaluated dosing in this population. The purpose of this study was to evaluate dosing and safety outcomes in children receiving warfarin after CTS. METHODS: A descriptive, retrospective review was conducted to evaluate warfarin dosing and INR outcomes in patients 18 years of age or younger who underwent CTS and received prophylactic warfarin with an INR goal of 1.5 to 2.0 from January 2014 through December 2018. The primary objective was to determine the median initial warfarin dose. Secondary objectives included identifying the percentage of documented INR values that were outside the therapeutic range, the percentage of patients with therapeutic INRs at discharge, and the 30-day readmission rate. RESULTS: Twenty-six patients were included in the review. The median initial warfarin dosage was 0.07 mg/kg/d (interquartile range [IQR], 0.05-0.10 mg/kg/d). Of the total of 177 INR values collected during the entire study period, 67 (37.9%) were therapeutic, 64 (36.2%) were subtherapeutic, and 46 (26.0%) were supratherapeutic. Eighteen patients (69.2%) had at least 1 supratherapeutic INR at any point during the study period, most frequently on days 2 through 4 of therapy. At discharge, 11 patients (42.3%) had therapeutic INRs. Four patients (15.4%) were readmitted within 30 days, with bleeding documented in 2 patients during their readmission. CONCLUSION: The majority of patients received an initial warfarin dose less than that specified in published recommendations but still had a supratherapeutic INR at least once during the study period. When initiating warfarin after CTS, a dosage of <0.1 mg/kg per day and frequent monitoring may be needed to achieve an INR goal of 1.5 to 2.0.

Thromboembolic Risk After Atriopulmonary, Lateral Tunnel, and Extracardiac Conduit Fontan Surgery.

BACKGROUND: Thromboembolic events contribute greatly to morbidity and mortality following Fontan surgery for univentricular hearts. OBJECTIVES: This study sought to evaluate the effect of type of Fontan surgery on thromboembolic risk. METHODS: A North American multicenter retrospective cohort study enrolled 522 patients with Fontan palliation consisting of an atriopulmonary connection (APC) (21.4%), lateral tunnel (LT) (41.8%), or extracardiac conduit (EC) (36.8%). Thromboembolic complications and new-onset atrial arrhythmia were reviewed and classified by a blinded adjudicating committee. Thromboembolic risk across surgical techniques was assessed by multivariable competing-risk survival regression. RESULTS: Over a median follow-up of 11.6 years, 10- and 20-year freedom from Fontan conversion, transplantation, or death was 94.7% and 78.9%, respectively. New-onset atrial arrhythmias occurred in 4.4, 1.2, and 1.0 cases per 100 person-years with APC, LT, and EC, respectively. APC was associated with a 2.82-fold higher risk of developing atrial arrhythmias (p < 0.001), with no difference between LT and EC (p = 0.95). A total of 71 thromboembolic events, 32 systemic and 39 venous, occurred in 12.8% of subjects, for an overall incidence of 1.1%/year. In multivariable analyses, EC was independently associated with a lower risk of systemic (hazard ratio [HR]: 0.20 vs. LT; 95% confidence interval [CI]: 0.04 to 0.97) and combined (HR: 0.34 vs. LT; 95% CI: 0.13 to 0.91) thromboembolic events. A lower incidence of combined thromboembolic events was also observed with antiplatelet agents (HR: 0.54; 95% CI: 0.32 to 0.92) but not anticoagulation (p = 0.53). CONCLUSIONS: The EC Fontan was independently associated with a lower thromboembolic risk after controlling for time-varying effects of atrial arrhythmias and thromboprophylaxis.

Differences in cerebral and muscle oxygenation patterns during exercise in children with univentricular heart after Fontan operation compared to healthy peers.

BACKGROUND: We assess whether the lower exercise tolerance in children with univentricular heart (UVH) after Fontan operation is associated with altered peripheral muscular and cerebral tissue oxygenation. METHODS: 18 children with UVH and 20 healthy subjects performed an incremental ramp exercise test. Changes in the cerebral and muscular pattern of oxygenated (O2Hb) and deoxygenated hemoglobin (HHb) and local tissue oxygenation (TOI) were analyzed by means of Near Infrared Spectroscopy (NIRS). Correlations between arterial saturation during exercise and tissue oxygenation were evaluated. RESULTS: In UVH, maximal oxygen consumption (VO2peak/kg, 28.9 ±â€¯7.9 vs. 46.3 ±â€¯11.9 ml/min/kg, P < 0.001), heart rate (HRpeak, 168 ±â€¯13 vs. 193 ±â€¯12 bpm, P < 0.001) and load (Ppeak, 73 ±â€¯19 vs. 133 ±â€¯68 W, P < 0.001) were lower, VE/VCO2 slope was higher (34.5 ±â€¯5.9 vs. 27.1 ±â€¯3.9, P < 0.001). A faster and steeper course up to the same level of HHb and absent increase in O2Hb was seen at cerebral level in UVH; tissue oxygenation index (TOI) demonstrated a steady decrease from the start of exercise. At the muscular level, HHb curve has a similar pattern compared to controls, with an early cessation. O2Hb has a similar pattern, but with early discontinuation at a higher O2Hb-level. Muscular TOI has the same course throughout exercise, starting from a lower level. Lower arterial saturation and higher age correlated with lower VO2peak; higher amplitude of muscular TOI and lower amplitude cerebral TOI correlated with higher VO2peak. CONCLUSION: Children after Fontan procedure have different oxygenation mechanisms at muscular and cerebral level. This reflects a different balance between O2 supply to O2 demand which might contribute to the reduced exercise tolerance in this patient population.

Resource Utilization for Prenatally Diagnosed Single-Ventricle Cardiac Defects: A Philadelphia Fetus-to-Fontan Cohort Study.

Background Healthcare resource utilization is substantial for single-ventricle cardiac defects ( SVCD ), with effort commencing at time of fetal diagnosis through staged surgical palliation. We sought to characterize and identify variables that influence resource utilization for SVCD from fetal diagnosis through death, completed staged palliation, or cardiac transplant. Methods and Results Patients with a prenatal diagnosis of SVCD at our institution from 2004 to 2011 were screened. Patients delivered with intent to treat who received cardiac care exclusively at our institution were included. Primary end points included the total days hospitalized and the numbers of echocardiograms and cardiac catheterizations. Subanalysis was performed on survivors of completed staged palliation on the basis of Norwood operation, dominant ventricular morphology, and additional risk factors. Of 202 patients born with intent to treat, 136 patients survived to 6 months after completed staged palliation. The median number of days hospitalized per patient-year was 25.1 days, and the median numbers of echocardiograms and catheterizations per patient-year were 7.2 and 0.7, respectively. Mortality is associated with increased resource utilization. Survivors had a cumulative length of stay of 57 days and underwent a median of 21 echocardiograms and 2 catheterizations through staged palliation. Right-ventricle-dominant lesions requiring Norwood operation are associated with increased resource utilization among survivors of staged palliation. Conclusions For fetuses with SVCD , those with dominant right-ventricular morphology requiring Norwood operation demand increased resource utilization regardless of mortality. Our findings provide insight into care for SVCD , facilitate precise prenatal counseling, and provide information about the resources utilized to successfully manage SVCD .

Pacemakers are associated with a higher risk of late death and transplantation in the Fontan population.

BACKGROUND: The need for permanent pacing has been identified as a predictor of poor outcomes in the late survivors of Fontan surgery. However, it is not clear if the need for a pacemaker is a surrogate marker of a declining Fontan state, or if pacing is deleterious to the Fontan circulation. OBJECTIVES: We sought to compare the long-term outcomes of propensity-matched Fontan patients with and without a permanent pacemaker. METHODS: Patients who have survived Fontan completion with a documented history of cardiac arrhythmia were identified from the Australia and New Zealand Fontan Registry. Pacemaker insertion details, cardiac function and electrophysiological data were obtained for the patients with a permanent pacemaker. Survival analysis was performed with propensity score matching to compare late survival and outcomes in patients with versus without a pacemaker. RESULTS: There was a total of 310 patients with a history of cardiac arrhythmia, of which 126 (41%) had a permanent pacemaker. After propensity-score matching, 99 pairs were generated (n = 198). Patients with a permanent pacemaker had a higher risk of death (HR 3.32 95% CI 1.60-6.90, p = 0.001) and death or transplantation (HR 3.55 95% CI 1.87-6.73, p < 0.001). Patients who were only paced atrially were not at a significantly increased risk of death or transplantation. However, patients who were ventricular paced >50% of the time were much more likely to encounter late death or transplantation (HR 3.82 95% CI 1.64-8.95, p = 0.002). CONCLUSIONS: Having a permanent pacemaker and needing ventricular pacing is likely associated with an increased risk of death and transplantation in patients with a Fontan circulation.

Mode of death and predictors of mortality in adult Fontan survivors: A Japanese multicenter observational study.

BACKGROUND: Mortality rates may be high in adult Fontan patients; however, the clinical determinants remain unclear. PURPOSE: We conducted a prospective multicenter study of adult Fontan survivors to determine the 5-year mortality rate and clarify the determinants. METHOD AND RESULTS: We followed 600 adult Fontan survivors from 40 Japanese institutions (307 men, 28 ±â€¯7 years old, follow-up: 18 ±â€¯6 years). The New York Heart Association (NYHA) functional class I and II was 51% and 42%, respectively. During the follow-up period of 4.1 ±â€¯1.6 years, 33 patients died, and the 5-year survival rate was 93.5%. The mode of death was heart failure in 11 patients (34%), arrhythmia or sudden death in 8 (24%), cancer in 5 (15%), perioperative problems and hemostatic problems in 4 each (12% for each), and infection in 1 (3%). Left isomerism, prior hospitalization, protein losing enteropathy (PLE), pulmonary arteriovenous fistulae, NYHA functional class, impaired hemodynamics, hyponatremia, hepatorenal dysfunction, and use of diuretics were associated with a high mortality rate (p < 0.05-0.0001). Further, PLE (hazard ratio [HR]: 14.4), left isomerism (HR: 3.5), and NYHA (HR: 2.4) independently predicted a high 5-year high mortality (p < 0.05 for all). The incidence of cancer-related mortality increased markedly with age >40 years. CONCLUSIONS: Majority of the Japanese adult Fontan survivors had good functional status, with an acceptable 5-year survival rate. However, the significant prevalence of non-cardiac mortality highlights Fontan pathophysiology as a multi-organ disease that requires a multidisciplinary management strategy to improve the long-term outcome.

The clinical spectrum of Fontan-associated liver disease: results from a prospective multimodality screening cohort.

AIMS: Liver fibrosis and cirrhosis are a consequence of a Fontan physiology, and determine prognosis. It is unclear whether non-invasive assessment of liver pathology is helpful to provide clinically relevant information. The aims of this study were to assess the spectrum of Fontan-associated liver disease (FALD) and usefulness of non-invasive methods to assess biopsy confirmed liver fibrosis. METHODS AND RESULTS: Hepatic screening of consecutive patients consisted of a blood panel, ultrasonography, elastography, contrast-enhanced magnetic resonance imaging (MRI)/computed tomography (CT) scan, and liver biopsy (scored with Fontan specific fibrosis scores and collagen proportionate area; CPA). Fibrosis parameters, varices, ascites, and splenomegaly were measured on imaging. Thirty-eight of 49 referred patients (27 ± 6.6 years, 73.7% male) underwent the complete screening protocol. Liver fibrosis on biopsy was present in all patients, and classified as severe (Stages 3-4) in 68%. Median CPA was 22.5% (16.9-29.5) and correlated with individual fibrosis scores. ELF® and liver stiffness were elevated, but MELD-XI scores were low in all patients. Fibrosis severity neither correlated to ELF® and liver stiffness, nor to (semi-) quantitative fibrosis parameters on MRI/CT. Varices were present in 50% and hyperenhancing nodules in 25% of patients, both independent of fibrosis stage, but varices were associated with higher CPA values. CONCLUSION: The FALD spectrum includes both hepatic congestion and severe fibrosis, with signs of portal hypertension and hyperenhancing nodules as significant manifestations. Routine imaging, transient elastography, and serum biomarkers are unable to accurately assess severity of liver fibrosis in this cohort. Future research should focus on validating new diagnostic tools with biopsy as the reference standard.

National trends in Fontan operation and in-hospital outcomes in the USA.

BACKGROUND: National prevalence and outcomes of Fontan operation in the USA is unknown. Study objective was to determine trends (temporal change) in the annual volume of Fontan operations, in-hospital mortality, postoperative complications and type of hospital discharge. METHODS: Review of the Nationwide Inpatient Sample for patients that underwent Fontan operation from 2001 to 2014 using the International Classification of Diseases-Ninth Revision, Clinical Modification procedure code for Fontan operation, that is, 35.94. To evaluate for change in patients' demographics over the years, we divided the patient population into four groups based on procedure year (2001-2004, 2005-2008, 2009-2011 and 2012-2014). RESULTS: An estimated 15 934 Fontan operations were performed in the USA from 2001 to 2014. Median (Q1-Q3) age was 3 (2-4) years and 39.8% were female. Hypoplastic left heart syndrome was the most common (29%) congenital heart disease diagnosis. An estimated 1175 procedures were performed in 2001 and 1340 in 2014, but there was no significant change in the number of procedures per year (p=0.47). There was significant decline in in-hospital mortality from 4.5% (53/1175) in 2001 to 1.1% (15/1340) in 2014 (p=0.009). When we compared event rates between 2001-2004 and 2012-2014 periods, there was significant decline in postoperative cardiac complications (12.6% (459/3640) to 8% (378/4706), p=0.007) and respiratory complications (17.1% (623/3640) to 10.2% (481/4706), p<0.001). However, there was increase in the number of patients discharged to home with healthcare assistance or transferred to another acute care facility (5.8% (211/3640) to 9.4% (443/4706), p=0.01) and inflation-adjusted hospitalisation cost (US$46 978 to US$60 383, p<0.001), but no significant change in length of stay (p=0.73). CONCLUSION: On the average, 1062 Fontan operations are performed annually in the USA with no change in volume of procedures but a decrease in in-hospital mortality and postoperative complications over a 15-year period.

Venous congestion and pulmonary vascular function in Fontan circulation: Implications for prognosis and treatment.

BACKGROUND: Elevation in central venous pressure (CVP) plays a fundamental pathophysiologic role in Fontan circulation. Because there is no sub-pulmonary ventricle in this system, CVP also provides the driving force for pulmonary blood flow. We hypothesized that this would make Fontan patients more susceptible to even low-level elevation in pulmonary vascular resistance index (PVRI), resulting in greater systemic venous congestion and adverse outcomes. METHODS: Adult Fontan patients and controls without congenital heart disease undergoing clinical evaluation that included cardiac catheterization and echocardiography were examined retrospectively. Outcomes including all-cause mortality and the development of Fontan associated diseases (FAD, defined as protein losing enteropathy, cirrhosis, heart failure hospitalization, arrhythmia, or thromboembolism) were assessed from longitudinal assessment. RESULTS: As compared to controls (n = 82), Fontan patients (n = 164) were younger (36 vs 45 years, p < 0.001), more likely to be on anticoagulation or antiplatelet therapy, and more likely to have atrial arrhythmia or cirrhosis. There was a strong correlation between CVP and PVRI in the Fontan group (r = 0.79, p < 0.001), but there was no such relationship in controls. Elevated PVRI identified patients at increased risk for FAD (HR 1.92, 95% CI 1.39-2.41, p = 0.01), and composite endpoint of FAD and/or death (HR 1.89, 95% CI 1.32-2.53, p = 0.01) per 1 WU∗m2 increment. CONCLUSIONS: Systemic venous congestion, which is the primary factor in the pathogenesis of FAD and death, is related to even low-level abnormalities in pulmonary vascular function. Multicenter studies are needed to determine whether interventions targeting pulmonary vascular structure and function can improve outcomes in the Fontan population.

Hepatic and renal end-organ damage in the Fontan circulation: A report from the Australian and New Zealand Fontan Registry.

BACKGROUND: Hepatic and renal dysfunction have been observed in survivors of the Fontan procedure, however their incidence and associated factors remain poorly defined. METHODS: A total of 152 participants from a Registry of 1528 patients underwent abdominal ultrasound, transient elastography (FibroScan), serum fibrosis score (FibroTest), in vivo Tc-99m DTPA measurement of glomerular filtration rate (mGFR), and urine albumin-creatinine ratio (ACR). RESULTS: Mean age and time since Fontan were 19.8 ±â€¯9.3 and 14.1 ±â€¯7.6 years, respectively. Features suggestive of hepatic fibrosis were observed on ultrasound in 87/143 (61%) and no patient was diagnosed with hepatocellular carcinoma. FibroScan median kPa was ≥10 in 117/133 (88%), ≥15 in 75/133 (56%), and ≥20 in 41/133 (31%). Fifty-four patients (54/118, 46%) had a FibroTest score ≥0.49 (equivalent to ≥F2 fibrosis). FibroTest score correlated with FibroScan value (r = 0.24, p = 0.015) and ACR (r = 0.29, p = 0.002), and patients with ultrasound features of hepatic fibrosis had a higher FibroScan median kPa (19.5 vs 15.4, p = 0.002). Renal impairment was mild (mGFR 60-89 ml/min/1.73 m2) in 46/131 (35%) and moderate (mGFR 30-59 ml/min/1.73 m2) in 3/131 (2%). Microalbuminuria was detected in 52/139 participants (37%). By multivariable analysis, time since Fontan was associated with increased FibroScan median kPa (ß = 0.89, 95% CI 0.54-1.25, p = 0.002) and decreased mGFR (ß = -0.77, 95% CI -1.29-0.24, p = 0.005). CONCLUSIONS: In the second decade after Fontan hepatic and renal structure and function are abnormal in a significant number of patients: close to 60% have ultrasonographic evidence of structural hepatic abnormalities, 46% have elevated serum hepatic fibrosis scores, and 57% have either reduced glomerular filtration rate or microalbuminuria. Hepatic and renal function should be monitored for potential impacts on outcomes after Fontan completion.

Blunted peripheral blood supply and underdeveloped skeletal muscle in Fontan patients: The impact on functional capacity.

BACKGROUND: Changes in circulatory physiology are common in Fontan patients due to suboptimal cardiac output, which may reduce the peripheral blood flow and impair the skeletal muscle. The objective of this study was to investigate the forearm blood flow (FBF), cross-sectional area (CSA) of the thigh and functional capacity in asymptomatic clinically stable patients undergoing Fontan surgery. METHODS: Thirty Fontan patients and 27 healthy subjects underwent venous occlusion plethysmography, magnetic resonance imaging of the thigh musculature and maximal cardiopulmonary exercise testing. Muscle sympathetic nerve activity (MSNA), norepinephrine measures, cardiovascular magnetic resonance, handgrip strength and 6-minute walk test were also performed. RESULTS: Fontan patients have blunted FBF (1.59 ±â€¯0.33 vs 2.17 ±â€¯0.52 mL/min/100 mL p < 0.001) and forearm vascular conductance (FVC) (1.69 ±â€¯0.04 vs 2.34 ±â€¯0.62 units p < 0.001), reduced CSA of the thigh (81.2 ±â€¯18.6 vs 116.3 ±â€¯26.4 cm2p < 0.001), lower peak VO2 (29.3 ±â€¯6 vs 41.5 ±â€¯9 mL/kg/min p < 0.001), walked distance (607 ±â€¯60 vs 701 ±â€¯58 m p < 0.001) and handgrip strength (21 ±â€¯9 vs 30 ±â€¯8 kgf p < 0.001). The MSNA (30 ±â€¯4 vs 22 ±â€¯3 bursts/min p < 0.001) and norepinephrine concentration [265 (236-344) vs 222 (147-262) pg/mL p = 0.006] were also higher in Fontan patients. Multivariate linear regression showed FVC (ß = 0.653; CI = 0.102-1.205; p = 0.022) and stroke volume (ß = 0.018; CI = 0.007-0.029; p = 0.002) to be independently associated with reduced CSA of the thigh adjusted for body mass index. The CSA of the thigh adjusted for body mass index (ß = 5.283; CI = 2.254-8.312; p = 0.001) was independently associated with reduced peak VO2. CONCLUSION: Patients with Fontan operation have underdeveloped skeletal muscle with reduced strength that is associated with suboptimal peripheral blood supply and diminished exercise capacity.

"How long will I continue to be normal?" Adults with a Fontan circulation's greatest concerns.

BACKGROUND: Little is known about adults living with a Fontan circulation's concerns outside the scope of their clinical outcomes. We examined adults with a Fontan circulations' greatest concerns, as well as their concerns around anti-coagulation, pregnancy and finances. METHODS: Adults with a Fontan circulation in the Australian and New Zealand Fontan Registry were invited to complete an anonymous online survey, of which 57 participated. A qualitative method approach using thematic analyses was used. RESULTS: The greatest concerns for adults living with a Fontan circulation were fear of death/uncertainty around life expectancy which for many individuals colored their concerns around physical health, pregnancy and having children, quality of life and finances. Improving information about outcomes to patients with a Fontan circulation might alleviate uncertainties about their future. CONCLUSIONS: Fear of death is the primary concern of adults with a Fontan circulation. It may require improved communication and targeted psychological interventions. Physical exercise incorporated as part of their lifestyle should be encouraged to alleviate physical concerns and also improve psychological well-being.

Clinical Outcomes in Adolescents and Adults After the Fontan Procedure.

BACKGROUND: Long-term outcomes of Fontan patients who survive to age ≥16 years have not been well characterized. The Australian and New Zealand Fontan Registry (ANZFR) provides a unique opportunity to understand survival and complication rates in Fontan patients who transition to adult congenital heart disease centers. OBJECTIVES: This study sought to describe the survival and complications of adult patients who have had a Fontan procedure. METHODS: The study analyzed outcomes in patients ≥16 years of age who were prospectively enrolled in the ANZFR. RESULTS: Data from all 683 adult survivors from the ANZFR were analyzed. Mortality status was confirmed from the National Death Index. There were 201 atriopulmonary (AP) connections and 482 total cavopulmonary connections (249 lateral tunnels and 233 extracardiac conduits). For these subjects, the survival rate at age 30 years was 90% (95% CI: 87% to 93%), and it was 80% (95% CI: 75% to 87%) at 40 years of age. Survival at age 30 years was significantly worse for the patients with AP connections (p = 0.03). At latest follow-up, only 53% of patients were in New York Heart Association functional class I. After the age of 16 years, 136 (20%) had experienced at least 1 new arrhythmia, 42 (6%) required a permanent pacemaker, 45 (7%) had a thromboembolic event, and 135 (21%) required a surgical reintervention. Only 41% (95% CI: 33% to 51%) of Fontan patients were free of serious adverse events at 40 years of age. CONCLUSIONS: This comprehensively followed cohort showed that a variety of morbid complications is common in Fontan adults, and that there is a substantial incidence of premature death, particularly in patients with AP connections.

Chronic kidney damage in the adult Fontan population.

OBJECTIVES: 1) To determine the accuracy of estimated GFR (eGFR) as compared to directly measured GFR (mGFR) in the adult Fontan population; 2) to determine the true prevalence of chronic kidney damage (CKD) as determined by uACR AND eGFR. METHODS: Prospective study of 81 patients Fontan patients (≥18years) followed at St. Paul's Hospital, University of British Columbia. CKD-EPI and MDRD equations used to calculate eGFR, mGFR determined by 99mTc-DTPA renal dynamic imaging and urine albumin to creatinine ratios were calculated. RESULTS: The mGFR was 93±27ml/min/1.73m2: 28 (53%) had an mGFR<90ml/min/1.73m2 and 1 (2%) had an mGFR <60ml/min/1.73m2. There was a modest correlation between mGFR and eGFR (EPI/MDRD) (r=0.50, p<0.0001 and r=0.54, p<0.0001 respectively). Both eGFR (EPI) (bias 27.0; 95% CI 18.0-27.7ml/min/m2, p<0.0001) and eGFR (MDRD) (bias 15.5; 95% CI 7.6-17.4ml/min/m2, p<0.0001) overestimated GFR as compared to mGFR. Among patients with an eGFR (EPI)/(MDRD) >90ml/min/1.73m2, 50% and 46% respectively had an mGFR <90ml/min/1.73m2. Significant albuminuria (>3mg/mmol) was present in 33% and upwards of 32% of patients with a normal eGFR (MDRD/EPI) had evidence of CKD with uACR >3mg/mmol. Using combined criteria of eGFR <90ml/min/1.73m2 and/or uACR >3mg/mmol, 46% of patients had evidence of CKD. CONCLUSIONS: This study draws attention to the need for stringent CKD screening as an important proportion of CKD is currently not being detected. Mild undetected CKD, an early marker of end organ damage, may also be an early sign of Fontan failure that requires warrants further research.

Temporal changes in liver stiffness after Fontan operation: Results of serial magnetic resonance elastography.

BACKGROUND: The relationship between temporal progression of magnetic resonance elastography derived liver stiffness (MRE-LS) and progression of Fontan associated liver disease (FALD) is unknown. To assess this relationship, we hypothesized that progression of MRE-LS correlated with progression FALD severity and clinical outcomes. METHODS: Retrospective review of Fontan patients who had >1 liver MRE, 2010-2016. Annual change in MRE-LS was the quotient of the difference between baseline and subsequent MRE-LS, and the interval between scans. RESULTS: 22 patients were enrolled; median age 29(19-38) years, 14 (64%) males and 10 (46%) with atriopulmonary Fontan. Baseline and subsequent MRE-LS values were 5.4 ±â€¯1.1 kPa and 5.8 ±â€¯0.9 kPa" for clarity, interval between scans was 25 ±â€¯5 months, and annual change in MRE-LS was 0.3 ±â€¯0.2 kPa. Temporal change in MRE-LS correlated with temporal changes in model for end-stage liver disease (MELD) score (r = 0.84, p < 0.001) and model for end-stage liver disease excluding international normalized ratio (MELD-XI) score (r = 0.75, p = 0.001). The study cohort was divided into 2 groups using the mean annual change in MRE-LS as the cut point. Groups A and B comprised of patients with annual increase in MRE-LS ≥0.3 kPa (n = 6) and <0.3 kPa (n = 16) respectively. Composite adverse event endpoint (death, heart-liver transplant listing, palliative care, hospitalization, paracentesis) was more common in Group A (4 of 6, 67%) compared to Group B (3 of 16, 19%), p = 0.13 although this did not reach statistical significance due to small sample size. CONCLUSIONS: Progression of MRE-LS correlated with clinical deterioration as measured by worsening liver disease severity scores and the occurrence of adverse events.

Evaluation of the relationship between ventricular end-diastolic pressure and echocardiographic measures of diastolic function in adults with a Fontan circulation.

BACKGROUND: Echocardiographic assessment of diastolic function in the setting of Fontan physiology is not well validated. We recently demonstrated that atrioventricular systolic to diastolic duration ratio (AVV S/D ratio) independently predicts mortality in Fontan-adults and that a value >1.1 was associated with poor prognosis. PURPOSE: To correlate echocardiographic measures of diastolic function with direct measurement of ventricular end-diastolic pressure (VEDP). METHODS: A retrospective analysis was undertaken of Fontan-adults who had transthoracic echocardiography (TTE) within 12 months of direct measurement of VEDP during cardiac catheterisation. RESULTS: Fifteen Fontan adults (3 males, mean age 29 ±â€¯9 years) were evaluated. Thirteen patients had dominant morphologic left ventricle and 2 had morphologic right ventricle. Four had atriopulmonary connection and 11 had total cavopulmonary connection. Twelve patients were NYHA Class I/II and 3 were Class III. Time between TTE and cardiac catheter was 46 ±â€¯113 days; VEDP was 8 ±â€¯5 mmHg. Ten patients had preserved ventricular function, 3 had mild and 2 had moderate systolic impairment by subjective TTE assessment. AVV S/D ratio had the strongest correlation with VEDP (r = 0.8, p = 0.001). AVV S/D ratio ≥ 1.1 had 100% positive predictive value and 92% negative predictive value for detecting VEDP >10 mmHg. The only conventional echocardiographic measure of diastolic function that correlated with VEDP was pulmonary vein A wave - atrioventricular A wave duration difference (r = 0.8, p = 0.02). CONCLUSIONS: TTE measures reflect VEDP in adults with a Fontan circulation. AVV S/D ratio is a simple parameter yet to enter standard practice that can be used to identify elevated VEDP.