Dorothy J. Radford

Redefining Expectations of Long-Term Survival After the Fontan Procedure Twenty-Five Years of Follow-Up From the Entire Population of Australia and New Zealand

Background— The life expectancy of patients undergoing a Fontan procedure is unknown. Methods and Results— Follow-up of all 1006 survivors of the 1089 patients who underwent a Fontan procedure in Australia and New Zealand was obtained from a binational population-based registry including all pediatric and adult cardiac centers. There were 203 atriopulmonary connections (AP; 1975–1995), 271 lateral tunnels (1988–2006), and 532 extracardiac conduits (1997–2010). The proportion with hypoplastic left heart syndrome increased from 1/173 (1%) before 1990 to 80/500 (16%) after 2000. Survival at 10 years was 89% (84%–93%) for AP and 97% (95% confidence interval [CI], 94%–99%) for lateral tunnels and extracardiac conduits. The longest survival estimate was 76% (95% CI, 67%–82%) at 25 years for AP. AP independently predicted worse survival compared with extracardiac conduits (hazard ratio, 6.2; P<0.001; 95% CI, 2.4–16.0). Freedom from failure (death, transplantation, takedown, conversion to extracardiac conduits, New York Heart Association III/IV, or protein-losing enteropathy/plastic bronchitis) 20 years after Fontan was 70% (95% CI, 63%–76%). Hypoplastic left heart syndrome was the primary predictor of Fontan failure (hazard ratio, 3.8; P<0.001; 95% CI, 2.0–7.1). Ten-year freedom from failure was 79% (95% CI, 61%–89%) for hypoplastic left heart syndrome versus 92% (95% CI, 87%–95%) for other morphologies. Conclusions— The long-term survival of the Australia and New Zealand Fontan population is excellent. Patients with an AP Fontan experience survival of 76% at 25 years. Technical modifications have further improved survival. Patients with hypoplastic left heart syndrome are at higher risk of failure. Large, comprehensive registries such as this will further improve our understanding of late outcomes after the Fontan procedure.

Molecular genetics of long QT syndrome

Long QT syndrome (LQTS) is a cardiac disorder associated with sudden death especially in young, seemingly healthy individuals. It is characterised by abnormalities of the heart beat detected as lengthening of the QT interval during cardiac repolarisation. The incidence of LQTS is given as 1 in 2000 but this may be an underestimation as many cases go undiagnosed, due to the rarity of the condition and the wide spectrum of symptoms. Presently 12 genes associated with LQTS have been identified with differing signs and symptoms, depending on the locus involved. The majority of cases have mutations in the KCNQ1 (LQT1), KCNH2 (LQT2) and SCN5A (LQT3) genes. Genetic testing is increasingly used when a clearly affected proband has been identified, to determine the nature of the mutation in that family. Unfortunately tests on probands may be uninformative, especially if the defect does not lie in the set of genes which are routinely tested. Novel mutations in these known LQTS genes and additional candidate genes are still being discovered. The functional implications of these novel mutations need to be assessed before they can be accepted as being responsible for LQTS. Known epigenetic modification affecting KCNQ1 gene expression may also be involved in phenotypic variability of LQTS. Genetic diagnosis of LQTS is thus challenging. However, where a disease associated mutation is identified, molecular diagnosis can be important in guiding therapy, in family testing and in determining the cause of sudden cardiac death. New developments in technology and understanding offer increasing hope to families with this condition.

The extracardiac conduit Fontan procedure in Australia and New Zealand: hypoplastic left heart syndrome predicts worse early and late outcomes

OBJECTIVES To identify factors associated with hospital and long-term outcomes in a binational cohort of extracardiac conduit (ECC) Fontan recipients. METHODS All patients who underwent an ECC Fontan procedure from 1997 to 2010 in Australia and New Zealand were identified, and perioperative, follow-up, echocardiographic and reintervention data collected. Risk factors for early and late mortality, failure and adverse outcomes were analysed. RESULTS A total of 570 patients were identified, and late follow-up was available in 529 patients. The mean follow-up was 6.7 years (standard deviation: 3.5) and completeness of the follow-up was 98%. There were seven hospital mortalities (1%) and 21 patients (4%) experienced early failure (death, Fontan takedown/revision or mechanical circulatory support). Prolonged length of stay occurred in 10% (57 patients), and prolonged effusions in 9% (51 patients). Overall survival at 14 years was 96% (95% confidence interval [CI]: 93-98%), and late survival for patients discharged with intact Fontan was 98% (95% CI: 94-99%). The rates of late failure (late death, transplantation, takedown, New York Heart Association class III/IV or protein-losing enteropathy) and adverse events (late failure, reoperation, percutaneous intervention, pacemaker, thromboembolic event or supraventricular tachycardia) per 100 patient-years were 0.8 and 3.8, and their 14-year freedoms were 83% (95% CI: 70-91%) and 53% (95% CI: 41-64%), respectively. After adjustment for confounders, hypoplastic left heart syndrome (HLHS) was strongly associated with prolonged effusions (OR: 2.9, 95% CI: 1.4-5.9), late failure (hazard ratio [HR]: 2.8, 95% CI: 1.1-7.5) and adverse events (HR: 3.6, 95% CI: 1.3-7.5). CONCLUSIONS The extracardiac Fontan procedure provides excellent survival into the second decade of life, but half of patients will suffer a late adverse event by 14 years. Patients with HLHS are at higher risk of late adverse events than other morphological groups, but their survival is still excellent.

Echocardiographic assessment of bicuspid aortic valves. Angiographic and pathological correlates.

Aortic root echocardiograms were recorded from 89 patients whose aortic valves had also been adequately defined by selective angiography or viewed surgically or at autopsy. The eccentricity index (E.I.) of the aortic leaflets was measured at the onset of diastole and an E.I. of 1.3 or greater was taken as abnormal.Of 31 patients with isolated nonobstructed or mildly obstructed bicuspid aortic valves (7 viewed previously at valvotomy and 24 diagnosed radiologically) 23 (74%) had an abnormal E.I. Varying eccentricity occurred in some of these patients. Central leaflet echoes (E.I. of 1.0 to 1.25) were present in the other eight patients. All 14 patients with nonobstructed tricuspid aortic valves had central echoes. Additional multilayered diastolic echoes were found in patients with bicuspid aortic valves as well as in two patients with abnormal tricuspid aortic valves.The valves of 13 patients with aortic stenosis or incompetence were viewed surgically and the E.I. was abnormal in all patients with a bicuspid aortic valve in this group. Aortic leaflet echo findings were not diagnostically helpful in ten patients with tetralogy of Fallot, one of whom had a normal E.I. with a surgically confirmed bicuspid aortic valve. Of 21 patients with VSD only one had a bicuspid aortic valve but six had an abnormal E.I. This false positive sign was related to a high membranous VSD, sometimes with aortic valve prolapse.It is concluded that an E.I. of ≤ 1.3 in the absence of an associated VSD is diagnostic of a bicuspid aortic valve and can be expected to be found in approximately three-quarters of subjects with this abnormality.

The Fontan epidemic: Population projections from the Australia and New Zealand Fontan Registry

BACKGROUND The number and age demographic of the future Fontan population is unknown. METHODS Population projections were calculated probabilistically using microsimulation. Mortality hazard rates for each Fontan recipient were calculated from survivorship of 1353 Fontan recipients in the Australia and New Zealand Fontan Registry, based on Fontan type, age at Fontan, gender and morphology. Projected rates of new Fontan procedures were generated from historical rates of Fontan procedures per population births. RESULTS At the end of 2014, the living Fontan population of Australia and New Zealand was 1265 people from an Australian and New Zealand regional population of 28 million (4.5 per 100,000 population). Of those, 165 (13%) received an atrio-pulmonary (AP) procedure, 262 (21%) a lateral tunnel (LT) procedure and 838 (66%) an extra-cardiac conduit (ECC) procedure. This population is expected to grow to 1917 (95% CI: 1846: 1986) by 2025 (5.8 per 100,000 population), with 149 (8%) AP procedures, 254 (13%) LT procedures, and 1514 (79%) ECC procedures. By 2045, the living Fontan population is expected to reach 2986 (95% CI: 2877: 3085; 7.2 per 100,000 population). The average age of the Fontan population is expected to increase from 18years in 2014 to 23years (95% CI: 22-23) by 2025, and 31years (95% CI: 30-31) by 2045. CONCLUSION The Australian and New Zealand population of patients alive after a Fontan procedure will double over the next 20years increasing the demand for heart-failure services and cardiac transplantation. Greater consideration for the needs of this mostly adult Fontan population will be necessary.

Facial and immunological anomalies associated with tetralogy of Fallot

Dysmorphic facial features were present in 9 of 31 children with tetralogy of Fallot anatomy (29%). These anomalies included hypertelorism, low-set ears, small mouth, short philtrum, and micrognathia. Ten children had pulmonary atresia, 13 (42%) had a right aortic arch, and 13 had extracardiac congenital anomalies. There were 16 children in the series (52%) who had hospital admissions for important or recurrent infections, and 18 who had immune deficiency: low levels of T lymphocytes were found in 9, low levels of complement in 8, and low immunoglobulins in 3. Embryologically, the cardiac outflow tracts, the aortic arch, the face, and the thymus develop at the same time, and all receive migrating cells from the neural crest. Teratogenic factors possibly produce this constellation of anomalies, which is in the spectrum of the Di George syndrome (third and fourth pharyngeal pouch syndrome). It is of importance for the management of such children, that their immune deficiency be recognized and treated appropriately.

Multiple valvar replacements for hypereosinophilic syndrome

A boy with familial eosinophilia had the hypereosinophilic syndrome, with involvement of mitral and tricuspid valves. Between the ages of 11 and 20 years, he underwent eight surgical procedures on his atrioventricular valves. The pathology included recurrent thrombotic vegetative masses related to hypereosinophilia. Initial repair of the mitral valve was shortlived, but recurrent repairs of the tricuspid valve were helpful. Mechanical prostheses inserted in the mitral position thrombosed despite anticoagulant therapy, and bioprosthetic valves deteriorated with thrombus, fibrosis, or tearing. The hypereosinophilic syndrome is unusual in children, and produces additional problems with valvar surgery.

Use of ACE inhibitors in Fontan: Rational or irrational?

BACKGROUND Despite a lack of evidence supporting the use of angiotensin-converting enzyme (ACE) inhibitors in patients with a Fontan circulation, their use is frequent. We decided to identify the rationale for ACE inhibitor therapy in patients within the Australia and New Zealand Fontan Registry. METHODS All patients in the Registry taking an ACE inhibitor at last follow up were identified, and a review of medical records was undertaken to determine the rationale for treatment initiation and reasons for treatment continuation or dose increase. RESULTS In 2015, 36% of the surviving patients in the Registry (462/1268) were taking an ACE inhibitor. Indications for initiation of therapy were ventricular systolic or diastolic dysfunction (29%), atrioventricular valve regurgitation (19%), preservation of normal ventricular function (7%), prolonged effusions at Fontan (6%), hypertension (6%), other (6%) and unknown (2%). No indication was stated in the remaining patients (25%). Those with hypoplastic left heart syndrome were more likely to be on an ACE inhibitor than those with an alternative primary morphology (70% vs 32%; p<0.001). Only 36% of the patients treated with an ACE inhibitor at last follow up (166/462) had an indication that would generally justify treatment in a two-ventricle circulation. CONCLUSION It is likely that the use of ACE inhibitors in patients with a Fontan circulation is excessive within our region. The coordination of prospective, multicentre studies and initiatives such as the Australia and New Zealand Fontan Registry will facilitate further investigations to guide treatment decisions in the growing Fontan population.

Outcomes of Truncus Arteriosus Repair in Children: 35 Years of Experience From a Single Institution

We evaluated the long-term outcomes following repair of truncus arteriosus (TA) from a single institution. We conducted a retrospective review of children (n = 171) who underwent TA repair between 1979 and 2014. Early mortality rate was 11.7% (20/171). There were 19 late deaths. Most deaths (74%, 29/39) occurred within the first year following surgery. The 1-year mortality rate in 1979-2004 was 18% (25/136) and decreased to 11% (4/35) in 2005-2014. The overall survival rate was 73.6% at 30 years. Multivariate analysis identified postoperative extracorporeal membrane oxygenation (P = 0.003), operative weight <2.5kg (P = 0.012), prior surgical intervention (P = 0.018), and coronary artery anomaly (P = 0.037) as risk factors for early mortality. A Cox regression model identified DiGeorge syndrome (P = 0.008) as a risk factor for late mortality. Freedom from right ventricular outflow tract reoperation was 4.6% at 20 years. Concomitant truncal valve (TV) repair or replacement was undertaken in 20 patients. Additionally, 14 patients underwent late TV repair or replacement. The overall survival rate in patients who underwent TV operation was 76.9% at 20 years. A total of 19 patients had concomitant interrupted aortic arch with a survival rate of 89.5% at 20 years. Median follow-up was 19 years (mean = 17 years, range: 1-34 years). All patients were in New York Heart Association Class I/II at last follow-up. Following repair of TA, patients had good long-term functional status but had high reoperation rates. Repair of interrupted aortic arch and TV were not risk factors for mortality. Postoperative extracorporeal membrane oxygenation, operative weight <2.5kg, prior surgical intervention, and coronary artery anomaly were risk factors for early death. DiGeorge syndrome was associated with late death, most commonly from infection.

The management of the older adult patient with anomalous left coronary artery from the pulmonary artery syndrome: a presentation of two cases and review of the literature.

ALCAPA (anomalous left coronary artery from pulmonary artery) syndrome is a rare congenital abnormality that involves an anomalous insertion of the left coronary artery into the pulmonary artery. Ninety percent of patients present in the first year of life with signs and symptoms of heart failure or sudden cardiac death secondary to chronic myocardial ischemia. There have been an increasing number of reports of ALCAPA patients surviving to adulthood. There seems, however, to be a tendency to die suddenly in the third decade of life. Adult survivors are either asymptomatic or present with mitral regurgitation, cardiomyopathy, myocardial ischemia, or malignant arrhythmias. The management of the older patient presenting with symptoms resulting from ischemia and progressive left ventricular dysfunction remains a challenge. Treatment is largely based on guidelines for adult congenital heart disease management and an extrapolation of evidence from heart failure practice. Currently, surgical reimplantation of the anomalous coronary onto the aorta is the mainstay of treatment. The management of heart failure, sudden cardiac death, and ventricular arrhythmia present problems that are not addressed by reimplantation of the anomalous vessel alone. In this report, we present two cases with different modes of presentation and discuss treatment options.ALCAPA (anomalous left coronary artery from pulmonary artery) syndrome is a rare congenital abnormality that involves an anomalous insertion of the left coronary artery into the pulmonary artery. Ninety percent of patients present in the first year of life with signs and symptoms of heart failure or sudden cardiac death secondary to chronic myocardial ischemia. There have been an increasing number of reports of ALCAPA patients surviving to adulthood. There seems, however, to be a tendency to die suddenly in the third decade of life. Adult survivors are either asymptomatic or present with mitral regurgitation, cardiomyopathy, myocardial ischemia, or malignant arrhythmias. The management of the older patient presenting with symptoms resulting from ischemia and progressive left ventricular dysfunction remains a challenge. Treatment is largely based on guidelines for adult congenital heart disease management and an extrapolation of evidence from heart failure practice. Currently, surgical reimplantation of the anomalous coronary onto the aorta is the mainstay of treatment. The management of heart failure, sudden cardiac death, and ventricular arrhythmia present problems that are not addressed by reimplantation of the anomalous vessel alone. In this report, we present two cases with different modes of presentation and discuss treatment options.