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.

Longitudinal sequential biventricular assessment in adults with transposition of the great arteries and relationship with adverse outcomes.

BACKGROUND: In a cohort of congenitally corrected transposition of the great arteries (cc-TGA) and transposition of the great arteries after atrial switch procedure (d-TGA) the study objectives were: 1) to assess the change of quantitative systemic right ventricle (sRV) parameters over time and; 2) to examine the relationship of quantitative sRV parameters with adverse clinical outcomes. METHODS AND RESULTS: Single-center cohort study that included 49 (39%) cc-TGA and 76 (61%) d-TGA patients >18years who had at least one MUGA sRV assessment, 18/39 had more than one respectively. The primary clinical endpoint was all-cause mortality, heart transplantation and/or heart failure hospitalization. At a median clinical follow-up of 7years following the first MUGA, the primary endpoint occurred more often in cc-TGA versus d-TGA patients (18 (36.7%) vs. 9 (11.8%), p=0.03). Median time between the MUGA assessments was 5.8 (cc-TGA) and 4.9years (d-TGA). At last MUGA follow-up: 6 (33%) cc-TGA/14 (36%) d-TGA patients showed a significant decline in sRVEF (>5%); 6 (33%) cc-TGA/17 (44%) d-TGA patients had a significant increase in sRVEDVi; and 7 (39%) cc-TGA/19 (49%) PA-TGA patients had a significant increase in sRVESVi. Baseline sRV parameters were not associated with the primary end point or sRV changes over time. CONCLUSIONS: An important proportion of both patient cohorts demonstrated a significant change in sRV parameters over time and these are likely related to multiple factors that vary between individuals given population heterogeneity. The TGA patients have distinct clinical trajectories with increased adverse heart failure outcomes in the cc-TGA population and sRV parameters were not related to adverse heart failure events in either group.

Balloon angioplasty of right ventricular outflow tract conduits.

Palliation of complex congenital heart disease, requiring reconstruction of the right ventricular outflow tract (RVOT), is standard practice. Survival of the homograft is a limiting factor. We examined the role of balloon angioplasty (BAP) in prolonging conduit life. Twelve patients underwent 15 BAP procedures between February 1989 and October 1997. The median age at conduit insertion was 28 months with detection of a significant echo gradient 42 months later. Calcification of homografts, with attendant obstruction and valve dysfunction, was present in all patients. BAP was performed within 1 month of echocardiography and reduced the gradient from a median of 57 to 38 mmHg (p < 0.0005). Echocardiographic follow-up showed persistent gradients (median 68 mmHg) and 11/12 patients went on to conduit replacement after BAP. Only one patient had replacement deferred as a result of BAP. Complications requiring intervention occurred in 20% of the procedures and included bleeding and an unusual balloon fracture. Although BAP can reduce the pressure gradient across the RVOT conduit, the effect is transient and the delay of surgery is not due to improved hemodynamic function. Approximately 10% of cases will benefit from BAP alone, but given the high rate of complications, we do not recommend this procedure as a means of prolonging conduit life.

The evolution of ductus arteriosus treatment.

The treatment of patent ductus arteriosus (PDA) has evolved over the years. We reviewed 231 non-premature children (group 1) undergoing surgical closure of a PDA between January 1985 and December 1997, and 30 children (group 2) undergoing transcatheter closure from May 1995 to December 1998. The median age and weight at operation in group 1 were 13 months (range, 0.5-174 months) and 9.5 kg (range, 1.9-49.7 kg), respectively. There was one intra-operative death (0.4%) secondary to hemorrhage. Immediate extubation was performed in 208 patients (90%). Intra-operative chest tube use decreased from 73.3% to 10% between the 1985-88 and 1996-97 periods (P < 0.001). Postoperative pneumothoraces occurred in 33/131 (25%) patients with only one patient (0.7%) requiring drainage. Eleven patients had complications including wound infection in four, vocal cord paralysis in three, and left pulmonary artery stenosis in one. The median length of stay (LOS) was 5 days (range, 2-43 days). Follow-up echocardiogram was performed in 146/230 patients (63%) and revealed a residual PDA in six (4%); two being re-ligated, two remaining clinically insignificant, and two spontaneously resolved at 7 and 28 months follow-up. The remaining 84 patients had no clinical signs of a residual PDA. In group 2, where a transcatheter coil occlusion technique was used, the median age and weight at procedure were 31 months (range, 9-320 months) and 14.9 kg (range, 9-69.7 kg), respectively. Vascular complications occurred in four patients (13.3%). One patient developed hemolysis and hemoglobinuria requiring hospital admission. Four patients required a second intervention. At the most recent echocardiographic assessment, four patients (13.3%) had a residual PDA.

Coil occlusion of the patent ductus arteriosus: lessons learned.

PURPOSE: To review the clinical outcomes of catheter-directed coil occlusion (coil occlusion) of persistently patent ductus arteriosus (PDA) at a pediatric tertiary care hospital. METHODS: A retrospective review of all patients referred to the Cardiac Catheterization Laboratory for coil occlusion at our institution was performed. Twenty-one consecutive patients (12 female) underwent coil occlusion and follow-up between May 1995 and December 1997. We undertook PDA occlusion if: (a) the PDA narrowed to less than 4 mm on echocardiogram and (b) the minimum body weight was approximately 10 kg. Standard right and retrograde left heart catheterization was performed, followed by coil occlusion. Color-flow mapping (CFM) was used intra-procedurally to confirm occlusion of the PDA with a follow-up study several weeks later. RESULTS: The median age and weight of the patients were 33 months and 13.2 kg, respectively. Fourteen patients received one coil, with six requiring a second coil and one requiring multiple coils. Initial follow-up was at a median of 2.4 months. At latest follow-up, 2 patients still have persistent flow at the ductal level. The coils were deployed without complication or embolization. CONCLUSIONS: A review of our first 21 cases demonstrated three important lessons: (1) the maximum diameter of the PDA suitable for coil occlusion is approximately 3 mm; (2) CFM must show complete obliteration of flow in the catheterization lab in order to ensure occlusion of the PDA at follow-up; and (3) the Jackson detachable system allows for precise placement of the coil, often within another coil.

Early and intermediate-term complications of self-expanding stents limit its potential application in children with congenital heart disease.

OBJECTIVES: We report on the early and intermediate-term follow-up results of self-expanding Wallstent (Schneider, Switzerland) implanted in children with congenital heart disease. BACKGROUND: The inherent shortcomings of balloon-expandable stents prompted the trial of an alternative stent. METHODS: Twenty patients underwent 22 implantations of 25 self-expanding Wallstents between December 1993 and June 1997 in two institutions. The mean age and weight were 10.8+/-4.5 years and 30.5+/-14.2 kg, respectively. The patients were divided into two groups: 1) Group I comprised 17 patients with pulmonary arterial stenoses, 2) Group II comprised four patients with venous stenoses (one belonged to both groups). Sixteen patients underwent recatheterization at a median of 5.8 months (range 0.5 to 31, mean 8.1 months) after stenting. Hemodynamic and angiographic changes after the interventional procedures and complications were documented. RESULTS: All the stents were successfully deployed in the intended position. In Group I, the narrowest diameter of the stented vessel increased from 4.1+/-1.5 to 8+/-2 mm (95% increase, p < 0.0001) while the systolic pressure gradient across decreased from 24.6+/-15.8 to 12.1+/-11.4 mm Hg (51% decrease, p = 0.001). In Group II, the dimensional changes of the narrowest segment increased from 4.3+/-0.5 to 7.5+/-0.4 mm (75% increase, p = 0.003), and the pressure gradient reduced from 5.0+/-2.9 to 0.9+/-1.0 mm Hg (82% decrease, p = 0.04) across the stented venous channel. Distal migration of two optimally positioned stents occurred within 24 h of implantation. At recatheterization, significant neointimal ingrowth (>30% of the expanded diameter) was noted in 7 (28%) of the 25 implanted stents. This responded poorly to balloon dilation. Predisposing factors for the neointimal ingrowth included stents of smaller diameter (<9 mm) and longer period after implantation. CONCLUSIONS: Self-expanding Wallstent could be deployed easily and safely to relieve vascular stenoses in children. The complications of distal migration, significant neointimal ingrowth and its unyielding design to overdilation limit its application to this patient group.

Extracardiac Fontan operation with tube fenestration allowing transcatheter coil occlusion.

A fenestration may improve the immediate postoperative course after a Fontan procedure by preserving the cardiac output. We describe a simple and safe technique of fenestration amenable to coil occlusion, which can be carried out in most cardiac catheterization laboratories.

Kawasaki disease in the older child.

OBJECTIVES: To determine the prevalence of Kawasaki disease in older children and to evaluate its clinical presentation, time to diagnosis, and outcome in comparison with younger patients with the disease. METHODOLOGY: A retrospective analysis of all patients discharged with a diagnosis of Kawasaki disease at a pediatric tertiary care hospital over a 12-year period. RESULTS: A total of 133 patients were included in this study; 7.5% were 9 years of age or older at the time of illness. Patients were grouped by age: infants included children age 1 to 8 years of age and children 9 years of age or older. Older children had a higher frequency of abnormal cardiovascular physical examination (50%) versus children (6%) and infants (10%). The older age group and the infants had a higher prevalence of coronary artery abnormalities and poor left ventricular function than did the 1- to 8-year-olds. Eighty percent of the older children had coronary arteries that were either dilated or aneurysmal, and 30% demonstrated left ventricular dysfunction on initial echocardiography. The number of days to diagnosis after meeting the diagnostic criteria was 5.8 +/- 2.3 for infants, 5.2 +/- 1.5 for older children, and 1.9 +/- 0.3 for children. Older children had a complicated course of Kawasaki disease compared with younger patients. CONCLUSION: We found a higher prevalence of older children with Kawasaki disease at our center than has previously been reported. Older patients, as well as infants, had a higher rate of coronary artery abnormalities than did the children between 1 and 8 years of age. Older age at the time of illness or a delay in treatment may be important factors in determining cardiac involvement in Kawasaki disease.

Congenitally corrected transposition of the great arteries and exercise-induced ventricular tachycardia.

Congenitally corrected transposition of the great arteries (CCTGA) is an uncommon condition. Few patients survive past 50 years of age, because of associated congenital defects, systemic (morphological right) ventricular dysfunction, atrioventricular valvular insufficiency or complete heart block. A unique case is presented of exercise-induced ventricular tachycardia, which led to the diagnosis of CCTGA, without atrioventricular block or other cardiac anomalies.

Technology assessment of nonsurgical closure of patent ductus arteriosus: an evaluation of the clinical effectiveness and costs of a new medical device.

OBJECTIVE: To assess the clinical efficacy and cost impact of a new medical device for the nonsurgical closure of patent ductus arteriosus (PDA). METHODS: This was a before-after study comparing the most recent 20 surgical procedures with the first 20 nonsurgical procedures for PDA using a new medical device. Clinical outcome, hospital stay, device cost, and physician fees were compared. RESULTS: Surgical closure was effective in all 20 patients, with an average cost of $4667. In a similar patient group, nonsurgical closure was achieved in 18 of 20 patients (90%), with an estimated average cost per successful procedure of $4690. A clinically insignificant PDA leak persisted beyond 12 months in four nonsurgically managed patients. CONCLUSION: Nonsurgical closure of PDA can be recommended as an effective new medical technique that is not associated with a measurable increase in direct costs and that provides significant indirect and intangible cost advantages.

Human immunodeficiency virus seroprevalence in an occupational cohort in a South African community.

BACKGROUND: In the early years of the worldwide pandemic, there were no reported cases of acquired immunodeficiency syndrome in Lesotho, a small, mountainous country in South Africa. Since 1986, when the first case of acquired immunodeficiency syndrome was identified, reported diagnoses have risen precipitously. The initiation of the Lesotho Highlands Water Project has resulted in the influx of a migrant workforce of predominantly single males into a relatively isolated, mountainous area where human immunodeficiency virus (HIV) was previously unknown. OBJECTIVE: To ascertain the HIV seroprevalence among a cohort of laborers at the Katse Dam construction site in Bokong, Lesotho. METHODS: During the 5-week study period in late 1992, construction workers (age range, 15 to 59 years) who were first-time clinic users for any chief complaint were randomly selected for serological study. Surveillance complied with the Lesotho National AIDS Control Programme guidelines, which required unlinked, anonymous testing. Serum samples were screened by an enzyme-linked immunosorbent assay; the results were confirmed by the Western blot technique. RESULTS: Unlinked, anonymous HIV testing of 486 persons revealed a seroprevalence of 5.3% (26/486; 95% confidence interval, 3.3% to 7.3%). These data contrasted with a 0.8% seroprevalence in a similar age group in nearby villages that surrounded the construction project. CONCLUSIONS: Lesotho, in the early phase of the HIV/acquired immunodeficiency syndrome epidemic in Africa in the 1980s, was seemingly protected by its relative isolation. Grave concern is now warranted as the country is destined to experience a rapid rise in HIV seroprevalence. Increased surveillance, health education opportunities, and aggressive prevention activities at the Katse Dam construction site are imperative to arrest the spread of HIV from construction workers to nearby villagers.

Trends in the prevalence of congenital heart disease: comprehensive observations over a 24-year period in a defined region of Canada.

OBJECTIVE: To determine the prevalence of congenital heart disease (CHD) in the three Maritime provinces, and to study prevalence differences among provinces and defined regions within these provinces. DESIGN: Each province was divided by counties into regions. All cases of CHD who were born alive in the study area between 1966 and 1989 were entered in a registry. Prevalences were analyzed for each province and for selected regions per year, per 1000 live births, and by diagnosis made by one year of age and by the 16th birthday. Comparison was then made with prevalences of a group who had severe lesions. INTERVENTIONS: Excepting a small number of CHD cases who were diagnosed by autopsy only, diagnosis was made by pediatric cardiologists using appropriate procedures, including cardiac ultrasound and cardiac catheterization. SETTING: The only tertiary care centre for children's heart disease in the provinces of Nova Scotia, New Brunswick and Prince Edward Island, areas of relative geographic isolation (combined population of 1.75 million people). MAIN RESULTS: A statistically significant positive linear trend occurred in these provinces during the study. The recorded prevalence of CHD in New Brunswick was significantly lower. Pooled prevalences by the first and 16th birthdays (8.0 and 12.5 per 1000 live births, respectively) of two regions of highest prevalence for 1980-86 were significantly higher (P < 0.05) than the pooled prevalence rate of all the remaining regions. Prevalence rates of a group with severe lesions were stable for 1976-86 in all regions. CONCLUSIONS: Differences in prevalence of CHD among provinces and regions were related to ascertainment levels. Prevalence of CHD with diagnosis by the first and 16th birthdays were approximately 8.0 and 12.5 per 1000 live births, respectively. The prevalence rate of a severe lesion group was a stable measure.

Plasma and cerebrospinal fluid arginine vasopressin in patients with and without fever.

Hyponatraemia has been described in association with a number of acute infectious diseases, mainly bacterial and tuberculous meningitis and pneumonia, and has been attributed to inappropriate secretion of arginine vasopressin (AVP). The mechanism of inappropriate AVP production is uncertain, but there is experimental evidence to suggest that fever may stimulate secretion of AVP into plasma and cerebrospinal fluid. In this study, AVP concentrations in plasma and cerebrospinal fluid from 37 febrile children with infections have been compared with those from 27 afebrile control subjects. Ten of the febrile children had meningitis (eight bacterial, two viral) and the remainder a variety of other infectious diseases. Seventy four per cent of febrile infected children were hyponatraemic (serum sodium less than 135 mmol/l) compared with only 8% of the afebrile controls. Plasma AVP concentrations were significantly higher in the febrile patients (median 2.92 pmol/l, range 1.0-23.25, n = 28) than in controls (median 1.67 pmol/l, range 0.57-6.0, n = 14) but there was no significant difference in cerebrospinal fluid AVP concentrations. There was no difference in plasma AVP concentrations between patients with meningitis and those with infections not involving the central nervous system. Careful attention should be paid to fluid and electrolyte balance in all children with acute infections.

Perinatal supraventricular tachycardia.

OBJECTIVE: To determine the incidence, therapy required and prognosis of perinatal supraventricular tachycardia (SVT). DESIGN: Retrospective chart review of eight years. SETTING: Tertiary level perinatal and pediatric centres in Halifax, Nova Scotia. PATIENTS: All newborn infants who developed SVT either in utero or in the first 30 days of life. RESULTS: SVT was present in 33 neonates, with a male:female ratio of 2.7:1 and an incidence of 1:4347. Fetal SVT was recorded in nine (group I) but these patients did not differ from those with postnatal SVT (group II) in birthweight, noncardiac illnesses and associated heart disease. Thirty-one of the babies (94%) received digoxin and eight (24%) also required propranolol. All were asymptomatic after 48 h. One late death occurred due to renal failure unrelated to the dysrhythmia. No major congenital heart disease was found in either group. Follow-up over 44 months revealed four late relapses requiring prolonged therapy. CONCLUSIONS: Perinatal SVT is a common disorder in a tertiary centre and may represent a transient adaptation phenomenon. It is usually benign, easily treated and rarely associated with major congenital heart disease.

Assessment of blood pressures and gradients by automated blood pressure device compared to invasive measurements in patients previously operated on for coarctation of the aorta.

The aim of the study was to compare invasive and non-invasive blood pressure measurements and gradients. Twenty-two children and 16 adults previously operated for coarctation of the aorta were included. Invasive blood pressures were recorded proximally and distally close to the former operation site and non-invasive systolic blood pressures were recorded by an automated sphygmomanometer on right arm and leg. The adults were investigated at rest and during supine exercise. The correlation between invasive and non-invasive measurements of proximal blood pressures in adults at rest and children were the following, r = 0.92, SD 7.6 mmHg (n = 16) and r = 0.85, SD 11 mmHg (n = 22) respectively. The corresponding correlation for the distal blood pressures were the following for adults at rest 0.64, SD 11.9 mmHg and in children r = 0.82, SD 9.2 mmHg. During exercise in adults we found a low correlation when comparing invasive and non-invasive proximal and distal blood pressures and a poor correlation regarding the gradients, r = 0.50, SD 16 mmHg, r = 0.45, SD 15.9 mmHg and r = 0.30, SD 22.9 mmHg respectively (n = 16). We also measured the time interval between cessation of exercise and completion of the blood pressure recordings, which gave a mean interval of 73 sec (range 45-115 sec). During that interval the mean fall in the proximal blood pressure was 37 mmHg (range 20-80 mmHg), and the mean fall of the gradient was from 41 mmHg (range 20-76 mmHg) to 23 mmHg (range 6-56 mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)