PubMed Health⌕ Search

Biomedical subjects

William T Mahle

Publications and source records attributed to William T Mahle.

At least 19 recordsLinked to original sources
PubMed2006

Reduction in initial ventricular systolic and diastolic velocities after heart transplantation in children: improvement over time identified by tissue Doppler imaging.

BACKGROUND: Tissue Doppler imaging (TDI) is a non-invasive method for measuring ventricular function that can provide insight into the changes in hemodynamics that occur after pediatric heart transplantation. The purpose of this study was to quantify longitudinal changes in myocardial velocities within the first 6 months after transplantation in children. METHODS: Thirteen patients were serially studied (median age at transplant 5.9 years) and compared with controls. Tissue Doppler systolic (S), early (E) and late (A) diastolic velocities were recorded at the tricuspid annulus, mitral annulus and interventricular septum. RESULTS: TDI studies were serially performed during 6 months post-transplantation: <10 days (n = 48); 11 to 30 days (n = 26); 31 to 60 days (n = 13); 61 to 120 days (n = 12); and 121 to 180 days (n = 16). Mean systolic tissue velocities at the tricuspid annulus were 3.8 cm/s (95% confidence interval [CI]: 3.1 to 4.6) at baseline (<10 days) and 6.3 cm/s (95% CI: 4.1 to 8.6) at 6 months post-transplantation (mean increase from baseline: 2.5 cm/s; 95% CI: 0.1 to 4.9). Systolic tissue velocities at the mitral annulus also increased over time (mean change from baseline: 0.9 cm/s; p = 0.02). Early diastolic (E) velocities at the tricuspid annulus and mitral annulus significantly improved over time (p < 0.0001 and p = 0.002, respectively). Systolic and diastolic velocities measured at >121 days after transplantation, however, remained significantly lower than those of normal controls. CONCLUSIONS: TDI demonstrated systolic and diastolic velocities improved during the initial 180 days after heart transplantation. Systolic and diastolic velocities were reduced in children after heart transplantation when compared with controls.

Adolescent↗
PubMed2006

Cost-effectiveness of pediatric heart transplantation.

BACKGROUND: Survival after pediatric heart transplantation has continued to improve. Nonetheless, graft survival is generally <15 years and the costs of transplantation and subsequent immunosuppression are substantial. In the present study, we sought to examine the cost-effectiveness of pediatric heart transplantation. METHODS: Data from 95 pediatric subjects undergoing transplantation at our institution from 1997 through 2004 were reviewed to determine the costs of pediatric heart transplantation. Costs included pre-transplant care, organ procurement, initial hospitalization and follow-up care. Life expectancy was derived from the United Network of Organ Sharing data set. Data were reported as cost per quality-adjusted life-years (QALYs) gained, which were discounted at 3%. Cost-effectiveness was stratified by primary transplantation vs re-transplantation. RESULTS: The mean cost of initial hospitalization and organ procurement was $221,897 per patient for primary transplant and $285,296 per patient for re-transplant. Annual follow-up costs were estimated to be $18,141 in the first year (excluding the first 90 days post-transplant) and $18,480 per year thereafter. Under base-case assumptions, costs per QALY gained were $49,679 for primary transplantation and $87,883 for re-transplantation. Sensitivity analysis yielded a cost-utility range of $44,943 to $57,628 per QALY gained for primary transplantation and $70,834 to $103,661 per QALY gained for re-transplantation. CONCLUSIONS: Costs of primary pediatric heart transplantation are within the accepted range of cost effectiveness. Pediatric heart re-transplantation has higher costs relative to benefits gained owing to shorter graft survival.

Adolescent↗
PubMed2006

Velocity-encoded magnetic resonance image assessment of regional aortic flow in coarctation patients.

BACKGROUND: During primary coarctation repair, collateral blood vessels contribute significantly to distal perfusion. We sought to determine if velocity-encoded cine magnetic resonance imaging (VENC-MRI) could provide insight into anatomy and hemodynamics of collateral flow in patients with unrepaired coarctation. METHODS: Sixteen patients (median age, 6.2 years; range, 1 to 18) with discrete coarctation (65% severe, 29% mild-moderate) and 10 controls (median age, 12.0 years; range, 9 to 15) without left-sided heart lesions were referred for cardiac MRI. Flow volumes were calculated from VENC-MRI images at the coarctation (proximal), diaphragm (distal), and midway between the two points (midpoint). A means model, repeated-measure analysis, was performed for volumes. RESULTS: In coarctation patients, flow volumes increased by 59% (p = 0.0002) from coarctation to diaphragm, primarily between the proximal and midpoint sites (by 77%, p < 0.0001). In controls, flow volumes decreased by 11% along the entire aortic study length. Coarctation volumes were lower than controls by 54% (p = 0.0003) at the proximal site but showed no statistical difference at the midpoint or diaphragm. CONCLUSIONS: Coarctation flow volumes maximally increase in the upper thoracic aorta, but approach normal flow volumes in the lower thoracic region. Arteries arising from mid and lower thoracic level, such as those supplying the anterior spinal cord, may have nearly normal flow if collaterals are present. Velocity-encoded MRI can evaluate flow in patients who have poor collateral circulation to improve surgical planning and decrease neurologic complications of coarctation repair.

Adolescent↗
PubMed2006

Elastic properties of the reconstructed aorta in hypoplastic left heart syndrome.

BACKGROUND: Patients with repaired coarctation of the aorta retain abnormal elastic properties of the aorta. It is not known whether patients with hypoplastic left heart syndrome also manifest abnormal elastic properties after palliative surgery. The presence of such abnormalities may have important clinical implications as reduced aortic compliance might adversely impact single right ventricular function. METHODS: We prospectively evaluated the elastic properties of the aorta in a cohort of patients with hypoplastic left heart syndrome who had undergone the Norwood procedure with aortic arch reconstruction and subsequent bidirectional Glenn or Fontan procedure. The hypoplastic left heart syndrome patients (n = 20) were compared with single-ventricle patients (n = 18) without history of arch reconstruction and patients with double-ventricular lesions (n = 22). Aortic elastic function was quantified by distensibility index and stiffness index. M-mode measurements of the transverse aortic arch were obtained with transesophageal echocardiography under general anesthesia. Patients were evaluated at a median age of 22.2 months with no age difference between patient subgroups. RESULTS: Distensibility index was significantly less (p = 0.007) and stiffness index greater (p = 0.005) in the reconstructed arch of hypoplastic left heart syndrome patients compared with single-ventricle and double-ventricle patients. CONCLUSIONS: Patients with hypoplastic left heart syndrome after Norwood palliation have increased aortic stiffness and decreased distensibility in the reconstructed transverse arch. As previous studies in adults have shown that decreased aortic compliance increases the energy cost of cardiac ejection, examination of modifications to the surgical technique that might improve elastic properties is warranted.

Aorta, Thoracic↗
PubMed2005

Relationship of surgical approach to neurodevelopmental outcomes in hypoplastic left heart syndrome.

OBJECTIVE: Two strategies for surgical management are used for infants with hypoplastic left heart syndrome (HLHS), primary heart transplantation and the Norwood procedure. We sought to determine how these 2 surgical approaches influence neurodevelopmental outcomes at school age. METHODS: A multicenter, cross-sectional study of neurodevelopmental outcomes among school-aged children (>8 years of age) with HLHS was undertaken between July 2003 and September 2004. Four centers enrolled 48 subjects, of whom 47 completed neuropsychologic testing. Twenty-six subjects (55%) had undergone the Norwood procedure and 21 (45%) had undergone transplantation, with an intention-to-treat analysis. The mean age at testing was 12.4 +/- 2.5 years. Evaluations included the Wechsler Abbreviated Scale of Intelligence, Clinical Evaluation of Language Fundamentals, Wechsler Individual Achievement Test, and Beery-Buktenica Developmental Test of Visual-Motor Integration. RESULTS: The mean neurocognitive test results were significantly below population normative values. The mean full-scale IQ for the entire cohort was 86 +/- 14. In a multivariate model, there was no association of surgical strategy with any measure of developmental outcome. A longer hospital stay, however, was associated significantly with lower verbal, performance, and full-scale IQ scores. Aortic valve atresia was associated with lower math achievement test scores. CONCLUSIONS: Neurodevelopmental deficits are prevalent among school-aged children with HLHS, regardless of surgical approach. Complications that result in prolonged hospitalization at the time of the initial operation are associated with neurodevelopmental status at school age.

Adolescent↗
PubMed2005

Pravastatin therapy is associated with reduction in coronary allograft vasculopathy in pediatric heart transplantation.

BACKGROUND: Hydroxymethylglutaryl CoA reductase inhibitors (statins) have been demonstrated to reduce the risk of developing coronary allograft vasculopathy (CAV) following heart transplantation in adults and are used routinely in many centers. CAV and lipid abnormalities have been reported to be less prevalent in pediatric heart transplant recipients. It is not known whether statins reduce the risk of CAV in this population METHODS: A retrospective review was performed to analyze the risk factors for developing CAV following pediatric heart transplantation with particular attention to the impact of pravastatin therapy. The study population was comprised of 129 pediatric patients who underwent 142 heart transplants at our institution from 1988 to 2003. The outcome variable was freedom from CAV, CAV being determined by coronary angiography or autopsy. RESULTS: CAV was identified in 25 recipients at a median of 3.7 years after transplantation. There were 331 patient-years of pravastatin therapy. Pravastatin therapy resulted in a reduction in total cholesterol levels, 162 +/- 29 to 137 +/- 20 mg/dl, p = 0.01. In multivariate analysis the use of pravastatin was associated with a lower incidence of CAV (p = 0.03), whereas an increased frequency of late rejection (p = 0.003) and earlier year of transplantation (p = 0.04) were associated with increased risk of CAV. CONCLUSIONS: The routine use of pravastatin was associated with a lower risk following pediatric heart transplantation. Further studies into the relationship between lipid abnormalities, inflammation and rejection, and the development of CAV in children are warranted.

Adolescent↗
PubMed2005

OKT3 treatment in refractory pediatric heart transplant rejection.

BACKGROUND: The anti-lymphocyte monoclonal antibody OKT3 has been shown to be effective in the management of steroid-resistant and/or fulminant heart transplant rejection in adults. In addition, some studies suggest that OKT3 may have a role in the management of transplant coronary artery disease (TxCAD). To date, there are limited data regarding the use of OKT3 treatment of refractory rejection or graft failure in children. Our study examines OKT3 treatment in steroid-resistant rejection, rejection with hemodynamic compromise, and TxCAD in children. METHODS: Thirty-eight patients received 53 courses of OKT3 for treatment of rejection and/or graft dysfunction. Primary indications for OKT3 were steroid-resistant rejection (n = 27), rejection with hemodynamic compromise (n = 22), and TxCAD (n = 4). Resolution of rejection was considered absence of biopsy-proven rejection (< grade 2) or resolved TxCAD. RESULTS: OKT3 use in steroid-resistant rejection was associated with a lower incidence of rejection in the 3 months after OKT3 than 3 months before OKT3, median rejection episodes of 2.5 vs 0, p < 0.0001. In rejection with hemodynamic compromise, 20 subjects (91%) demonstrated improved hemodynamics after OKT3 and survived to hospital discharge. The use of OKT3 treatment for TxCAD failed to demonstrate resolution or improvement in angiographic TxCAD in any subject. Only 5 OKT3 treatment courses were stopped secondary to severe adverse side effects. CONCLUSIONS: OKT3 treatment in refractory pediatric heart transplant rejection is efficacious in acute rejection. OKT3 management in pediatric TxCAD is less clear, with no proven benefit identified in this study. OKT3 use in pediatric refractory heart rejection has significant side effects, but is tolerable and safe with close monitoring.

Adolescent↗
PubMed2005

Disparities in outcome for black patients after pediatric heart transplantation.

OBJECTIVE: To examine the relationship of black race to graft survival after heart transplantation in children. STUDY DESIGN: United Network for Organ Sharing records of heart transplantation for subjects <18 years of age from 1987 to 2004 were reviewed. Analysis was performed using proportional hazards regression controlling for other potential risk factors. RESULTS: Of the 4227 pediatric heart transplant recipients, 717 (17%) were black. The 1-year graft survival rate did not differ among groups; however, the 5-year graft survival rate was significantly lower for black recipients, 51% versus 69%, P < .001. The median graft survival for black recipients was 5.3 years as compared with 11.0 years for other recipients. Black recipients had a greater number of human leukocyte antigen mismatches, lower median household income, and a greater percentage with Medicaid as primary insurance, P < .001, P < .001, and P < .001. After adjusting for economic disparities, black race remained significantly associated with graft failure, odds ratio = 1.67 (95% CI 1.47 to 1.87), P < .001. CONCLUSIONS: Median graft survival after pediatric heart transplantation for black recipients is less than half that of other racial groups. These differences do not appear to be related primarily to economic disparities.

Adolescent↗
PubMed2005

Cost-utility analysis of salvage cardiac extracorporeal membrane oxygenation in children.

BACKGROUND: Indications for extracorporeal membrane oxygenation therapy have expanded to include cardiopulmonary arrest and support after congenital heart surgery. Data from a national registry have reported that cardiac patients have the poorest survival of all extracorporeal membrane oxygenation recipients. Concerns have been raised about the appropriateness of such an aggressive strategy, especially in light of the high costs and potential for long-term neurologic disability. We reviewed our experience with salvage cardiac extracorporeal membrane oxygenation to determine the cost-utility, which accounts for both costs and quality of life. METHODS: Medical records of patients with congenital heart disease receiving salvage cardiac extracorporeal membrane oxygenation between January 2000 and May 2004 were reviewed. Charges for all medical care after the institution of extracorporeal membrane oxygenation were determined and converted to costs by published standards. The quality-of-life status of survivors was determined with the Health Utilities Index Mark II. RESULTS: Salvage cardiac extracorporeal membrane oxygenation was instituted in 32 patients (18 for cardiopulmonary arrest and 14 for cardiac failure after heart surgery) at a median age of 2.0 months (range, 4 days to 5.1 years). Congenital heart disease was present in 27 (84%). The mean duration of extracorporeal membrane oxygenation support was 5.1 +/- 4.1 days. Survival to hospital discharge was 50%, including 1 patient bridged to heart transplantation. Survival to 1 year was 47%. The mean score of the Health Utilities Index for the survivors was 0.75 +/- 0.19 (range, 0.41-1.0). The median cost for hospital stay after the institution of extracorporeal membrane oxygenation was USD 156,324 per patient. The calculated cost-utility for salvage extracorporeal membrane oxygenation in this population was USD 24,386 per quality-adjusted life-year saved, which would be considered within the range of accepted cost-efficacy (< USD 50,000 per quality-adjusted life-year saved). CONCLUSIONS: Salvage cardiac extracorporeal membrane oxygenation results in reasonable survival and is justified on a cost-utility basis.

Child, Preschool↗
PubMed2005

Cardiac retransplantation in childhood: analysis of data from the United Network for Organ Sharing.

OBJECTIVE: For children in whom graft failure develops after cardiac transplantation, retransplantation is often considered. Although some centers have reported equivalent results for retransplantation as for primary transplantation, this strategy remains controversial. We sought to examine outcomes after retransplantation in children and to identify risk factors for mortality. METHODS: United Network for Organ Sharing records of heart transplantation for subjects younger than 18 years from 1987 to 2004 were reviewed. Indications for retransplantation and patient characteristics were evaluated. Analysis was performed with proportional hazards regression, controlling for other potential risk factors. RESULTS: Among the 4227 pediatric heart transplants, there were 219 retransplants. The most common indication for retransplantation was coronary allograft vasculopathy (51%). The mean interval from initial heart transplant to retransplantation was 4.7 +/- 3.8 years. Forty-two retransplants (19%) were performed within 180 days of primary transplantation. Survivals at 1, 5, and 10 years after retransplantation were 79%, 53%, and 44%, respectively. In multivariate analysis, retransplantation was associated with significantly higher mortality than primary transplantation (odds ratio 1.67, 95% confidence interval 1.32-2.12, P < .001). Patients who underwent retransplantation within 180 days of primary transplantation had a significantly lower 1-year survival than did other retransplant recipients (53% vs 86%, respectively, P < .02). Subjects who required mechanical ventilation before retransplantation also had poorer survival (P < .03). CONCLUSION: Survival after cardiac retransplantation in children is inferior to that after primary transplantation. Although results are acceptable, the impact of retransplantation on the availability of donor hearts requires further consideration.

Adolescent↗
PubMed2005

Nesiritide in infants and children with congestive heart failure.

OBJECTIVES: Nesiritide (synthetic B-type natriuretic peptide) has been shown to be effective in the management of acute decompensated heart failure in adults. The role of nesiritide in pediatric heart failure has not been examined. In the present study, we reviewed our initial experience with nesiritide in children with primary heart failure or low cardiac output after heart surgery. METHODS: Nesiritide was administered in an open-label fashion to patients with heart failure who were already receiving inotropic and diuretic therapy. Between July 2003 and August 2004, 30 patients aged 5 days to 16.7 yrs (median age, 4.6 months) received nesiritide therapy. Diagnoses included single-ventricle congenital defect (n = 5), two-ventricle congenital defect (n = 13), heart transplant (n = 5), and dilated cardiomyopathy (n = 7). Sixteen patients were started on nesiritide within 2 wks of corrective or palliative heart surgery. The majority of subjects (n = 24) received an initial bolus dose. Continuous infusion dosage ranged between 0.005 and 0.02 microg.kg.min. Nesiritide was discontinued for possible side effects in two patients (arrhythmia and hypotension). Duration of therapy ranged from 1 to 24 days (median, 4 days). RESULTS: Administration of nesiritide was associated with improvement in fluid balance from positive 0.8 +/- 1.9 mL.kg.hr at baseline to negative 0.3 +/- 1.8 mL.kg.hr after 24 hrs of therapy (p = .02). There was a nonsignificant trend toward a reduction in right atrial pressure (9.2 +/- 3.9 vs. 11.2 +/- 4.1, p = .08). CONCLUSIONS: Nesiritide is well tolerated in children with heart failure and is associated with improved diuresis. Further prospective studies will be needed to compare nesiritide with other vasoactive agents and examine the cost-efficacy of this therapy.

Adolescent↗
PubMed2004

Initial experience with bosentan therapy in patients with the Eisenmenger syndrome.

Bosentan, an endothelin-1 antagonist that can be administered orally, has been shown to be effective in the treatment of idiopathic pulmonary arterial hypertension and may be of benefit to patients with the Eisenmenger syndrome. Nine patients with Eisenmenger's syndrome were treated with bosentan at a dose of 125 mg twice a day. After treatment with bosentan, 6 of 9 patients (67%) had an improvement in New York Heart Assocation classification of >/=1 grades (p = 0.03). Oxygen saturation levels increased from 79 +/- 5% to 88 +/- 6%, (p = 0.03). The side effects of bosentan therapy were minor; no significant changes in liver function tests were noted. These preliminary data suggest that oral administration of bosentan therapy for Eisenmenger's syndrome results in improved oxygenation and functional status with minimal side effects.

Adult↗
PubMed2004

Diagnostic assessment before Fontan operation in patients with bidirectional cavopulmonary anastomosis: are noninvasive methods sufficient?

OBJECTIVES: This study was designed to determine if a subset of patients who have undergone bidirectional cavopulmonary anastomosis could be identified in which catheterization was of little benefit before completion of the Fontan procedure. BACKGROUND: Diagnostic evaluation before Fontan procedure has typically included cardiac catheterization. However, the overall management strategy for patients with functional single ventricle has evolved to include staging bidirectional cavopulmonary anastomosis in most, and it has become uncommon to exclude patients from Fontan based on catheterization data. METHODS: Patients who underwent bidirectional cavopulmonary anastomosis and had complete echocardiograms and catheterizations within three months of each other between January 1992 and October 1997 were evaluated with a series of clinical and echocardiographic characteristics to identify a subset in whom catheterization was predicted to be of little added value ("no-cath" group). The predictive value and sensitivity of these criteria in excluding patients who required additional intervention, were excluded from Fontan, or died within 30 days of Fontan was determined. RESULTS: A total of 99 patients who underwent bidirectional cavopulmonary anastomosis at 6.7 months (range 2.9 months to 14 years) were studied; 46 met criteria for the "no-cath" group. Noninvasive criteria stratified all patients who died (n = 5) or did not proceed to Fontan (n = 1) and 9 of 11 who required additional interventions to the "cath" group. Thus, the negative predictive value of these criteria was 93%. CONCLUSIONS: Our data suggest that catheterization before Fontan could be avoided in a large percentage of patients without adversely affecting outcome; prospective evaluation of this strategy is warranted.

Adolescent↗
PubMed2004

Cardiac retransplantation in children.

BACKGROUND: Experience with pediatric cardiac retransplantation is limited. Outcomes should be inspected to insure proper use of donor hearts. METHODS: Of 152 pediatric heart transplantations, we performed 20 retransplants in 17 children (3 had a second retransplant). The retransplant children were older than the primary transplant children (11.1 +/- 4.4 years versus 7.1 +/- 6.0 years; p = 0.005). Excluding 1 early retransplant, the interval from primary transplant to retransplant was 5.5 +/- 3.3 years (range, 1.1 to 11.1). The retransplant patients were clinically more ill than the primary transplant patients (United Network for Organ Sharing status I, 75% versus 63%; mechanical circulatory support or dialysis, 20% versus 3.8%). RESULTS: Donor ischemia time (188 versus 165 minutes) and cardiopulmonary bypass time (127 versus 127 minutes) were not significantly different for the retransplant patients. Excluding 1 retransplant patient who required a tracheostomy, days on the ventilator (2.7 versus 2.7), days on inotropic support (3.0 versus 3.2), intensive care unit days (7.2 versus 6.7), and hospital days (15.9 versus 13.8) were similar in the retransplant group. Freedom from rejection at 90 days and 1 year was not different in the retransplant patients. Actuarial patient survival in the patients undergoing first retransplant was similar to the primary transplant patients at 30 days (95% versus 94.7%), 1 year (94.1% versus 80.7%), and 3 years (78.4% versus 73.1%). Two of 3 children receiving a third transplant died within 1 year of redo retransplantation. CONCLUSIONS: Cardiac retransplantation can be performed in children with results comparable with those for primary transplantation despite increased clinical acuity. These early results suggest that cardiac retransplantation in children is a reasonable therapeutic option. Children with repeat retransplantation do not fare as well.

Adolescent↗
PubMed2004

The short term effects of cardiopulmonary bypass on neurologic function in children and young adults.

OBJECTIVE: Cognitive deficits are common in adults following surgery utilizing cardiopulmonary bypass (CPB). A previous retrospective study suggested that surgical closure of an ASD in children was associated with neurologic injury, while transcather therapy was not. In a prospective study, we sought to determine whether neurologic deficits occur following repair of non-complex congenital heart lesions in school-age children and young adults. METHODS: Inclusion criteria were: age between 5 and 20 years, cardiac surgery utilizing CPB without deep hypothermic circulatory arrest, and no prior cardiac surgery. Patients underwent psychometric testing 1-3 days prior to surgery and re-evaluation 7-18 days after surgery. In order to determine the test/re-test effect an age-matched cohort of children undergoing transcather closure of ASD under general anesthesia was also evaluated. The primary outcome measures were verbal and picture memory. Additional psychometric tests included: computerized performance test (CPT) and Digit Span (DS). Forty-one patients were enrolled, 29 undergoing surgery with CPB and 12 controls. Surgical procedures included ASD closure (n=13), VSD closure (n=10), resection of sub-aortic stenosis (n=3), mitral valvuloplasty (n=3). Mild hypothermia was used in all cases. The mean duration of CPB was 54+/-22 min. RESULTS: There was no significant difference in any of the psychometric test scores between subjects undergoing surgery with CPB or controls. CONCLUSIONS: There are no marked adverse neurologic effects of CPB in school-age children and young adults undergoing non-complex open-heart surgery. These data are important in counseling patients and families and should be considered in the debate as to the relative merits of transcather versus open-heart repair of various heart lesions.

Adolescent↗
PubMed2004

Periventricular leukomalacia is common after neonatal cardiac surgery.

OBJECTIVES: Periventricular leukomalacia is necrosis of the cerebral white matter adjacent to the lateral ventricles and results from injury to immature oligodendroglia. In infants without congenital heart disease, periventricular leukomalacia is associated with an increased incidence of developmental delay and attention deficit/hyperactivity disorder. The incidence of periventricular leukomalacia and the risk factors for development of periventricular leukomalacia after infant cardiac surgery are not known. METHODS: Magnetic resonance imaging of the brain was performed 6 to 14 days after cardiac surgery utilizing cardiopulmonary bypass with or without deep hypothermic circulatory arrest in 105 neonates and infants < or = 6 months of age. RESULTS: Median age at surgery was 6 days (range 1-178), with 82 neonates (age < or = 30 days). Periventricular leukomalacia was found in 44 of the neonates (54%) compared with 1 of 23 infants (4%). Forward logistic regression using age at surgery as a continuous variable identified a model containing longer total support time (cardiopulmonary bypass plus deep hypothermic circulatory arrest), lower systolic blood pressure at cardiac intensive care unit admission postoperatively, lower minimum diastolic blood pressure, and Po(2) in the first 48 hours after surgery. When age at surgery was considered as a dichotomous variable (neonate versus infant), younger age at surgery replaced systolic blood pressure, Po(2), and total support time in the model. Lower minimum diastolic blood pressure was a significant risk factor in both models. CONCLUSIONS: Periventricular leukomalacia was found in >50% of neonates after cardiac surgery but rarely in older infants. Hypoxemia and hypotension in the early postoperative period, particularly diastolic hypotension, may be important risk factors for periventricular leukomalacia.

Apolipoproteins E↗