Alaina K. Kipps

BLOOD TRANSFUSION IS ASSOCIATED WITH PROLONGED DURATION OF MECHANICAL VENTILATION IN INFANTS UNDERGOING REPARATIVE CARDIAC SURGERY

Objective: Perioperative transfusion has adverse effects in adults undergoing cardiac surgery. We sought to investigate whether greater use of blood and blood products might be an independent predictor of prolonged postoperative recovery, indicated by duration of mechanical ventilation (DMV), after reparative infant heart surgery. Design: Secondary analysis of prospectively collected data from two randomized trials of hematocrit strategy during cardiopulmonary bypass in infant heart surgery to explore the association of DMV with perioperative transfusion and other variables. Setting: Tertiary pediatric hospital. Patients: Two hundred seventy infants undergoing two ventricle corrective cardiac surgery without aortic arch reconstruction. Measurements and Main Results: In univariable analyses, longer DMV was associated with younger age and lower weight at surgery, diagnostic group, and higher intraoperative and postoperative blood product transfusion (each p < .001). In multivariable proportional hazard regression, longer total support time and greater intraoperative and early postoperative blood products per kg were the strongest predictors of longer DMV. Patients in the highest tertile of intraoperative blood products per kg had an instantaneous risk of being extubated approximately half that of patients in the lowest tertile (hazard ratio, 0.51; 95% confidence interval, 0.35, 0.73). Patients who received any blood products on postoperative day 1, compared with those who did not, had a hazard ratio for extubation of 0.65 (95% confidence interval, 0.50, 0.85). Conclusions: In this exploratory secondary analysis of infants undergoing two ventricular repair of congenital heart disease without aortic arch obstruction, greater intraoperative and early postoperative blood transfusion emerged as potential important risk factors for longer DMV. Future prospective clinical trials are needed to determine whether reduction in blood product administration hastens postoperative recovery after infant heart surgery.

Prenatal Diagnosis of Hypoplastic Left Heart Syndrome in Current Era

We sought to evaluate the relation of a prenatal diagnosis (preDx) with morbidity and mortality during the initial hospitalization in a contemporary cohort of patients with hypoplastic left heart syndrome (HLHS). A retrospective study of patients with HLHS presenting from 1999 to 2010 was performed. Patients with genetic disorders or a gestational age <34 weeks or who had intentionally received comfort care only were excluded. Of the 81 patients meeting the study criteria, 49 had a preDx and 32 were diagnosed postnatally (postDx). Birth weight (median 3.0 vs 3.4 kg; p = 0.007) and gestational age (median 38 vs 39 weeks; p <0.001) were lower in the preDx than in the postDx patients. Preoperatively, the postDx patients were intubated more frequently (97% vs 71%, p = 0.004) and ventilated longer (median 96 vs 24 hours, p = 0.005) than the preDx patients. They also had more preoperative acidosis, multiorgan failure, tricuspid valve regurgitation, and right ventricular dysfunction. Of the 73 patients undergoing surgery, no difference in survival was seen between the preDx and postDx groups (91% vs 89%). The median duration of postoperative ventilation was 7 days and the median length of stay was 36 days for the 66 survivors, with no difference between the 2 groups. Postoperative morbidities, including chylothorax and infection, were also similar in the preDx and postDx patients. No studied preoperative factor was associated with death, duration of postoperative ventilation, or length of stay. In conclusion, our recent experience has shown that preDx of HLHS was not associated with a survival advantage, fewer postoperative complications, or shorter length of stay. Improved preoperative status was observed in the preDx patients; however, they were born earlier with a lower birthweight. What effect these factors might have on longer term morbidity remains unknown.

Longitudinal Exercise Capacity of Patients With Repaired Tetralogy of Fallot

Patients with repaired tetralogy of Fallot have a reduced percentage of predicted peak oxygen consumption (VO(2)) and percentage of oxygen pulse (O(2)P%) compared to healthy controls. Because data regarding the progression of exercise intolerance in these patients is limited, we sought to analyze the serial exercise data from patients with Tetralogy of Fallot to quantify the changes in their exercise capacity over time and to identify associations with clinical and cardiac magnetic resonance imaging variables. The data from cardiopulmonary exercise tests (CPXs) from 2002 to 2010 for patients with repaired tetralogy of Fallot with ≥2 CPXs separated by ≥12 months were analyzed. Tests occurring after interventional catheterization or surgery were excluded. A total of 70 patients had 179 CPXs. They had a median age at the initial study of 23.6 years and an interval between the first and last CPX of 2.8 years. At the initial CPX, the peak VO(2) was 27.6 ± 8.8 ml/kg/min (78 ± 19% of predicted), and the peak O(2)P% was 89 ± 22% of predicted. At the most recent study, the peak VO(2) averaged 25.0 ± 7.4 ml/kg/min (73 ± 16% of predicted), and the peak O(2)P% averaged 83 ± 20% (p <0.01) for each versus the initial CPX. The decrease in the peak VO(2) was strongly associated with a decrease in O(2)P% and an increase (worsening) in the slope of the minute ventilation-versus-carbon dioxide production relation. Changes in the peak VO(2) did not correlate with concomitant changes in any other CPX variable. The rate of decrease was not related to a history of shunt palliation, age at CPX, or any other baseline clinical parameter, including cardiac magnetic resonance measurements. In conclusion, the exercise capacity of patients with repaired tetralogy of Fallot tends to decrease over time. This deterioration is variable and unpredictable and is primarily related to a decrease in the forward stroke volume at peak exercise.

Echocardiographic risk stratification of fetuses with sacrococcygeal teratoma and twin-reversed arterial perfusion.

Objective: To evaluate pre-intervention echocardiographic parameters of cardiac function in fetuses who survive without hydrops as compared to fetuses who develop hydrops or perinatal death in the setting of sacrococcygeal teratoma (SCT) and twin-reversed arterial perfusion sequence (TRAP). Methods: Clinical, echocardiographic and sonographic data of fetuses with SCT or TRAP during 1999–2009 were reviewed retrospectively. Measurements of cardiothoracic ratio (CTR), cardiac dimension Z-scores, combined ventricular output (CVO), valvular regurgitation, and cardiovascular profile scores (CVPS) were obtained. Results: In total, 19 fetuses (11 SCT, 8 TRAP) met the inclusion criteria and 26 detailed fetal echocardiographic studies were reviewed. Outcome was poor in 7 pregnancies (group A) and good in 12 (group B). Group A had worse CVPS (8.5 vs. 10, p < 0.01) and higher CTR (0.37 vs. 0.30, p = 0.04). At least one of the following was present in each group A fetus: CTR >0.5, CVO >550 ml/min/kg, tricuspid or mitral regurgitation, or mitral valve Z-score >2. No group B fetus had any of these abnormalities. No fetus in either group had abnormal venous Doppler waveforms at presentation. Conclusions: Fetal echocardiography can identify abnormalities of cardiac size and systolic, but not diastolic, function in all fetuses who subsequently died or developed hydrops.

Children with cardiomyopathy: complications after noncardiac procedures with general anesthesia.

Background:  Children with cardiomyopathy (CM) often undergo procedures that require general anesthesia (GA) but little is known about anesthesia‐related adverse events or postprocedural outcomes.

Prenatal diagnosis of atrial restriction in hypoplastic left heart syndrome is associated with decreased 2‐year survival

To compare the course of hypoplastic left heart syndrome (HLHS) patients diagnosed prenatally with any degree of atrial restriction with those without evidence of atrial restriction.

Natural history of exercise function in patients with Ebstein anomaly: A serial study

BACKGROUND The clinical manifestations of Ebstein anomaly (EA) vary greatly; criteria for surgical intervention remain undefined. Decisions regarding surgical intervention in asymptomatic/mildly symptomatic patients would be helpfully informed by a detailed, quantitative understanding of the natural history of exercise intolerance in these patients. However, past studies of exercise function in EA have been of a cross-sectional, rather than a serial, nature. We, therefore, analyzed serial cardiopulmonary exercise (CPX) tests from patients with unrepaired EA to better appreciate the natural history of their exercise function. METHODS All patients with EA who had had at least 2 CPX tests, separated by at least 6 months, between November 2002 and October 2010 were identified. Patients with prior tricuspid valve surgery were excluded from the study. RESULTS Cardiopulmonary exercise data from 23 patients (64 CPX tests; 2.8 ± 1.0 tests/patient) were analyzed. The median time interval between the first and last CPX tests was 3.3 (range, 0.6-7.3) years. The percentage of predicted peak oxygen consumption declined slowly (1.87 ± 8.04 percentage points/y) during the follow-up period. The decline was more pronounced (3.04 ± 6.78 percentage points/y) in patients <18 years old. On multivariate modeling, only the change in oxygen pulse at peak exercise (a surrogate for forward stroke volume) and the change in peak heart rate over time emerged as statistically significant correlates of the change in percentage of predicted peak oxygen consumption. CONCLUSION The exercise function of patients with EA tends to deteriorate over time. This deterioration appears to be related to a progressive decline in their ability to augment their forward stroke volume and heart rate during exercise.

Muscular Infundibular Atresia Is Associated with Coronary Ostial Atresia in Pulmonary Atresia with Intact Ventricular Septum

OBJECTIVE To determine whether infundibular morphology is associated with coronary ostial atresia and/or right ventricle dependent coronary circulation in patients with pulmonary atresia with intact ventricular septum. DESIGN Neonatal echocardiograms of patients with pulmonary atresia with intact ventricular septum were evaluated for tricuspid valve size and infundibular anatomy (muscular pulmonary atresia vs. membranous pulmonary atresia). Right ventricle dependent coronary circulation and coronary ostial atresia were diagnosed angiographically. Medical record review determined patient outcome. SETTING Tertiary-care pediatric hospital. RESULTS Of 72 patients, 24 had muscular pulmonary atresia including 23 with right ventricle dependent coronary circulation. Fourteen of these had unilateral or bilateral coronary ostial atresia. Of 46 patients with membranous pulmonary atresia, 5 five had right ventricle dependent coronary circulation and none had coronary ostial atresia. Muscular pulmonary atresia patients had smaller tricuspid valve z-scores and were less likely to achieve a biventricular repair than those with membranous pulmonary atresia (P < .01). Muscular pulmonary atresia had 82% sensitivity, 98% specificity, and 96% positive predictive value for presence of right ventricle dependent coronary circulation. In the group with membranous pulmonary atresia, there were two deaths, no transplants, and 23 (48%) achieved a biventricular repair. In contrast, of the 24 with muscular pulmonary atresia, there were seven deaths, two transplants, and no biventricular repairs. CONCLUSIONS In this cohort, muscular pulmonary atresia was strongly associated with right ventricle dependent coronary circulation and coronary ostial atresia, and appears to be a useful morphologic marker for poor outcome among pulmonary atresia with intact ventricular septum patients. This information may be useful during prenatal counseling and for presurgical evaluation.

Exercise function of children with congenital aortic stenosis following aortic valvuloplasty during early infancy.

OBJECTIVES The objectives of this study were to characterize the exercise function of patients treated with balloon aortic valvuloplasty at <or=6 months of age, and identify factors associated with exercise dysfunction. BACKGROUND Balloon aortic valvuloplasty is the primary therapy for neonatal aortic stenosis (AS). Residual and/or acquired abnormalities of left heart structure and function may adversely affect exercise capacity. Methods. We prospectively recruited patients >6 years old with a history of neonatal AS to undergo exercise testing. RESULTS We enrolled 30 patients (median age 13.1 years) who underwent balloon aortic valvuloplasty at a median age of 12 days. At time of exercise testing, the median maximum Doppler AS gradient was 34 mm Hg (0-70 mm Hg); 11 patients had moderate or severe aortic regurgitation. All patients were asymptomatic. Overall, peak oxygen consumption (VO(2)) was below normal (87 +/- 18% predicted; P < .001), and was severely depressed (<or=70% predicted) in 7 patients (23%). Although peak O(2) pulse was well preserved overall (97 +/- 22% predicted; P= .36), 11 patients had an O(2) pulse <85% predicted, including all patients with VO(2)<or= 70% predicted. Peak heart rate was below normal overall (91 +/- 7% predicted, P < .001), but severe chronotropic dysfunction (<or=70% predicted) was rare (n = 1). Age at testing correlated inversely with peak VO(2) (R(2)= 0.30; P= .002). No other demographic, historical, or echocardiographic variables were associated with peak VO(2). CONCLUSION Although exercise function is preserved in most patients with a history of AS treated in early infancy, a subset have markedly reduced peak VO(2), usually because of inability to increase stroke volume.

Prenatal Tricuspid Valve Size as a Predictor of Postnatal Outcome in Patients with Severe Pulmonary Stenosis or Pulmonary Atresia with Intact Ventricular Septum

Introduction: Tricuspid valve (TV) size at birth correlates with intervention strategy in patients with severe pulmonary stenosis (SPS) or pulmonary atresia/intact ventricular septum (PA/IVS). Prenatal features that might predict postnatal TV size have not been well studied. We hypothesized that prenatal echocardiographic measurements predict the postnatal TV Z-score in fetuses with SPS and PA/IVS. Materials and Methods: We identified 16 neonates (gestational age 28 ± 4.8 weeks) with a fetal diagnosis of SPS or PA/IVS from 2001 to 2010. Measurements were performed offline. ROC (receiver operating characteristic) analysis was used to generate AUC (areas under the curve) for each of the variables. Results: AUC was 0.94 for tricuspid to mitral valve (TV/MV) ratio, 0.88 for TV Z-score, and 0.85 for TV inflow duration. A cut-off value of >0.63 for TV/MV yielded a sensitivity of 78%, specificity of 100% for predicting postnatal TV Z-score >-3. Neonates with TV Z-score ≥-3 and all fetuses with antegrade flow across the pulmonary valve or more than moderate tricuspid regurgitation had biventricular circulation in follow-up. Conclusion: Fetal TV/MV >0.63 predicts favorable TV Z-score at birth in patients with SPS and PA/IVS. Antegrade pulmonary valve flow and more than moderate tricuspid regurgitation also conferred a favorable outcome.