- Email: [email protected]
PULMONARY ARTERY WALL THICKNESS IN CHILDREN WITH FONTAN PHYSIOLOGY – AN OPTICAL COHERENCE TOMOGRAPHY CASE CONTROL STUDY
S6
Canadian Journal of Cardiology Volume 33 2017
Questionnaire for Adolescents (PAQ-A), a valid 7-day recall tool that yields a physical activity summary PAQ-score between 1 (inactive) and 5 (highly active). Adolescents also self-reported attitudes and perceptions. Parents self-reported on family demographics, encouragement and support for their child’s physical activity, as well as their own physical activity behaviours. Adolescents’ medical history, including cardiac diagnosis, surgical history and physical activity restrictions, were obtained from medical charts. We assessed associations between PAQ-scores and relevant explanatory variables via independent t-tests and multiple linear regression (Stata v. 14, p < 0.05). RESULTS: We included 147 parent-adolescent dyads with complete data. In most cases (86%), mothers completed the parent questionnaire. Adolescents were 15.81.6yrs old, 50% were female, and overall PAQ-score was 2.340.77. Expectedly, PAQ-scores were inversely associated with age (r¼-0.406, p < 0.001). More than half of participants had a cardiac diagnosis (n¼77), of whom most had a history of surgery or catheter-based intervention (n¼54), and very few had received formal physical activity restrictions by their cardiologist (n¼15); PAQ-scores did not differ according to any of these factors. PAQ-scores were significantly higher in adolescents whose parents reported to provide transport to physical activity/ sport (n¼111), or who offered daily encouragement for their child to be physically active (n¼54; all p < 0.001). Parents’ own physical activity levels, or whether they had concerns over their child’s heart health during physical activity (n¼41) was not related to adolescents’ PAQ-scores. In multiple regression adjusted for cardiac diagnosis (non-significant), age and sex explained 18% of the variance in PAQ-scores (r2¼0.179, p < 0.001); parental encouragement and provision of transport explained an additional 10% of the variance in PAQ-scores (r2¼0.272, p < 0.001). CONCLUSION: Physical activity levels are similar for adolescents with and without cardiovascular disease, irrespective of disease severity. Aside from the expected effects of age and sex, supportive parental behaviours emerged as the most important correlates for physical activity participation in these adolescents.
Canadian Pediatric Cardiology Association ePosters CONGENITAL HEART POTPOURRI Saturday, October 21, 2017 010 DOES LATE GADOLINIUM ENHANCEMENT IDENTIFY THE PATIENTS AT RISK IN CHILDHOOD HYPERTROPHIC CARDIOMYOPATHY? A MULTICENTER STUDY S Ide, L Grosse-Wortmann, D Mroczek, R Chan Toronto, Ontario BACKGROUND:
Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) has emerged as a
potential marker for risk of adverse events in adult patients with hypertrophic cardiomyopathy (HCM). However, previous studies of pediatric patients have been limited to small cohorts with short follow-up periods and therefore the clinical significance of LGE in the pediatric HCM population remains uncertain. The aims of this study were 1) to quantify the prevalence and amount of LGE in an unselected pediatric population with HCM and 2) to assess the relation between LGE and ventricular arrhythmia, episodes of circulatory collapse, sudden cardiac death (SCD), and degree of heart failure at the time of MRI and during follow-up. METHODS: Cine and contrast-enhanced CMR exams were performed on 492 HCM patients (13.8 3.9 years; 75% males) in 30 pediatric HCM centers. CMR images were analyzed at a single data coordinating center. Mean follow-up period was 1.9 2.2 years. RESULTS: Mean LVEF was 53 10%, with mean maximal wall thickness of 186mm. Prevalence of LGE was 38%, with mean LGE extent of 2.0 5.1% left ventricular mass. Adverse HCM-related adverse events occurred in 18.7% (n¼92). Sudden cardiac death (SCD) events occurred in 5.5% (n¼27), or 2.7% per year, of which all were asymptomatic or minimally symptomatic (21 with NYHA Class I, and 6 with NYHA Class II). There was a significant relationship between the presence of LGE and all HCM-related adverse disease events (OR 3.10, 95% CI 1.26-7.66, p¼0.01). LGE by percent ventricular mass was also associated with a substantially increased risk of SCD events (Odds ratio, 3.70 per 10% increase in LGE; P¼0.008). LGE of only w5% of LV mass conferred a 2-fold increase in SCD event risk in those patients without LGE. CONCLUSION: In pediatric patients with HCM, LGE detected by contrast-enhanced CMR is associated with an increased risk of HCM-related adverse events, including sudden death.
011 PULMONARY ARTERY WALL THICKNESS IN CHILDREN WITH FONTAN PHYSIOLOGY e AN OPTICAL COHERENCE TOMOGRAPHY CASE CONTROL STUDY E McGovern, C Voss, S Duncombe, M Hosking, K Harris Vancouver, British Columbia BACKGROUND:
Fontan failure in patients with preserved ventricular function is not well understood. Loss of pulsatile flow in the pulmonary arteries leads to lack of shear stress, which is believed to result in endothelial dysfunction. This endothelial dysfunction may further promote vascular remodelling. Subsequent increased pulmonary vascular resistance is considered to be a potential contributing mechanism for Fontan failure. We sought to perform an in vivo case control study to evaluate structural changes in the pulmonary arteries of children with a
Abstracts
Fontan circulation compared to those with a normal pulmonary circulation. METHODS: Since May 2016, we have recruited patients undergoing cardiac catheterization at BC Children’s Hospital. The control group comprised of children with normal pulmonary circulation undergoing cardiac catheterization or invasive electrophysiology evaluation. We performed intravascular imaging of the pulmonary arteries using Optical Coherence Tomography (OCT, Abbott). For quantitative OCT image analyses, we identified a series of 10 crosssectional frames that were each 0.5 mm apart along the vessel. Using digital planimetry, we measured lumen diameter (mm), lumen cross-sectional area (CSA, mm2), wall CSA (mm2), vessel CSA (lumen+wall CSA, mm2) and mean wall thickness (mm) for each frame. To standardize wall thickness by vessel size, we calculated wall CSA to vessel CSA ratios. We calculated median values across frames for each case. Betweengroup differences were assessed by Mann-Whitney U tests; associations by Spearman Rank correlation (Stata v. 14.0; p < 0.05). RESULTS: We quantitatively analysed OCT images of the pulmonary arteries in 10 children with a Fontan circulation (10.83.9yrs at OCT, 40% female) and 8 control children (10.54.2yrs at OCT, 75% female). Overall, there were no significant differences between groups in terms of wall thickness (overall median 0.11mm, interquartile range 0.100.15) or wall/vessel ratio (0.13, IQR 0.11-0.15). There was no association between wall thickness or wall/vessel ratio with age at OCT, age at Fontan completion, or time since Fontan completion. Median pulmonary artery pressure at time of OCT was 11.8mmHg (10.5-14.0), which was not associated with normalized wall thickness. CONCLUSION: OCT findings suggest that during childhood, pulmonary artery wall dimensions are normal in children with Fontan physiology and reassuring hemodynamic status. Further evaluation of vascular function and correlating structure with function in this population would be worthwhile. Serial evaluation of pulmonary artery structure and correlation with clinical course into adulthood is needed.
012 WITHDRAWN
013 RISK FACTORS FOR DEATH OR HEART TRANSPLANT FOR PATIENTS WITH RIGHT VENTRICULAR DYSFUNCTION AFTER THE NORWOOD PROCEDURE: A SECONDARY ANALYSIS OF THE SINGLE VENTRICLE RECONSTRUCTION TRIAL E Jean-St-Michel, J Meza, J Maguire, J Coles, B McCrindle Toronto, Ontario
S7 BACKGROUND: Prediction of mortality for hypoplastic left heart syndrome (HLHS) patients with right ventricular (RV) dysfunction could facilitate early decision-making, such as transplant listing, and potentially improve outcomes. Therefore, we sought to investigate patient and procedural factors associated with failure of staged palliation after the Norwood procedure in patients with RV dysfunction. METHODS: Patients from the NIH/NHLBI Pediatric Heart Network Single Ventricle Reconstruction Trial 3 public dataset were selected if RV dysfunction was present, defined as an ejection fraction of less than 44% and fractional area of change of less than 35% on the post-Norwood echocardiogram. Transplant-free survival after the Norwood was analyzed using multiphase parametric hazard analysis and factors associated with death or heart transplantation were identified. Prediction nomograms were constructed using the final model equation. RESULTS: There were 123 (34%) infants with RV dysfunction, of which 100 (81%) proceeded to stage II, 22 (18%) died and 2 (2%) received a heart transplant. The independent risk factors for death or transplant without achieving Stage II completion are shown in the Table. The cohort average transplant-free survival at 6 months was lowest for the BT shunt cohort (67% (70%CI 58-75%)) compared to RVPA conduit (97 % (70%CI 92-99%)). Using our model equation, we predicted the transplant-free survival for the best and worst risk factor scenarios, and showed that both shunt types with no other risk factor was associated with excellent survival (96 % (70 % (CI 91-98 %) for the BT and 99 % (70% CI 23-87%) for the RVPA conduit bestcase scenarios). However, BT shunt with all three other risk factors was associated with poor 6 month transplant-free survival (1% (70% CI 0-13 %), Figure). CONCLUSION: The presence of additional risk factors, such as presence of modified BT shunt or a dilated RV, might help identify patients with post-Norwood RV dysfunction who are at very high risk of death, and who might potentially benefit from early listing for transplant.
Canadian Journal of Cardiology Volume 33 2017
Questionnaire for Adolescents (PAQ-A), a valid 7-day recall tool that yields a physical activity summary PAQ-score between 1 (inactive) and 5 (highly active). Adolescents also self-reported attitudes and perceptions. Parents self-reported on family demographics, encouragement and support for their child’s physical activity, as well as their own physical activity behaviours. Adolescents’ medical history, including cardiac diagnosis, surgical history and physical activity restrictions, were obtained from medical charts. We assessed associations between PAQ-scores and relevant explanatory variables via independent t-tests and multiple linear regression (Stata v. 14, p < 0.05). RESULTS: We included 147 parent-adolescent dyads with complete data. In most cases (86%), mothers completed the parent questionnaire. Adolescents were 15.81.6yrs old, 50% were female, and overall PAQ-score was 2.340.77. Expectedly, PAQ-scores were inversely associated with age (r¼-0.406, p < 0.001). More than half of participants had a cardiac diagnosis (n¼77), of whom most had a history of surgery or catheter-based intervention (n¼54), and very few had received formal physical activity restrictions by their cardiologist (n¼15); PAQ-scores did not differ according to any of these factors. PAQ-scores were significantly higher in adolescents whose parents reported to provide transport to physical activity/ sport (n¼111), or who offered daily encouragement for their child to be physically active (n¼54; all p < 0.001). Parents’ own physical activity levels, or whether they had concerns over their child’s heart health during physical activity (n¼41) was not related to adolescents’ PAQ-scores. In multiple regression adjusted for cardiac diagnosis (non-significant), age and sex explained 18% of the variance in PAQ-scores (r2¼0.179, p < 0.001); parental encouragement and provision of transport explained an additional 10% of the variance in PAQ-scores (r2¼0.272, p < 0.001). CONCLUSION: Physical activity levels are similar for adolescents with and without cardiovascular disease, irrespective of disease severity. Aside from the expected effects of age and sex, supportive parental behaviours emerged as the most important correlates for physical activity participation in these adolescents.
Canadian Pediatric Cardiology Association ePosters CONGENITAL HEART POTPOURRI Saturday, October 21, 2017 010 DOES LATE GADOLINIUM ENHANCEMENT IDENTIFY THE PATIENTS AT RISK IN CHILDHOOD HYPERTROPHIC CARDIOMYOPATHY? A MULTICENTER STUDY S Ide, L Grosse-Wortmann, D Mroczek, R Chan Toronto, Ontario BACKGROUND:
Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) has emerged as a
potential marker for risk of adverse events in adult patients with hypertrophic cardiomyopathy (HCM). However, previous studies of pediatric patients have been limited to small cohorts with short follow-up periods and therefore the clinical significance of LGE in the pediatric HCM population remains uncertain. The aims of this study were 1) to quantify the prevalence and amount of LGE in an unselected pediatric population with HCM and 2) to assess the relation between LGE and ventricular arrhythmia, episodes of circulatory collapse, sudden cardiac death (SCD), and degree of heart failure at the time of MRI and during follow-up. METHODS: Cine and contrast-enhanced CMR exams were performed on 492 HCM patients (13.8 3.9 years; 75% males) in 30 pediatric HCM centers. CMR images were analyzed at a single data coordinating center. Mean follow-up period was 1.9 2.2 years. RESULTS: Mean LVEF was 53 10%, with mean maximal wall thickness of 186mm. Prevalence of LGE was 38%, with mean LGE extent of 2.0 5.1% left ventricular mass. Adverse HCM-related adverse events occurred in 18.7% (n¼92). Sudden cardiac death (SCD) events occurred in 5.5% (n¼27), or 2.7% per year, of which all were asymptomatic or minimally symptomatic (21 with NYHA Class I, and 6 with NYHA Class II). There was a significant relationship between the presence of LGE and all HCM-related adverse disease events (OR 3.10, 95% CI 1.26-7.66, p¼0.01). LGE by percent ventricular mass was also associated with a substantially increased risk of SCD events (Odds ratio, 3.70 per 10% increase in LGE; P¼0.008). LGE of only w5% of LV mass conferred a 2-fold increase in SCD event risk in those patients without LGE. CONCLUSION: In pediatric patients with HCM, LGE detected by contrast-enhanced CMR is associated with an increased risk of HCM-related adverse events, including sudden death.
011 PULMONARY ARTERY WALL THICKNESS IN CHILDREN WITH FONTAN PHYSIOLOGY e AN OPTICAL COHERENCE TOMOGRAPHY CASE CONTROL STUDY E McGovern, C Voss, S Duncombe, M Hosking, K Harris Vancouver, British Columbia BACKGROUND:
Fontan failure in patients with preserved ventricular function is not well understood. Loss of pulsatile flow in the pulmonary arteries leads to lack of shear stress, which is believed to result in endothelial dysfunction. This endothelial dysfunction may further promote vascular remodelling. Subsequent increased pulmonary vascular resistance is considered to be a potential contributing mechanism for Fontan failure. We sought to perform an in vivo case control study to evaluate structural changes in the pulmonary arteries of children with a
Abstracts
Fontan circulation compared to those with a normal pulmonary circulation. METHODS: Since May 2016, we have recruited patients undergoing cardiac catheterization at BC Children’s Hospital. The control group comprised of children with normal pulmonary circulation undergoing cardiac catheterization or invasive electrophysiology evaluation. We performed intravascular imaging of the pulmonary arteries using Optical Coherence Tomography (OCT, Abbott). For quantitative OCT image analyses, we identified a series of 10 crosssectional frames that were each 0.5 mm apart along the vessel. Using digital planimetry, we measured lumen diameter (mm), lumen cross-sectional area (CSA, mm2), wall CSA (mm2), vessel CSA (lumen+wall CSA, mm2) and mean wall thickness (mm) for each frame. To standardize wall thickness by vessel size, we calculated wall CSA to vessel CSA ratios. We calculated median values across frames for each case. Betweengroup differences were assessed by Mann-Whitney U tests; associations by Spearman Rank correlation (Stata v. 14.0; p < 0.05). RESULTS: We quantitatively analysed OCT images of the pulmonary arteries in 10 children with a Fontan circulation (10.83.9yrs at OCT, 40% female) and 8 control children (10.54.2yrs at OCT, 75% female). Overall, there were no significant differences between groups in terms of wall thickness (overall median 0.11mm, interquartile range 0.100.15) or wall/vessel ratio (0.13, IQR 0.11-0.15). There was no association between wall thickness or wall/vessel ratio with age at OCT, age at Fontan completion, or time since Fontan completion. Median pulmonary artery pressure at time of OCT was 11.8mmHg (10.5-14.0), which was not associated with normalized wall thickness. CONCLUSION: OCT findings suggest that during childhood, pulmonary artery wall dimensions are normal in children with Fontan physiology and reassuring hemodynamic status. Further evaluation of vascular function and correlating structure with function in this population would be worthwhile. Serial evaluation of pulmonary artery structure and correlation with clinical course into adulthood is needed.
012 WITHDRAWN
013 RISK FACTORS FOR DEATH OR HEART TRANSPLANT FOR PATIENTS WITH RIGHT VENTRICULAR DYSFUNCTION AFTER THE NORWOOD PROCEDURE: A SECONDARY ANALYSIS OF THE SINGLE VENTRICLE RECONSTRUCTION TRIAL E Jean-St-Michel, J Meza, J Maguire, J Coles, B McCrindle Toronto, Ontario
S7 BACKGROUND: Prediction of mortality for hypoplastic left heart syndrome (HLHS) patients with right ventricular (RV) dysfunction could facilitate early decision-making, such as transplant listing, and potentially improve outcomes. Therefore, we sought to investigate patient and procedural factors associated with failure of staged palliation after the Norwood procedure in patients with RV dysfunction. METHODS: Patients from the NIH/NHLBI Pediatric Heart Network Single Ventricle Reconstruction Trial 3 public dataset were selected if RV dysfunction was present, defined as an ejection fraction of less than 44% and fractional area of change of less than 35% on the post-Norwood echocardiogram. Transplant-free survival after the Norwood was analyzed using multiphase parametric hazard analysis and factors associated with death or heart transplantation were identified. Prediction nomograms were constructed using the final model equation. RESULTS: There were 123 (34%) infants with RV dysfunction, of which 100 (81%) proceeded to stage II, 22 (18%) died and 2 (2%) received a heart transplant. The independent risk factors for death or transplant without achieving Stage II completion are shown in the Table. The cohort average transplant-free survival at 6 months was lowest for the BT shunt cohort (67% (70%CI 58-75%)) compared to RVPA conduit (97 % (70%CI 92-99%)). Using our model equation, we predicted the transplant-free survival for the best and worst risk factor scenarios, and showed that both shunt types with no other risk factor was associated with excellent survival (96 % (70 % (CI 91-98 %) for the BT and 99 % (70% CI 23-87%) for the RVPA conduit bestcase scenarios). However, BT shunt with all three other risk factors was associated with poor 6 month transplant-free survival (1% (70% CI 0-13 %), Figure). CONCLUSION: The presence of additional risk factors, such as presence of modified BT shunt or a dilated RV, might help identify patients with post-Norwood RV dysfunction who are at very high risk of death, and who might potentially benefit from early listing for transplant.