- Email: [email protected]
LEFT VENTRICULAR MECHANICS AND EXERCISE CAPACITY IN CLINICALLY STABLE PEDIATRIC HEART TRANSPLANT RECIPIENTS
Abstracts
S247
reports of children diagnosed with acute KD between 2004 and 2014 from five participating institutions (including two routinely using low dose ASA). This abstract presents the preliminary results of three out of five institutions, for a total of 997 eligible subjects. Treatment groups were defined according to the ASA dose prescribed during the acute phase. All patients received at least one course of intravenous immune globulin. A non-inferiority trial design was used to assess the risk difference of CA aneurysm according ASA dose. Low dose ASA was considered noninferior if the 95% confidence interval of the risk difference was < 5% for the main outcome (any CA abnormality). Results were adjusted for sex, age, treatment resistance, incomplete KD, and delayed diagnosis. RESULTS:
Patients in the low dose and high dose groups were prescribed a mean ASA dose of 4.2 mg/kg/d and 82.6 mg/kg/d, respectively. We observed a non-statistically significant difference in the risk of CA abnormality (any Z score > 2.5) in the low dose versus high dose ASA group (19.8% vs. 16.3%) with an adjusted risk difference of 1.9% [95%CI of 3.0% to 6.9%]. However, the risk difference was mainly due to small transient CA dilatations (Z scores between 2.5 and 5 at diagnosis but returning to normal at first follow-up - see Table). When only CA dilatation persisting beyond the acute phase were considered, the adjusted risk difference was close to zero and the upper bound of the 95% confidence interval was well below 5%: risk difference of 1.9 % [95%CI: 5.4% to 1.6%]). Adjusted risk difference for medium and giant CA aneurysm were also close to zero and not statistically significant. CONCLUSION: In conjunction with IVIG, ASA at anti-platelet dose during the acute phase of KD is not inferior to higher dosages of ASA for reducing the risk of persistent CA aneurysm in children.
Table: Coronary Artery aneurysms according to ASA dose Adjusted* risk difference and [95%CI] (lo w dose vs. high dose) 1.9 % [−3.0% ; 6.9%]
314 THE NORWOOD-SANO OPERATION: A COMPARISON OF TWO-YEAR CLINICAL AND NEURODEVELOPMENTAL OUTCOMES BETWEEN PATIENTS WITH CLASSICAL HYPOPLASTIC LEFT HEART SYNDROME AND THOSE WITH VARIANT ANATOMY B Martin, D Jonker, AR Joffe, G Bond, DB Ross, IM Rebeyka, CM Robertson, J Atallah Edmonton, Alberta BACKGROUND:
Neurodevelopmental outcomes have been suggested by previous studies to be inferior in hypoplastic left heart syndrome (HLHS) as opposed to other variants of a hypoplastic left heart configuration following single ventricle palliation. Our objective was to compare survival and neurodevelopmental outcome during the same surgical era in a large, well-described cohort. METHODS: All subjects who underwent a Norwood-Sano operation between April 2005 and December 2012 were included. Follow-up clinical, neurological and developmental data were obtained from the Western Canadian Complex Pediatric Therapies Follow-up Program database. Developmental outcomes were assessed at 2 years of age using the Bayley Scales of Infant and Toddler Development (3rd edition). Survival and outcomes were compared between those with and without classic hypoplastic left heart syndrome. Survival was assessed by Kaplan- Meier analysis. RESULTS: The study comprised 103 infants (61 male), 65 (43 male) of whom had classic HLHS. All subjects underwent a Norwood-Sano. There were 9 deaths prior to hospital discharge post-Norwood Sano, and an additional 12 interstage deaths. Mortality was the same for classic and variant HLHS (p¼1.000). Of the remaining 82, 78 patients underwent second stage (Glenn) palliation, followed by 7 deaths prior to assessment age (3 classical, 4 variants). Two children did not have Glenn and went directly to Fontan (both variants) or heart transplant (both classical). Seventy-five patients underwent neurodevelopmental assessment including Bayley-III scores. The overall mean cognitive composite score was 91.5 (SD 15.2) and overall mean motor composite score was 85.8 (SD 14.5). Neither the cognitive nor motor scores differed between those with classic and variant HLHS (both p>0.05). CONCLUSIONS: In our cohort of patients undergoing a Norwood procedure, survival and neurodevelopmental outcomes at 2 years did not differ between those with classical HLHS and variant anatomy.
High dose ASA n (%)
Low dose ASA n (%)
Unadjusted risk difference and [95%CI](lo w dose vs. high dose)
All CA 175/997 abnormalities (a (17.6%) ny Z score > 2.5)
107/653(16.3 %)
68/344(19.8 %)
3.4% [−1.7% ; 8.5%]
Transient small CA dilatation (Z 64/997 between > 2.5 (6.4%) and 5 only during acute phase)
31/653(4.8%)
33/344(9.6%) 4.9% [1.3% ; 8.4%]
Persistent CA aneurysm (Z > 2.5 persisting beyond acute phase)
76/653(11.6%) 35/344(10.2 %)
−1.9 % −1.5% [−5.5% ; [−5.4% ; 2.6%] 1.6%]
315 LEFT VENTRICULAR MECHANICS AND EXERCISE CAPACITY IN CLINICALLY STABLE PEDIATRIC HEART TRANSPLANT RECIPIENTS
31/653(4.8%) 9/344(2.6%)
−2.1 % [−4.5%; −1.0% [−3.0 0.2%] % ; 1.0%]
AT Cote, S Moodley, AM De Souza, T Zadorsky, JE Potts, TW Rowland, GG Sandor, KC Harris
Outcomes
Medium or larger CA aneurysm (Z > 5) Giant CA aneurysm (Z > 10)
All subjectsn ( %)
111/997 (11.1%)
40/997(4.0%)
21/997(2.1%) 16/653(2.45%)
5/344(1.4%)
4.4% [0.7% ; 8.1%]
−1.0% [−2.7 %; 0.4% [−1.1 0.7%] % ; 1.8%]
* adjusted for sex, age, treatment resistance, incomplete versus complete KD, and delayed diagnosis.
Vancouver, British Columbia BACKGROUND:
Both exercise capacity and left ventricular (LV) function have been reported to be suboptimal in children who have
S248
undergone heart transplantation (HTx) compared to their peers. Ventricular twist is important for optimal systolic and diastolic function. However, the nature of LV twist in pediatric HTx has not been investigated. The objective of this study was to assess LV mechanics at rest and during exercise in children who have undergone HTx and determine the relationship with exercise capacity. METHODS: Hemodynamics and measures of cardiac function were assessed in 28 children (n¼14 HTx free from rejection, n¼14 Controls; Age ¼ 12.6 2.2 years). Speckle-tracking echocardiography was used to assess peak twist, twist and untwist rates, at rest and during semi-supine cycle exercise. Independent t-tests were used to assess group differences in baseline hemodynamics and exercise capacity. Repeated-measures ANOVA was used to assess interactions and main effects for LV mechanics over time (rest to peak exercise) by group (HTx versus Controls). Linear regression analysis was used to assess the relationship between measures of exercise capacity and LV mechanics. RESULTS: Children with HTx displayed reduced baseline stroke volume and cardiac indices (SVI, CI), twist rate and untwist rate (all p<0.05). Work (1185 407 versus 740 249 joules) and VO2 at peak exercise (36.2 8.8 versus 27.7 7.0 ml/kg/min) were higher in Controls than HTx (p¼0.002 and p¼0.013, respectively). LV twist increased during exercise in all children; however, was lower in HTx than Controls independent of time (rest to exercise: 14 4 to 19 6 in HTx versus 17 6 to 25 4 in Controls; p<0.001), as was twist rate (rest to exercise: 134 21 to 187 66 /s in HTx versus 234 63 to 358 105 /s in Controls; p<0.001). An interaction was found for systolic rotation rate at the base, where Controls increased to a greater extent during exercise than HTx (p¼0.02). Peak VO2 was associated with change in LV twist and work (r2 ¼ 0.84, p<0.001). CONCLUSION: LV twist is reduced in pediatric HTx in the absence of rejection both at rest and during exercise and may contribute to the reduced exercise capacity displayed during exercise in these children. 316 PHYSICAL ACTIVITY PERCEPTIONS AND BEHAVIOURS IN EMERGING ADULTS WITH CONGENITAL HEART DISEASE: A MIXED METHODS STUDY AL McKillop, BW McCrindle, G Dimitropoulos, SL Grace, AH Kovacs
Canadian Journal of Cardiology Volume 32 2016 RESULTS: Fifteen patients (67% male; 213 years old) with moderate (n¼10) or complex (n¼5) CHD were recruited from an outpatient adult CHD clinic. Accelerometer data indicated that patients accumulated a mean of 26 minutes of moderate-to-vigorous physical activity (MVPA) per day. Participants were interviewed to explore perceptions towards physical activity as a child/adolescent and current activity as an emerging adult. Thematic analysis identified the following 4 main themes: (1) Importance of family: patients reported more positive perceptions towards activity if their family members encouraged physical activity participation, including siblings that engaged in physical activity alongside patients; (2) Parental support: parents were recalled as being supportive rather than over-protective, and activity precautions were perceived as instructions from cardiologists rather than parents; (3) Physical activity as a health-promoting behaviour: whereas physical activity in childhood was viewed as recreational, the cardiac health-promoting aspects became more prominent in adulthood; and (4) Emphasis on occupational activities: patients often considered activities performed during one’s employment to be sufficient to meet the recommended daily physical activity levels, and reported limited time and/or energy to participate in activity outside of work. CONCLUSION: Emerging adults with CHD described supportive families who encouraged activity participation. This positive influence of family may have helped patients have a positive perception towards activity participation as adults. Patients engaged in MVPA to a similar degree as healthy adults 20-39 years old, as reported in the Canadian Health Measures Survey (28.5 minutes of MVPA per day). However, patients were still below the current physical activity recommendations for adults (30 minutes of MVPA at least 5 days/week). Future work should aim to educate families about communicating positive messages regarding physical activity. Interventions should be developed to help adults with CHD increase their activity participation, which patients themselves acknowledge is so important to their current and future cardiac health.
Canadian Cardiovascular Society (CCS) Oral BIOMARKERS AND IMAGING IN VALVULAR HEART DISEASE Monday, October 24, 2016
Toronto, Ontario BACKGROUND:
Adults with congenital heart disease (CHD) present with unique experiences compared to both healthy peers and adults with acquired heart disease. Despite the benefits of exercise, they are less active than healthy adults. Reasons for this are not fully understood. This study explored the physical activity perceptions and behaviours among emerging adults (aged 18-25 years) with CHD. METHODS: This was a cross-sectional, observational study, where both quantitative (i.e., accelerometer) and qualitative (i.e., interviews) data collection methods were used.
317 RECLASSIFICATION OF PARADOXICAL LOW-FLOW, LOW-GRADIENT SEVERE AORTIC STENOSIS BASED ON BIPLANE-DERIVED STROKE VOLUME M Chamberlain, TS Tsang, K Gin, MY Tsang, P Nair, PK Lee, J Jue Vancouver, British Columbia BACKGROUND:
Incumbent to the diagnosis of paradoxical lowflow, low-gradient severe aortic stenosis (LFLG AS) is a low
S247
reports of children diagnosed with acute KD between 2004 and 2014 from five participating institutions (including two routinely using low dose ASA). This abstract presents the preliminary results of three out of five institutions, for a total of 997 eligible subjects. Treatment groups were defined according to the ASA dose prescribed during the acute phase. All patients received at least one course of intravenous immune globulin. A non-inferiority trial design was used to assess the risk difference of CA aneurysm according ASA dose. Low dose ASA was considered noninferior if the 95% confidence interval of the risk difference was < 5% for the main outcome (any CA abnormality). Results were adjusted for sex, age, treatment resistance, incomplete KD, and delayed diagnosis. RESULTS:
Patients in the low dose and high dose groups were prescribed a mean ASA dose of 4.2 mg/kg/d and 82.6 mg/kg/d, respectively. We observed a non-statistically significant difference in the risk of CA abnormality (any Z score > 2.5) in the low dose versus high dose ASA group (19.8% vs. 16.3%) with an adjusted risk difference of 1.9% [95%CI of 3.0% to 6.9%]. However, the risk difference was mainly due to small transient CA dilatations (Z scores between 2.5 and 5 at diagnosis but returning to normal at first follow-up - see Table). When only CA dilatation persisting beyond the acute phase were considered, the adjusted risk difference was close to zero and the upper bound of the 95% confidence interval was well below 5%: risk difference of 1.9 % [95%CI: 5.4% to 1.6%]). Adjusted risk difference for medium and giant CA aneurysm were also close to zero and not statistically significant. CONCLUSION: In conjunction with IVIG, ASA at anti-platelet dose during the acute phase of KD is not inferior to higher dosages of ASA for reducing the risk of persistent CA aneurysm in children.
Table: Coronary Artery aneurysms according to ASA dose Adjusted* risk difference and [95%CI] (lo w dose vs. high dose) 1.9 % [−3.0% ; 6.9%]
314 THE NORWOOD-SANO OPERATION: A COMPARISON OF TWO-YEAR CLINICAL AND NEURODEVELOPMENTAL OUTCOMES BETWEEN PATIENTS WITH CLASSICAL HYPOPLASTIC LEFT HEART SYNDROME AND THOSE WITH VARIANT ANATOMY B Martin, D Jonker, AR Joffe, G Bond, DB Ross, IM Rebeyka, CM Robertson, J Atallah Edmonton, Alberta BACKGROUND:
Neurodevelopmental outcomes have been suggested by previous studies to be inferior in hypoplastic left heart syndrome (HLHS) as opposed to other variants of a hypoplastic left heart configuration following single ventricle palliation. Our objective was to compare survival and neurodevelopmental outcome during the same surgical era in a large, well-described cohort. METHODS: All subjects who underwent a Norwood-Sano operation between April 2005 and December 2012 were included. Follow-up clinical, neurological and developmental data were obtained from the Western Canadian Complex Pediatric Therapies Follow-up Program database. Developmental outcomes were assessed at 2 years of age using the Bayley Scales of Infant and Toddler Development (3rd edition). Survival and outcomes were compared between those with and without classic hypoplastic left heart syndrome. Survival was assessed by Kaplan- Meier analysis. RESULTS: The study comprised 103 infants (61 male), 65 (43 male) of whom had classic HLHS. All subjects underwent a Norwood-Sano. There were 9 deaths prior to hospital discharge post-Norwood Sano, and an additional 12 interstage deaths. Mortality was the same for classic and variant HLHS (p¼1.000). Of the remaining 82, 78 patients underwent second stage (Glenn) palliation, followed by 7 deaths prior to assessment age (3 classical, 4 variants). Two children did not have Glenn and went directly to Fontan (both variants) or heart transplant (both classical). Seventy-five patients underwent neurodevelopmental assessment including Bayley-III scores. The overall mean cognitive composite score was 91.5 (SD 15.2) and overall mean motor composite score was 85.8 (SD 14.5). Neither the cognitive nor motor scores differed between those with classic and variant HLHS (both p>0.05). CONCLUSIONS: In our cohort of patients undergoing a Norwood procedure, survival and neurodevelopmental outcomes at 2 years did not differ between those with classical HLHS and variant anatomy.
High dose ASA n (%)
Low dose ASA n (%)
Unadjusted risk difference and [95%CI](lo w dose vs. high dose)
All CA 175/997 abnormalities (a (17.6%) ny Z score > 2.5)
107/653(16.3 %)
68/344(19.8 %)
3.4% [−1.7% ; 8.5%]
Transient small CA dilatation (Z 64/997 between > 2.5 (6.4%) and 5 only during acute phase)
31/653(4.8%)
33/344(9.6%) 4.9% [1.3% ; 8.4%]
Persistent CA aneurysm (Z > 2.5 persisting beyond acute phase)
76/653(11.6%) 35/344(10.2 %)
−1.9 % −1.5% [−5.5% ; [−5.4% ; 2.6%] 1.6%]
315 LEFT VENTRICULAR MECHANICS AND EXERCISE CAPACITY IN CLINICALLY STABLE PEDIATRIC HEART TRANSPLANT RECIPIENTS
31/653(4.8%) 9/344(2.6%)
−2.1 % [−4.5%; −1.0% [−3.0 0.2%] % ; 1.0%]
AT Cote, S Moodley, AM De Souza, T Zadorsky, JE Potts, TW Rowland, GG Sandor, KC Harris
Outcomes
Medium or larger CA aneurysm (Z > 5) Giant CA aneurysm (Z > 10)
All subjectsn ( %)
111/997 (11.1%)
40/997(4.0%)
21/997(2.1%) 16/653(2.45%)
5/344(1.4%)
4.4% [0.7% ; 8.1%]
−1.0% [−2.7 %; 0.4% [−1.1 0.7%] % ; 1.8%]
* adjusted for sex, age, treatment resistance, incomplete versus complete KD, and delayed diagnosis.
Vancouver, British Columbia BACKGROUND:
Both exercise capacity and left ventricular (LV) function have been reported to be suboptimal in children who have
S248
undergone heart transplantation (HTx) compared to their peers. Ventricular twist is important for optimal systolic and diastolic function. However, the nature of LV twist in pediatric HTx has not been investigated. The objective of this study was to assess LV mechanics at rest and during exercise in children who have undergone HTx and determine the relationship with exercise capacity. METHODS: Hemodynamics and measures of cardiac function were assessed in 28 children (n¼14 HTx free from rejection, n¼14 Controls; Age ¼ 12.6 2.2 years). Speckle-tracking echocardiography was used to assess peak twist, twist and untwist rates, at rest and during semi-supine cycle exercise. Independent t-tests were used to assess group differences in baseline hemodynamics and exercise capacity. Repeated-measures ANOVA was used to assess interactions and main effects for LV mechanics over time (rest to peak exercise) by group (HTx versus Controls). Linear regression analysis was used to assess the relationship between measures of exercise capacity and LV mechanics. RESULTS: Children with HTx displayed reduced baseline stroke volume and cardiac indices (SVI, CI), twist rate and untwist rate (all p<0.05). Work (1185 407 versus 740 249 joules) and VO2 at peak exercise (36.2 8.8 versus 27.7 7.0 ml/kg/min) were higher in Controls than HTx (p¼0.002 and p¼0.013, respectively). LV twist increased during exercise in all children; however, was lower in HTx than Controls independent of time (rest to exercise: 14 4 to 19 6 in HTx versus 17 6 to 25 4 in Controls; p<0.001), as was twist rate (rest to exercise: 134 21 to 187 66 /s in HTx versus 234 63 to 358 105 /s in Controls; p<0.001). An interaction was found for systolic rotation rate at the base, where Controls increased to a greater extent during exercise than HTx (p¼0.02). Peak VO2 was associated with change in LV twist and work (r2 ¼ 0.84, p<0.001). CONCLUSION: LV twist is reduced in pediatric HTx in the absence of rejection both at rest and during exercise and may contribute to the reduced exercise capacity displayed during exercise in these children. 316 PHYSICAL ACTIVITY PERCEPTIONS AND BEHAVIOURS IN EMERGING ADULTS WITH CONGENITAL HEART DISEASE: A MIXED METHODS STUDY AL McKillop, BW McCrindle, G Dimitropoulos, SL Grace, AH Kovacs
Canadian Journal of Cardiology Volume 32 2016 RESULTS: Fifteen patients (67% male; 213 years old) with moderate (n¼10) or complex (n¼5) CHD were recruited from an outpatient adult CHD clinic. Accelerometer data indicated that patients accumulated a mean of 26 minutes of moderate-to-vigorous physical activity (MVPA) per day. Participants were interviewed to explore perceptions towards physical activity as a child/adolescent and current activity as an emerging adult. Thematic analysis identified the following 4 main themes: (1) Importance of family: patients reported more positive perceptions towards activity if their family members encouraged physical activity participation, including siblings that engaged in physical activity alongside patients; (2) Parental support: parents were recalled as being supportive rather than over-protective, and activity precautions were perceived as instructions from cardiologists rather than parents; (3) Physical activity as a health-promoting behaviour: whereas physical activity in childhood was viewed as recreational, the cardiac health-promoting aspects became more prominent in adulthood; and (4) Emphasis on occupational activities: patients often considered activities performed during one’s employment to be sufficient to meet the recommended daily physical activity levels, and reported limited time and/or energy to participate in activity outside of work. CONCLUSION: Emerging adults with CHD described supportive families who encouraged activity participation. This positive influence of family may have helped patients have a positive perception towards activity participation as adults. Patients engaged in MVPA to a similar degree as healthy adults 20-39 years old, as reported in the Canadian Health Measures Survey (28.5 minutes of MVPA per day). However, patients were still below the current physical activity recommendations for adults (30 minutes of MVPA at least 5 days/week). Future work should aim to educate families about communicating positive messages regarding physical activity. Interventions should be developed to help adults with CHD increase their activity participation, which patients themselves acknowledge is so important to their current and future cardiac health.
Canadian Cardiovascular Society (CCS) Oral BIOMARKERS AND IMAGING IN VALVULAR HEART DISEASE Monday, October 24, 2016
Toronto, Ontario BACKGROUND:
Adults with congenital heart disease (CHD) present with unique experiences compared to both healthy peers and adults with acquired heart disease. Despite the benefits of exercise, they are less active than healthy adults. Reasons for this are not fully understood. This study explored the physical activity perceptions and behaviours among emerging adults (aged 18-25 years) with CHD. METHODS: This was a cross-sectional, observational study, where both quantitative (i.e., accelerometer) and qualitative (i.e., interviews) data collection methods were used.
317 RECLASSIFICATION OF PARADOXICAL LOW-FLOW, LOW-GRADIENT SEVERE AORTIC STENOSIS BASED ON BIPLANE-DERIVED STROKE VOLUME M Chamberlain, TS Tsang, K Gin, MY Tsang, P Nair, PK Lee, J Jue Vancouver, British Columbia BACKGROUND:
Incumbent to the diagnosis of paradoxical lowflow, low-gradient severe aortic stenosis (LFLG AS) is a low