Shaine A. Morris

Increased Vertebral Artery Tortuosity Index Is Associated With Adverse Outcomes in Children and Young Adults With Connective Tissue Disorders

Background— Arterial tortuosity is described as a common and distinctive feature of Loeys-Dietz syndrome (LDS), yet reports on arterial tortuosity are based on qualitative observations and none have investigated an association between tortuosity and cardiovascular outcomes in LDS or other connective tissue disorders. Methods and Results— We performed a retrospective analysis of 90 patients ⩽50 years of age with Marfan syndrome, LDS, Ehlers-Danlos syndrome, or nonspecific connective tissue disorder who underwent thoracic contrast-enhanced magnetic resonance angiography. Controls (n=30) underwent magnetic resonance imaging to exclude arrhythmogenic right ventricular dysplasia. Using a volume-rendered angiogram, vertebral arteries were measured along the curvature of the vessel (actual length) and linearly (straight length), and distance factor was calculated: [(actual/straight length−1)×100]. Each subjects maximum distance factor was designated the Vertebral Tortuosity Index (VTI). The VTI was compared among diagnostic groups and among patients with cardiac surgery, dissection, and death. Median age at magnetic resonance imaging was 19.6 years (range 0.2 to 50.1). VTI interrater reliability was excellent (intraclass correlation coefficient =0.987). The VTI was higher in Marfan syndrome (n=57, median 26; interquartile range 10 to 49) and LDS (n=13, median 58; interquartile range 18 to 92) compared with controls (median 4.5; interquartile range 3 to 6; P<0.001 for both). Higher VTI was associated with younger age at surgery even when controlling for root size (adjusted P=0.002). Vertebral tortuosity index ≥50 was associated with earlier age at dissection and death compared with VTI <50 (P=0.001 versus P<0.001). We found no difference in age at surgery, dissection, or death in Marfan syndrome compared with LDS. Conclusion— Arterial tortuosity measured by magnetic resonance angiography is a reproducible marker of adverse cardiovascular outcomes in connective tissue disorders.

Prenatal Diagnosis, Birth Location, Surgical Center, and Neonatal Mortality in Infants With Hypoplastic Left Heart Syndrome

Background— Most studies have not demonstrated improved survival after prenatal diagnosis of critical congenital heart disease, including hypoplastic left heart syndrome (HLHS). However, the effect of delivery near a cardiac surgical center (CSC), the recommended action after prenatal diagnosis, on HLHS mortality has been poorly investigated. Methods and Results— Using Texas Birth Defects Registry data, 1999 through 2007, which monitored >3.4 million births, we investigated the association between distance (calculated driving time) from birth center to CSC and neonatal mortality in 463 infants with HLHS. Infants with extracardiac birth defects or genetic disorders were excluded. The associations between prenatal diagnosis, CSC HLHS volume, and mortality were also examined. Neonatal mortality in infants born <10 minutes from a CSC was 21.0%, 10 to 90 minutes 25.2%, and >90 minutes 39.6% (P for trend <0.001). Prenatal diagnosis alone was not associated with improved survival (P=0.14). In multivariable analysis, birth >90 minutes from a CSC remained associated with increased mortality (odds ratio, 2.03; 95% confidence interval, 1.19–3.45), compared with <10 minutes. In subanalysis, birth >90 minutes from a CSC was associated with higher pretransport mortality (odds ratio, 6.69; 95% confidence interval, 2.52–17.74) and birth 10 to 90 minutes with higher presurgical mortality (odds ratio, 4.45; 95% confidence interval, 1.17–17.00). Higher surgical mortality was associated with lower CSC HLHS volume (odds ratio per 10 patients, 0.88; 95% confidence interval, 0.84–0.91). Conclusions— Infants with HLHS born far from a CSC have increased neonatal mortality, and most of this mortality is presurgical. Efforts to improve prenatal diagnosis of HLHS and subsequent delivery near a large volume CSC may significantly improve neonatal HLHS survival.

Reforming Procedural Skills Training for Pediatric Residents: A Randomized, Interventional Trial

BACKGROUND: Pediatric housestaff are required to learn basic procedural skills and demonstrate competence during training. To our knowledge, an evidenced-based procedural skills curriculum does not exist. OBJECTIVE: To create, implement, and evaluate a modular procedural skills curriculum for pediatric residents. METHODS: A randomized, controlled trial was performed. Thirty-eight interns in the Boston Combined Residency Program who began their training in 2005 were enrolled and randomly assigned. Modules were created to teach residents bag-mask ventilation, venipuncture, peripheral intravenous catheter (PIV) insertion, and lumbar puncture skills. The curriculum was administered to participants in the intervention group during intern orientation. Interns in the control group learned procedural skills by usual methods. Subjects were evaluated by using a structured objective assessment on simulators immediately after the intervention and 7 months later. Success in performing live-patient procedures was self-reported by subjects. The primary outcome was successful performance of the procedure on the initial assessment. Secondary outcomes included checklist and knowledge examination scores, live-patient success, and qualitative assessment of the curriculum. RESULTS: Participants in the intervention group performed PIV placement more successfully than controls (79% vs 35%) and scored significantly higher on the checklist for PIV placement (81% vs 61%) and lumbar puncture (77% vs 68%) at the initial assessment. There were no differences between groups at month 7, and both groups demonstrated declining skills. There were no statistically significant differences in success on live-patient procedures. Those in the intervention group scored significantly higher on knowledge examinations. CONCLUSIONS: Participants in the intervention group were more successful performing certain simulated procedures than controls when tested immediately after receiving the curriculum but demonstrated declining skills thereafter. Future efforts must emphasize retraining, and residents must have sufficient opportunities to practice skills learned in a formal curriculum.

Outcomes and Predictors of Perinatal Mortality in Fetuses With Ebstein Anomaly or Tricuspid Valve Dysplasia in the Current Era A Multicenter Study

Background— Ebstein anomaly and tricuspid valve dysplasia are rare congenital tricuspid valve malformations associated with high perinatal mortality. The literature consists of small, single-center case series spanning several decades. We performed a multicenter study to assess the outcomes and factors associated with mortality after fetal diagnosis in the current era. Methods and Results— Fetuses diagnosed with Ebstein anomaly and tricuspid valve dysplasia from 2005 to 2011 were included from 23 centers. The primary outcome was perinatal mortality, defined as fetal demise or death before neonatal discharge. Of 243 fetuses diagnosed at a mean gestational age of 27±6 weeks, there were 11 lost to follow-up (5%), 15 terminations (6%), and 41 demises (17%). In the live-born cohort of 176 live-born patients, 56 (32%) died before discharge, yielding an overall perinatal mortality of 45%. Independent predictors of mortality at the time of diagnosis were gestational age <32 weeks (odds ratio, 8.6; 95% confidence interval, 3.5–21.0; P<0.001), tricuspid valve annulus diameter z-score (odds ratio, 1.3; 95% confidence interval, 1.1–1.5; P<0.001), pulmonary regurgitation (odds ratio, 2.9; 95% confidence interval, 1.4–6.2; P<0.001), and a pericardial effusion (odds ratio, 2.5; 95% confidence interval, 1.1–6.0; P=0.04). Nonsurvivors were more likely to have pulmonary regurgitation at any gestational age (61% versus 34%; P<0.001), and lower gestational age and weight at birth (35 versus 37 weeks; 2.5 versus 3.0 kg; both P<0.001). Conclusion— In this large, contemporary series of fetuses with Ebstein anomaly and tricuspid valve dysplasia, perinatal mortality remained high. Fetuses with pulmonary regurgitation, indicating circular shunt physiology, are a high-risk cohort and may benefit from more innovative therapeutic approaches to improve survival.

The Need for Standardized Methods for Measuring the Aorta Multimodality Core Lab Experience from the GenTAC Registry

OBJECTIVES This study sought to evaluate variability in aortic measurements with multiple imaging modalities in clinical centers by comparing with a standardized measuring protocol implemented in a core laboratory. BACKGROUND In patients with aortic disease, imaging of thoracic aorta plays a major role in risk stratifying individuals for life-threatening complications and in determining timing of surgical intervention. However, standardization of the procedures for performance of aortic measurements is lacking. METHODS To characterize the diversity of methods used in clinical practice, we compared aortic measurements performed by echocardiography, computed tomography (CT), and magnetic resonance imaging (MRI) at the 6 GenTAC (National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions) clinical centers to those performed at the imaging core laboratory in 965 studies. Each center acquired and analyzed their images according to local protocols. The same images were subsequently analyzed blindly by the core laboratory, on the basis of a standardized protocol for all imaging modalities. Paired measurements from clinical centers and core laboratory were compared by mean of differences and intraclass correlation coefficient (ICC). RESULTS For all segments of the ascending aorta, echocardiography showed a higher ICC (0.84 to 0.93) than CT (0.84) and MRI (0.82 to 0.90), with smaller mean of differences. MRI showed higher ICC for the arch and descending aorta (0.91 and 0.93). In a mixed adjusted model, the different imaging modalities and clinical centers were identified as sources of variability between clinical and core laboratory measurements, whereas age groups or diagnosis at enrollment were not. CONCLUSIONS By comparing core laboratory with measurements from clinical centers, our study identified important sources of variability in aortic measurements. Furthermore, our findings with regard to CT and MRI suggest a need for imaging societies to work toward the development of unifying acquisition protocols and common measuring methods.

Segmental Aortic Stiffness in Children and Young Adults With Connective Tissue Disorders Relationships With Age, Aortic Size, Rate of Dilation, and Surgical Root Replacement

Background— Aortic diameter is an imperfect predictor of aortic complications in connective tissue disorders (CTDs). Novel indicators of vascular phenotype severity such as aortic stiffness and vertebral tortuosity index have been proposed. We assessed the relation between aortic stiffness by cardiac MRI, surgical root replacement, and rates of aortic root dilation in children and young adults with CTDs. Methods and Results— Retrospective analysis of cardiac MRI data on children and young adults with a CTD was performed to derive aortic stiffness measures (strain, distensibility, and &bgr;-stiffness index) at the aortic root, ascending aorta, and descending aorta. Vertebral tortuosity index was calculated as previously described. Rate of aortic root dilation before cardiac MRI was calculated as change in echocardiographic aortic root diameter z score per year. In 83 CTD patients (median age, 24 years; range, 1–55; 17% <18 years of age; 60% male), ascending aorta distensibility was reduced in comparison with published normative values: median z score, –1.93 (range, –8.7 to 1.3; P<0.0001 versus normals). Over a median follow-up period of 2.7 years, there were no aortic dissections or deaths, but 16 of 83 (19%) patients underwent surgical aortic root replacement. In multivariable analysis, lower aortic root strain (P=0.05) and higher vertebral tortuosity index (P=0.01) were independently associated with aortic root replacement. Lower ascending aorta strain (P=0.02) was associated with a higher rate of aortic root dilation. Conclusions— Higher aortic stiffness is associated with higher rates of surgical aortic replacement and aortic root dilation in children and young adults with CTDs.

International Registry of Patients Carrying TGFBR1 or TGFBR2 Mutations: Results of the MAC (Montalcino Aortic Consortium)

Background—The natural history of aortic diseases in patients with TGFBR1 or TGFBR2 mutations reported by different investigators has varied greatly. In particular, the current recommendations for the timing of surgical repair of the aortic root aneurysms may be overly aggressive. Methods and Results—The Montalcino Aortic Consortium, which includes 15 centers worldwide that specialize in heritable thoracic aortic diseases, was used to gather data on 441 patients from 228 families, with 176 cases harboring a mutation in TGBR1 and 265 in TGFBR2. Patients harboring a TGFBR1 mutation have similar survival rates (80% survival at 60 years), aortic risk (23% aortic dissection and 18% preventive aortic surgery), and prevalence of extra-aortic features (29% hypertelorism, 53% cervical arterial tortuosity, and 27% wide scars) when compared with patients harboring a TGFBR2 mutation. However, TGFBR1 males had a greater aortic risk than females, whereas TGFBR2 males and females had a similar aortic risk. Additionally, aortic root diameter prior to or at the time of type A aortic dissection tended to be smaller in patients carrying a TGFBR2 mutation and was ⩽45 mm in 6 women with TGFBR2 mutations, presenting with marked systemic features and low body surface area. Aortic dissection was observed in 1.6% of pregnancies. Conclusions—Patients with TGFBR1 or TGFBR2 mutations show the same prevalence of systemic features and the same global survival. Preventive aortic surgery at a diameter of 45 mm, lowered toward 40 in females with low body surface area, TGFBR2 mutation, and severe extra-aortic features may be considered.Background— The natural history of aortic diseases in patients with TGFBR1 or TGFBR2 mutations reported by different investigators has varied greatly. In particular, the current recommendations for the timing of surgical repair of the aortic root aneurysms may be overly aggressive. Methods and Results— The Montalcino Aortic Consortium, which includes 15 centers worldwide that specialize in heritable thoracic aortic diseases, was used to gather data on 441 patients from 228 families, with 176 cases harboring a mutation in TGBR1 and 265 in TGFBR2 . Patients harboring a TGFBR1 mutation have similar survival rates (80% survival at 60 years), aortic risk (23% aortic dissection and 18% preventive aortic surgery), and prevalence of extra-aortic features (29% hypertelorism, 53% cervical arterial tortuosity, and 27% wide scars) when compared with patients harboring a TGFBR2 mutation. However, TGFBR1 males had a greater aortic risk than females, whereas TGFBR2 males and females had a similar aortic risk. Additionally, aortic root diameter prior to or at the time of type A aortic dissection tended to be smaller in patients carrying a TGFBR2 mutation and was ≤45 mm in 6 women with TGFBR2 mutations, presenting with marked systemic features and low body surface area. Aortic dissection was observed in 1.6% of pregnancies. Conclusions— Patients with TGFBR1 or TGFBR2 mutations show the same prevalence of systemic features and the same global survival. Preventive aortic surgery at a diameter of 45 mm, lowered toward 40 in females with low body surface area, TGFBR2 mutation, and severe extra-aortic features may be considered.

Aortic Complications Associated With Pregnancy in Marfan Syndrome: The NHLBI National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions (GenTAC)

Background The risk of aortic complications associated with pregnancy in women with Marfan syndrome (MFS) is not fully understood. Methods and Results MFS women participating in the large National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions (GenTAC) were evaluated. Among 184 women with MFS in whom pregnancy information was available, 94 (51%) had a total of 227 pregnancies. Among the women with pregnancies, 10 (10.6%) experienced a pregnancy‐related aortic complication (4 type A and 3 type B dissections, 1 coronary artery dissection, and 2 with significant [≥3 mm] aortic growth). Five of 7 aortic dissections, including all 3 type B, and the coronary dissection (75% of all dissections) occurred in the postpartum period. Only 5 of 8 women with pregnancy‐associated dissection were aware of their MFS diagnosis. The rate of aortic dissection was higher during the pregnancy and postpartum period (5.4 per 100 person‐years vs 0.6 per 100 person‐years of nonpregnancy; rate ratio, 8.4 [95% CI=3.9, 18.4]; P<0.0001). Conclusions Pregnancy in MFS is associated with an increased risk of aortic dissection, both types A and B, particularly in the immediate postpartum period. Lack of knowledge of underlying MFS diagnosis before aortic dissection is a major contributing factor. These findings underscore the need for early diagnosis, prepregnancy risk counseling, and multidisciplinary peripartum management.

Effect of Branch Pulmonary Artery Stenosis on Right Ventricular Volume Overload in Patients With Tetralogy of Fallot After Initial Surgical Repair

Right ventricular (RV) volume overload secondary to pulmonary regurgitation is common in patients after initial repair of tetralogy of Fallot (TOF) and is associated with adverse long-term outcomes. The objective of the present study was to determine the effect of branch pulmonary artery stenosis on the RV volume in patients with repaired TOF. We reviewed 178 cardiac magnetic resonance imaging studies in patients with repaired TOF. We defined bilateral stenosis as a Nakata index of ≤200 mm(2)/m(2) and concordant branch pulmonary artery cross-sectional area, unilateral stenosis as 1 branch pulmonary artery cross-sectional area ≤100 mm(2)/m(2) and 1 branch pulmonary artery cross-sectional area >100 mm(2)/m(2), and restrictive physiology as prograde main pulmonary artery diastolic flow. Of the 178 patients, 20 (11%) had bilateral stenosis, 47 (26%) unilateral stenosis, and 111 (63%) had no stenosis. The RV end-diastolic volume was lower in patients with bilateral (125 ± 27 ml/m(2)) or unilateral (131 ± 43 ml/m(2)) stenosis than in those without stenosis (149 ± 35 ml/m(2), p = 0.021 and p = 0.019, respectively). The main pulmonary artery regurgitant fraction was greater in patients without stenosis (47%, range 2% to 69%) than in those with bilateral (33%, range 9% to 59%; p = 0.009) or unilateral stenosis (40%, range 0% to 71%; p = 0.033). Restrictive physiology was more common in patients with bilateral (13 of 15, 87%) or unilateral (21 of 38, 55%) stenosis than in those without stenosis (28 of 85, 33%; p <0.001 and p = 0.017, respectively). In conclusion, in patients with repaired TOF, bilateral and unilateral branch pulmonary artery stenosis was associated with a greater main pulmonary artery regurgitant fraction and smaller RV end-diastolic volume than those in patients without stenosis, likely owing to the development of restrictive physiology. Branch pulmonary artery stenosis might effectively delay the referral for pulmonary valve replacement.

Pediatric ventricular assist device use as a bridge to transplantation does not affect long-term quality of life.

OBJECTIVE The present study sought to determine the long-term quality of life (QOL) of children who required long-term ventricular assist device (VAD) support as a bridge to transplantation (BTT) compared with children who underwent heart transplantation without VAD support. Currently, 20% of children undergoing heart transplantation have required a VAD as a BTT. Few data have been published assessing how children requiring a VAD as a BTT will fair in terms of their long-term QOL. METHODS The present study used a cross-sectional design, using the Core and Cardiac modules of the Pediatric Quality of Life Inventory survey. In a secondary analysis, the factors associated with worse QOL outcomes among the VAD patients were also investigated. RESULTS At follow-up (median, 4.2 years), between the 21 children who required a VAD as a BTT and 42 who went straight to transplantation, no significant differences were found in the QOL as measured using the Psychosocial Health Summary Score, Physical Health Summary Score, or Total Score in the surveys Core Module, nor were any differences found in the outcomes assessed using the surveys Cardiac Module. Of the patients who required a VAD, only the presence of a neurologic complication was associated with worse QOL, which was demonstrated by decreased Physical Health Summary and Cardiac Communication scores. CONCLUSIONS Over the long term, surviving children who required a long-term VAD as a BTT experience a similar QOL as those who went straight to transplantation.