Serial tissue Doppler imaging in the evaluation of bronchopulmonary dysplasia-associated pulmonary hypertension among extremely preterm infants: a prospective observational study

Objectives

To evaluate serial tissue Doppler cardiac imaging (TDI) in the evolution of bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH) among extremely preterm infants.

Design

Prospective observational study.

Setting

Single-center, tertiary-level neonatal intensive care unit.

Patients

Infant born <28 weeks gestation.

Main outcome measures

Utility of TDI in the early diagnosis and prediction of BPD-PH and optimal timing for screening of BPD-PH.

Results

A total of 79 infants were included. Of them, 17 (23%) had BPD-PH. The mean gestational age was 25.9 ± 1.1 weeks, and mean birth weight was 830 ± 174 g. The BPD-PH group had a high incidence of hemodynamically significant patent ductus arteriosus (83% vs. 56%, p < 0.018), longer oxygen days (96.16 ± 68.09 vs. 59.35 ± 52.1, p < 0.008), and prolonged hospital stay (133.8 ± 45.9 vs. 106.5 ± 37.9 days, p < 0.005). The left ventricular eccentricity index (0.99 ± 0.1 vs. 1.1 ± 0.7, p < 0.01) and the ratio of acceleration time to right ventricular ejection time showed a statistically significant trend from 33 weeks (0.24 ± 0.05 vs. 0.28 ± 0.05, p < 0.05). At 33 weeks, the BPD-PH group showed prolonged isovolumetric contraction time (27.84 ± 5.5 vs. 22.77 ± 4, p < 0.001), prolonged isovolumetric relaxation time (40.3 ± 7.1 vs. 34.9 ± 5.3, p < 0.003), and abnormal myocardial performance index (0.39 ± 0.05 vs. 0.32 ± 0.03, p < 0.001). These differences persisted at 36 weeks after conceptional gestational age.

Conclusions

TDI parameters are sensitive in the early evolution of BPD-PH. Diagnostic accuracy can be increased by combining the TDI parameters with conventional echocardiographic parameters. BPD-PH can be recognizable as early as 33-34 weeks of gestation.

The siRNA-mediated knockdown of AP-1 restores the function of the pulmonary artery and the right ventricle by reducing perivascular and interstitial fibrosis and key molecular players in cardiopulmonary disease

BACKGROUND

Pulmonary hypertension (PH) is a complex multifactorial vascular pathology characterized by an increased pulmonary arterial pressure, vasoconstriction, remodelling of the pulmonary vasculature, thrombosis in situ and inflammation associated with right-side heart failure. Herein, we explored the potential beneficial effects of treatment with siRNA AP-1 on pulmonary arterial hypertension (PAH), right ventricular dysfunction along with perivascular and interstitial fibrosis in pulmonary artery-PA, right ventricle-RV and lung in an experimental animal model of monocrotaline (MCT)-induced PAH.

METHODS

Golden Syrian hamsters were divided into: (1) C group-healthy animals taken as control; (2) MCT group obtained by a single subcutaneous injection of 60 mg/kg MCT at the beginning of the experiment; (3) MCT-siRNA AP-1 group received a one-time subcutaneous dose of MCT and subcutaneous injections containing 100 nM siRNA AP-1, every two weeks. All animal groups received water and standard chow ad libitum for 12 weeks.

RESULTS

In comparison with the MCT group, siRNA AP-1 treatment had significant beneficial effects on investigated tissues contributing to: (1) a reduction in TGF-β1/ET-1/IL-1β/TNF-α plasma concentrations; (2) a reduced level of cytosolic ROS production in PA, RV and lung and notable improvements regarding the ultrastructure of these tissues; a decrease of inflammatory and fibrotic marker expressions in PA (COL1A/Fibronectin/Vimentin/α-SMA/CTGF/Calponin/MMP-9), RV and lung (COL1A/CTGF/Fibronectin/α-SMA/F-actin/OB-cadherin) and an increase of endothelial marker expressions (CD31/VE-cadherin) in PA; (4) structural and functional recoveries of the PA [reduced Vel, restored vascular reactivity (NA contraction, ACh relaxation)] and RV (enlarged internal cavity diameter in diastole, increased TAPSE and PRVOFs) associated with a decrease in systolic and diastolic blood pressure, and heart rate; (5) a reduced protein expression profile of AP-1S3/ pFAK/FAK/pERK/ERK and a significant decrease in the expression levels of miRNA-145, miRNA-210, miRNA-21, and miRNA-214 along with an increase of miRNA-124 and miRNA-204.

CONCLUSIONS

The siRNA AP-1-based therapy led to an improvement of pulmonary arterial and right ventricular function accompanied by a regression of perivascular and interstitial fibrosis in PA, RV and lung and a down-regulation of key inflammatory and fibrotic markers in MCT-treated hamsters.

Bronchopulmonary dysplasia - associated pulmonary hypertension: An updated review

Bronchopulmonary dysplasia (BPD) is the leading cause of chronic lung disease in infants and the commonest complication of prematurity. Advances in respiratory and overall neonatal care have increased the survival of extremely low gestational age newborns, leading to the continued high incidence of BPD. Pulmonary hypertension (PH) represents the severe form of the pulmonary vascular disease associated with BPD, and affects almost one-third of infants with moderate to severe BPD. PH responds suboptimally to pulmonary vasodilators and increases morbidity and mortality in BPD infants. An up-to-date knowledge of the pathogenesis, pathophysiology, diagnosis, treatment, and outcomes of BPD-PH can be helpful to develop meaningful and novel strategies to improve the outcomes of infants with this disorder. Therefore, our multidisciplinary team has attempted to thoroughly review and summarize the latest advances in BPD-PH in preventing and managing this morbid lung disorder of preterm infants.

Multicentre prospective observational study exploring the predictive value of functional echocardiographic indices for early identification of preterm neonates at risk of developing chronic pulmonary hypertension secondary to chronic neonatal lung disease

INTRODUCTION

Although chronic pulmonary hypertension (cPH) secondary to chronic neonatal lung disease is associated with increased mortality and respiratory and neurodevelopmental morbidities, late diagnosis (typically ≥36 weeks postmenstrual age, PMA) and the use of qualitative echocardiographic diagnostic criterion (flat interventricular septum in systole) remain significant limitations in clinical care. Our objective in this study is to evaluate the utility of relevant quantitative echocardiographic indices to identify cPH in preterm neonates, early in postnatal course and to develop a diagnostic test based on the best combination of markers.

METHODS AND ANALYSIS

In this ongoing international prospective multicentre observational diagnostic accuracy study, we aim to recruit 350 neonates born <27 weeks PMA and/or birth weight <1000 g and perform echocardiograms in the third week of age and at 32 weeks PMA (early diagnostic assessments, EDA) in addition to the standard diagnostic assessment (SDA) for cPH at 36 weeks PMA. Predefined echocardiographic markers under investigation will be measured at each EDA and examined to create a scoring system to identify neonates who subsequently meet the primary outcome of cPH/death at SDA. Diagnostic test characteristics will be defined for each EDA. Pulmonary artery acceleration time and tricuspid annular plane systolic excursion are the primary markers of interest.

ETHICS AND DISSEMINATION

Ethics approval has been received by the Mount Sinai Hospital Research Ethics Board (REB) (#16-0111-E), Sunnybrook Health Sciences Centre REB (#228-2016), NHS Health Research Authority (IRAS 266498), University of Iowa Human Subjects Office/Institutional Review Board (201903736), Rotunda Hospital Research and Ethics Committee (REC-2019-008), and UBC Children's and Women's REB (H19-02738), and is under review at Boston Children's Hospital Institutional Review Board. Study results will be disseminated to participating families in lay format, presented to the scientific community at paediatric and critical care conferences and published in relevant peer-reviewed journals.

TRAIL REGISTRATION NUMBER

NCT04402645.

Cardiac Function and Ventricular Interactions in Persistent Pulmonary Hypertension of the Newborn

OBJECTIVES

The aim of this study was to use a comprehensive imaging protocol to identify echocardiographic correlations of right and left ventricular size, function, and hemodynamics in neonates with persistent pulmonary hypertension of newborn and describe their relationship with key clinical variables.

DESIGN

Retrospective case-control echocardiography-based study of persistent pulmonary hypertension of newborn.

SETTING

A tertiary neonatal ICU in Canada.

PATIENTS

Forty-nine neonates (gestational age ≥ 35 wk old) diagnosed with persistent pulmonary hypertension of newborn within first 3 days after birth and 50 age-matched controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The echocardiographic measurements comprised of right ventricular and left ventricular functional markers, including tricuspid annular plane systolic excursion, fractional area change, tissue Doppler imaging, and deformation imaging. Sample size was based on detecting an intergroup difference of 10% in tricuspid annular plane systolic excursion, which was considered the primary outcome. Linear correlations between the right and left ventricular indices, as well as their association with the outcome of death or extracorporeal membrane oxygenation were evaluated. Persistent pulmonary hypertension of newborn was associated with lower tricuspid annular plane systolic excursion (6.81 ± 1.92 vs 9.25 ± 1.30 mm), right-ventricular global longitudinal strain (16.9% ± 5.4% vs -21.6% ± 4.6%); left ventricular ejection fraction (49% ± 7% vs 55% ± 6%), left ventricular global longitudinal strain (-16.7% ± 3.3% vs -21.4% ± 2.0%) (all p < 0.01). Right and left ventricular diastolic and global function was also lower in persistent pulmonary hypertension of newborn, with more pronounced changes seen for the right ventricle. Moderate-to-strong linear correlations were observed between the right and left ventricular functional markers, with right ventricular global longitudinal strain and left ventricular global longitudinal strain being the strongest (r = 0.8). Within persistent pulmonary hypertension of newborn group, hypoxic ischemic encephalopathy was associated with lower right and left ventricular systolic and right ventricular diastolic performance. Tricuspid annular plane systolic excursion (p =0.08) and left ventricular systolic velocity (p = 0.09) tended to be lower in patients who subsequently died/needed extracorporeal membrane oxygenation.

CONCLUSIONS

Persistent pulmonary hypertension of newborn is characterized by global cardiac dysfunction, involving both the right and left ventricles, with significant interventricular functional correlation. Cardiac dysfunction early in disease course may identify patients at highest risk of adverse outcome.

Echocardiographic Changes and Long-Term Clinical Outcomes in Pediatric Patients With Pulmonary Arterial Hypertension Treated With Bosentan for 72 Weeks: A Post-hoc Analysis From the FUTURE 3 Study

FormUlation of bosenTan in pUlmonary arterial hypeRtEnsion (FUTURE) 3 was a 24-week open-label, prospective, and randomized phase 3 study that assessed the pharmacokinetics of bosentan 2 mg/kg b.i.d. or t.i.d. in children with pulmonary arterial hypertension (PAH). We report findings from a post-hoc analysis that explored the prognostic value of echocardiographic changes during FUTURE 3 in relation to clinical outcomes observed during the 24-week core study and 48-week extension. Patients aged ≥3 months to <12 years (n = 64) received oral doses of bosentan 2 mg/kg b.i.d. or t.i.d. (1:1) for 24 weeks, after which they were eligible to enter the extension with continued bosentan administration. Echocardiographic evaluations were performed at baseline, Week 12, and 24 of the core study via central reading, and analyzed post-hoc for correlation with clinical outcomes (time to PAH worsening, time to death, and vital status). Sixty-four patients were randomized in the core study [median (IQR) age 3.8 (1.7-7.8) years]; and 58 patients (90.6%) entered the 48-week extension. Most of the patients (68.8%) were receiving ≥1 PAH medication at baseline. Echocardiographic changes during the core study were small but with high variability. There were statistically significant associations at Week 24 between worsening of the parameters, systolic left ventricular eccentricity index (LVEIS) and E/A ratio mitral valve flow, and the outcomes of time to death and time to PAH worsening. Additional studies that utilize simple and reproducible echocardiographic assessments are needed to confirm these findings and subsequently identify potential treatment goals in pediatric PAH.

Pulmonary hypertension and right ventricular function in Nigerian children with sickle cell anaemia

Background

Pulmonary hypertension (PH), a complication of sickle cell anaemia (SCA), results in considerable morbidity. This study aims to determine the prevalence and associations of echocardiography-suggested PH in children with SCA.

Methods

We performed a cross-sectional comparative study involving 100 systematically sampled SCA subjects 3–14 y of age in their steady state with matched haemoglobin AA phenotype controls. Clinical, laboratory and echocardiography data (including tricuspid regurgitation velocity [TRV], mean pulmonary arterial pressure [mPAP] and tricuspid annular plane systolic excursion [TAPSE]) were obtained from all patients. Statistical analyses were performed using SPSS version 22 (IBM, Armonk, NY, USA). A p-value <0.05 was considered statistically significant.

Results

Of the 100 SCA subjects studied, 22 (22%) had echocardiographic findings suggestive of PH compared with none in the controls. The median TAPSE was significantly lower in the PH group (2.55 cm [interquartile range {IQR} 2.2–2.8]) compared with the no PH group (2.77 cm [IQR 2.4–3.2]) (p=0.03). No significant correlation existed between mPAP and age, nor any laboratory parameters studied. The odds ratio (OR) suggested PH significantly increased with an increase in the frequency of hospitalizations for vaso-occlusive crises within a 12-month period (OR 15.15 [95% CI 1.57 to 146.35], p=0.02) and a lifetime history of blood transfusion (OR 5.44 [95% CI 1.09 to 27.24], p=0.04).

Conclusions

Echocardiography-suggested PH is common in children with SCA and is associated with poorer right ventricular function, frequent vaso-occlusive crises and blood transfusions.

Novel Strategies to Reduce Pulmonary Hypertension in Infants With Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a developmental lung disorder of preterm infants primarily caused by the failure of host defense mechanisms to prevent tissue injury and facilitate repair. This disorder is the most common complication of premature birth, and its incidence remains unchanged over the past few decades. Additionally, BPD increases long-term cardiopulmonary and neurodevelopmental morbidities of preterm infants. Pulmonary hypertension (PH) is a common morbidity of BPD. Importantly, the presence of PH increases both the short- and long-term morbidities and mortality in BPD infants. Further, there are no curative therapies for this complex disease. Besides providing an overview of the pathogenesis and diagnosis of PH associated with BPD, we have attempted to comprehensively review and summarize the current literature on the interventions to prevent and/or mitigate BPD and PH in preclinical studies. Our goal was to provide insight into the therapies that have a high translational potential to meaningfully manage BPD patients with PH.

Echocardiographic assessment of right ventricular function in experimental pulmonary hypertension

Echocardiography, a non-invasive and cost-effective method for monitoring cardiac function, is commonly used for evaluation and pre-clinical diagnostics of pulmonary hypertension (PH). Previous echocardiographic studies in experimental models of PH are fragmentary in terms of the evaluation of right ventricle (RV) function. In this study, three rodent models of PH: a mouse model of hypoxia-induced PH, a rat model of hypoxia+Sugen induced PH and a rat model of monocrotaline-induced PH, were employed to measure RV fractional area change (RVFAC), RV free wall thickness (RVFWT), pulmonary acceleration time (PAT), pulmonary ejection time (PET), and tricuspid annular plane systolic excursion (TAPSE). We found that, in these models, RVFWT significantly increased, but RVFAC, PAT, or PAT/PET ratios and TAPSE values significantly decreased. Accurate and complete TAPSE patterns were demonstrated in the three rodent models of PH. The RV echocardiography data matched the corresponding invasive hemodynamic and heart histologic data in each model. This serves as a reference study for real-time and non-invasive evaluation of RV function in rodent models of PH using echocardiography.

Speckle Tracking of the Basal Lateral and Septal Wall Annular Plane Systolic Excursion of the Right and Left Ventricles of the Fetal Heart

OBJECTIVE

Annular plane systolic excursion (APSE) has been evaluated for the right (RV) and left (LV) ventricles using M-mode echocardiography. This study examined APSE using 2-dimensional speckle tracking (2DST) of the lateral and septal annuli of the RV and LV in normal fetuses.

METHODS

Two hundred normal fetuses were prospectively examined between 20 and 40 weeks' gestation, in which the end-diastolic and end-systolic lengths were measured from the apex to the insertion of the annuli into the lateral and septal walls of the RV and LV using 2DST. Subtracting the end-systolic from the end-diastolic length resulted in the APSE measurement. The APSE values from the ventricular and septal locations were regressed against biometric and gestational age independent variables, and the mean and standard deviation computed using fractional polynomial analysis. Within-subject repeated measures of variance were used to compare results within and between the right ventricular and left ventricular basal APSE values.

RESULTS

When regressed against the independent variables the R² for the APSE of the right ventricular lateral wall ranged from 0.39 to 0.40, the left ventricular lateral wall 0.29 to 0.31, the right ventricular septal wall 0.22 to 0.40, and the left ventricular septal wall 0.05 to 0.07. There was a significant difference (P < .001) for APSE between the right ventricular and left ventricular lateral wall and their respective septal annuli, the left ventricular and right ventricular lateral wall annuli, and the left ventricular and right ventricular septal annuli.

CONCLUSIONS

The right ventricular and left ventricular lateral and septal wall APSE can be computed using 2DST and are associated with changing fetal biometric and age measurements.

Prospective study of pulmonary hypertension in preterm infants with bronchopulmonary dysplasia

OBJECTIVE

To evaluate the prevalence, risk factors, and optimal timing of echocardiogram for pulmonary hypertension (PH) in infants with bronchopulmonary dysplasia (BPD).

DESIGN

In this prospective study, infants with gestational age (GA) <30 weeks admitted to a tertiary NICU between July 2015 and June 2017 who required positive pressure ventilation or oxygen therapy at ≥28 days of life were evaluated with serial echocardiograms at study enrollment (4-6 weeks of age), 32 weeks (only for ≤25 weeks), 36, and 40 weeks post-menstrual age (PMA) for PH.

RESULTS

Of 126 infants (mean birth weight 858 ± 221 g; mean GA 26.1 ± 1.6 wks), 48 (38%) developed PH at any time during their hospital stay. The first study echocardiogram was performed at a median age of 31 weeks PMA. The prevalence of PH was 36/126 (28.5%) at enrollment, at 6/30 (20%) at 32 weeks, 24/111 (21.6%) at 36 weeks, and 10/59 (17%) at 40 weeks. No new cases of PH were identified at 40 weeks. At 36 weeks, none of the infants with mild BPD had PH, whereas 20% of moderate and 32% of severe BPD infants had PH. After controlling for confounding variables severe BPD (OR 3.31, 95%CI 1.12, 9.74), and ventilator associated pneumonia (VAP) (OR 17.9, 95%CI 3.9, 82.11) remained independent risk factors for BPD-associated PH.

CONCLUSION

Echocardiographic screening for PH can be safely restricted to infants with moderate or severe BPD at 36 weeks PMA. We identified VAP as an independent risk factor for PH.

Longitudinal Annular Systolic Displacement Compared to Global Strain in Normal Fetal Hearts and Those With Cardiac Abnormalities

OBJECTIVES

The purpose of this study was to compare a new technique that measures the midventricular basal-apical longitudinal diastolic and systolic lengths, computes the longitudinal displacement fractional shortening, and compares it to global strain.

METHODS

Two hundred control fetuses were examined between 20 and 40 weeks' gestation, in whom the longitudinal displacement fractional shortening was computed from end-diastolic and end-systolic lengths measured from the apex to the mid portion of the distance between the level of the basal lateral and septal walls using 2-dimnsional speckle tracking. In addition, global strain was computed using speckle tracking. A correlation analysis was used to compare the longitudinal displacement fractional shortening to global strain. The longitudinal displacement fractional shortening of the right ventricle (RV) and left ventricle (LV) was measured in 10 fetuses with heart abnormalities.

RESULTS

The longitudinal displacement fractional shortening for the RV (mean ± SD, 22.94% ± 4.73%) and LV (21.05% ± 4.21%) was independent of gestational age and other biometric growth parameters, as was global strain (RV, -22.7% ± 4.07%); LV, -22.93% ± 3.52%). The RV longitudinal displacement fractional shortening was greater than that of the LV (P < .024). The correlations between the longitudinal displacement fractional shortening and global strain were 0.95 for the RV and 0.97 for the LV. Comparing the longitudinal displacement fractional shortening and global strain in fetuses with abnormal cardiac findings showed concordant findings in 9 of 10 fetuses.

CONCLUSIONS

The RV and LV longitudinal displacement fractional shortening can be computed from 2-dimensional images of the 4-chamber view and correlated with global strain. The longitudinal displacement fractional shortening was significantly greater for the RV than the LV and was abnormal in fetuses with RV and LV cardiac abnormalities.

Tricuspid annular plane systolic excursion is preserved in young patients with pulmonary hypertension except when associated with repaired congenital heart disease

Aims

Tricuspid annular plane systolic excursion (TAPSE) is a measure of right ventricular (RV) longitudinal function that correlates with functional status and mortality in adults with pulmonary hypertension (PH). The diagnostic and predictive value of TAPSE in children with PH has not been fully examined. We aimed to define TAPSE across aetiologies of paediatric PH and assess the correlation between TAPSE and measures of disease severity.

Methods and results

TAPSE measurements were obtained in 84 children and young adults undergoing treatment for PH and 315 healthy children to establish z-scores at moderate altitude for comparison. The relationships between TAPSE and echocardiographic, biomarker, and functional measures of disease severity between aetiologies were assessed. TAPSE z-scores in PH patients with congenital heart disease (CHD) repaired with open cardiac surgery (n = 20, mean -2.73) were significantly decreased compared with normal children and patients with other aetiologies of PH (P < 0.001) but did not reflect poorer clinical status. TAPSE z-scores in children with idiopathic PH (n = 29, -0.41), unrepaired CHD (n = 11, -0.1), and PH related to systemic disease (n = 14, -0.39) were not different from normal. TAPSE correlated modestly with brain natriuretic peptide, echocardiographic function parameters, and functional class except in patients with repaired CHD.

Conclusion

Children with PH maintain normal TAPSE values early except when associated with repaired CHD. Superior RV adaptation to high afterload in children compared with adults may account for this finding. Reduced TAPSE after repair of CHD does not correlate with functional status and may reflect post-operative changes rather than poor function primarily due to PH.

Clinical Utility of Echocardiography for Early and Late Pulmonary Hypertension in Preterm Infants: Relation with Bronchopulmonary Dysplasia

Background

We evaluated early and late pulmonary hypertension (PH) in preterm infants and its relation with bronchopulmonary dysplasia (BPD).

Methods

Sixty-seven preterm infants < 30 weeks' gestation underwent echocardiography within 14 days after birth for early PH and over 28 days after birth for late PH. We measured tricuspid regurgitation (TR) peak velocity, pulse Doppler-derived myocardial performance index (MPI) of right ventricle (RV) (RV MPI), eccentricity index (EI), and tricuspid annular plane systolic excursion (TAPSE).

Results

The median gestation age of patients was 27 weeks (range, 23–30 weeks) and median birth weight was 1030 g (range, 450–1780 g). TR peak velocity was measured only in 19 patients (28.4%). Patients with symptomatic early PH (n = 11) showed a significantly lower systolic EI and a significantly higher incidence of RV MPI > 0.38 and TAPSE < 0.5 cm than patients without PH. The incidence of symptomatic early PH was highest in severe BPD, although this was not statistically significant. Early echocardiographic parameters are not associated with BPD development. Patients with severe BPD showed a significantly higher RV MPI and a significantly higher incidence of RV MPI > 0.38 than patients with mild BPD, and a significantly lower systolic EI and a significantly higher incidence of systolic EI < 0.81 than patients without BPD.

Conclusion

Systolic EI, RV MPI, and TAPSE were well represented symptomatic early PH, while systolic EI and RV MPI could be useful parameters for identifying late PH in preterm infants with BPD, even if they did not present PH symptoms.

Mid-childhood outcomes after pre-viable preterm premature rupture of membranes

OBJECTIVES

Investigate cardiorespiratory outcomes in children surviving previable preterm premature rupture of membranes (PV-PPROM) before 22 weeks' gestational age (GA) with minimum 2 weeks latency.

STUDY DESIGN

Single institution, follow-up of retrospectively identified children who were born after PV-PPROM during 2000-2004, and individually matched preterm-born controls.

RESULTS

Eleven PV-PPROM and matched control children were included at mean age of 10.5 and 10.7 years. Rupture of membranes occurred at mean GA 18² and 27⁶ weeks and birth at 28³ and 28⁶ weeks, respectively. Compared to controls, the PV-PPROM group had significantly poorer lung function, findings on echocardiography indicating mild pulmonary hypertension, and lower peak oxygen consumption. Chart reviews suggested more motor difficulties and a tendency towards more problems with learning and attention.

CONCLUSION

The findings highlight a preterm-born sub-group in need of targeted long-term monitoring and possibly interventions regarding future cardiorespiratory and neurodevelopmental function.

Assessing Myocardial Function in Infants with Pulmonary Hypertension: The Role of Tissue Doppler Imaging and Tricuspid Annular Plane Systolic Excursion

Transthoracic echocardiography is the most common noninvasive method of evaluating pulmonary hypertension (PH) in infants. Identification of reliable, quantitative indices of myocardial function may enhance the diagnostic value of echocardiography in this population. We hypothesized that pulsed wave tissue Doppler imaging (TDI) and tricuspid annular plane systolic excursion (TAPSE) would be reproducible measurements and would suggest decreased ventricular function, in infants with PH. This retrospective case-control study involved subjects diagnosed clinically and echocardiographically with PH at <12 months of age, matched with controls by age and gestational age (GA). TAPSE was measured by M-mode in the apical 4-chamber view. TDI velocities were averaged from three consecutive cardiac cycles. Observers were blinded to patient identity and clinical status. Fifty-seven subjects, including 35 term or near-term infants ≥35 weeks GA [mean GA 39 weeks (±1.7), median age 1 day (range 0-2)] and 22 preterm infants [median GA 25.4 weeks (24.1-26.6), age 66 days (4-128)], were matched with 57 controls. Subjects with PH had lower TAPSE (term p < 0.001, preterm p = 0.03) and TAPSE indexed to body surface area (term p < 0.001, preterm p = 0.005). Mitral annular, septal, and tricuspid annular systolic (S') and early diastolic (E') TDI velocities were also decreased compared to controls (all p < 0.05). Intraclass correlation demonstrated 84-99% agreement between observers in measuring TDI and 92% for TAPSE. Intraobserver reliability for these measures was 98-99% and 96%, respectively. We concluded that TDI and TAPSE are reproducible indices of myocardial function and may serve as useful adjuncts to standard echocardiographic measures in infants with PH.

Right atrial contractile dynamics are impaired in patients with postcapillary pulmonary hypertension

Left ventricular (LV) dysfunction in conjunction with postcapillary pulmonary hypertension (PH) is frequently associated with right ventricular (RV) dysfunction, determining the patient prognosis. Compensatory mechanisms for RV dysfunction have not been previously evaluated in detail. Since calcium dependent right atrial (RA) dynamics are a surrogate for RA contractile properties, the present study examined the calcium dependency of RA tissue obtained from patients with or without postcapillary PH. In total, 15 patients with PH (PH group; mean age, 70.7±7.2 years) and 10 patients without postcapillary PH (non-PH group; mean age, 55.7±11.8 years) who were scheduled to undergo elective left heart valve surgery were included in the current study. Calcium concentration (pCa; shown as the negative log₁₀) against force curves were generated, while LV and RV function was evaluated by echocardiography. Echocardiography data revealed a significantly reduced LV function in the PH group, while the RV function was preserved in the two groups, precluding overt RV dysfunction. In the PH group, significantly reduced force values were detected at high pCa values when compared with the non-PH group force, indicating impaired RA function. Furthermore, reduced calcium sensitivity was observed (which was determined as the pCa at half maximal activation) in the PH group, and the presence of a compensatory mechanism for reduced force capacity was hypothesized. In conclusion, the preliminary results of the current study showed impaired RA contractile properties in postcapillary hypertension with preserved RV function. The diminished RA compensatory mechanisms may lead to accelerated RV dysfunction in the clinical course of postcapillary PH.

Persistent Challenges in Pediatric Pulmonary Hypertension

Pulmonary hypertension and related pulmonary vascular diseases cause significant morbidities and high mortality and present many unique challenges toward improving outcomes in neonates, infants, and children. Differences between pediatric and adult disease are reflected in controversies regarding etiologies, classification, epidemiology, diagnostic evaluations, and therapeutic interventions. This brief review highlights several key topics reflecting recent advances in the field and identifies persistent gaps in our understanding of clinical pediatric pulmonary hypertension.

Semiautomatic Evaluation of Tricuspid Annular Plane Systolic Excursion from Two Dimensional Echocardiographic Images

BACKGROUND

Tricuspid annular plane systolic excursion (TAPSE) has emerged as a reliable marker of right ventricular (RV) systolic function. Recently, TAPSE derived using 2D images (2D-TAPSE) was shown to correlate with M-mode TAPSE (MM-TAPSE). We have developed a novel technique for semiautomatic evaluation of TAPSE (SA-TAPSE). The purpose of this study was to determine the accuracy of this novel technique and validate it on normal hearts and pulmonary hypertension (PH).

METHODS

A total of 110 patients (56 with normal heart and 54 with PH) were retrospectively identified for analysis. The semiautomatic algorithm tracked the lateral tricuspid valve hinge point (TVHP) and the apex in the apical 4-chamber view. SA-TAPSE was calculated as displacement of the TVHP in end-diastole (ED) and end-systole (ES). The same points were manually identified to derive 2D-TAPSE.

RESULTS

The system was able to accurately identify ED and ES in 304/330 heartbeats within three cardiac frames. The automatically identified TVHP points were within 1.2 ± 0.7 mm from the manually identified points. Intra-class correlation between SA-TAPSE and 2D-TAPSE was 0.96 (95% CI 0.93-0.98) for normal hearts and 0.92 (95% CI 0.87-0.96) for those with PH. Bland-Altman analysis showed a strong agreement between SA-TAPSE and 2D-TAPSE for normal hearts and those with PH.

CONCLUSION

Using the novel custom-made software, SA-TAPSE could be measured in majority of our patients and was accurate when applied to normal hearts and those with PH. Future work will focus on fully automating the system for a rapid retrospective analysis of TAPSE.

Association of Apical Longitudinal Rotation with Right Ventricular Performance in Patients with Pulmonary Hypertension: Insights into Overestimation of Tricuspid Annular Plane Systolic Excursion

BACKGROUND

Current guidelines recommend the routine use of tricuspid annular plane systolic excursion (TAPSE) as a simple method for estimating right ventricular (RV) function. However, when ventricular apical longitudinal rotation (apical-LR) occurs in pulmonary hypertension (PH) patients, it may result in overestimated TAPSE.

METHODS

We studied 105 patients with PH defined as mean pulmonary artery pressure >25 mmHg at rest measured by right heart cardiac catheterization. TAPSE was defined as the maximum displacement during systole in the RV-focused apical four-chamber view. RV free-wall longitudinal speckle tracking strain (RV-free) was calculated by averaging 3 regional peak systolic strains. The apical-LR was measured at the peak rotation in the apical region including both left and right ventricle. The eccentricity index (EI) was defined as the ratio of the length of 2 perpendicular minor-axis diameters, one of which bisected and was perpendicular to the interventricular septum, and was obtained at end-systole (EI-sys) and end-diastole (EI-dia). Twenty age-, gender-, and left ventricular ejection fraction-matched normal controls were studied for comparison.

RESULTS

The apical-LR in PH patients was significantly lower than that in normal controls (-3.4 ± 2.7° vs. -1.3 ± 1.9°, P = 0.001). Simple linear regression analysis showed that gender, TAPSE, EI-sys, and EI-dia/EI-sys were associated with apical-LR, but RV-free was not. Multiple regression analysis demonstrated that gender, EI-dia/EI-sys, and TAPSE were independent determinants of apical-LR.

CONCLUSIONS

TAPSE may be overestimated in PH patients with clockwise rotation resulting from left ventricular compression. TAPSE should thus be evaluated carefully in PH patients with marked apical rotation.