Optimal Global Longitudinal Strain Thresholds for Pediatric Heart Surgery: Insights from a University Hospital

Congenital heart diseases impact millions annually, with pediatric care lacking suitable risk assessment tools. This research seeks to illuminate the association between the global longitudinal strain (GLS) and the subsequent impact on postoperative outcomes, contributing to a deeper understanding of its predictive value in the pediatric population affected by congenital heart diseases. An observational, analytic, longitudinal, and prospective study was conducted from May 2022 to May 2023, including all patients under 18 undergoing heart surgery with cardiopulmonary bypass (CBP). Patients not classifiable within the Risk Adjustment for Congenital Heart Surgery were excluded. Using transesophageal echocardiography, GLS was measured pre- and post-CPB. Receiver operating characteristic curve analysis determined GLS cut-off points for 30-day mortality risk, using Youden's method for optimal sensitivity and specificity. Bivariate and multivariate analysis identified the relationships between clinical variables. Eighty-nine patients undergoing congenital heart surgery were included. Fifteen deaths occurred. The area under the curve (AUC) for each GLS classification (pre, post, index) demonstrated effective discriminatory capacity (> 0.70) in predicting 30-day mortality. Pre-CBP GLS showed the strongest predictive power (AUC 0.833, IQR: 0.731 - 0.936) with a cut-off point of 12. Values lower than the cut-off point of pre-CPB GLS correlated with increased vasoactive-inotropic Scores and longer mechanical ventilation. GLS measurement is a reproducible method for assessing ventricular function in pediatric heart surgery, showing potential as a prognostic tool. This study marks the initial effort to establish cut-off points for preoperative GLS, postoperative GLS, and the strain index.

Cardiac Function and Serum Biomarkers throughout Staged Fontan Palliation: A Prospective Observational Study

Fontan patients undergo multiple cardiothoracic surgeries in childhood. Following these procedures, ventricular function is temporarily decreased, and recovers over months. This is presumably related to cardiopulmonary bypass, but this is incompletely understood. Throughout the Fontan palliation, cardiac function is also affected by volume unloading. We aimed to gain insight into the biological processes related to impaired ventricular function and recovery following Fontan palliations using a panel of biomarkers. Furthermore, we described changes in ventricular function across the Fontan palliation due to volume unloading. We performed a prospective multicenter observational study in patients undergoing partial (PCPC) or total cavo-pulmonary connection (TCPC). Patients underwent assessment-including echocardiography and blood sampling-before surgery (T1), at first follow-up (T2), and 1 year after their procedures (T3). Blood samples were analyzed using a biomarker panel (OLINK CVD-III). Ninety-two biomarkers were expressed as principal components (PC) to limit multiple statistical testing. We included 32 PCPC patients aged 7.2 [5.3-10.3] months, and 28 TCPC patients aged 2.7 [2.2-3.8] years. The single ventricular longitudinal strain (SV GLS) temporarily decreased for PCPC patients at T2 (-15.1 ± 5.6 (T1) to -13.5 ± 5.2 (T2) to -17.3 ± 4.5 (T3), p < 0.047 for all differences), but not following TCPC. The serum biomarkers were expressed as 4 PCs. PC1, including biomarkers of cell-cell adhesion, was not related to any patient characteristic. PC2, including biomarkers of superoxide anion regulation, increased at T2. PC3, including biomarkers of cardiovascular development, related to the stage of Fontan palliation. PC4 was of uncertain biological or clinical significance. No PC was found that related to ventricular performance. The SV GLS was temporarily diminished following PCPC, but not following TCPC. Several biomarkers were related to post-operative stress and adaptation to the PCPC or TCPC circulation, but none were related to the outcome.

Venous waveform analysis detects acute right ventricular failure in a rat respiratory arrest model

BACKGROUND

Peripheral intravenous analysis (PIVA) has been shown to be more sensitive than central venous pressure (CVP) for detecting hemorrhage and volume overload. We hypothesized that PIVA is superior to CVP for detecting right ventricular (RV) failure in a rat model of respiratory arrest.

METHODS

Eight Wistar rats were studied in accordance with the ARRIVE guidelines. CVP, mean arterial pressure (MAP), and PIVA were recorded. Respiratory arrest was achieved with IV Rocuronium. PIVA utilizes Fourier transform to quantify the amplitude of the peripheral venous waveform, expressed as the "f1 amplitude". RV diameter was measured with transthoracic echocardiography.

RESULTS

RV diameter increased from 0.34 to 0.54 cm during arrest, p = 0.001, and returned to 0.33 cm post arrest, p = 0.97. There was an increase in f1 amplitude from 0.07 to 0.38 mmHg, p = 0.01 and returned to 0.08 mmHg, p = 1.0. MAP decreased from 119 to 67 mmHg, p = 0.004 and returned to 136 mmHg, p = 0.50. There was no significant increase in CVP from 9.3 mmHg at baseline to 10.5 mmHg during respiratory arrest, p = 0.91, and recovery to 8.6 mmHg, p = 0.81.

CONCLUSIONS

This study highlights the utility of PIVA to detect RV failure in small-caliber vessels, comparable to peripheral veins in the human pediatric population.

IMPACT

Right ventricular failure remains a diagnostic challenge, particularly in pediatric patients with small vessel sizes limiting invasive intravascular monitor use. Intravenous analysis has shown promise in detecting hypovolemia and volume overload. Intravenous analysis successfully detects right ventricular failure in a rat respiratory arrest model. Intravenous analysis showed utility despite utilizing small peripheral venous access and therefore may be applicable to a pediatric population. Intravenous analysis may be helpful in differentiating various types of shock.

Functional Echocardiographic and Serum Biomarker Changes Following Surgical and Percutaneous Atrial Septal Defect Closure in Children

Background

Ventricular performance is temporarily reduced following surgical atrial septal defect closure. Cardiopulmonary bypass and changes in loading conditions are considered important factors, but this phenomenon is incompletely understood. We aim to characterize biventricular performance following surgical and percutaneous atrial septal defect closure and to relate biomarkers to ventricular performance following intervention.

Methods and Results

In this multicenter prospective study, children scheduled for surgical or percutaneous atrial septal defect closure were included. Subjects were assessed preoperatively, in the second week postintervention (at 2‐weeks follow‐up), and 1‐year postintervention (1‐year follow‐up). At each time point, an echocardiographic study and a panel of biomarkers were obtained. Sixty‐three patients (median age, 4.1 [interquartile range, 3.1–6.1] years) were included. Forty‐three patients underwent surgery. At 2‐weeks follow‐up, right ventricular global longitudinal strain was decreased for the surgical, but not the percutaneous, group (−17.6±4.1 versus −27.1±3.4; P<0.001). A smaller decrease was noted for left ventricular global longitudinal strain at 2‐weeks follow‐up for the surgical group (surgical versus percutaneous, −18.6±3.2 versus −20.2±2.4; P=0.040). At 1‐year follow‐up, left ventricular performance returned to baseline, whereas right ventricular performance improved, but did not reach preintervention levels. Eight biomarkers relating to cardiovascular and immunological processes differed across study time points. Of these biomarkers, only NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide) correlated with less favorable left ventricular global longitudinal strain at 2‐weeks follow‐up.

Conclusions

Right, and to a lesser degree left, ventricular performance was reduced early after surgical atrial septal defect closure. Right ventricular performance at 1‐year follow‐up remained below baseline levels. Several biomarkers showed a pattern over time similar to ventricular performance. These biomarkers may provide insight into the processes that affect ventricular function.

Registration

URL: https://www.trialregister.nl/; Unique identifier: NL5129

Atrial Function Impairments after Pediatric Cardiac Surgery Evaluated by STE Analysis

Background: Applications of atrial speckle tracking echocardiography (STE) strain (ε) analysis in pediatric cardiac surgery have been limited. This study aims to evaluate the feasibility of atrial STE ε analysis and the progression of atrial ε values as a function of post-operative time in children after pediatric cardiac surgery. Methods: 131 children (mean 1.69 ± 2.98; range 0.01−15.16 years) undergoing cardiac surgery were prospectively enrolled. Echocardiographic examinations were performed pre-operatively and at 3 different post-operative intervals: Time 1 (24−36 h), Time 2 (3−5 days), Time 3 (>5 days, before discharging). The right and left atrium longitudinal systolic contractile (Ct), Conduit (Cd), and Reservoir (R) ε were evaluated with a novel atrial specific software with both P- and R-Gating methods. One hundred and thirty-one age-matched normal subjects (mean 1.7 ± 3.2 years) were included as controls. Results: In all, 309 examinations were performed over the post-operative times. For each post-operative interval, all STE atrial ε parameters assessed were significantly lower compared to controls (all p < 0.0001). The lowest atrial ε values were found at Time 1, with only partial recovery thereafter (p from 0.02 to 0.04). All atrial ε values at discharge were decreased compared to the controls (all p < 0.0001). Significant correlations of the atrial ε values with cardio-pulmonary-bypass time, left and right ventricular ε values (p < 0.05), and ejection fraction (p < 0.05) were demonstrated. Conclusions: Atrial ε is highly reduced after surgery with only partial post-operative recovery in the near term. Our study additionally demonstrates that post-surgical atrial and ventricular ε responses correlated with each other.

Left Ventricular Systolic Impairment after Pediatric Cardiac Surgery Assessed by STE Analysis

Background: Speckle-tracking echocardiography (STE) has gained increasing value in the evaluation of congenital heart diseases (CHD); however, its use in pediatric cardiac surgery is limited. Aim: To evaluate left ventricular (LV) systolic impairment after biventricular pediatric cardiac surgery by STE strain (ε) analysis. Methods: We prospectively enrolled 117 children undergoing cardiac surgery for CHD. Echocardiography was performed at four different times: pre-operatively, 12–36 h (Time 1), 3–5 days (Time 2), and 6–8 days (Time 3). Images were obtained in the 4-2-and 3 apical chamber’s views to derive LV global and regional (basal/mid/apical) ε values. Results: At different postoperative times, we performed 320 examinations in 117 children (mean age: 2.4 ± 3.9, range: 0–16 years); 117 age-matched healthy children served as controls. All global, basal, and mid LVε values decreased after surgery; the lowest values being at Time 1 (p < 0.0001), which increased thereafter. At discharge, all global, basal, and mid LVε values remained lower than in pre-operative and healthy children (p < 0.05). Instead, apical segments (lowest at baseline) increased after surgery (p < 0.0001) but remained lower compared to controls. LV ejection fraction (LVEF) decreased at Time 1 (p = 0.0004) but promptly recovered to Time 2 and normalized at Time 3. Conclusions: STE ε analysis revealed a significant LV systolic impairment after surgery with amelioration thereafter but incomplete normalization at discharge. Base-apex differences emerged with apical segments that, contrary to all the other regions, showed relative hypercontractility after surgery. The slower recovery of LVε values compared to LVEF suggests that STE ε analysis may be more accurate for the follow-up of mild LV post-surgical impairment.

Left and Right Ventricular Impairment Shortly After Correction of Tetralogy of Fallot

Surgical repair of Tetralogy of Fallot (ToF) is usually performed in the first months of life with low early postoperative mortality. During long-term follow-up, however, both right (RV) and left ventricular (LV) performances may deteriorate. Tissue Doppler imaging (TDI) and speckle tracking echocardiography (ST) can unmask a diminished RV and LV performance. The objective of the current study was to assess the cardiac performance before and shortly after corrective surgery in ToF patients using conventional, TDI and ST echocardiographic techniques. Thirty-six ToF patients after surgery were included. Transthoracic echocardiography including TDI and ST techniques was performed preoperatively and at hospital discharge after surgery (10 days to 4 weeks after surgery). Median age at surgery was 7.5 months [5.5-10.9]. Regarding the LV systolic function there was a significant decrease in interventricular septum (IVS) S' at discharge as compared to preoperatively (pre IVS S' = 5.4 ± 1.4; post IVS S' = 3.9 ± 1.2; p < 0.001) and in global longitudinal peak strain (GLS) (pre = - 18.3 ± 3.4; post = - 14.2 ± 4.1; p = 0.003); but not in the fractional shortening (FS). Both conventional and TDI parameters showed a decrease in diastolic function at discharge. Tricuspid Annular Plane Systolic Excursion and RV S' were significantly lower before discharge. When assessing the RV diastolic performance, only the TDI demonstrated a RV impairment. There was a negative correlation between age at surgery and postoperative LV GLS (R = - 0.41, p = 0.031). There seems to be an impairment in left and right ventricle performance at discharge after ToF corrective surgery compared to preoperatively. This is better determined with TDI and ST strain imaging than with conventional echocardiography.

The Relationship Between Pre-operative Left Ventricular Longitudinal Strain and Post-operative Length of Stay in Patients Undergoing Arterial Switch Operation Is Age Dependent

INTRODUCTION

Post-operative length of stay (LOS) after the arterial switch operation (ASO) is variable. The association between pre-operative non-invasive measures of ventricular function and post-operative course has not been well established. The aims of this study were to (1) evaluate the relationship between pre-operative non-invasive measures of ventricular function and post-operative LOS and (2) evaluate the change in ventricular function after ASO.

METHODS

Data were reviewed in consecutive ASO patients between 2010 and 2016. The primary outcome was post-operative LOS. Echocardiograms obtained during the pre-operative period and at the time of discharge were retrospectively analyzed using speckle-tracking echocardiography. Pearson's correlation between patient-specific, pre-operative, and echocardiographic data versus post-operative LOS was assessed.

RESULTS

Fifty-two patients were included in analyses, 39 neonates and 13 infants. Left ventricular (LV) longitudinal strain correlated with post-operative LOS for infants age > 28 days (r = 0.62, p = 0.03), but not for neonates (r = 0.14, p = 0.40). Operative age (r = - 0.42, p = 0.003), weight at surgery (r = - 0.48, p ≤ 0.001), and cardiopulmonary bypass time (r = 0.30, p = 0.045) also correlated with post-operative LOS. Standard 2D measures of ventricular function did not correlate with post-operative LOS. LV ejection fraction and longitudinal strain worsened post-operatively.

CONCLUSION

Higher pre-operative LV longitudinal strain (representing worse LV function) is associated with increased post-operative LOS after ASO in infants > 28 days, but not in neonates. LV ejection fraction and longitudinal strain worsened after ASO. Future studies should assess the utility of performing STE in risk stratifying patients prior to ASO.