Myocardial performance after successful intervention for native aortic coarctation

Circulating biomarkers of left ventricular hypertrophy in pediatric coarctation of the aorta

OBJECTIVE

Patients undergoing surgical repair of aortic coarctation have a 50% risk of pathologic left ventricular remodeling (increased left ventricular mass or relative wall thickness). Endothelin 1, ST2, galectin 3, norepinephrine and B-natriuretic peptide are biomarkers that have been associated with pathologic LV change in adult populations but their predictive value following pediatric coarctation repair are not known.

HYPOTHESIS

Biomarker levels at coarctation repair will predict persistent left ventricular remodeling at 1-year follow up.

DESIGN

Prospective, cohort study of 27 patients' age 2 days-12 years with coarctation of the aorta undergoing surgical repair. Echocardiograms were performed preoperation, postoperation, and at 1-year follow-up. Plasma biomarker levels were measured at the peri-operative time points. Association between biomarker concentrations and echocardiographic parameters was assessed.

RESULTS

Neither left ventricular mass index nor relative wall thickness varied from pre-op to post-op. At pre-op, relative wall thickness was elevated in 52% and left ventricular mass index was elevated in 22%; at follow-up, relative wall thickness was elevated in 13% and left ventricular mass index was elevated in 8%. Presence of residual coarctation did not predict left ventricular remodeling (AUC 0.59; P > .05). Multivariable receiver operating characteristic curve combining pre-op ST2 and endothelin 1 demonstrated significant predictive ability for late pathologic left ventricular remodeling (AUC 0.85; P = .02).

CONCLUSIONS

Persistent left ventricular hypertrophy and abnormal relative wall thickness at intermediate-term follow-up was rare compared to previous studies. A model combining pre-op endothelin 1 and ST2 level demonstrated reasonable accuracy at predicting persistent abnormalities in this cohort. Larger studies will be needed to validate this finding and further explore the mechanism of persistent left ventricular remodeling in this population.

Endothelin-1 activation in pediatric patients undergoing surgical coarctation of the aorta repair

AIM

To determine endothelin-1 (ET-1) concentration before and after surgical coarctectomy and evaluate its association with left ventricular geometric change.

METHODS

A prospective, cohort study of 24 patients aged 2 d to 10 years with coarctation of the aorta undergoing surgical repair. A sub-cohort of patients with age < 1 mo was classified as “neonates”. Echocardiograms were performed just prior to surgery and in the immediate post-op period to assess left ventricle mass index and relative wall thickness (RWT). Plasma ET-1 levels were assessed at both time points. Association between ET-1 levels and ventricular remodeling was assessed.

RESULTS

Patients < 1 year demonstrated higher pre-op ET-1 than post-op (2.8 pg/mL vs 1.9 pg/mL, P = 0.02). Conversely, patients > 1 year had no change in ET-1 concentration before and after surgery (1.1 vs 1.4, NS). Pre-op, patients < 1 year demonstrated significantly higher ET-1 than older children (2.8 vs 1.1, P = 0.001). Post-op there was no difference between the age groups (1.9 vs 1.4, NS). Neither RWT nor left ventricle mass index (LVMI) varied from pre-op to post-op. The subset of neonates showed a strong positive correlation between pre-op ET-1 and RWT (r = 0.92, P = 0.001). Patients with ET-1 > 2 pg/mL pre-op demonstrated higher LVMI (65.7 g/m^2.7vs 38.5 g/m^2.7, P = 0.004) and a trend towards higher RWT (45% vs 39%, P = 0.07) prior to repair than those with lower ET-1 concentration.

CONCLUSION

ET-1 concentration is significantly variable in the peri-operative period surrounding coarctectomy. Older children and infants have different responses to surgical repair suggesting different mechanisms of activation.

Atrial Functions and Aortic Elasticity in Children with Aortic Coarctation

BACKGROUND

Coarctation of the aorta (CoA) is a chronic vascular disease characterized by a persistence of myocardial and vascular alterations. We aimed to evaluate children who have had successful coarctation surgery or balloon dilatation to evaluate the elasticity of the aorta, left atrial ejection force (AEF) and myocardial performance collectively at midterm follow-up.

METHODS

Nineteen patients (7.15 ± 0.9 years of age) and 21 age-sex matched healthy children were included in this study. Left AEF index is defined as the product of mass and acceleration of blood expelled from the left atrium. Aortic stiffness and distensibility were estimated using ascending and descending aorta diameters.

RESULTS

The left atrial force index [(g∙cm/s(2))/m(2)] in the patient group was found to be significantly higher (12.69 ± 7.29, 5.74 ± 2.59, respectively, p = 0.001). Distensibility of the ascending aorta (cm(2)/dynes 10(-6)) was significantly lower in the patient group than in the control group (42.13 ± 24.02, 78.79 ± 20.49, respectively, p < 0.001). The stiffness index of the ascending aorta was significantly higher in the patient group (p < 0.001). We also documented that atrial force index is associated with peak E velocity, right arm systolic blood pressure and left ventricular mass index.

CONCLUSIONS

Our investigation showed that AEF is higher in children who have had successful coarctation surgery or balloon dilatation, and AEF is associated with systolic blood pressure, peak E velocity and left ventricular mass index. Distensibility of the ascending aorta was lower, and stiffness index was higher in children with corrected CoA than in healthy subjects.

KEY WORDS

Atrial ejection force; Balloon dilatation; CoA; Coarctation surgery; Distensibility; Stiffness index.

Clinical utility of B-type natriuretic peptide (NP) in pediatric cardiac surgery--a systematic review

BACKGROUND

NP is a biomarker that has been used in the diagnosis, management, and prognostication of a number of cardiovascular disorders in the pediatric population. The physiological role of this hormone is to allow the myocardium to adapt to stress or strain imposed by a volume and/or pressure load.

OBJECTIVE

The aim of this study was to determine the utility of preoperative and postoperative NP to predict outcome in pediatric patients undergoing cardiac surgery for structural congenital heart disease.

METHOD

We conducted a systematic review by searching three electronic databases using the search terms 'paediatric' or 'pediatric' and 'B-type natriuretic peptide'. Twenty peer-reviewed papers were included in the study.

RESULTS

Preoperative NP levels were associated with the severity of cardiac failure in several studies. Preoperative NPs also correlated with early postoperative outcome measures such as duration of cardiopulmonary bypass, duration of mechanical ventilation, presence of low cardiac output syndrome, length of stay in the intensive care unit and in one study, death. Early (within 24 h) postoperative NPs showed a stronger correlation than preoperative NPs to early postoperative adverse events.

CONCLUSION

NPs provide a simple, noninvasive and complementary tool to echocardiography that can be used to assist clinicians in the assessment and management of pediatric patients with congenital heart disease in the perioperative period.

Cardiovascular changes in children with coarctation of the aorta treated by endovascular stenting

The aim of this study was to investigate the echocardiographic, biochemical short- and mid-term effects of the stenting procedure on left ventricular function, aortic stiffness, elasticity and systemic hypertension in children with coarctation of the aorta (CoA). Fifteen patients with native or recurrent CoA and 30 healthy controls who were sex and age matched were included in the study. The blood pressure values, echocardiographic measurements, elastic functions of ascending aorta and serum N-Terminal ProBNP (NT-ProBNP) levels were recorded prospectively before and at the first and sixth month after stenting. The mean arterial pressure recorded before stenting was 134.4±16.3 mm Hg; at the sixth month it was 115.5±9.5 mm Hg and in the control group it was 107.3±9.4 mm Hg. Although blood pressure levels were lower compared with the pre-stenting measurements (P<0.05), they were still significantly higher compared with the control group (P<0.05). Although a significant reduction was detected in the LVMIz at the end of the sixth month (50.4±14.3 g m(-2.7)) compared with the baseline (66.6±17.9 g m(-2.7); P<0.05), it was still higher compared with the control group (35.7±6.2 g m(-2.7); P<0.05). The baseline aortic elasticity (6.4±3.4 cm(2) dyn(-1) 10(-6)) was lower compared with the control group (10.0±1.7 cm(2) dyn(-1) 10(-6); P<0.05), and prestenting aortic stiffness was higher than that of the control group (5.6±1.6 dyn(-1) 10(-6); 2.5±0.45  dyn(-1) 10(-6); P<0.05). A statistically significant negative correlation was detected between the pressure gradient at the lesion site and aortic elasticity (r: -0.53, P: 0.04). Although resolution of the coarctation by endovascular stenting led to a reduction in the arteriopathy that had already begun before treatment, it was demonstrated that these children did not completely return to normal.

[Surgery repair of aortic coarctation in infancy]

OBJECTIVE

The study's purpose is to present our experience with surgical correction of aortic coarctation in infants, at short and medium term, particularly morbidity and mortality.

METHOD

This is a retrospective observational and descriptive trial. We included all infant patients undergoing surgical correction of AC. All data were obtained from the clinical database of the hospital.

RESULTS

We included 20 patients with AC. The surgical technique was extended coarctectomy in 19 patients and, in one patient, a subclavian artery flap was performed. In all patients, the average time of aortic clamping was 18min. The residual gradient measured by echocardiography was in average of 12.2mmHg. One patient died of sepsis secondary to pneumonia. The main cause of immediate postoperative morbidity was systemic hypertension in seven patients, nosocomial infection in four patients with development of sepsis, one patient had to be reoperated due to high gradient. One patient had cholestatic syndrome. Eighteen patients required a transfusion at some time during their hospital stay. Average in-hospital stay was of 12 days.

CONCLUSION

The aortic coarctation surgery has had favorable results so far and we can conclude that the program has been successful. The surgical technique has shown low mortality and complications and midterm follow-up shows low rate of recoarctation.