Increased myocardial performance index correlates with biopsy-proven rejection in pediatric heart transplant recipients.

BACKGROUND: To date, cardiac catheterization and endomyocardial biopsy have been considered the "gold standard" for rejection surveillance after heart transplantation. Factors such as patient size (i.e., infant transplantation), loss of vascular access after repeated catheterizations, and anesthesia requirements all present unique problems and risks related to pediatric rejection surveillance. Therefore, additional methods to monitor for rejection in a non-invasive, reliable and frequent manner have been sought. We studied the utility of echocardiographic measurement of the left ventricular myocardial performance index (LVMPI), a reproducible measure of combined systolic and diastolic performance, in pediatric heart transplant recipients as a method of identifying acute rejection. METHODS: Two-dimensional/Doppler echocardiographic studies (n = 36) were performed on 21 cardiac transplant patients (ages 6.2 to 21.9 years) at the time of endomyocardial biopsy. The LVMPI, the sum of the isovolumic contraction time and isovolumic relaxation time divided by aortic ejection time, was determined at each study, as well as other echocardiographic measures of systolic and diastolic function. Patients were grouped by concurrent histologic rejection grade and the results compared between groups. RESULTS: Significant differences in LVMPI (p < 0.001) were noted between patients with no rejection (Grade 0; n = 23) and those with moderate to severe rejection (Grade 3; n = 5), as well as between those with no rejection and those with focal moderate (Grade 2; n = 8) rejection (p < 0.05). The LVMPI was 0.42 +/- 0.03 (mean +/- SEM) for the group without rejection, 0.57 +/- 0.06 for those with Grade 2 rejection and 0.73 +/- 0.05 for those with Grade 3 rejection. Although 9 of the 23 studies in the non-rejection group had LVMPI values exceeding 0.44 (upper threshold value), 12 of 13 patients in the rejection groups exceeded this threshold. LVMPI >or= 0.64 was associated with significant rejection in all cases in this study (n = 7). No significant differences were noted between groups for left ventricular ejection fraction or shortening fraction, percent septal or posterior wall thickening, left ventricular mass index or mitral valve deceleration time. In addition, for those individual patients with multiple studies, the LVMPI consistently increased with higher rejection grades and decreased after therapy. CONCLUSIONS: In this series, increased LVMPI correlated with biopsy-proven rejection, and frequent serial assessments using this technique may provide a relatively sensitive non-invasive means of rejection surveillance after pediatric cardiac transplantation. False positive results may be encountered, likely due to alterations in diastolic function that have been previously observed in transplant recipients.

Atrial septal stent implant: atrial septal defect creation in the management of complex congenital heart defects in infants.

OBJECTIVES: Certain congenital heart defects require the creation of an unrestrictive atrial septal defect (ASD) to relieve atrial hypertension, to maintain systemic cardiac output, or to achieve adequate atrial mixing to improve systemic oxygen saturation. We describe a series of patients, ranging in age from 5 weeks to 17 months, in whom we implanted a stent across the atrial septum to create a lasting, unrestrictive interatrial communication. METHODS: Five patients with left heart obstructive defects presented with severe left atrial hypertension. The patients weighed 3.5-10.1 kg. Patients 1 and 2 presented at 5 and 9 weeks of age, respectively. Patient 1 had a restrictive patent foramen ovale, and patient 2 had an intact atrial septum. Patients 3, 4, and 5 had previous cardiac surgery including atrial septectomy. At presentation, all patients were poor surgical candidates. RESULTS: Using standard percutaneous technique, a premounted Palmaz-Genesis stent (Cordis Corporation) was implanted across the atrial septum in all 5 patients, using balloons ranging from 7 to 10 mm diameter. Each patient had a dramatic decrease in left atrial pressure and increased ASD diameter. All stented ASDs remained widely patent, confirmed by Doppler echocardiography, until elective surgical stent explant. CONCLUSION: Patients presenting beyond the neonatal period with left heart obstructive defects and intact atrial septum or restrictive ASD present a challenging problem. We report a safe and effective technique for relief of left atrial hypertension in infants using premounted intravascular stents. All patients had immediate marked hemodynamic improvement.

Use of cutting balloon for palliative treatment in tetralogy of Fallot.

In tetralogy of Fallot, severe cyanosis due to insufficient pulmonary blood flow necessitates early intervention. The Cutting Balloon, developed for percutaneous coronary angioplasty, was used successfully for transcatheter incision and dilation of infundibular and valvar pulmonary stenosis in four patients with tetralogy of Fallot.

Anatomic reconstruction for recurrent aortic obstruction in infants and children.

BACKGROUND: Patients undergoing operative repair of aortic obstruction are at a lifelong risk of recurrent obstruction, and there is controversy regarding the optimal surgical technique. We have used an alternative strategy for recurrent aortic obstruction, typically involving anatomic reconstruction by means of a median sternotomy, and describe our techniques and results. METHODS: Twenty-one patients presented with recurrent aortic arch obstruction. Mean age and weight were 7.8 +/- 5.4 years (range, 0.21 to 15.2 years) and 30.6 +/- 21.8 kg (range, 3.6 to 90 kg), respectively. Recurrence involved the aortic arch to some degree in each case, as the mean preoperative transverse aortic arch z score was -2.9 +/- 1.6 (range, -7.0 to 0.1). Thoracotomy was possible in 2 patients, using re-resection with end-to-end anastomosis (n = 1) and patch aortoplasty (n = 1). The remaining 19 patients required median sternotomy, cardiopulmonary bypass, and deep hypothermic circulatory arrest for complete relief of obstruction by aortic arch advancement (n = 10), patch aortoplasty (n = 8), or interposition grafting (n = 1). RESULTS: There was 1 hospital death. Invasive blood pressure monitoring revealed no residual arm-to-leg gradient in 19 patients and a 20-mm Hg gradient in 2 patients. There have been no late deaths. No patients have undergone subsequent aortic intervention, and all are asymptomatic up to 85 months postoperatively. Two patients are currently followed with a 10-mm Hg arm-to-leg blood pressure gradient. CONCLUSIONS: Anatomic reconstruction for recurrent aortic obstruction can be safely accomplished in the majority of patients. We favor median sternotomy because of the ability of establishing cardiopulmonary bypass, the facility of anatomic reconstruction techniques, and the ability to repair concomitant cardiovascular lesions.