David F. Wax

Procedural Results and Acute Complications in Stenting Native and Recurrent Coarctation of the Aorta in Patients Over 4 Years of Age: A Multi-Institutional Study

Background: We report a multi‐institutional experience with intravascular stenting (IS) for treatment of coarctation of the aorta. Methods and Results: Data was collected retrospectively by review of medical records from 17 institutions. The data was broken down to prior to 2002 and after 2002 for further analysis. A total of 565 procedures were performed with a median age of 15 years (mean = 18.1 years). Successful reduction in the post stent gradient (<20 mm Hg) or increase in post stent coarctation to descending aorta (DAo) ratio of >0.8 was achieved in 97.9% of procedures. There was significant improvement (P < 0.01) in pre versus post stent coarctation dimensions (7.4 mm ± 3.0 mm vs. 14.3 ± 3.2mm), systolic gradient (31.6 mm Hg ± 16.0 mm Hg vs. 2.7 mm Hg ± 4.2 mm Hg) and ratio of the coarctation segment to the DAo (0.43 ± 0.17 vs. 0.85 ± 0.15). Acute complications were encountered in 81/565 (14.3%) procedures. There were two procedure related deaths. Aortic wall complications included: aneurysm formation (n = 6), intimal tears (n = 8), and dissections (n = 9). The risk of aortic dissection increased significantly in patients over the age of 40 years. Technical complications included stent migration (n = 28), and balloon rupture (n = 13). Peripheral vascular complications included cerebral vascular accidents (CVA) (n = 4), peripheral emboli (n = 1), and significant access arterial injury (n = 13). Older age was significantly associated with occurrence of CVAs. A significant decrease in the technical complication rate from 16.3% to 6.1% (P < 0.001) was observed in procedures performed after January 2002. Conclusions: Stent placement for coarctation of aorta is an effective treatment option, though it remains a technically challenging procedure. Technical and aortic complications have decreased over the past 3 years due to, in part, improvement in balloon and stent design. Improvement in our ability to assess aortic wall compliance is essential prior to placement of ISs in older patients with coarctation of the aorta.

Intermediate follow‐up following intravascular stenting for treatment of coarctation of the aorta

Background: We report a multiinstitutional study on intermediate‐term outcome of intravascular stenting for treatment of coarctation of the aorta using integrated arch imaging (IAI) techniques. Methods and Results: Medical records of 578 patients from 17 institutions were reviewed. A total of 588 procedures were performed between May 1989 and Aug 2005. About 27% (160/588) procedures were followed up by further IAI of their aorta (MRI/CT/repeat cardiac catheterization) after initial stent procedures. Abnormal imaging studies included: the presence of dissection or aneurysm formation, stent fracture, or the presence of reobstruction within the stent (instent restenosis or significant intimal build‐up within the stent). Forty‐one abnormal imaging studies were reported in the intermediate follow‐up at median 12 months (0.5–92 months). Smaller postintervention of the aorta (CoA) diameter and an increased persistent systolic pressure gradient were associated with encountering abnormal follow‐up imaging studies. Aortic wall abnormalities included dissections (n = 5) and aneurysm (n = 13). The risk of encountering aortic wall abnormalities increased with larger percent increase in CoA diameter poststent implant, increasing balloon/coarc ratio, and performing prestent angioplasty. Stent restenosis was observed in 5/6 parts encountering stent fracture and neointimal buildup (n = 16). Small CoA diameter poststent implant and increased poststent residual pressure gradient increased the likelihood of encountering instent restenosis at intermediate follow‐up. Conclusions: Abnormalities were observed at intermediate follow‐up following IS placement for treatment of native and recurrent coarctation of the aorta. Not exceeding a balloon:coarctation ratio of 3.5 and avoidance of prestent angioplasty decreased the likelihood of encountering an abnormal follow‐up imaging study in patients undergoing intravascular stent placement for the treatment of coarctation of the aorta. We recommend IAI for all patients undergoing IS placement for treatment of CoA.

Balloon Dilation of Severe Aortic Stenosis in the Neonate: Comparison of Anterograde and Retrograde Catheter Approaches

OBJECTIVES We sought to compare anterograde and retrograde balloon dilation of severe aortic valve stenosis in neonates. BACKGROUND There is a high incidence of iliofemoral artery complications after retrograde balloon dilation of the aortic valve in the neonate. Therefore, a nonarterial technique of catheter access to the aortic valve would be worth exploring. METHODS Group 1 included 11 consecutive patients (median age 6 days, range 1 to 42; median weight 3.5 kg, range 2.16 to 4.25) undergoing attempted anterograde dilation through a femoral venous approach. Group 2 included 15 patients (median age 3 days, range 1 to 35; median weight 3.4 kg, range 2.5 to 4.4 kg) who underwent attempted retrograde dilation, including 2 in whom attempted anterograde approach had failed. RESULTS The valve was successfully crossed in 9 of 11 anterograde and 13 of 15 retrograde dilations. In both groups, the peak gradient across the valve decreased significantly (both p = 0.001). On echocardiography, the jet width of the aortic incompetence/ annulus diameter ratio was 0.16 +/- 0.08 (mean +/- SD) after anterograde and 0.51 +/- 0.24 after retrograde dilation (p = 0.03), possibly because of unrecognized valve leaflet perforation. Two patients in group 1 developed persistent, mild mitral insufficiency. Femoral artery thrombosis developed in one patient after anterograde dilation and in eight after retrograde dilation (p = 0.03). CONCLUSIONS This series demonstrates that an anterograde approach for balloon angioplasty of severe neonatal aortic valve stenosis is feasible, achieves good hemodynamic relief and lessens morbidity compared with retrograde arterial techniques.

Coarctation of the Aorta: Midterm Outcomes of Resection With Extended End-to-End Anastomosis

BACKGROUND We began using the technique of resection with extended end-to-end anastomosis for infants and children with coarctation of the aorta in 1991. The purpose of this review is to evaluate the midterm outcomes of this technique, specifically determining the incidence of and risk factors for transcatheter or surgical reintervention. METHODS A retrospective analysis of the cardiac surgery database was performed to identify all patients who had a diagnosis of coarctation of the aorta with or without ventricular septal defect and had resection with extended end-to-end anastomosis from 1991 to 2007. Perioperative course and follow-up with physical examination, echocardiogram, and cardiology evaluation were obtained. RESULTS From 1991 through 2007, 201 patients had repair of coarctation of the aorta with resection with extended end-to-end anastomosis. The median age was 23 days, and the median weight was 4.0 kg. Surgical approach was by left thoracotomy in 157 patients (78%) with a mean cross-clamp time of 18 +/- 4 minutes. Median sternotomy approach was used in 44 patients (22%) to repair a hypoplastic transverse aortic arch (n = 16) or because of associated ventricular septal defect (n = 28) with a mean circulatory arrest time of 14 +/- 9 minutes. Early mortality occurred in 4 patients (2.0%). Three patients (1.5%) required early arch revision: 2 intraoperatively and 1 on postoperative day 1. Follow-up data were available for 182 patients (91%) with a mean follow-up of 5.0 +/- 4.3 years (908 patient-years). Reinterventions (n = 8; 4.0%) included three balloon angioplasties and five reoperations; 75% of the reinterventions occurred in the first postoperative year. Hypoplastic transverse aortic arch was not a risk factor for reintervention (p = 0.36), but was a risk factor for mortality (p = 0.039). Aberrant right subclavian artery was the only risk factor for recoarctation (p = 0.007). CONCLUSIONS Repair of coarctation of the aorta with resection with extended end-to-end anastomosis has a low early mortality, effectively addresses transverse arch hypoplasia, and at midterm follow-up has a low rate of reintervention for recurrent coarctation.

Pediatric coronary artery bypass for Kawasaki, congenital, post arterial switch, and iatrogenic lesions

BACKGROUND Pediatric coronary artery bypass (PCAB) has been recently employed for expanding indications to treat acquired, congenital, post arterial switch, and other iatrogenic pediatric coronary artery problems. METHODS Between 1987 and 1998, 3 infants and 13 children (n = 16, mean age 6.1 years, range 2 months-18 years) underwent one or more internal thoracic artery (ITA) to coronary artery (CA) bypass grafts for Kawasaki disease (n = 4), congenital lesions (n = 3), post arterial switch (n = 4), and other iatrogenic obstructions (n = 5). Proximal left main CA arterioplasty was performed concurrently with ITA-CA bypass in 4 patients. RESULTS Survival is 93.8%. All bypass grafts in surviving patients are patent 2 months-11 years postoperation. The 11 elective patients are well (NYHA I-II). The 5 emergent operations were performed in 2 infants and 3 adolescents who had poor ventricular function prior to ITA-CA bypass due to iatrogenic injuries in 3, congenital critical left main stenosis in 1, and intraoperative iatrogenic coronary injury in 1. The 3 adolescents fared worse, resulting in death in the first, cardiac transplantation in the second, and full recovery in the third. The 2 infants have steadily improving ventricular function. CONCLUSIONS ITA-CA bypass can be successfully performed in infants and children for expanding elective and life-saving indications with excellent results. Poor preoperative ventricular function often persists, especially in those older children with iatrogenic injuries, and may result in death or cardiac transplantation.

Bidirectional Glenn shunt in association with congenital heart repairs: the 1 1 2 ventricular repair

BACKGROUND The bidirectional Glenn shunt has been used to incorporate a smaller tripartite ventricle into the circulation and create pulsatile pulmonary artery flow. We reviewed our operative experience and assessed hemodynamics of the bidirectional Glenn shunt in 1(1/2) ventricular repair or in conjunction with other repairs of congenital heart defects. METHODS Between 1992 and 1998, 15 patients (mean age, 8.1+/-7.9 years) had bidirectional Glenn shunt in association with repair of congenital heart defects. Eighty-seven percent had at least one previous operation. All patients had simultaneous or previous intracardiac repair and had bidirectional Glenn shunt to volume unload the small right ventricle (group A, n = 7), to unload the poorly functioning right ventricle (group B, n = 2), to redirect superior vena cava-pulmonary venous atrial connection to treat cyanosis (group C, n = 2), or to unload the pulmonary left ventricle for residual intracavitary hypertension in patients with L-transposition of the great arteries, ventricular septal defect, and pulmonary stenosis (group D, n = 4). Intraoperative hemodynamic assessment was done in 2 patients in group A by selective use of inflow occlusion and flow probes. RESULTS All patients survived. Four patients had successful, concurrent arrhythmia circuit cryoablation for Wolf-Parkinson-White syndrome (n = 1) or atrial reentry tachycardia (n = 3). Superior and inferior vena caval flow averaged 36% and 64% of cardiac output, respectively. Postoperative superior vena caval pressure (n = 13) was 13.7+/-4.0 mm Hg with pulmonary arterial flow pattern contributed by the ventricle in systole (pulsatile) and the superior vena cava in diastole (laminar). CONCLUSIONS The bidirectional Glenn shunt is an effective adjunct to congenital heart repair to treat pulmonary ventricular pressure-volume problems and anomalous superior vena caval to left atrial connections.

A comparison of intravascular ultrasound with coronary angiography for evaluation of transplant coronary disease in pediatric heart transplant recipients

BACKGROUND The purpose of this study was to assess the sensitivity of coronary angiography versus intravascular ultrasound for detecting significant transplant coronary artery disease in children. We also examined associations between potential risk factors for transplant coronary artery disease and intravascular ultrasound findings, and evaluated the safety of intravascular ultrasound. METHODS All pediatric heart transplant patients who had intravascular ultrasound following routine coronary angiography were included. Transplant coronary artery disease was quantified by assigning Stanford classes and calculating intimal indices for intravascular ultrasound images. These findings were compared with qualitative coronary angiography findings. Risk factors for transplant coronary artery disease, cardiac events and complications were recorded. RESULTS Sixteen patients had 27 intravascular ultrasound procedures during the study period. All patients had evidence of transplant coronary artery disease at their latest intravascular ultrasound study. Of the patients whose most severely afflicted coronary artery underwent both imaging modalities at the latest study, 50% had significant transplant coronary artery disease (Stanford Class >/=II) by intravascular ultrasound and normal coronary angiography. A higher mean first-year biopsy score may be associated with significant transplant coronary artery disease by intravascular ultrasound, but a large number of patients will be required to determine this with statistical certainty. One major complication occurred early in the experience. CONCLUSIONS In children, intravascular ultrasound is more sensitive for detecting significant transplant coronary artery disease than coronary angiography, but may add cost, time and potential morbidity to screening protocols. Prospective, multicenter studies are needed to best utilize intravascular ultrasound in this patient population.

Usefulness of Troponin I as a Marker of Myocardial Injury After Pediatric Cardiac Catheterization

Cardiac troponin I (cTnI) is a sensitive and specific marker of myocardial injury. The degree of myocardial injury associated with pediatric cardiac catheterization is unknown. We sought to investigate cTnI after pediatric cardiac catheterization, and to evaluate the degree of elevation observed with specific types of interventions. Seventy-three pediatric catheterizations were evaluated. Diagnostic procedures and interventions not expected to cause myocardial injury were assigned to group I, whereas interventional procedures expected to be associated with cardiac injury were assigned to group II. Group II procedures were further subdivided based on type of intervention. Serum samples were obtained before and after all procedures and analyzed for cTnI. Postprocedure cTnI levels were compared across groups and correlated with age and weight. Procedures in group II were associated with significantly higher cTnI levels than group I (median 2.65 ng/ml; interquartile range 0.9 to 4.9 ng/ml for group II vs 0.3; 0.3 to 1.6 ng/ml for group I, p <0.001). Within group II, cTnI was inversely correlated with age (p <0.05) and weight (p <0.05). Radiofrequency catheter ablation (RFA) caused higher cTnI levels than other types of interventions (median 3.7 ng/ml; 1.9 to 9.5 ng/ml for RFA vs 1.75; 0.7 to 4.9 ng/ml for non-RFA, p <0.05). Most pediatric interventional catheterization procedures are associated with myocardial injury, as evidenced by elevation of cTnI, with RFA causing higher levels than other interventions. Conversely, most diagnostic procedures are associated with no detectable myocardial injury. When compared with adult studies, pediatric patients seem to be at higher risk for myocardial injury from interventional cardiac catheterization.

Reversal of severe late left ventricular failure after pediatric heart transplantation and possible role of plasmapheresis

Late acute cardiac graft failure carries a high mortality in adults. Vascular mediators and factors other than classic T-cell-mediated rejection may play a role in this process, and aggressive multimodality therapy may improve survival. We report experience with plasmapheresis in treating late severe acute left ventricular dysfunction in a group of pediatric heart transplant recipients. We retrospectively reviewed clinical records, echocardiograms, hemodynamics, coronary angiograms, biopsy specimens, and treatment regimens for 5 patients with 7 episodes of late-onset severe graft failure who recovered. Plasmapheresis was applied in all cases, in addition to methylprednisolone, cyclophosphamide, lympholytic agents, and aggressive supportive care including mechanical ventilation and hemofiltration. All patients presented with acute severe left ventricular dysfunction 1.4 to 7.9 years (mean 3.6) after orthotopic heart transplantation. Mean shortening fraction at presentation was 13 to 23% (mean 16), initial endomyocardial biopsy specimens were grade 0 to 3B, and immunofluorescence studies were negative. Treatment included plasmapheresis, cyclophosphamide, mechanical ventilation, hemofiltration, and inotropes. Clinical recovery was slow, with 4 to 8 weeks until left ventricular function normalized, and 2.2 to 9.4 (mean 4.6) weeks to hospital discharge. At follow-up (50 to 38 months, mean 24), all are alive. Two patients are well, whereas coronary vasculopathy developed in 3. Thus, survival may improve in patients with late graft failure with low biopsy score and plasmapheresis combined with multimodality therapy.

Standardizing radiation dose reporting in the pediatric cardiac catheterization laboratory-a multicenter study by the CCISC (Congenital Cardiovascular Interventional Study Consortium).

We examine normalized air Kerma area product (PKA) by body weight (PKA/BW) as a reference value of radiation dose and benchmark PKA/BW in pediatric laboratories using a multicenter registry database.