John F. Rhodes

Comparison of shunt types in the Norwood procedure for single-ventricle lesions.

BACKGROUND The Norwood procedure with a modified Blalock-Taussig (MBT) shunt, the first palliative stage for single-ventricle lesions with systemic outflow obstruction, is associated with high mortality. The right ventricle-pulmonary artery (RVPA) shunt may improve coronary flow but requires a ventriculotomy. We compared the two shunts in infants with hypoplastic heart syndrome or related anomalies. METHODS Infants undergoing the Norwood procedure were randomly assigned to the MBT shunt (275 infants) or the RVPA shunt (274 infants) at 15 North American centers. The primary outcome was death or cardiac transplantation 12 months after randomization. Secondary outcomes included unintended cardiovascular interventions and right ventricular size and function at 14 months and transplantation-free survival until the last subject reached 14 months of age. RESULTS Transplantation-free survival 12 months after randomization was higher with the RVPA shunt than with the MBT shunt (74% vs. 64%, P=0.01). However, the RVPA shunt group had more unintended interventions (P=0.003) and complications (P=0.002). Right ventricular size and function at the age of 14 months and the rate of nonfatal serious adverse events at the age of 12 months were similar in the two groups. Data collected over a mean (+/-SD) follow-up period of 32+/-11 months showed a nonsignificant difference in transplantation-free survival between the two groups (P=0.06). On nonproportional-hazards analysis, the size of the treatment effect differed before and after 12 months (P=0.02). CONCLUSIONS In children undergoing the Norwood procedure, transplantation-free survival at 12 months was better with the RVPA shunt than with the MBT shunt. After 12 months, available data showed no significant difference in transplantation-free survival between the two groups. (ClinicalTrials.gov number, NCT00115934.)

Patent Foramen Ovale Closure or Antiplatelet Therapy for Cryptogenic Stroke

BACKGROUND The efficacy of closure of a patent foramen ovale (PFO) in the prevention of recurrent stroke after cryptogenic stroke is uncertain. We investigated the effect of PFO closure combined with antiplatelet therapy versus antiplatelet therapy alone on the risks of recurrent stroke and new brain infarctions. METHODS In this multinational trial involving patients with a PFO who had had a cryptogenic stroke, we randomly assigned patients, in a 2:1 ratio, to undergo PFO closure plus antiplatelet therapy (PFO closure group) or to receive antiplatelet therapy alone (antiplatelet‐only group). Imaging of the brain was performed at the baseline screening and at 24 months. The coprimary end points were freedom from clinical evidence of ischemic stroke (reported here as the percentage of patients who had a recurrence of stroke) through at least 24 months after randomization and the 24‐month incidence of new brain infarction, which was a composite of clinical ischemic stroke or silent brain infarction detected on imaging. RESULTS We enrolled 664 patients (mean age, 45.2 years), of whom 81% had moderate or large interatrial shunts. During a median follow‐up of 3.2 years, clinical ischemic stroke occurred in 6 of 441 patients (1.4%) in the PFO closure group and in 12 of 223 patients (5.4%) in the antiplatelet‐only group (hazard ratio, 0.23; 95% confidence interval [CI], 0.09 to 0.62; P=0.002). The incidence of new brain infarctions was significantly lower in the PFO closure group than in the antiplatelet‐only group (22 patients [5.7%] vs. 20 patients [11.3%]; relative risk, 0.51; 95% CI, 0.29 to 0.91; P=0.04), but the incidence of silent brain infarction did not differ significantly between the study groups (P=0.97). Serious adverse events occurred in 23.1% of the patients in the PFO closure group and in 27.8% of the patients in the antiplatelet‐only group (P=0.22). Serious device‐related adverse events occurred in 6 patients (1.4%) in the PFO closure group, and atrial fibrillation occurred in 29 patients (6.6%) after PFO closure. CONCLUSIONS Among patients with a PFO who had had a cryptogenic stroke, the risk of subsequent ischemic stroke was lower among those assigned to PFO closure combined with antiplatelet therapy than among those assigned to antiplatelet therapy alone; however, PFO closure was associated with higher rates of device complications and atrial fibrillation. (Funded by W.L. Gore and Associates; Gore REDUCE ClinicalTrials.gov number, NCT00738894.)

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.

Melody Valve Implant Within Failed Bioprosthetic Valves in the Pulmonary Position A Multicenter Experience

Background—Transcatheter pulmonary valve implantation using the Melody valve has emerged as an important therapy for the treatment of postoperative right ventricular outflow tract dysfunction. Melody-in-bioprosthetic valves (BPV) is currently considered an off-label indication. We review the combined experience with transcatheter pulmonary valve implantation within BPVs from 8 centers in the United States and discuss technical aspects of the Melody-in-BPV procedure. Methods and Results—A total of 104 patients underwent Melody-in-BPV in the pulmonary position at 8 US centers from April 2007 to January 2012. Ten different types of BPVs were intervened on, with Melody valve implantation at the intended site in all patients. Following Melody valve implant, the peak right ventricle-to-pulmonary artery gradient decreased from 38.7±16.3 to 10.9±6.7 mm Hg (P<0.001), and the right ventricular systolic pressure fell from 71.6±21.7 to 46.7±15.9 mm Hg (P<0.001). There was no serious procedural morbidity, and no deaths related to the catheterization or implant. At a median follow-up of 12 months (1–46 months), no patients had more than mild regurgitation, and 4 had a mean right ventricular outflow tract gradient ≥30 mm Hg. During follow-up, there were 2 stent fractures, 3 cases of endocarditis (2 managed with surgical explant), and 2 deaths that were unrelated to the Melody valve. Conclusions—Transcatheter pulmonary valve implantation using the Melody valve within BPVs can be accomplished with a high rate of success, low procedure-related morbidity and mortality, and excellent short-term results. The findings of this preliminary multicenter experience suggest that the Melody valve is an effective transcatheter treatment option for failed BPVs.

Clinical Outcomes of Palliative Surgery Including a Systemic-to-Pulmonary Artery Shunt in Infants With Cyanotic Congenital Heart Disease Does Aspirin Make a Difference?

Background— Aspirin (ASA) often is used to prevent thrombosis in infants with congenital heart disease after placement of a systemic-to–pulmonary artery shunt, but its effect on outcomes is unknown. Methods and Results— The present multicenter study prospectively collected data on 1-year postoperative rates of death, shunt thrombosis, or hospitalization age <4 months for bidirectional Glenn/hemi-Fontan surgery in 1004 infants. The use and dose of ASA were recorded. Kaplan-Meier event rates were calculated for each event and the composite outcome, and a Cox regression model was constructed for time to event. Model terms were ASA use and type of surgery, with adjustment for age at surgery. Diagnoses were hypoplastic left heart syndrome (n=346), tricuspid atresia (n=103), tetralogy of Fallot (n=127), pulmonary atresia (n=177), heterotaxy syndrome (n=38), and other (n=213). There were 344 shunts placed without cardiopulmonary bypass (closed shunt), 287 shunts with bypass (open shunt), 323 Norwood procedures, and 50 Sano procedures. Overall, 80% of patients received ASA. One-year postoperative events rates were high: 38% for the composite end point, 26% for death, and 12% for shunt thrombosis. After the exclusion of patients with early mortality, patients receiving ASA had a lower risk of shunt thrombosis (hazard ratio, 0.13; P=0.008) and death (closed shunt: hazard ratio, 0.41, P=0.057; open shunt: hazard ratio, 0.10, P<0.001; Norwood: hazard ratio, 0.34, P<0.001; Sano: hazard ratio, 0.68, P=NS) compared with those not receiving ASA. Conclusions— The morbidity and mortality for infants after surgical placement of a systemic-to–pulmonary artery shunt are high. ASA appears to lower the risk of death and shunt thrombosis in the present observational study.

Pathophysiology of Congenital Heart Disease in the Adult Part I: Shunt Lesions

Congenital heart disease is common, occurring in ≈8 of 1000 live births.1 With the successes in cardiothoracic surgery over the past 3 decades and the ongoing improvements in the diagnostic, interventional, and critical care skills of pediatric cardiologists, ≈90% of children born with heart defects now survive to adulthood.2 In addition, using improved noninvasive techniques, adult cardiologists are increasingly identifying adults with septal defects that were undiagnosed in childhood. The adult congenital heart disease patients carry a spectrum of disease, from small septal defects and minor valvar obstructions to complex single-ventricle lesions that have been palliated with staged surgical repairs. It is estimated that >1 million adults in the United States now have congenital heart disease, outnumbering their pediatric counterparts for the first time.3,4 While the adult cardiology community struggles with a population that once was the exclusive domain of pediatricians, governmental agencies, national physician associations, and cardiology advisory boards are trying to define the scope of this national healthcare issue and to figure out how to train current and future generations of doctors.5 This specialized cardiac care will require the diagnosis of adult congenital heart disease in patients presenting de novo with new or chronic symptoms, the long-term maintenance of those previously diagnosed, and the ability to recognize when primary or additional interventions are required. As these patients increasingly present to cardiologists’ offices for care, healthcare professionals will need to develop a better level of comfort with adult congenital heart disease. This 3-part series focuses on the pathophysiology of congenital heart lesions, which are seen commonly in adult patients. In this first portion, simple shunt lesions are reviewed. For each, the natural history and common clinical presentations resulting from the shunt are discussed. A discussion of therapeutic options and the literature supporting these options is …

Major Complications Associated with Transcatheter Atrial Septal Occluder Implantation: A Review of the Medical Literature and the Manufacturer and User Facility Device Experience (MAUDE) Database

OBJECTIVE To summarize major complications and outcome for patients receiving percutaneous closure of atrial septal communications. DESIGN The Medline database and the United States Food and Drug Administration manufacturer and user facility device experience databases (MAUDE) were searched for reports related to complications with atrial septal occluding devices. The medical literature documenting complication rates for these devices were reviewed and summarized. The MAUDE database complication reports were compared with those reported in the medical literature using national implant estimates. OUTCOME The MAUDE database correlated in the type of complications most frequently encountered with each device. However, based on estimated total implant numbers, there is a higher incidence of major complications, including death. AGA devices had a 0.3% erosion/perforation rate with a higher morbidity and mortality (29%) than previously reported. NMT devices had a lower incidence of erosion/perforation rate of 0.05%. Embolization rates for the NMT devices were also lower than published European studies, possibly reflecting the US restriction of the device for closure of patent foramen ovale. Thrombus was more frequently encountered on the NMT device. Both AGA and NMT devices have been shown to be safe and effective alternatives to cardiac surgery. The MAUDE database correlated, with a very low overall complication rate, but showed a higher estimated major complication rate than the medical literature. These data demonstrate the difficulty in quantifying rare complications in the premarketing analysis and the obligation providers have to report and evaluate complications through vigilant postmarketing surveillance.

Variation in Perioperative Care across Centers for Infants Undergoing the Norwood Procedure

OBJECTIVES In the Single Ventricle Reconstruction trial, infants undergoing the Norwood procedure were randomly allocated to undergo a right ventricle-to-pulmonary artery shunt or a modified Blalock-Taussig shunt. Apart from shunt type, subjects received the local standard of care. We evaluated variation in perioperative care during the Norwood hospitalization across 14 trial sites. METHODS Data on preoperative, operative, and postoperative variables for 546 enrolled subjects who underwent the Norwood procedure were collected prospectively on standardized case report forms, and variation across the centers was described. RESULTS Gestational age, birth weight, and proportion with hypoplastic left heart syndrome were similar across sites. In contrast, all recorded variables related to preoperative care varied across centers, including fetal diagnosis (range, 55%-85%), preoperative intubation (range, 29%-91%), and enteral feeding. Perioperative and operative factors were also variable across sites, including median total support time (range, 74-189 minutes) and other perfusion variables, arch reconstruction technique, intraoperative medication use, and use of modified ultrafiltration (range, 48%-100%). Additional variation across centers was seen in variables related to postoperative care, including proportion with an open sternum (range, 35%-100%), median intensive care unit stay (range, 9-44 days), type of feeding at discharge, and enrollment in a home monitoring program (range, 1%-100%; 5 sites did not have a program). Overall, in-hospital death or transplant occurred in 18% (range across sites, 7%-39%). CONCLUSIONS Perioperative care during the Norwood hospitalization varies across centers. Further analysis evaluating the underlying causes and relationship of this variation to outcome is needed to inform future studies and quality improvement efforts.

Pathophysiology of Congenital Heart Disease in the Adult Part III: Complex Congenital Heart Disease

With the successes in cardiothoracic surgery and pediatric cardiology over the past 3 decades, for the first time, adults with congenital heart disease (CHD) outnumber their pediatric counterparts.1,2 As a result, adult patients with CHD are beginning to appear more frequently in the practices of adult cardiologists. The present series is designed to provide a review of the pathophysiology and natural history of common congenital heart problems that are now being seen by adult cardiologists. In the first 2 parts of the series, simple shunts and congenital obstructive lesions were reviewed. This final chapter will examine the physiology and natural history of and the indications for intervention in common complex congenital cardiac malformations seen in adult patients. These patients include those with singleventricle physiology who are reaching adulthood in significant numbers for the first time, the early survivors of innovative surgical techniques developed a generation ago. The combination of shunts, obstructive lesions, chamber hypoplasia, and abnormal arterial and venous connections that is seen in this group of patients creates some of the most interesting and complex changes in the normal physiology of the heart. Each patient must be considered individually, because small differences in septal defect size or pathway obstruction may have an enormous impact on the overall effectiveness of the circulation and on management of the patient. For the purposes of this article, only the most common types of complex CHD will be considered (those that are most likely to be seen in the adult cardiologist’s office). However, the principles of flow and resistance, as reviewed in the prior 2 portions of this series and as related below, are easily generalized to give the practicing physician insight into the physiological consequences of a myriad of rare cardiac malformations. Adults with complex CHD can be divided into 2 groups: those who have not previously had an intervention and those who have. The former will present with new-onset symptoms in adulthood or may be identified as a result of a physical examination with a new physician, an abnormal ECG, or before they begin a new job. Children in the latter group who have had good outcomes from surgical interventions are frequently lost to follow-up during adolescence. They may return for care in early adulthood with ongoing or new symptoms or for clearance for employment, higher education, insurance, or sports. These patients are often unfamiliar with their diagnoses and their surgical history, have long since stopped taking medication, and have adapted to a lifestyle that fits their level of cardiac function.