Pediatric cardiology centers vary in treatment of infants with single-ventricle congenital heart disease

Research Activities, January 2012, No. 377

Pediatric cardiology centers vary greatly in their initial treatment of infants and newborns with single-ventricle congenital heart defects (CHD) such as hypoplastic left heart syndrome (HLHS), according to three studies supported in part by the Agency for Healthcare Research and Quality (HS16957). This variability makes the initial treatment of these congenital heart problems, in which the infant is missing the left ventricle, a clear target for quality improvement efforts, note the researchers from the Joint Council on Congenital Heart Disease's National Pediatric Cardiology Quality Improvement Collaborative (NPC-QIC).

Repair of HLHS involves a series of surgeries that are typically performed over the child's first 4 years of life, with stage-I surgery typically occurring within days after birth. Additional corrective surgeries are performed at later ages (typically between 4-6 months and 18 months to 3 years, respectively). Since the infant is missing the left ventricle, which normally pumps oxygen-rich blood to the body, the goal of the initial Norwood procedure is to reroute blood flow from the right ventricle to serve this function.

To conduct the studies, the researchers drew on data for the first 100 infants enrolled in the NPC-QIC registry through 21 participating centers. Most of the infants (75 percent) had received a prenatal diagnosis of their heart disease. The three studies are briefly described here.

Brown, D.A., Connor, J.A., Pigula, F.A., and others. "Variation in preoperative and intraoperative first-stage palliation of single-ventricle heart disease: A report from the Joint Council on Congenital Heart Disease National Pediatric Cardiology Quality Improvement Cooperative." (2011, March/April). Congenital Heart Disease 6(2), pp. 108-115.

This study found substantial variation across surgical centers in the successful initial palliation of infants with single-ventricle heart disease, particularly with regard to choice of palliation strategy and intraoperative techniques such as use of regional perfusion and depth of hypothermia. Infants with a prenatal diagnosis of CHD were significantly less likely to have preoperative problems than those diagnosed after birth (45 percent versus 84 percent). The median age of stage-I repair was 5 days, but ranged from 2-78 days.

The majority of infants (55 percent) were treated with a stage-I right ventricle to pulmonary artery (RV-PA) conduit, with 28 percent receiving a stage-I Norwood shunt. There was great variation in the surgical approach taken by the 11 centers contributing at least 4 patients to the database. Several of the centers used only the RV-PA conduit procedure, while another center performed mostly hybrid stage-I procedures (and accounted for 89 percent of such procedures in the registry).

Excluding the patients who underwent hybrid stage-I repairs, the median time for a patient to be on total cardiopulmonary bypass during surgery was 137 minutes, with most participating centers' medians staying in the 100 to 200 minute range. The intraoperative procedures with the greatest degree of center-specific variation were circulatory arrest (used in 77 percent of the patients for a median of 10 minutes; range = 0-9 minutes) and hypothermia (median lowest temperature in the operating room of 18 C, and under 20 C for most of the participating centers). Immediately after surgery, three patients required use of extracorporeal membrane oxygenation support, but most only required postoperative mechanical ventilation (a median of 9 days on ventilation in the intensive care unit). Reoperations were done on 19 patients, in 6 cases to manage recurrent bleeding.

Baker-Smith, C.M., Neish, S.R., Klitzner, T.S., and others (2011, March/April). "Variation in postoperative care following stage I palliation for single-ventricle patients: A report from the Joint Council on Congenital Heart Disease National Pediatric Cardiology Quality Improvement Cooperative." Congenital Heart Disease 6(2), pp. 116-127.

This study examined variations in treatment while the infant was still in the hospital after stage-I surgery for HLHS. Infants stayed a median of 11 days in the intensive care unit (ICU) following stage-I surgery, with a range between 3 and 68 days. The 47 infants with the aortic atresia variety of HLHS stayed in the ICU longer than 24 infants with the aortic hypoplasia variety (10 vs. 8 median days). The length of postoperative stay in the ICU also varied depending on the type of surgery performed, from a median of 18 days for the 16 patients who underwent the modified Blalock-Taussig shunt (mBTS), to a median of 11 days for the 44 patients undergoing the RV-PA shunt, to a median of 9 days for the 10 patients undergoing hybrid repair. However, ICU stays varied by center, as did use of inotropic agents (that affect the strength of cardiac contraction), need for reoperation or cardiac catheterization, and postoperative complications.

Neurologic injury was the most common complication (15 events occurred in 13 patients); 20 postoperative infections occurred in 15 patients; and 22 instances of arrhythmia occurred in 19 patients. Complications occurred least frequently for infants who underwent the hybrid procedure (2 patients, or 20 percent) and were most common for those who underwent the RV-PA shunt (27 patients, or 49 percent). Some patients experienced more than one complication.

Schidlow, D.N., Anderson, J.B., Klitzner, T.S., and others. "Variation in interstage outpatient care after the Norwood Procedure: A report from the Joint Council on Congenital Heart Disease National Quality Improvement Collaborative." (2011, March/April). Congenital Heart Disease 6(2); pp. 98-107.

This study examined the care and outcomes of infants after discharge from the hospital following stage-I repair of HLHS. Of the 100 infants in the group, 62 received outpatient care from the center that performed their surgery, 25 infants were cared for at another center, and 13 infants received care from more than one center. Communication with the patients' outpatient physicians (a written medication list, nutrition plan, and red-flag checklist) was quite variable and incomplete for the majority of these practitioners. Nearly half of the outpatient primary cardiologists (45 percent) received all three elements of the communications compared with only 26 percent of the primary care physicians (PCPs). None of the elements of communications were received by 10 outpatient cardiologists and 19 PCPs.

Nutrition management was quite variable, with 49 infants fed orally, 38 receiving a combination of oral and nasogastric/nasojejunal feeding, and 6 receiving a combination of oral and gastronomy tube feeding. One infant was fed by gastronomy tube exclusively. Caloric density ranged from 20 to 30 kcal/oz of nonfortified formula or breast milk, with more than half the infants using fortified formula initially (24 kcal/oz at time of hospital discharge).

The use, type, location, and frequency of monitoring strategies varied widely. Nineteen of the infants had no monitoring done between visits to the cardiology center. Surveillance strategies were used in 81 infants; the majority were monitored in the home. Of these infants, 77 had both weight and blood-oxygen levels measured regularly, and 4 had only oxygen levels monitored.

Current as of January 2012
Internet Citation: Pediatric cardiology centers vary in treatment of infants with single-ventricle congenital heart disease: Research Activities, January 2012, No. 377. January 2012. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/news/newsletters/research-activities/jan12/0112RA19.html