Acute myocardial infarction as a cause of death in palliated hypoplastic left heart syndrome

Acute coronary artery obstruction following surgical repair of congenital heart disease

OBJECTIVES

Acute coronary artery obstruction is a rare complication of congenital heart disease surgery but imposes a high burden of morbidity and mortality. Previous case series have described episodes in specific congenital heart lesions or surgical repairs but have not examined the complication in all-comers to congenital heart surgery. We hypothesize that shorter time from a clinically recognized postoperative sentinel event suggestive of coronary ischemia to diagnosis of coronary obstruction is associated with improved clinical outcomes.

METHODS

This was a single-center, retrospective review of patients diagnosed with acute coronary artery obstruction by angiography following surgical repair of congenital heart disease between January 2000 and June 2016.

RESULTS

In total, 34 patients were identified. The most common procedures associated with coronary artery obstruction were the Norwood procedure, arterial switch operation, and aortic valve repair/replacement. In total, 79% required mechanical circulatory support, 41% died, and 27% were listed for heart transplant. Patients who died or were listed for heart transplant had longer median sentinel-event-to-cardiac-catheterization time (28 [6-168] hours vs 10 [3-56] hours, P = .001), and longer median sentinel-event-to-intervention time (32 [11-350] hours vs 13 [5-59] hours, P = .003). Patients with hypoplastic left heart syndrome were at greater risk of death or transplant listing (odds ratio, 9.23, P = .03).

CONCLUSIONS

Time from clinically relevant postoperative sentinel event to diagnosis of coronary artery obstruction by angiography was associated with transplant-listing-free survival. Clinicians should maintain a high index of suspicion for coronary obstruction and consider early catheterization and coronary angiography for patients in whom post-operative coronary compromise is suspected.

The effect of modified Blalock-Taussig shunt size and coarctation severity on coronary perfusion after the Norwood operation

BACKGROUND

The size of the modified Blalock-Taussig shunt and the additional presence of aortic coarctation can affect the hemodynamics of the Norwood physiology. Multiscale modeling was used to gather insight into the effects of these variables, in particular on coronary perfusion.

METHODS

A model was reconstructed from cardiac magnetic resonance imaging data of a representative patient, and then simplified with computer-aided design software. Changes were systematically imposed to the semi-idealized three-dimensional model, resulting in a family of nine models (3-, 3.5-, and 4-mm shunt diameter; 0%, 60%, and 90% coarctation severity). Each model was coupled to a lumped parameter network representing the remainder of the circulation to run multiscale simulations. Simulations were repeated including the effect of preserved cerebral perfusion.

RESULTS

The concomitant presence of a large shunt and tight coarctation was detrimental in terms of coronary perfusion (13.4% maximal reduction, 1.07 versus 0.927 mL/s) and oxygen delivery (29% maximum reduction, 422 versus 300 mL·min(-1)·m(-2)). A variation in the ratio of pulmonary to systemic blood flow from 0.9 to 1.6 also indicated a "stealing" phenomenon to the detriment of the coronary circulation. A difference could be further appreciated in the computational ventricular pressure-volume loops, with augmented systolic pressures and decreased stroke volumes for tighter coarctation. Accounting for constant cerebral perfusion did not produce substantially different results.

CONCLUSIONS

Multiscale simulations performed in a parametric fashion revealed a reduction in coronary perfusion in the presence of a large modified Blalock-Taussig shunt and severe coarctation in Norwood patients.

Clinical outcomes and resource use for infants with hypoplastic left heart syndrome during bidirectional Glenn: summary from the Joint Council for Congenital Heart Disease National Pediatric Cardiology Quality Improvement Collaborative registry

The National Pediatric Cardiology Quality Improvement Collaborative (NPC-QIC) registry captures information on interstage management of infants with hypoplastic left heart syndrome (HLHS). The purpose of this study was to identify interstage risk factors for increased resource use and adverse outcomes during bidirectional Glenn (BDG) hospitalization. All infants in the NPC-QIC registry (31 United States hospitals) undergoing BDG surgery were included (December 2009 to August 2010). Patient demographics, interstage variables, operative procedures, and complications were recorded. Days of hospitalization, ventilation, inotrope use, and complications were surrogates of resource use. Logistic regression analysis determined the associations between predictor variables and resource use. Of 162 infants, 105 (65 %) were males. At BDG, the median age was 155 days (range 78-128), mean weight-for-age z-score was -1.6 ± 1.1, mean length-for-age z-score was -1.5 ± 1.7, and mean preoperative oxygen saturation was 78 % ± 7 %. Caloric recommendations were met in 60 % of patients, and 85 % of patients participated in a home-surveillance program. Median days of intubation, inotrope use, and hospitalization were 1, 2, and 7, respectively. There were 4 post-BDG deaths and 55 complications. In multivariate analysis, lower weight-for-age z-score, female sex, and aortic atresia with mitral stenosis were associated with a higher risk of BDG complications. Meeting caloric recommendations before BDG was associated with fewer hospitalization days. Lower weight-for-age z-score was an independent and potentially modifiable risk factor for BDG complications. HLHS infants who met caloric recommendations before BDG had a lower duration of hospitalization at BDG. These data justify targeting nutrition in interstage strategies to improve outcomes and decrease costs for patients with HLHS.

Ventriculocoronary artery connections with the hypoplastic left heart: a 4-year prospective study: incidence, echocardiographic and clinical features

Ventriculocoronary connections (VCCs), also called sinusoids, occur with hypoplastic left heart (HLH). Previous reports are limited to case reports, pathologic series, and surgical series with limited detail, which may underestimate the incidence and overestimate the severity of VCCs in HLH. A study was conducted to determine the incidence VCCs in HLH, their effect on survival, and their echocardiographic and clinical features. The echocardiograms and medical records of 100 consecutive neonatal HLH cases were analyzed. All had an aortic and a mitral valve diameter and a left ventricular (LV) volume less than Z-3. For palliation, Norwood, Sano, or hybrid procedures were used, and if the patient was alive, subsequent bidirectional Glenn and extracardiac Fontan procedures were applied. Cases were classified as manifesting mitral and aortic atresia (MAAA), mitral and aortic stenosis (MSAS), or mitral stenosis and aortic atresia (MSAA). All other diagnoses or any case with additional cardiac anomalies were excluded from the study. Overall, VCCs were found in 15% of the cases. They occurred in 56% of the MSAA subtype cases and were not statistically associated with a high mortality rate. However, in one case, large and multiple VCCs definitely caused or contributed to early death. All VCCs had a transmyocardial course, a turbulent color-Doppler flow, and a dominant usually retrograde systolic coronary artery flow pattern. The VCCs were associated (p < 0.05) with MSAA, endocardial fibroelastosis, and ascending aortic size less than 2 mm. As shown by the findings, 15% of the HLH patients had MSAA with VCCs. Unless the VCCs were large or extensive, they did not contribute to mortality. Detailed echocardiographic analysis of VCCs in HLH was feasible. Recent reports emphasize more severe cases.

Risk factors for deaths occurring within 30 days and 1 year after hospital discharge for cardiac surgery among pediatric patients

BACKGROUND

Little is known regarding the risk factors for early and late death after hospital discharge among pediatric patients undergoing cardiac surgery.

METHODS

Statewide hospital discharge data from California in 1989 to 1999 were used to study outcomes of children <18 years old who had a procedure code (by International Classification of Diseases, Ninth Revision, Clinical Modification) indicating cardiac surgery. The outcome variable was death occurring after hospital discharge. Postdischarge deaths were identified by linking hospital discharge data to statewide death registry data. Cardiac surgical procedures were grouped into 23 categories to adjust for risk involved with the procedures. We used logistic regression to evaluate risk factors for postdischarge mortality, including variables age, sex, race and ethnicity, type of insurance, home income, date and month of surgery, type of admission, hospitals case volume, and the various types of procedures.

RESULTS

There were 25,402 cardiac surgery cases with 1505 inhospital deaths. Of 23,897 hospital discharges, 148 deaths (0.62%) occurred within 365 days after discharge, including 37 deaths within 30 days; 44 deaths at 31 to 90 days; and 67 deaths at 91 to 365 days. Logistic regression showed young age was an important risk factor for postdischarge death with an odds ratio of 4.8 for neonates and 3.5 for infants, compared with children >1 year old. Another significant risk factor was the type of procedure. For death <30 days after discharge, Norwood operation (odds ratio 8.4 compared with closure of ventricular septal defect) was a risk factor. For death that occurred between 31 and 365 days, significant risk factors were truncus arteriosus repair, total anomalous pulmonary vein repair, aortopulmonary shunt, and open valvotomy. Sex, race/ethnicity, home income, and hospital case volume were not significant predictors of postdischarge deaths.

CONCLUSIONS

Many demographic and socioeconomic variables affecting inhospital death were not significant predictors for postdischarge death. Important risk factors for postdischarge death were young age and the type of surgery performed.