Factors associated with morbidity, mortality, and hemodynamic failure after biventricular conversion in borderline hypoplastic left hearts.

OBJECTIVE: A subset of patients with borderline hypoplastic left heart may be candidates for single to biventricular conversion, but long-term morbidity and mortality persist. Prior studies have shown conflicting results regarding the association of preoperative diastolic dysfunction and outcome, and patient selection remains challenging. METHODS: Patients with borderline hypoplastic left heart undergoing biventricular conversion from 2005 to 2017 were included. Cox regression identified preoperative factors associated with a composite outcome of time to mortality, heart transplant, takedown to single ventricle circulation, or hemodynamic failure (defined as left ventricular end-diastolic pressure >20 mm Hg, mean pulmonary artery pressure >35 mm Hg, or pulmonary vascular resistance >6 international Woods units). RESULTS: Among 43 patients, 20 (46%) met the outcome, with a median time to outcome of 5.2 years. On univariate analysis, endocardial fibroelastosis, lower left ventricular end-diastolic volume/body surface area (when <50 mL/m2), lower left ventricular stroke volume/body surface area (when <32 mL/m2), and lower left:right ventricular stroke volume ratio (when <0.7) were associated with outcome; higher preoperative left ventricular end-diastolic pressure was not. Multivariable analysis demonstrated that endocardial fibroelastosis (hazard ratio, 5.1, 95% confidence interval, 1.5-22.7, P = .033) and left ventricular stroke volume/body surface area 28 mL/m2 or less (hazard ratio, 4.3, 95% confidence interval, 1.5-12.3, P = .006) were independently associated with a higher hazard of the outcome. Approximately all patients (86%) with endocardial fibroelastosis and left ventricular stroke volume/body surface area 28 mL/m2 or less met the outcome compared with 10% of those without endocardial fibroelastosis and with higher stroke volume/body surface area. CONCLUSIONS: History of endocardial fibroelastosis and smaller left ventricular stroke volume/body surface area are independent factors associated with adverse outcomes among patients with borderline hypoplastic left heart undergoing biventricular conversion. Normal preoperative left ventricular end-diastolic pressure is insufficient to reassure against diastolic dysfunction after biventricular conversion.

Quality Improvement in a Pediatric Echocardiography Laboratory: A Collaborative Process.

Transthoracic echocardiography (TTE) is an essential tool for diagnosis and management of congenital heart disease. Pediatric echocardiography presents unique challenges including complex anatomy, variable patient cooperation and provider expertise. Diagnostic errors inevitably occur. We designed a collaborative and stepwise quality improvement (QI) process to address diagnostic errors within our laboratory. We retrospectively reviewed medical records to identify diagnostic TTE errors in 100 consecutive cardiac surgery patients ≤ 5 years old (July 2020-January 2021). We identified 18 diagnostic errors. Most errors had minor impact (14/18), and 13 were preventable or possibly preventable. We presented these results to our sonographers and faculty and requested input on preventing and managing diagnostic errors. Our root cause analysis based on their responses yielded 7 areas for improvement (imaging, reporting, systems, time, environment, people, QI processes). Our faculty and sonographers chose QI processes and imaging as initial areas for intervention. We defined our SMART goal as a 10% reduction in diagnostic errors. We implemented interventions focused on QI processes. On initial follow up in May 2022, we identified 7 errors in 70 patients (44% reduction in error rate). Utilizing a stepwise and team-based approach, we successfully developed QI initiatives in our echocardiography laboratory. This approach can serve as a model for a collaborative QI process in other institutions.