Abstract 17596: Readmissions After Adult Congenital Heart Surgery: Frequency and Risk Factors

Abstract

Introduction: Readmissions after adult cardiac surgery is an important clinical outcome. Despite case complexity, 30-day readmission after adult congenital heart surgery (CHS) has been under studied. Hypothesis: Readmissions after adult CHS are common. There exist identifiable risk factors for unplanned readmission. Methods: We obtained State Inpatient Databases for Washington, New York, Florida, and California 2009-2011 and selected admissions 18 - 49 years with ICD-9 CM codes indicating adult CHS. We defined readmission as any non-elective hospitalization for a given patient < 30 days of discharge from the index CHS admission. We examined patient demographic and clinical variables and defined complications using the Society of Thoracic Surgeons Congenital Heart complication short list. Case complexity was grouped using the Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1) categories. High resource use (HRU) admissions were defined as those > 90 th percentile for total hospital charges. Multivariate analyses using generalized estimating equations were performed to identify adjusted risk factors for readmission. Results: Of 9860 admissions, there were 1675 readmissions (17%). Median length of stay for readmissions was 4 days and mortality rate 2.1%. Most common indications for readmission were cardiac (pericardial disease, atrial fibrillation, heart failure) and infectious (endocarditis, post-operative infection). On multivariable analysis, black race (adjusted odds ratio [AOR] 1.2 p<0.04), renal insufficiency (AOR 1.8 p<0.001), drug abuse (AOR 1.4 p=0.001), obesity (AOR 1.2 p=0.03), government-sponsored insurance (AOR 1.3 p<0.001), median income <$40,000 (AOR 1.3 p=0.001), index admissions with complication (AOR 1.1 p=0.04), RACHS-1 3 complexity (AOR 1.3 p=0.04), HRU (AOR 1.4 p=0.003), and emergent (AOR 1.5 p<0.001) were risk factors for readmission. Conclusions: One out of 6 adult CHS hospitalizations result in unplanned readmission. Lower socioeconomic status, black race, renal failure, obesity, drug abuse, HRU, emergent index admission, and complications are risk factors for subsequent unplanned 30-day readmission. These risk factors may serve as potential quality improvement targets to reduce readmissions.