Post-Infarction Ventricular Septal Defect: An STS Adult Cardiac Surgery Database Analysis of Outcomes Over Time

B. David. Seadler¹, T. Chen¹, J. Zelten¹, S. Carlson², J. Liu¹, A. Szabo¹, L. Joyce¹, D. Joyce³, P. Pearson^1
1Medical College of Wisconsin, Milwaukee, Wisconsin ²University of Iowa Health Care, Iowa City, Iowa ³Eastern Idaho Regional Medical Center, Idaho Falls, Idaho

Purpose: Post-infarction ventricular septal defect (PIVSD) is associated with a high rate of morbidity and mortality.1 Management strategies continue to be debated, particularly regarding timing of intervention and use of extracorporeal life support (ECLS).2,3 We hypothesized that increasing rates of preoperative ECLS would lead to reduced mortality from surgical repair.

Methods: The STS database was queried to identify patients who underwent operative repair of a PIVSD from 2014 to 2022. Demographic and clinical characteristics were summarized as counts with percentages for categorical variables, and median with range for continuous outcomes. Between-group comparisons by timing of myocardial infarction (MI) and surgery, and use of preoperative ECLS were performed using chi-squared test and Wilcoxon’s rank-sum test based on variable type. Change in the timing of ECLS by year of surgery was assessed by the Cochran-Armitage trend test. Chi-square test was used to evaluate the effect of the timing of ECLS on outcomes, including operative mortality, in-hospital mortality, and complications. Multivariable logistic regression was used to evaluate the predictors of ECLS timing based on year of surgery, demographic characteristics, and risk factors. No variable selection was performed. All analyses were performed using SAS 9.4 (SAS Institute, Cary, NC).

Results: The cohort consisted of 2,024 patients over a 9-year period, of which 744 required ECLS at any time point. Analysis of trends over time demonstrated that from 2014 to 2022, the number of patients that receive surgery more than 24 hours after MI has increased (72% to 88%, p< 0.001), as has the use of preoperative ECLS (6% to 68%, p< 0.001) while operative mortality continues to decrease (47% to 34%, p=0.003) (Table & Figure 1). When comparing outcomes, patients who underwent surgery more than 24 hours after MI were found to have a longer preoperative and postoperative length of stay, but a decreased in-hospital and 30-day mortality (p < 0.001). Patients who received preoperative ECLS, compared to all other patients, were more likely to undergo delayed sternal closure (22% vs 11%, p< 0.001), reoperation (29% vs 15%, p< 0.001), and postoperative renal failure (36% vs 25%, p< 0.001). In contrast, when preoperative ECLS is compared to only intra/postoperative ECLS, preoperative ECLS patients were less likely to undergo delayed sternal closure (22 vs 33%, p=0.004), reoperation (29% vs 50%, p< 0.001), bleeding requiring reoperation (21% vs 29%, p=0.028), postoperative renal failure (36% vs 50%, p=0.002), and required fewer transfusions of red blood cells and fresh frozen plasma (p < 0.001).

Conclusion: Mortality following surgical repair of PIVSD continues to decrease over time, while the use of preoperative ECLS increases. Preoperative ECLS, when compared to intra/postoperative implementation, is associated with improved postoperative outcomes. Future investigation will focus on which patients benefit most from immediate repair versus delayed repair with preoperative ECLS.

Identify the source of the funding for this research project: Internal/institutional funds.