Introduction: There are no guidelines regarding the use of bovine pericardial or porcine valves for aortic valve replacement, and prior studies have yielded conflicting results. The current study sought to compare short- and long-term outcomes in propensity-matched cohorts of patients undergoing isolated AVR with bovine versus porcine valves. Methods: This was a retrospective study utilizing an institutional database of all isolated bioprosthetic surgical aortic valve replacements performed at our center from 2010 to 2020. Patients were stratified according to type of bioprosthetic valve (bovine pericardial or porcine), and 1:1 propensity-score matching was applied. Kaplan-Meier survival estimation and multivariable Cox regression for mortality were performed. Cumulative incidence functions were generated for all-cause readmissions and aortic valve reinterventions. Results: A total of 1,502 patients were identified, 1,090 (72.6%) of whom received a bovine prosthesis and 412 (27.4%) of whom received a porcine prosthesis. Propensity-score matching resulted in 412 risk-adjusted pairs. There were no significant differences in clinical or echocardiographic postoperative outcomes in the matched cohorts. Kaplan-Meier survival estimates were comparable, and, on multivariable Cox regression, valve type was not significantly associated with long-term mortality (HR 1.02, 95% CI: 0.74, 1.40, p=0.924). Additionally, there were no significant differences in competing-risk cumulative incidence estimates for all-cause readmissions (p=0.68) or aortic valve reinterventions (p=0.25) in the matched cohorts. Conclusion: The use of either bovine or porcine bioprosthetic aortic valves yields comparable postoperative outcomes, long-term survival, freedom from reintervention, and freedom from readmission.

Background: While prior data have suggested worse outcomes in women after acute type A aortic dissection (ATAAD) repair when compared to men, results have been inconsistent across studies over time. This study sought to evaluate the impact of sex on short- and long-term outcomes after ATAAD repair. Methods: This was a retrospective study utilizing an institutional database of ATAAD repairs from 2007 to 2021. Patients were stratified according to sex. Kaplan-Meier survival estimation and multivariable Cox regression were performed. Supplementary analysis using propensity score matching was also performed. Results: Of the 601 patients who underwent ATAAD repair, 361 were males (60.1%) and 240 (39.9%) were females. Females were significantly older, more likely to have hypertension, and more likely to have chronic lung disease. Females were also significantly more likely than males to undergo hemiarch replacement, while males were significantly more likely than females to undergo total arch replacement and frozen elephant trunk. Operative mortality was 9.4% among males and 13.8% among females, though this was not a statistically significant difference (p=0.098). Postoperative complications were comparable between groups. Kaplan-Meier survival estimates were similar for men and women, and, on multivariable Cox regression, sex was not significantly associated with long-term survival (HR 1.00, 95% CI: 0.73, 1.37, p=0.986). Outcomes remained comparable after supplementary propensity score matched analysis. Conclusion: ATAAD repair can be performed with comparable short-term and long-term outcomes in both men and women.

Objective The Model for End- Stage Liver Disease (MELD) score is a composite number of physiologic parameters and likely has non-linear effects on operative outcomes. . We use machine learning to evaluate the relationship between MELD score and outcomes of cardiac surgery. Methods All STS indexed elective cardiac surgical procedures at our institution between 2011 and 2018 were included. MELD score was retrospectively calculated. Logistic regression models and an imbalanced random forest classifier was created on operative mortality using 30 preoperative characteristics. Cox regression models and random forest survival models were created for long-term survival. Variable importance analysis (VIMP) was conducted to rank variables by predictive power. Linear and machine learned models were compared with their receiver operating characteristic (ROC) and Brier score respectively. Results The patient population included 3,872 individuals. Operative mortality was 1.7% and 5-year survival was 82.1%. MELD score was the 4th largest positive predictor on VIMP analysis for both operative long-term survival and the strongest negative predictor for operative mortality. The logistic model ROC area was 0.762, compared to the random forest classifier ROC of 0.674. The Brier score of the random forest survival model was larger (worse) than the cox regression starting at 2 years and continuing throughout the study period. Conclusions MELD score and other continuous variables had high degrees of non-linearity to mortality. This is demonstrated by the fact that MELD score was not significant in the cox multivariable regression but was strongly important in the random forest survival model.

Background: The introduction of integrated thoracic surgery residency programs has led to increased recruitment efforts of medical students to pursue a career in cardiac surgery. With little representation of cardiac surgery in medical school curriculum, we assessed a cardiac surgery mini-elective’s efficacy in improving perceived knowledge among medical students. Methods: Preclinical medical students were offered the opportunity to participate in a cardiac surgery mini-elective, which consisted of five 2-hour sessions. These sessions consisted of didactic and simulation components and covered topics including cardiopulmonary bypass (CPB) and extracorporeal membrane oxygenation (ECMO), aortic disease, aortic valve replacement (AVR), transplant and left ventricular assist devices (LVAD), and coronary artery bypass grafting (CABG). Students completed pre- and post-session survey’s describing their perceived knowledge in these topics. Results: Overall, 22 students completed at least one session of the mini-elective. Fourteen (73.7%) of the students were male. Fifteen (68.2%) students completed at least three out of five sessions. The post-session survey responses showed significantly higher perceived knowledge compared to pre-session responses for all survey prompts of all five sessions. The CPB/ECMO and aortic disease sessions showed the greatest increase in post-session familiarity and perceived knowledge after the session (p<0.001) compared to the CABG, AVR, and transplant/LVAD sessions (p<0.05). Conclusions: Beyond developing interest in cardiac surgery, these data indicate that a well-planned didactic and surgical simulation program may build confidence in students’ knowledge of various cardiac surgical topics. Further studies will need to address how this increase in perceived ability lasts over time and impacts career selection.

BACKGROUND Prior studies have suggested that LVAD implantation technique and positioning may be associated with subsequent thromboembolic complications. This study evaluated the impact of inflow cannula positioning of the HeartWare LVAD (HVAD) on clinical outcomes. METHODS Adults undergoing primary HVAD implantation between 2009-2018 at a single center were reviewed. HVAD position parameters were calculated from plain chest radiographs and included cannula angle, pump depth, and pump area. These were measured at the day of HVAD implant, at 1 month post-HVAD, and at 6 months post-HVAD. Changes in these parameters over time were measured. Multivariable analysis was also conducted to evaluate associations between pump position parameters on the day of implant and one-year composite outcome of thromboembolic complication (embolic stroke or pump thrombosis) and death. RESULTS 159 HVAD recipients were included with a median follow up of 2.6 years (IQR 1.3 - 4.8 years). Pump area decreased from immediate post-HVAD implantation to one-month follow up (-0.7 cm2; p=0.002), but no significant changes were noted with other position parameters. Increasing preoperative serum creatinine level (HR 1.46, 95% CI 1.03 - 2.08, p=0.034) was associated with increased hazards for the composite outcome in multivariable analysis. Cannula angle, pump depth, nor pump area were associated with the one-year composite outcome, readmission, or other one-year complications including thromboembolic events or mortality when separately modeled. CONCLUSION This review of HVAD recipients demonstrates device position as assessed by chest X-ray does not have significant predictive associations with one-year outcomes.