The Long-Term Impact of Diastolic Dysfunction After Routine Cardiac Surgery.

OBJECTIVE: To determine the impact of diastolic dysfunction (DD) on survival after routine cardiac surgery. DESIGN: This was an observational study of consecutive cardiac surgeries from 2010 to 2021. SETTING: At a single institution. PARTICIPANTS: Patients undergoing isolated coronary, isolated valvular, and concomitant coronary and valvular surgery were included. Patients with a transthoracic echocardiogram (TTE) longer than 6 months prior to their index surgery were excluded from the analysis. INTERVENTIONS: Patients were categorized via preoperative TTE as having no DD, grade I DD, grade II DD, or grade III DD. MEASUREMENTS AND MAIN RESULTS: A total of 8,682 patients undergoing a coronary and/or valvular surgery were identified, of whom 4,375 (50.4%) had no DD, 3,034 (34.9%) had grade I DD, 1,066 (12.3%) had grade II DD, and 207 (2.4%) had grade III DD. The median (IQR) time of the TTE prior to the index surgery was 6 (2-29) days. Operative mortality was 5.8% in the grade III DD group v 2.4% for grade II DD, 1.9% for grade I DD, and 2.1% for no DD (p = 0.001). Atrial fibrillation, prolonged mechanical ventilation (>24 hours), acute kidney injury, any packed red blood cell transfusion, reexploration for bleeding, and length of stay were higher in the grade III DD group compared to the rest of the cohort. The median follow-up was 4.0 (IQR: 1.7-6.5) years. Kaplan-Meier survival estimates were lower in the grade III DD group than in the rest of the cohort. CONCLUSIONS: These findings suggested that DD may be associated with poor short-term and long-term outcomes.

A Novel Risk Score to Predict Thirty-Day Readmissions after Acute Type A Aortic Dissections.

BACKGROUND: Readmissions following acute type A aortic dissections (ATAAD) are associated with potentially worse clinical outcomes and increased hospital costs. Predicting which patients are at risk for readmission may guide patient management prior to discharge. METHODS: The National Readmissions Database was utilized to identify patients treated for ATAAD between 2010 and 2018. Univariate mixed effects logistic regression was used to assess each variable. Variables were assigned risk points based off the bootstrapped (bias-corrected) odds ratio of the final variable model according to the Johnson's scoring system. A mixed effect logistic regression was run on the risk score (sum of risk points) and 30-day readmission. Calibration plots and predicted readmission curves were generated for model assessment. RESULTS: A total of 30,727 type A aortic dissections were identified. The majority of ATAAD (66%) were in men with a median age of 61 years and 30-day readmission rate of 19.4%. The risk scores ranging from -1 to 14 mapped to readmission probabilities between 3.5% and 29% for ATAAD. The predictive model showed good calibration and receiver operator characteristics with an area under the curve (AUC) of 0.81. Being a resident of the hospital state (OR: 2.01 [1.64, 2.47], p < 0.001) was the highest contributor to readmissions followed by chronic kidney disease (1.35 [1.16, 1.56], p = 0), discharge to a short-term facility (1.31 [1.09, 1.57], p = 0.003), and developing a myocardial infarction (1.20 [1.00, 1.45], p = 0.048). CONCLUSIONS: The readmission model had good predictive capability given by the large AUC. Being a resident in the State of the index admission was the most significant contributor to readmission.

Midterm Outcomes of Isolated Coronary Artery Bypass Grafting in the Setting of Moderate Ischemic Mitral Regurgitation.

INTRODUCTION: Although randomized trial data exist for 2-y outcomes comparing isolated coronary artery bypass grafting (CABG) versus CABG with concomitant mitral valve repair (CABG + MVr) for the treatment of moderate ischemic mitral regurgitation (IMR), longer term outcomes are unclear. This study evaluated the longitudinal outcomes of isolated CABG for moderate IMR. METHODS: Patients with moderate IMR undergoing isolated CABG from January 2010 to February 2018 at a single institution were included. Outcomes included longitudinal freedom from heart failure readmission, survival, rates of persistent mitral regurgitation (MR), and freedom from mitral valve reinterventions. A subanalysis was conducted comparing CABG versus CABG + MVr. Multivariable Cox regression was used for risk adjustment. RESULTS: A total of 528 patients with moderate IMR underwent isolated CABG. Postoperatively, 26% of patients had at least moderate MR at 1-mo follow-up, although at 5 y progression to severe MR was rare (2.2%) as were mitral valve reinterventions (0.2%). Survival at 30 d (95.8%), 1 y (89.6%), and 5 y (76.6%) was acceptable. Furthermore, the freedom from readmission for heart failure was also acceptable at 30 d (92.6%), 1 y (79.9%), and 5 y (65.0%) postoperatively. In a subanalysis comparing CABG versus CABG + MVr, unadjusted and risk-adjusted survival, freedom from heart failure readmissions, mitral valve reinterventions, and degrees of MR were comparable between the groups at all intervals (all P > 0.05). CONCLUSIONS: The majority of patients with moderate IMR can undergo isolated CABG with acceptable rates of heart failure readmissions, survival, progression to severe MR, and the need for subsequent mitral interventions. These data support the use of isolated CABG in patients with moderate IMR.

Fate of the Kidneys in Patients with Post-Operative Renal Failure After Cardiac Surgery.

BACKGROUND: This study evaluates the clinical and renal-related outcomes in patients with acute renal failure (ARF) following cardiac surgery. METHODS: Index adult cardiac operations at a single institution from 2010-2018 were reviewed. Patients requiring dialysis pre-operatively were excluded. ARF was stratified as either creatinine rise (≥3-times baseline or ≥4.0 mg/dL) or post-operative dialysis. Outcomes included mortality, rates of progression to dialysis, and renal recovery. Multivariable Cox regression was used for risk-adjustment. RESULTS: A total of 10,037 patients, including 6,275 (62.5%) isolated coronary artery bypass grafting (CABG), 2,243 (22.3%) isolated valve, and 1,519 (15.1%) CABG plus valve cases, were included. Post-operative ARF occurred in 346 (3.5%) patients, with 230 (66.5%) requiring dialysis. Survival was significantly reduced in patients with ARF at 30-days (97.9 versus 70.8%, P <0.001), 1-year (94.9 versus 48.0%, P <0.001), and 5-years (86.2 versus 38.2%, P <0.001) with more profound reductions in those requiring dialysis, findings which persisted after risk-adjustment. Progression to subsequent dialysis in the creatinine rise group was rare (n = 1). The median time to dialysis initiation in the dialysis group was 5 days (IQR 2-12 days) with a median time of dialysis dependence of 72 days (IQR 38-1229 days). Of those patients requiring postoperative dialysis, 30.9% demonstrated renal recovery. CONCLUSIONS: Post-operative ARF and in particular the need for dialysis are associated with substantial reductions in survival that persist during longitudinal follow-up. This occurs despite the finding that patients experiencing creatinine rise only rarely progress to dialysis, and that nearly one-third of patients requiring post-operative dialysis recover renal function.

A machine learning approach to model for end-stage liver disease score in cardiac surgery.

OBJECTIVE: Model for end-stage liver disease (MELD) likely has nonlinear effects on operative outcomes. We use machine learning to evaluate the nonlinear (dependent variable may not correlate one to one with an increased risk in the outcome) relationship between MELD and outcomes of cardiac surgery. METHODS: Society of Thoracic Surgery indexed elective cardiac operations between 2011 and 2018 were included. MELD was retrospectively calculated. Logistic regression models and an imbalanced random forest classifier were created on operative mortality. Cox regression models and random forest survival models evaluated survival. Variable importance analysis (VIMP) ranked variables by predictive power. Linear and machine-learned models were compared with receiver operator characteristic (ROC) and Brier score. RESULTS: We included 3872 patients. Operative mortality was 1.7% and 5-year survival was 82.1%. MELD was the fourth largest positive predictor on VIMP analysis for operative long-term survival and the strongest negative predictor for operative mortality. MELD was not a significant predictor for operative mortality or long-term survival in the logistic or Cox regressions. 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 than the Cox regression starting at 2 years and continuing throughout the study period. Bootstrap estimation on linear regression demonstrated machine-learned models were superior. CONCLUSIONS: MELD and mortality are nonlinear. MELD was insignificant in the Cox multivariable regression but was strongly important in the random forest survival model and when using bootstrapping, the superior utility was demonstrated of the machine-learned models.

Impact of ethnicity and race on outcomes after thoracic endovascular aortic repair.

INTRODUCTION: Thoracic endovascular aortic repair (TEVAR) became the standard of care for treating Type B aortic dissections and descending thoracic aortic aneurysms. We aimed to describe the racial/ethnic differences in TEVAR utilization and outcomes. METHODS: The National Inpatient Sample was reviewed for all TEVARs performed between 2010 and 2017 for Type B aortic dissection and descending thoracic aortic aneurysm (DTAA). We compared groups stratifying by their racial/ethnicity background in White, Black, Hispanic, and others. Mixed-effects logistic regression was performed to assess the relationship between race/ethnicity and the primary outcome, in-hospital mortality. RESULTS: A total of 25,260 admissions for TEVAR during 2010-2017 were identified. Of those, 52.74% (n = 13,322) were performed for aneurysm and 47.2% (n = 11,938) were performed for Type B dissection. 68.1% were White, 19.6% were Black, 5.7% Hispanic, and 6.5% were classified as others. White patients were the oldest (median age 71 years; p < .001), with TEVAR being performed electively more often for aortic aneurysm (58.8% vs. 34% vs. 48.3% vs. 48.2%; p < .001). In contrast, TEVAR was more likely urgent or emergent for Type B dissection in Black patients (65.6% vs. 41.1% vs. 51.6% vs. 51.7%; p < .001). Finally, the Black population showed a relative increase in the incidence rate of TEVAR over time. The adjusted multivariable model showed that race/ethnicity was not associated with in-hospital mortality. CONCLUSION: Although there is a differential distribution of thoracic indication and comorbidities between race/ethnicity in TEVAR, racial disparities do not appear to be associated with in-hospital mortality after adjusting for covariates.

Long-term outcomes of patients undergoing mechanical versus bioprosthetic aortic root replacement.

BACKGROUND: We evaluated the impact of valve type (mechanical vs. bioprosthetic) on survival after aortic root replacement (ARR). METHODS: In a propensity-matched analysis, we evaluated consecutive operations from 2010 to 2018. Patients were identified using a prospectively maintained institutional database. Patients with infective endocarditis were excluded. Kaplan-Meier survival estimation and multivariable Cox regression analysis were performed. Cox regression adjusted for age, sex, baseline comorbidities, and operative variables. Propensity score matching yielded 153 pairs of patients. RESULTS: A total of 893 patients were identified. We excluded 192 patients with endocarditis and evaluated 701 patients. Of these patients, 455 (64.9%) received a bioprosthetic valve, 246 (35.1%) received a mechanical valve. Median follow-up was 4.06 years. The proportion of aortic dissections and circulatory arrest as well as cardiopulmonary bypass and ischemic times were similar across groups (p = .207, p = .086, p = .668, p = .454, respectively). Operative mortality was significantly higher in the bioprosthetic valve group (7.9% vs. 2.4%, p = .004). Total length of hospital stay was longer (11.4 ± 11.0 vs. 9.5 ± 10.1, p < .001) and there was a higher proportion of prolonged postoperative ventilation >24 h (21.3% vs. 13.0%, p = .007) in the bioprosthetic group. Postoperative outcomes were similar, regarding stroke (p = .077), re-exploration for bleeding (p = .211), new dialysis requirement (p = .077), long-term bleeding complications (p = .561), and reoperations (p = .755). Mechanical valve replacement was associated with improved long-term survival (adjusted HR 0.42, 95% CI: 0.23-0.77, p = .005). CONCLUSIONS: These findings suggest that mechanical valves for ARRs may confer a survival benefit over bioprosthetic valves. Surgeon bias was likely to account for this survival advantage.

The impact of prior cardiac surgery on patients undergoing surgical repair for acute type A aortic dissection.

OBJECTIVE: To determine the impact of reoperative versus first-time sternotomy for emergent open repair of acute Type A aortic dissection (ATAAD). METHODS: This was an observational study of consecutive aortic surgeries from 2007 to 2021. Kaplan-Meier survival estimation and multivariable Cox regression analysis were performed to assess the impact of reoperative versus first-time sternotomy upon survival after ATAAD repair. RESULTS: A total of 601 patients with ATAAD were identified, of which 72 (12%) underwent reoperative sternotomy. The reoperative group had a higher prevalence of baseline comorbidities, including hypertension, diabetes, peripheral vascular disease, atrial fibrillation, and coronary artery disease. Central cannulation of the aorta was achieved at a similar rate across each group (81.9% vs. 81.5%, p = .923), and cardiopulmonary bypass (CPB) time was similar across each group (204 ± 84.8 vs. 203 ± 72.4 min, p = .923). Postoperative outcomes were similar across both groups, including in-hospital mortality, stroke, pulmonary complications, renal failure, and reexploration for excessive bleeding. Five-year survival was 74.5% (70.5, 78.3) for the first-time group and was 71.6% (60.0, 81.9) for the reoperative group. After multivariable Cox regression, reoperative sternotomy was not significantly associated with an increased hazard of death compared to first-time sternotomy (hazards ratio: 0.90, 95% confidence interval: 0.56, 1.43, p = .642). CONCLUSIONS: These findings suggest that re-sternotomy can be safely performed with similar outcomes as first-time sternotomy. Central initiation of CPB after sternal reentry limits CPB time and may therefore represent a protective strategy that enhances outcomes for patients presenting with ATAAD and prior cardiac surgery.

Outcomes of bovine versus porcine surgical aortic valve replacement.

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 aortic valve replacement (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 1502 patients were identified, 1090 (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 (hazard ratio: 1.02, 95% confidence interval: 0.74, 1.40, p = .924). Additionally, there were no significant differences in competing-risk cumulative incidence estimates for all-cause readmissions (p = .68) or aortic valve reinterventions (p = .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.

Sex-based outcomes after surgery for acute type A aortic dissection.

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 = .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 (hazard ratio: 1.00, 95% confidence interval: 0.73, 1.37, p = .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.

Outcomes of transcatheter aortic valve replacement at teaching versus nonteaching hospitals.

INTRODUCTION: Prior studies have demonstrated that outcomes of invasive cardiac interventions may vary by hospital teaching status and volume. As transcatheter aortic valve replacement (TAVR) rapidly expands from teaching to nonteaching hospitals across the country, the clinical impact of hospital teaching status has not been clearly established. This study aimed to compare TAVR outcomes between nonteaching and teaching hospitals. METHODS: An observational study was conducted using the Nationwide Readmission Database (NRD). Patients undergoing TAVR from 2011 to 2018 were included. Data was analyzed using multivariable logistic regression to determine outcomes of 30-day mortality and readmission between nonteaching and teaching hospitals. RESULTS: A total of 235,321 patients underwent TAVR during the study period. Patients undergoing TAVR at teaching hospitals presented with a higher frequency of baseline comorbidities compared to nonteaching hospitals. Postprocedure complications such as myocardial infarction, arrhythmia, pneumonia, acute kidney injury, sepsis, stroke, and hemorrhage occurred more often at teaching centers (p < 0.001); translating to a higher rate of in-hospital mortality (2.27% vs. 1.99%, p = 0.006) and hospital cost ($48,300 vs. $44,900, p < 0.001) in teaching versus nonteaching hospitals. After adjusting for baseline characteristics and postoperative morbidity, in-hospital mortality (p = 0.095) and readmission rate (p = 0.420) on multivariable analysis were not statistically different between centers. CONCLUSION: With the evolution and expansion of TAVR to nonteaching centers, mortality, and readmission rates are not significantly different between nonteaching and teaching hospitals. Higher unadjusted in-hospital mortality at teaching centers suggest these centers more often treat high risk patients with associated increased complications.

National trends in thoracic aortic aneurysms and dissections in patients with Marfans and Ehlers Danlos syndrome.

INTRODUCTION: Connective tissue disorders predispose patients to earlier aortic dissections and aneurysms. However, there is limited large cohort data given its low incidence. METHODS: The National Inpatient Sample was searched for all adults with Marfans (MFS) and Ehlers Danlos (EDS) disease between 2010 and 2017. ICD codes were used to select those with a type A aortic dissection or aneurysm. RESULTS: There was a total of 19,567 cases, giving the estimated incidence of MFS and EDS of 18 and 22.4 per 100k people, respectively. After inclusion criteria, there were 2553 MF and 180 EDS patients. There was no statistical difference in mortality between the MFS and EDS cohorts (4.6% vs. 2.8%, p = .26). EDS patients were more likely to undergo a TEVAR procedure (2.8% vs. 1.0%, p = .03). MF patients were more likely to have a complication of acute kidney injury (p = .02). EDS patients were more likely older (50 vs. 42, p < .001) and female (47% vs. 33%, p < .001). MFS patients were more likely to have a type A aortic dissection (44% vs. 31%, p < .001). The majority (89%) of patients were treated at urban teaching hospitals. On univariable logistic regression, aortic dissection was a predictor for mortality (odds ratio 7.31, p < .001). The type of connective tissue disease was not a significant predictor. CONCLUSIONS: National level estimates show low mortality for patients with MF or ED presenting to the hospital with aortic dissection or aneurysm. The differences in age and gender can guide surveillance for these patient populations, leading to more elective admissions and reduced hospital mortality.

The long-term impact of acute renal failure after aortic arch replacement for acute type A aortic dissection.

OBJECTIVE: To determine the long-term impact of developing acute renal failure (ARF) on survival after open aortic arch reconstruction for acute type A aortic dissection (ATAAD). METHODS: This was an observational study of consecutive aortic surgeries from 2007 to 2021. Patients with ATAAD were identified via a prospectively maintained institutional database and were stratified by the presence or absence of postoperative ARF (by RIFLE criteria). Kaplan-Meier survival estimation and multivariable Cox regression analysis were performed. RESULTS: A total of 601 patients undergoing open surgery for ATAAD were identified, of which 516 (85.9%) did not develop postoperative ARF, while 85 (14.1%) developed ARF, with a median follow-up time of 4.6 years (1.6, 7.9). Baseline characteristics were similar across each group, except for higher rates of branch vessel malperfusion and lower preoperative ejection fraction in the ARF group. Patients with ARF underwent more total arch replacement and elephant trunk procedures, with longer cardiopulmonary bypass and circulatory arrest times than patients without ARF. ARF was associated with worse short-term outcomes, including increased in-hospital mortality, prolonged mechanical ventilation, higher rates of sepsis, more blood transfusions, and longer length of hospital stay. Unadjusted Kaplan-Meier survival estimates were significantly lower in the ARF group, compared to the group without ARF (p < .001, log-rank test). After multivariable adjustment, the development of postoperative ARF was significantly associated with an increased hazard of death over the study's follow-up time-period (hazard ratio: 2.74, 95% confidence interval: 1.95, 3.86, p < .001). CONCLUSIONS: ARF is a highly morbid postoperative event that may adversely impact long-term survival after aortic surgery.

A Cardiac Surgery Mini-Elective Increases Specialty Knowledge Acquisition Among Pre-Clinical Medical Students.

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 surveys 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 with 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 with 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.

Long-term Outcomes of Percutaneous Coronary Intervention in Patients with Prior Coronary Artery Bypass Grafting.

BACKGROUND Patients with a prior coronary artery bypass graft (CABG) may have a need for repeat revascularization, which is typically attempted first via percutaneous coronary intervention (PCI) of either a bypass graft or native vessel. Long-term outcomes of native vessel compared to graft PCI after CABG have not yet been explored in a large institution study. METHODS Patients with history of prior CABG who underwent PCI at our institution during 2010-2018 were included. Baseline characteristics and long-term outcomes of up to 5 years were compared between native vessel and bypass graft PCI groups. Cox regression was used to adjust for significant covariates in estimation of risk and calculation of hazard ratios. RESULTS During the study, 4,251 patients with a prior CABG underwent PCI. Native vessel PCI represented 67.1% (n=2,851) of the cohort. After adjusting for significant covariates, bypass graft PCI compared to native vessel PCI had a higher risk of overall mortality (HR 1.15; 95% CI, 1.04-1.29; p<0.05), all-cause readmission (HR 1.16; 95% CI, 1.1-1.3; p<0.05), readmission for PCI (HR 1.25; 95% CI, 1.13-1.38; p<0.05), readmission for heart failure (HR 1.16; 95% CI, 1.06-1.26; p<0.05), and composite of myocardial infarction and revascularization (HR 1.23; 95% CI, 1.12-1.35; p<0.05). CONCLUSIONS Among patients with prior CABG, bypass graft PCI compared to native vessel PCI was associated with higher risk of adverse long-term outcomes.

Impact of a Surgical Subspecialty Roundtable on Career Perception for Preclerkship Medical Students.

BACKGROUND: Limited exposure to surgical subspecialties during medical school may be responsible for decreasing medical student interest in surgery. Although most medical schools have surgery interest groups to increase exposure, our aim was to evaluate the impact of a focused surgical subspecialty roundtable on preclerkship students' perceptions of surgical careers. METHODS: Faculty members from each surgical subspecialty shared their experiences and led roundtable discussions with five to seven first- and second-year medical students at a time (total n = 59). Pre-event and post-event surveys were administered to assess students' interest in surgery, knowledge of training paths, values related to specialty selection, and perception of surgeons. RESULTS: Forty students completed pre-event and post-event surveys. The number of students who were extremely or very interested in surgery increased after this event (65% versus 72.5%, P < 0.001). The greatest number of students indicated an interest in orthopedic surgery, and the fewest indicated an interest in neurosurgery. After the event, thirteen (32.5%) students changed their preferences for the subspecialty in which they were most interested. Students demonstrated improved knowledge of training length and integrated residencies (83.8% versus 96.3%, P = 0.003). The perceived importance of intellectual challenge, research opportunities, and training length decreased, whereas the importance of compensation, work/life balance, long-term patient follow-up, and the job market increased. Students' perceptions of surgeons' work/life balance (10% versus 25%, P < 0.001) and ability to be team players (82.5% versus 85%, P = 0.01) improved significantly after the roundtable. CONCLUSIONS: The surgical specialty roundtable increased students' interest in surgery, improved knowledge of training paths, and altered perceptions related to career decision-making.

Computational methods for parametric evaluation of the biventricular mechanics of direct cardiac compression.

Despite the increasing incidence of heart failure, advancements in mechanical circulatory support have become minimal. A new type of mechanical circulatory support, direct cardiac compression, is a novel support paradigm that involves a soft deformable cup around the ventricles, compressing it during systole. No group has yet investigated the biomechanical consequences of such an approach. This article uses a multiscale cardiac simulation software to create a patient-specific beating heart dilated cardiomyopathy model. Left and right ventricle (LV and RV) forces are applied parametrically, to a maximum of 2.9 and 0.46 kPa on each ventricle, respectively. Compression increased the ejection fraction in the left and right ventricles from 15.3% and 27.4% to 24.8% and 38.7%, respectively. During applied compression, the LV freewall thickening increased while the RV decreased; this was found to be due to a change in the balance of the preload and afterload in the freewalls. Principal strain renderings demonstrated strain concentrations on the anterior and posterior LV freewall. Strains in these regions were found to exponentially increase after 0.75 normalized LV force was applied. Component analysis of these strains illuminated a shift in the dominating strain from transmural to cross fiber once 0.75 normalized LV force is exceeded. An optimization plot was created by nondimensionalizing the stroke volume and maximum principal strain for each compression profile, selecting five potential compression schemes. This work demonstrates not only the importance of a computational approach to direct cardiac compression but a framework for tailoring compression profiles to patients.

The use of free versus in situ right internal mammary artery in coronary artery bypass grafting.

INTRODUCTION: Coronary artery bypass grafting (CABG) continues to be the most commonly performed cardiac surgical procedure in the world. The use of multiarterial grafting may confer a long-term survival benefit over the use of vein grafts. However, there is a paucity of data comparing the use of in situ versus free right internal mammary artery (RIMA) in isolated CABG. METHODS: Patients that underwent isolated CABG between 2010 and 2018 where RIMA was used in addition to a left internal mammary artery graft. Patients with prior cardiac surgery or percutaneous coronary intervention were excluded. Propensity matching was used for subanalysis. Mortality and major adverse cardiac and cerebrovascular events (MACCE) were analyzed with Kaplan-Meier survival curves and Cox multivariable regression. Heart failure-specific readmissions were assessed with cumulative incidence curves with Fine and Gray competing risk regression. RESULTS: A total of 667 patients underwent isolated CABG. Of those, 422 had free RIMA and 245 had in situ RIMA utilized. Mortality was similar between cohorts (p = 0.199) with 5-year mortality rates of 6.6% (free) and 4.1% (in situ). MACCE was similar between cohorts, with 5-year event rates of 33.6% and 33.9% (p = 0.99). RIMA style was not a significant predictor of any outcome. CONCLUSION: There was no difference in long-term mortality, complications, MACCE, or heart failure readmissions when comparing a contemporary cohort of patients undergoing isolated CABG utilizing RIMA as a conduit. These data may allow surgeons to consider using RIMA either as an in situ or a free conduit.

Cardiac surgery in the afternoon is not associated with increased operative morbidity and mortality.

BACKGROUND: Time of day for surgical procedures has been a topic of considerable controversy, with some suggesting that later operating times are associated with worse outcomes. METHODS: All patients who underwent open cardiac surgery from 2011 to 2018 were included. Patients that had ventricular assist devices, heart transplant, transcatheter aortic valves, aortic dissections, and emergent operations were excluded. Primary outcomes included postoperative mortality and survival; secondary outcomes included postoperative complications and readmission. RESULTS: The initial patient population consisted of 7883 patients who underwent index cardiac surgery. Following propensity matching (3:1), there were 2569 patients in the a.m. cohort (7-11 a.m.) and 860 patients in the p.m. cohort (3-11 p.m.). All baseline characteristics were matched to equivalent proportions. Total intensive care unit time following surgery was longer for the a.m. cohort (46.5 vs. 40.0 h; p<.001). Otherwise, there was no significant difference between cohorts including operative mortality (1.83% vs 2.21%; p= .48). On multivariable analysis, p.m. surgery was not significantly associated with 30 days mortality (hazard ratio [HR]: 0.96 [0.60, 1.53]; p= .86] or mortality over the study follow-up (HR: 0.87 [0.73, 1.03]; p= .10]. For propensity-matched cohorts, Kaplan-Meier survival at 30 days (97.9% vs. 97.4%; p= .44), 1 (93.4% vs 93.9%; p= .51), and 5 years (80.9% vs. 80.2%; p= .84) was not significantly different between cohorts. CONCLUSION: Short- and long-term mortality, hospital readmission, and postoperative complications were not significantly different between patients that underwent cardiac surgery starting in the a.m. versus patients who had cases that started in the afternoon.

Urgent transcatheter aortic valve replacement may be performed with acceptable long-term outcomes.

BACKGROUND: The wide availability of transcatheter aortic valve replacement (TAVR) and broadening of its indications to most patients with aortic stenosis may increase its utilization in the urgent setting. However, a comparison of long-term outcomes of patients undergoing urgent TAVR when compared to elective TAVR have not been well studied. METHODS: All patients that underwent TAVR from 2011 to 2018 were included. Primary outcomes included operative (30-day), 1-, and 5-year survival and readmissions. RESULTS: The total patient population undergoing TAVR was divided into urgent (n = 247) and elective (n = 946) cohorts. Thirty days mortality (6.5% vs. 2.3%; p = .001), acute kidney injury (2.8% vs. 0.6%; p = .003), and length of stay (12 vs. 3 days; p < .001) were higher for the urgent cohort. There was no significant difference between cohorts for 30-day all-cause (14.6% vs. 10.8%; p = .097) readmissions. Freedom from readmission for heart failure at 1-year (73.6% vs. 83.4%; p < .001) was lower for the urgent cohort. One- (79.0% vs. 87.1%; p < .001) and five-year (39.6% vs. 43.5%; p = .005) survival was lower for the urgent cohort. This difference was eliminated after risk adjustment (hazard ratio [HR]: 1.3; p = .158 and HR: 1.1; p = .639, respectively). CONCLUSION: Unadjusted survival was significantly worse for the urgent cohort up to 1 year. This trend continued for 5-year survival, however, after risk adjustment there was no significant difference in survival between cohorts. Although urgent TAVR is associated with increased periprocedural risk due to more comorbid disease, outcomes and long-term survival are encouraging and support the consideration of urgent TAVR as a viable alternative for this patient population.