Machine Learning on 50,000 Manuscripts Shows Increased Clinical Research by Academic Cardiac Surgeons.

INTRODUCTION: Academic cardiac surgeons are productive researchers and innovators. We sought to perform a comprehensive machine learning (ML)-based characterization of cardiac surgery research over the past 40 y to identify trends in research pursuits. METHODS: US-based academic websites were queried for surgeon profiles. Publications since 1980 were obtained from Web of Science, and publication classifications (e.g., "human", "animal") were collected through the National Institutes of Health iCite tool. Publications were deemed "basic or translational" if >50% of their classification was under "animal" or "molecular or cell", and "clinical" if otherwise. ML-based clustering was performed on publication titles and Medical Subject Heading terms to identify research topics. RESULTS: A total of 944 cardiac surgeons accounted for 48,031 unique publications. Average citations per year have decreased since 1980 (P < 0.001). The percentage of basic or translational publications by cardiac surgeons has decreased over time (P < 0.001), comprising of only 8% of publications in 2022. Adult cardiac surgeons, those who received an F32, K08, or R01, and those with a PhD were more likely to publish basic or translational research. Top areas of basic or translational research were myocardial reperfusion, aortic aneurysms or remodeling, and transplant immunology. Major areas of clinical research included aortic disease, aortic valve disease, and mechanical circulatory support. Collaboration analysis revealed that 55% of publications were single-center, and the yearly percentage of these publications has decreased over time (P < 0.001). CONCLUSIONS: Cardiac surgeons are performing less basic or translational research relative to clinical research than ever before. The majority of publications over the past 40 y did not involve cross-center collaboration. Continued support for clinical research is needed, while also encouraging collaborative basic or translational science to foster innovation in patient care.

Trends in the Use of Recombinant Activated Factor VII and Prothrombin Complex Concentrate in Heart Transplant Patients in Virginia.

OBJECTIVES: To explore trends in intraoperative procoagulant factor concentrate use in patients undergoing heart transplantation (HTx) in Virginia. Secondarily, to evaluate their association with postoperative thrombosis. DESIGN: Patients who underwent HTx were identified using a statewide database. Trends in off-label recombinant activated factor VII (rFVIIa) use and on-label and off-label prothrombin complex concentrate (PCC) use were tested using the Mantel-Haenszel test. Multivariate logistic regression was used to test for an association between procoagulant factor concentrate administration and thrombosis. SETTING: Virginia hospitals performing HTx. PARTICIPANTS: Adults undergoing HTx between 2012 and 2022. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among 899 patients who required HTx, 100 (11.1%) received off-label rFVIIa, 69 (7.7%) received on-label PCC, and 80 (8.9%) received off-label PCC. There was a downward trend in the use of rFVIIa over the 10-year period (p = 0.04). There was no trend in on-label PCC use (p = 0.12); however, there was an increase in off-label PCC use (p < 0.001). Patients who received rFVIIa were transfused more and had longer cardiopulmonary bypass time (p < 0.001). Receipt of rFVIIa was associated with increased thrombotic risk (odds ratio [OR] 1.92; 95% CI 1.12-3.29; p = 0.02), whereas on-label and off-label PCC use had no association with thrombosis (OR 0.98, 95% CI 0.49-1.96, p = 0.96 for on-label use; and OR 0.61, 95% CI 0.29-1.30, p = 0.20 for off-label use). CONCLUSIONS: Use of rFVIIa in HTx decreased over the past decade, whereas off-label PCC use increased. Receipt of rFVIIa was associated with thrombosis; however, patients who received rFVIIa were more severely ill, and risk adjustment may have been incomplete.

Outcomes of heparinized adult veno-arterial extracorporeal membrane oxygenation patients managed with low and high activated partial thromboplastin time targets: A systematic review and meta-analysis.

INTRODUCTION: There are no randomized controlled trials comparing low and high activated partial thromboplastin time (aPTT) targets in heparinized adult veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) patients. Our systematic review and meta-analysis summarized complication rates in adult VA ECMO patients treated with low and high aPTT targets. METHODS: Studies published from January 2000 to May 2022 were identified using Pubmed, Embase, Cochrane Library, and LILACS (Latin American and Caribbean Health Sciences Literature). Studies were included if aPTT was primarily used to guide heparin anticoagulation. For the low aPTT group, we included studies where aPTT goal was ≤60 seconds and for the high aPTT group, we included studies where aPTT goal was ≥60 seconds. Proportional meta-analysis with a random effects model was used to calculate pooled complication rates for patients in the two aPTT groups. RESULTS: Twelve studies met inclusion criteria (5 in the low aPTT group and 7 in the high aPTT group). The pooled bleeding complication incidence for low aPTT studies was 53.6% (95% CI = 37.4%-69.4%, I2 = 60.8%) and for high aPTT studies was 43.8% (95% CI = 21.7%-67.1%, I2 = 91.8%). No studies in the low aPTT group reported overall thrombosis incidence, while three studies in the high aPTT group reported overall thrombosis incidence. The pooled thrombosis incidence for high aPTT studies was 16.1% (95% CI = 9.0%-24.5%, I2 = 13.1%). CONCLUSIONS: Adult ECMO patients managed with low and high aPTT goals appeared to have similar bleeding and other complication rates further highlighting the need for a randomized controlled trial.

Preemptive alcohol septal ablation prior to transcatheter mitral valve replacement.

BACKGROUND: Alcohol septal ablation (ASA) has been shown to increase the neo-left ventricular outflow tract (LVOT) area before transcatheter mitral valve replacement (TMVR) but there is little literature on its success and use with dedicated devices. AIMS: To describe our experience with preemptive ASA to increase the predicted neo-LVOT area and its utility with both dedicated TMVR devices and balloon-expandable valves. METHODS: All patients who underwent ASA for TMVR candidacy in our center between May 2018 and October 2022 and had computed tomography (CT) scans done before and after ASA were included. Each CT was assessed for the minimum predicted neo-LVOT area at end-systole, using a virtual valve of the desired TMVR device for each patient. The primary outcome was an increase in the predicted neo-LVOT area after ASA that was deemed sufficient for safe implantation of the desired TMVR device. The secondary outcome was the absence of acute LVOT obstruction after TMVR. RESULTS: A total of 12 patients underwent ASA and all but 1 (n = 11, 91.6%) achieved the primary outcome of having sufficient predicted neo-LVOT area to proceed with TMVR. The mean increase in neo-LVOT area after ASA was 126 ± 64 mm2 (median 119.5, interquartile range: 65.0-163.5 mm2 ). Two patients (16.7%) required a permanent pacemaker after ASA. Nine patients went on and underwent TMVR with their respective devices and none had LVOT obstruction after the procedure. Among the remaining three patients, one had insufficient neo-LVOT clearance after ASA, one had unrelated mortality before TMVR, and one had advanced heart failure before TMVR. CONCLUSION: In appropriately selected patients and at centers experienced with ASA, preemptive ASA can achieve sufficient neo-LVOT clearance for TMVR with a variety of devices in approximately 90% of patients.

Pulmonary Hypertension and Operative Risk in Mitral Valve and Coronary Surgery.

INTRODUCTION: Pulmonary hypertension (PHT) is a known risk factor for coronary artery bypass grafting (CABG), though less well understood for valve operations. We hypothesized PHT is associated with lower risk during mitral valve operations compared to CABG. METHODS: Patients undergoing isolated mitral valve or CABG operations (2011-2019) in a regional Society of Thoracic Surgeons (STS) database were stratified by pulmonary artery systolic pressure (PASP). The association of PASP by procedure type was assessed by hierarchical regression modeling, adjusting for STS predicted risk scores. RESULTS: Of the 2542 mitral and 11,059 CABG patients, the mitral population had higher mean STS risk of mortality (3.6% versus 2.4%, P < 0.0001) and median PASP (42 mmHg versus 32 mmHg, P < 0.0001). PASP was independently associated with operative mortality and major morbidity in both mitral and CABG patients. However, for mitral patients a 10-mmHg increase in PASP was associated with lower odds of morbidity (odds ratio: 1.06 versus 1.13), mortality (odds ratio: 1.11 versus 1.18) and intensive care unit time (4.3 versus 7.6 h) compared with CABG patients (interaction terms P < 0.0001). Among mitral patients, median PASP was higher in stenotic versus regurgitant disease (57 mmHg versus 40 mmHg, P < 0.0001). However, there was no differential association of PASP on morbidity or mortality (interaction terms P > 0.05). CONCLUSIONS: Although mitral surgery patients tend to have higher preoperative pulmonary artery pressures, PHT was associated with a lower risk for mitral outcomes compared with CABG. Further research on the management and optimization of patients with PHT perioperatively is needed to improve care for these patients.

Temporal Cluster Analysis of Deep Sternal Wound Infection in a Regional Quality Collaborative.

INTRODUCTION: Deep sternal wound infection (DSWI) is a rare complication associated with high mortality. Seasonal variability in surgical site infections has been demonstrated, however, these patterns have not been applied to DSWI. The purpose of this study was to assess temporal clustering of DSWIs. METHODS: All cardiac surgery patients who underwent sternotomy were queried from a regional Society of Thoracic Surgeons database from 17 centers from 2001 to 2019. All patients with the diagnosis of DSWI were then identified. Cluster analysis was performed at varying time intervals (monthly, quarterly, and yearly) at the hospital and regional level. DSWI rates were calculated by year and month, and compared using mixed-effects negative binomial regression. RESULTS: A total of 134,959 patients underwent a sternotomy for cardiac surgery, of whom 469 (0.35%) developed a DSWI. Rates of DSWI per hospital across all years ranged from 0.12% to 0.69%. Collaborative-level rates of DSWIs were the greatest in September (0.44%) and the lowest in January (0.30%). Temporal clustering was not seen across seasonal quarters (high rate in preceeding quarter was not associated with a high rate in the next quarter) (P = 0.39). There were yearly differences across all institutions in the DSWI rates. A downward trend in DSWI rates was seen from 2001 to 2019 (P < 0.001). A difference among hospitals in the cohort was observed (P < 0.001). CONCLUSIONS: DSWI are a rare event within our region. Unlike other surgical site infection, there does not appear to be a seasonal pattern associated with DSWI.

Discordance among assays for monitoring? Anticoagulation during extracorporeal life support.

OBJECTIVES: The optimal method for monitoring of anticoagulation in patients on extracorporeal life support (ECLS) is unknown. The objective of this study was to assess the relationship between anti-factor Xa level (anti-Xa; IU/mL) and activated partial thromboplastin time (aPTT; seconds) for monitoring intravenous unfractionated heparin anticoagulation in adult ECLS patients. METHODS: Charts of all adult patients cannulated for ECLS from 2015 through 2017 were reviewed and laboratory and heparin infusion data were extracted for analysis. Time matched pairs of anti-Xa and aPTT were considered concordant if both laboratory values were within the same clinically utilized range. A hierarchical logistic regression model was used to determine factors associated with discordance while accounting for patient level effects. RESULTS: A total of 1016 paired anti-Xa and aPTT values from 65 patients were evaluated. 500 (49.2%) paired samples were discordant with a degree of variability on linear regression (r2 = 0.315). The aPTT fell into a higher therapeutic range compared to the anti-Xa in 31.6% and lower in 17.3%. Logistic regression demonstrated that discordance was independently associated with time from initiation of ECLS (OR 1.17 per day, p < 0.001), average heparin infusion rate (OR 1.25 per U/kg/hr, p < 0.001), and INR (OR 3.22, p < 0.001). CONCLUSIONS: Nearly half of all aPTT and anti-Xa values were in discordant ranges and discordance is more likely as the time on ECLS and the INR level increase. The use of either assay in isolation to guide heparin anticoagulation may lead to misestimation of the degree of anticoagulation in complex ECLS patients.

Cerebrovascular Events in Patients With Centrifugal-Flow Left Ventricular Assist Devices: Propensity Score-Matched Analysis From the Intermacs Registry.

BACKGROUND: Ischemic and hemorrhagic cerebrovascular accidents remain common among patients with centrifugal-flow left ventricular assist devices, despite improvements in survival and device longevity. We compared the incidence of neurologic adverse events (NAEs) associated with 2 contemporary centrifugal-flow left ventricular assist devices: the Abbott HeartMate3 (HM3) and the Medtronic HeartWare HVAD (HVAD). METHODS: Using the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs), we collected data on adult patients who received a centrifugal-flow left ventricular assist device as a primary isolated implant between January 1, 2017, and September 30, 2019. Major NAEs were defined as transient ischemic attack, ischemic cerebrovascular accident, or hemorrhagic cerebrovascular accident. The association of HVAD with risk of NAE in the first year after implant was evaluated using propensity score matching to balance for preimplant risk factors. After matching, freedom from first major NAE in the HM3 and HVAD cohorts was compared with Kaplan-Meier curves. A secondary analysis using multivariable multiphase hazard models was used to identify predictors of NAE, which uses a data-driven parametric fit of the early declining and constant phase hazards and the associations of risk factor with either phase. RESULTS: Of 6205 included patients, 3129 (50.4%) received the HM3 and 3076 (49.6%) received the HVAD. Median follow-up was 9 and 12 months (HM3 and HVAD, respectively). Patients receiving HVAD had more major NAEs (16.4% versus 6.4%, P<0.001) as well as each subtype (transient ischemic attack: 3.3% versus 1.0%, P<0.001; ischemic cerebrovascular accident: 7.7% versus 3.4%, P<0.001; hemorrhagic cerebrovascular accident: 7.2% versus 2.0%, P<0.001) than did patients receiving HM3. A propensity-matched cohort balanced for preimplant risk factors showed that HVAD was associated with higher probabilities of major NAEs (% freedom from NAE 82% versus 92%, P<0.001). Device type was not significantly associated with NAEs in the early hazard phase, but HVAD was associated with higher incidence of major NAEs during the constant hazard phase (hazard ratio, 5.71 [CI, 3.90-8.36]). CONCLUSIONS: HM3 is associated with lower hazard of major NAEs than is HVAD beyond the early postimplantation period and during the constant hazard phase. Defining the explanation for this observation will inform device selection for individual patients.

Cerebrovascular Events in Patients With Centrifugal-Flow Left Ventricular Assist Devices: Propensity Score-Matched Analysis From the Intermacs Registry.

BACKGROUND: Ischemic and hemorrhagic cerebrovascular accidents remain common among patients with centrifugal-flow left ventricular assist devices, despite improvements in survival and device longevity. We compared the incidence of neurologic adverse events (NAEs) associated with 2 contemporary centrifugal-flow left ventricular assist devices: the Abbott HeartMate3 (HM3) and the Medtronic HeartWare HVAD (HVAD). METHODS: Using the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs), we collected data on adult patients who received a centrifugal-flow left ventricular assist device as a primary isolated implant between January 1, 2017, and September 30, 2019. Major NAEs were defined as transient ischemic attack, ischemic cerebrovascular accident, or hemorrhagic cerebrovascular accident. The association of HVAD with risk of NAE in the first year after implant was evaluated using propensity score matching to balance for preimplant risk factors. After matching, freedom from first major NAE in the HM3 and HVAD cohorts was compared with Kaplan-Meier curves. A secondary analysis using multivariable multiphase hazard models was used to identify predictors of NAE, which uses a data-driven parametric fit of the early declining and constant phase hazards and the associations of risk factor with either phase. RESULTS: Of 6205 included patients, 3129 (50.4%) received the HM3 and 3076 (49.6%) received the HVAD. Median follow-up was 9 and 12 months (HM3 and HVAD, respectively). Patients receiving HVAD had more major NAEs (16.4% versus 6.4%, P<0.001) as well as each subtype (transient ischemic attack: 3.3% versus 1.0%, P<0.001; ischemic cerebrovascular accident: 7.7% versus 3.4%, P<0.001; hemorrhagic cerebrovascular accident: 7.2% versus 2.0%, P<0.001) than did patients receiving HM3. A propensity-matched cohort balanced for preimplant risk factors showed that HVAD was associated with higher probabilities of major NAEs (% freedom from NAE 82% versus 92%, P<0.001). Device type was not significantly associated with NAEs in the early hazard phase, but HVAD was associated with higher incidence of major NAEs during the constant hazard phase (hazard ratio, 5.71 [CI, 3.90-8.36]). CONCLUSIONS: HM3 is associated with lower hazard of major NAEs than is HVAD beyond the early postimplantation period and during the constant hazard phase. Defining the explanation for this observation will inform device selection for individual patients.

Access to Left Ventricular Assist Device: Travel Time Does Not Tell The Whole Story.

BACKGROUND: Negative health effects of traveling longer distances for surgical services have been reported. Given the high complexity of multidisciplinary care required for management of Left Ventricular Assist Device (LVAD) implantation, only 4 of 18 centers in our state perform these operations. Given the limited access we hypothesized increased travel time would adversely affect postoperative outcomes and 30-d mortality. METHODS: A statewide Society of Thoracic Surgeons database was queried to identify patients undergoing Heartmate II/III and HVAD implantation, and 725 patients were identified. Travel time was calculated by zip code. Patients were stratified into regional and distant groups by the upper quartile of travel time (1-h). Preoperative variables and outcomes were compared between the groups. Multivariate analysis was performed to evaluate the impact of travel time in risk-adjusted models of 30-d mortality. RESULTS: Median patient travel time to their LVAD center in our state is 32 min (mean 53 ± 65 min, 46 ± 71 miles). Patients in the distant group (n = 191) had lower median incomes, higher self-pay status, higher rates of medical comorbid disease. Despite these differences there was no difference between the groups in ICU and/or hospital length of stay, readmission, postoperative complications, or 30-d mortality. Multivariate regression demonstrated insurance status, age, and prior surgery predicted 30-d mortality, but not travel time. CONCLUSIONS: Despite only four centers in the state performing LVAD implantation, travel time was strongly associated with preoperative risk, and socioeconomic status but not postoperative outcomes or 30-d mortality. Therefore, increasing access should focus on insurance, and patient characteristics not travel time.

Aortic valve biologic protheses: A cohort comparison of premature valve failure.

BACKGROUND: Recent reports suggest an increased rate of early structural valve degeneration (SVD) in the Trifecta bioprosthesis (Abbott Cardiovascular). We sought to compare the intermediate-term outcomes of the Magna (Edwards Life Sciences) and Trifecta valves. METHODS: All surgical aortic valve replacements (SAVRs) with Trifecta or Magna/Magna Ease bioprostheses at an academic medical center were extracted from an institutional database. Patients who survived until after discharge (2011-2019) were included. The primary outcome was valve failure for any reason requiring reintervention or contributing to death, identified by reintervention or review of cause of death. Time to failure was estimated with Kaplan-Meier analysis and Cox Proportional Hazards Modeling. RESULTS: Out of 1444 patients, 521 (36%) underwent Trifecta and 923 (64%) underwent Magna implantation with a median follow-up of 27.6 months. Trifecta patients had larger median valve size (25 vs. 23 mm, p < .001) and lower median gradient (8.0 vs. 10.9 mmHg, p < .001). Trifecta patients had higher 48-month estimated failure rates (20.2 ± 7.6% vs. 2.6 ± 0.7%, p < .0001), with failure rates of 21.4 versus 9.2 failures per 1000 person-years (p < .001). After risk-adjustment, Trifecta patients had a 5.3 times hazard of failure (95% confidence interval: 2.78-12.34, p < .001) compared to Magna patients. Only Trifecta valves failed due to sudden aortic regurgitation, 8 out of 521 (1.5%). CONCLUSION: Despite lower postoperative mean gradients, the Trifecta bioprosthesis may have an increased risk of intermediate-term SVD. Further research is warranted to confirm the potential for sudden valve failure.

Meaningful Patient-centered Outcomes 1 Year Following Cardiac Surgery.

OBJECTIVE: To evaluate meaningful, patient-centered outcomes including alive-at-home status and patient-reported quality of life 1 year after cardiac surgery. BACKGROUND: Long-term patient-reported quality of life after cardiac surgery is not well understood. Current operative risk models and quality metrics focus on short-term outcomes. METHODS: In this combined retrospective/prospective study, cardiac surgery patients at an academic institution (2014-2015) were followed to obtain vital status, living location, and patient-reported outcomes (PROs) at 1 year using the NIH Patient-Reported Outcomes Measurement Information System (PROMIS). We assessed the impact of cardiac surgery, discharge location, and Society of Thoracic Surgeons perioperative predicted risk of morbidity or mortality on 1-year outcomes. RESULTS: A total of 782 patients were enrolled; 84.1% (658/782) were alive-at-home at 1 year. One-year PROMIS scores were global physical health (GPH) = 48.8 ±â€Š10.2, global mental health (GMH) = 51.2 ±â€Š9.6, and physical functioning (PF) = 45.5 ±â€Š10.2 (general population reference = 50 ±â€Š10). All 3 PROMIS domains at 1 year were significantly higher compared with preoperative scores (GPH: 41.7 ±â€Š8.5, GMH: 46.9 ±â€Š7.9, PF: 39.6 ±â€Š9.0; all P < 0.001). Eighty-two percent of patients discharged to a facility were alive-at-home at 1 year. These patients, however, had significantly lower 1-year scores (difference: GPH = -5.1, GMH = -5.1, PF = -7.9; all P < 0.001). Higher Society of Thoracic Surgeons perioperative predicted risk was associated with significantly lower PRO at 1 year (P < 0.001). CONCLUSIONS: Cardiac surgery results in improved PROMIS scores at 1 year, whereas discharge to a facility and increasing perioperative risk correlate with worse long-term PRO. One-year alive-at-home status and 1-year PRO are meaningful, patient-centered metrics that help define long-term quality and the benefit of cardiac surgery.

Early Versus Delayed Pacemaker for Heart Block After Valve Surgery: A Cost-Effectiveness Analysis.

BACKGROUND: A significant percentage of patients who acutely develop high-grade atrioventricular block after valve surgery will ultimately recover, yet the ability to predict recovery is limited. The purpose of this analysis was to evaluate the cost-effectiveness of two different management strategies for the timing of permanent pacemaker implantation for new heart block after valve surgery. METHODS: A cost-effectiveness model was developed using costs and probabilities of short- and long-term complications of pacemaker placement, short-term atrioventricular node recovery, intensive care unit stays, and long-term follow-up. We aggregated the total expected cost and utility of each option over a 20-y period. Quality-adjusted survival with a pacemaker was estimated from the literature and institutional patient-reported outcomes. Primary decision analysis was based on an expected recovery rate of 36.7% at 12 d with timing of pacemaker implantation: early placement (5 d) versus watchful waiting for 12 d. RESULTS: A strategy of watchful waiting was more costly ($171,798 ± $45,695 versus $165,436 ± $52,923; P < 0.0001) but had a higher utility (9.05 ± 1.36 versus 8.55 ± 1.33 quality-adjusted life years; P < 0.0001) than an early pacemaker implantation strategy. The incremental cost-effectiveness ratio of watchful waiting was $12,724 per quality-adjusted life year. The results are sensitive to differences in quality-adjusted survival and rates of recovery of atrioventricular node function. CONCLUSIONS: Watchful waiting for pacemaker insertion is a cost-effective management strategy compared with early placement for acute atrioventricular block after valve surgery. Although this is cost-effective from a population perspective, clinical risk scores predicting recovery will aid in personalized decision-making.

Outcomes of surgical mitral valve replacement: A benchmark to assess transcatheter technologies.

BACKGROUND: Clinical trials are underway to evaluate the safety and efficacy of transcatheter mitral valve replacement in intermediate and high surgical risk patients. We analyzed outcomes of surgical mitral valve replacement in a regional consortium to provide benchmark data for emerging alternative therapies. METHODS: All patients undergoing mitral replacement with a Society of Thoracic Surgeons predicted risk of mortality (STS PROM) in a regional consortium from 2001 to 2017 were analyzed. Patients with endocarditis were excluded. Patients were stratified by STS PROM into low (<4%), moderate (4%-8%), and high risk (>8%) cohorts. Mortality, postoperative complications, and resource utilization were evaluated for each group. RESULTS: A total of 1611 patients were analyzed including 927 (58%) low, 370 (23%) moderate, and 314 (20%) high-risk patients. The mean STS PROM was 2%, 5.6%, and 15.4% for each group. Mortality was adequately predicted for all groups while the most common complications included prolonged ventilation, reoperation, and renal failure. Higher risk patients had longer intensive care unit and hospital lengths of stay (2 vs. 3 vs. 5 days, p < .0001 and 7 vs. 8 vs. 10 days, p < .0001) and higher total hospital costs ($38,029 vs. $45,075 vs. $59,171 p < .0001). CONCLUSIONS: Mitral valve replacement is associated with acceptable morbidity and mortality, particularly for low and intermediate-risk patients. These outcomes also serve as a benchmark with which to compare forthcoming results of transcatheter mitral valve replacement trials.

Concomitant Left Atrial Appendage Closure Outcomes and Cost: A Multi-institutional Cohort Analysis.

BACKGROUND: Left atrial appendage closure (LAAC) is frequently performed during cardiac operations, but the impact of LAAC on patient outcomes is not fully known. We hypothesized that the addition of LAAC would increase morbidity and resource utilization. METHODS: All patients undergoing cardiac surgery from a multi-institutional Society of Thoracic Surgeons database from 2011 to 2016 were stratified by LAAC. The effect of LAAC on risk-adjusted outcomes was assessed by hierarchical regression modeling accounting for preoperative risk factors, planned surgical procedure, hospital, and year. RESULTS: Concomitant LAAC was performed on 2384 of 28,311 patients (9.3%), who were older, with a greater burden of preoperative atrial fibrillation and heart failure. Although the addition of LAAC increased the risk of new-onset postoperative atrial fibrillation (OR 1.69, P < 0.01), it did not increase rates of major morbidity (OR 1.00, P = 0.970), stroke (OR 0.92, P = 0.787), or mortality (OR 0.93, P = 0.684). Although cardiopulmonary bypass time was not significantly increased by LAAC, patients' total hospitalization costs were $3035 higher (P = 0.018). CONCLUSIONS: Although concomitant LAAC was not associated with major complications, there were higher risk-adjusted rates of new-onset postoperative atrial fibrillation. Furthermore, LAAC added approximately $3000 to a patient's total hospital cost. These short-term risks and costs should be weighed against potential long-term benefits of left atrial appendage closure.

Gastrointestinal Complications After Cardiac Surgery: Highly Morbid but Improving Over Time.

BACKGROUND: Gastrointestinal complications after cardiac surgery are associated with high morbidity and mortality. We sought to determine the granular impact of individual gastrointestinal complications after cardiac surgery and assess contemporary outcomes. MATERIALS AND METHODS: Patients undergoing cardiac surgery from 2010 to 2017 (6070 patients) were identified from an institutional Society of Thoracic Surgeons database. Records were paired with institutional data assessing gastrointestinal complications and cost. Patients were stratified by early (2010-2013) and current (2014-2017) eras. RESULTS: A total of 280 (4.6%) patients experienced gastrointestinal complications including Clostridiumdifficile infection (94, 33.6%), gastrointestinal bleed (86, 30.7%), hepatic failure (66, 23.6%), prolonged ileus (59, 21.1%), mesenteric ischemia (47, 16.8%), acute cholecystitis (17, 6.0%), and pancreatitis (14, 5.0%). Gastrointestinal complications were associated with higher rates of early postoperative major morbidity [206 (73.6%) versus 773 (13.4%), P < 0.0001], mortality [78 (27.9%) versus 161 (2.8%), P < 0.0001], length of stay (23 versus 6 d, P < 0.0001), and discharge to a facility [115 (41.1%) versus 1395 (24.1%), P < 0.0001]. Patients suffering gastrointestinal complications had worse risk-adjusted long-term survival (hazard ratio: 3.0, P < 0.0001) and higher adjusted cost ($9,173, P = 0.05). Between eras, there was no difference in incidence of gastrointestinal complications [139 (4.4%) versus 141 (4.8%), P = 0.51] or rate of specific complications (all P > 0.05). However, long-term survival increased in modern era (P < 0.0001). CONCLUSIONS: Although incidence of gastrointestinal complications after cardiac surgery has not changed over time, long-term survival has improved. Gastrointestinal complications remain associated with high resource utilization and major morbidity, but patients are now more likely to recover, highlighting the benefit of quality improvement efforts.

Endovascular repair of left ventricular assist device outflow graft defect.

Outflow graft complications after left ventricular assist device placement are infrequent but highly morbid. In this case report, we describe endovascular repair of multiple outflow graft defects with external hemorrhage in a complex patient using overlapping stent grafts. This approach successfully stopped the outflow graft hemorrhage and temporized the patient for subsequent cardiac transplantation.

Pulmonary-Systemic Pressure Ratio Correlates with Morbidity in Cardiac Valve Surgery.

OBJECTIVES: Pulmonary hypertension portends worse outcomes in cardiac valve surgery; however, isolated pulmonary artery pressures may not reflect patients' global cardiac function accurately. To better account for the interventricular relationship, the authors hypothesized that patients with greater pulmonary-systemic ratios (mean pulmonary arterial pressure)/(mean systemic arterial pressure) would correlate with worse outcomes after valve surgery. DESIGN: Retrospective cohort study. SETTING: Single academic hospital. PARTICIPANTS: The study comprised 314 patients undergoing valve surgery with or without coronary artery bypass grafting (2004-2016) with Society of Thoracic Surgeons predicted risk scores and preoperative right heart catheterization. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The pulmonary-systemic ratio was calculated as follows: mean pulmonary arterial pressure/mean systemic arterial pressure. Patients were stratified by pulmonary-systemic ratio quartile. Logistic regression was used to assess the risk-adjusted association between pulmonary-systemic ratio or mean pulmonary arterial pressure. Median pulmonary-systemic ratio was 0.33 (Q1-Q3: 0.23-0.65); median pulmonary arterial pressure was 29 (21-30) mmHg. Patients with the highest pulmonary-systemic ratio had the highest rates of morbidity and mortality (p < 0.0001). A high pulmonary-systemic ratio was associated with longer duration in the intensive care unit (p < 0.0001) and hospital (p < 0.0001). After risk-adjustment, pulmonary-systemic ratio and pulmonary arterial pressure were independently associated with morbidity and mortality, but the pulmonary-systemic ratio (odds ratio 23.88, p = 0.008, Wald 7.1) was more strongly associated than the pulmonary arterial pressure (odds ratio 1.035, p = 0.011, Wald 6.5). CONCLUSIONS: The pulmonary-systemic ratio is more strongly associated with risk-adjusted morbidity and mortality in valve surgery than pulmonary arterial pressure. By integrating ventricular interactions, this metric may better characterize the risk of valve surgery.

Primary graft dysfunction after heart transplantation: Outcomes and resource utilization.

BACKGROUND: A unified definition of primary graft dysfunction (PGD) after heart transplantation was adopted in 2014, with moderate and severe PGD defined as a need for mechanical circulatory support. While risk factors for PGD are well identified, outcomes and resource utilization have not been well-studied. We examined the resource utilization and associated costs with PGD. METHODS: All adult heart transplantations (2001-2016) from a statewide Society of Thoracic Surgery database were analyzed by dividing them into two groups-with PGD (requiring mechanical circulatory support) and without PGD. RESULTS: Of the 718 heart transplants, 110 (15.3%) patients developed PGD. Prevalence of PGD for the study duration ranged from 3.7% to 22.7% with no significant trend. The most frequently used mechanical circulatory support device was intra-aortic balloon pump (88%), followed by extracorporeal membrane oxygenation (17%), and catheter-based circulatory support devices (3%). There were no significant differences in demographics or preoperative variables between the two groups. Resource utilization such as total intensive care unit hours, ventilation hours, reoperation for bleeding, blood product transfusions, and length of stay were significantly higher in the PGD group. Postoperative complications were also higher in PGD group including operative mortality (31.8% vs 3.8%, P < .0001). The median cost of heart transplantation was significantly higher in the PGD group $229 482 ($126 044-$388 889) vs $101 788 ($72 638-$181 180) P < .0001. CONCLUSION: Primary graft dysfunction following heart transplantation developed in 15% of patients. Patients with PGD had significantly higher complications, resource utilization, and mortality. Preventive measures to address the development of PGD would reduce resource utilization and improve outcomes.

Travel distance and regional access to cardiac valve surgery.

OBJECTIVE: Evidence in other surgical subspecialties suggests patients traveling farther to undergo surgery have worse outcomes. We sought to determine the impact of travel distance and travel beyond closest center on outcomes after valve surgery. METHODS: Patients who underwent valve surgery ±CABG with a Society of Thoracic Surgeons (STS) predicted risk and zip code were extracted from a statewide STS database (2011-016). Patients were stratified by those receiving care greater than or equal to 20 miles from the closest surgical center (Traveler) or at the closest center (Non-Traveler). Multivariate logistic regression assessed the effects of travel distance and traveler status on mortality and major morbidity adjusted for STS predicted risk, median income by zip code, and payer status. RESULTS: Median travel distance for all patients (n = 4765) was 19 miles and after risk-adjustment increasing distance was associated with reduced operative mortality (odds ratio [OR], 0.94 [0.89-1.00], P = .049) with no impact on major morbidity. Travelers (445 patients, 9.3%) had lower median income, higher self-pay and reoperative status, but similar urgent/emergent status and STS risk as Non-Travelers. Travelers had lower operative mortality (1.6% vs 4.3%, P = .005) which remained statistically lower after risk-adjustment (OR, 0.32 [0.14-0.75], P = .009). This mortality difference was particularly pronounced in patients with postoperative complications (3.1% vs 7.9%, P = .005). CONCLUSIONS: Contrary to other surgical subspecialties, farther travel distance and bypassing the nearest surgical center were associated with lower rates of operative mortality and failure to rescue. Either referral patterns or financials reasons may result in Travelers ending up at high performing centers that prevent escalation of complications.