The Society of Thoracic Surgeons Definition of Failure to Rescue Should Consider Including Cardiac Arrest.

BACKGROUND: Failure to rescue (FTR) is a new quality measure in The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database. The STS defines FTR as death after permanent stroke, renal failure, reoperation, or prolonged ventilation. Our objective was to assess whether cardiac arrest should be included in this definition. METHODS: Patients undergoing an STS index operation in a regional collaborative (2011-2021) were included. The performance of the STS definition of FTR was compared with a definition that included the STS complications plus cardiac arrest (STS+). Centers were grouped into FTR rate terciles using the STS and STS+ definitions of FTR, and changes in their relative performance rating were assessed. RESULTS: A total of 43,641 patients were included across 17 centers. Cardiac arrest was the most lethal complication: 55.0% of patients who experienced cardiac arrest died. FTR after any complication (13 total) occurred among 884 patients. The STS definition of FTR accounted for 83% (735 of 884) of all FTR. The addition of cardiac arrest to the STS definition significantly increased the proportion of overall FTR accounted for (92.2% [815 of 884]; P < .001). Choice of FTR definition led to substantial differences in center-level relative performance rating by FTR rate. CONCLUSIONS: Mortality after cardiac arrest is not completely captured by the STS definition of FTR and represents an important source of potentially preventable death after cardiac surgery. Future quality improvement efforts using the STS definition of FTR should account for this.

Long term employment following heart transplantation in the United States.

BACKGROUND: Employment is an important metric of post-transplant functional status and the quality of life yet remains poorly described after heart transplant. We sought to characterize the prevalence of employment following heart transplantation and identify patients at risk for post-transplant unemployment. METHODS: Adults undergoing single-organ heart transplantation (2007-2016) were evaluated using the UNOS database. Univariable analysis was performed after stratifying by employment status at 1-year post-transplant. Fine-Gray competing risk regression was used for risk adjustment. Cox regression evaluated employment status at 1 year with mortality. RESULTS: Of 10,132 heart transplant recipients who survived to 1 year and had follow-up, 22.0% were employed 1-year post-transplant. Employment rate of survivors increased to 32.9% by year 2. Employed individuals were more likely white (70.8% vs 60.4%, p < 0.01), male (79.6% vs 70.7% p < 0.01), held a job at listing/transplant (37.6% vs 7.6%, p < 0.01), and had private insurance (79.1% vs 49.5%, p < 0.01). Several characteristics were independently associated with employment including age, employment status at time of listing or transplant, race and ethnicity, gender, insurance status, education, and postoperative complications. Of 1,657 (14.0%) patients employed pretransplant, 58% were working at 1-year. Employment at 1year was independently associated with mortality with employed individuals having a 26% decreased risk of mortality. CONCLUSION: Over 20% of heart transplant patients were employed at 1 year and over 30% at 2 years, while 58% of those working pretransplant had returned to work by 1-year. While the major predictor of post-transplant employment is preoperative employment status, our study highlights the impact of social determinants of health.

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.

Prediction of Prolonged Intensive Care Unit Length of Stay Following Cardiac Surgery.

Intensive care unit (ICU) costs comprise a significant proportion of the total inpatient charges for cardiac surgery. No reliable method for predicting intensive care unit length of stay following cardiac surgery exists, making appropriate staffing and resource allocation challenging. We sought to develop a predictive model to anticipate prolonged ICU length of stay (LOS). All patients undergoing coronary artery bypass grafting (CABG) and/or valve surgery with a Society of Thoracic Surgeons (STS) predicted risk score were evaluated from an institutional STS database. Models were developed using 2014-2017 data; validation used 2018-2019 data. Prolonged ICU LOS was defined as requiring ICU care for at least three days postoperatively. Predictive models were created using lasso regression and relative utility compared. A total of 3283 patients were included with 1669 (50.8%) undergoing isolated CABG. Overall, 32% of patients had prolonged ICU LOS. Patients with comorbid conditions including severe COPD (53% vs 29%, P < 0.001), recent pneumonia (46% vs 31%, P < 0.001), dialysis-dependent renal failure (57% vs 31%, P < 0.001) or reoperative status (41% vs 31%, P < 0.001) were more likely to experience prolonged ICU stays. A prediction model utilizing preoperative and intraoperative variables correctly predicted prolonged ICU stay 76% of the time. A preoperative variable-only model exhibited 74% prediction accuracy. Excellent prediction of prolonged ICU stay can be achieved using STS data. Moreover, there is limited loss of predictive ability when restricting models to preoperative variables. This novel model can be applied to aid patient counseling, resource allocation, and staff utilization.

Two Hours of In Vivo Lung Perfusion Improves Lung Function in Sepsis-Induced Acute Respiratory Distress Syndrome.

Sepsis is the leading cause of acute respiratory distress syndrome (ARDS) in adults and carries a high mortality. Utilizing a previously validated porcine model of sepsis-induced ARDS, we sought to refine our novel therapeutic technique of in vivo lung perfusion (IVLP). We hypothesized that 2 hours of IVLP would provide non-inferior lung rehabilitation compared to 4 hours of treatment. Adult swine (n = 8) received lipopolysaccharide to develop ARDS and were placed on central venoarterial extracorporeal membrane oxygenation. Animals were randomized to 2 vs 4 hours of IVLP. The left pulmonary vessels were cannulated to IVLP using antegrade Steen solution. After IVLP treatment, the left lung was decannulated and reperfused for 4 hours. Total lung compliance and pulmonary venous gases from the right lung (control) and left lung (treatment) were sampled hourly. Biochemical analysis of tissue and bronchioalveolar lavage was performed along with tissue histologic assessment. Throughout IVLP and reperfusion, treated left lung PaO2/FiO2 ratio was significantly higher than the right lung control in the 2-hour group (332.2 ± 58.9 vs 264.4 ± 46.5, P = 0.01). In the 4-hour group, there was no difference between treatment and control lung PaO2/FiO2 ratio (258.5 ± 72.4 vs 253.2 ± 90.3, P = 0.58). Wet-to-dry weight ratios demonstrated reduced edema in the treated left lungs of the 2-hour group (6.23 ± 0.73 vs 7.28 ± 0.61, P = 0.03). Total lung compliance was also significantly improved in the 2-hour group. Two hours of IVLP demonstrated superior lung function in this preclinical model of sepsis-induced ARDS. Clinical translation of IVLP may shorten duration of mechanical support and improve outcomes.

Strategies for Mechanical Right Ventricular Support During Left Ventricular Assist Device Implant.

BACKGROUND: Refractory right ventricular failure at the time of left ventricular assist device implantation requires treatment with supplemental mechanical circulatory support. However, the optimal strategy for support remains unknown. METHODS: All patients undergoing first-time durable left ventricular assist device implantation with a contemporary device were selected from The Society of Thoracic Surgeons National Database (2011 to 2019). Patients requiring right ventricular assist device (RVAD) or venoarterial extracorporeal membrane oxygenation (VA-ECMO) were included in the analysis. Patients were stratified by RVAD or VA-ECMO and by timing of placement (intraoperative vs postoperative). RESULTS: In all, 18 423 left ventricular assist device implants were identified, of which 940 (5.1%) required RVAD (n = 750) or VA-ECMO (n = 190) support. Patients receiving an RVAD more frequently had preoperative inotrope requirement (76% vs 62%, P < .01) and severe tricuspid regurgitation (20% vs 13%, P < .01). The RVAD patients had lower rates of postoperative renal failure (40% vs 51%, P = .02) and limb ischemia (4% vs 13%, P < .01), as well as significantly less operative mortality (41% vs 54%, P < .01). After risk adjustment with propensity score analysis, support with VA-ECMO was associated with a higher risk of mortality (risk ratio 1.46; 95% confidence interval, 1.21 to 1.77; P < .01) compared with patients receiving an RVAD. Importantly, institution of right ventricular support postoperatively was associated with higher mortality (1.43, P < .01) compared with intraoperative initiation. CONCLUSIONS: Patients with severe right ventricular failure in the setting of durable left ventricular assist device implantation may benefit from the use of RVAD over VA-ECMO. Regardless of the type of support, initiation at the index operation was associated with improved outcomes.

Impact of tricuspid regurgitation with and without repair during aortic valve replacement.

BACKGROUND: Long-term outcomes of aortic valve replacement (AVR) are worse in patients with tricuspid regurgitation (TR), but the impact of concomitant tricuspid valve intervention remains unclear. The purpose of this study was to determine the effect of tricuspid intervention in patients with TR undergoing AVR. METHODS: Patients undergoing AVR in a regional Society of Thoracic Surgeons database (2001-2017) were stratified by severity of TR and whether or not they underwent concomitant tricuspid intervention. Operative morbidity and mortality were compared between the 2 groups. Further analysis was performed using propensity score-matched pairs. RESULTS: Among 17,483 patients undergoing AVR, 8984 (51%) had no TR, 7252 (41%) had mild TR, 1060 (6%) had moderate TR, and 187 (1%) had severe TR. Overall, more severe TR was associated with higher morbidity and mortality. Tricuspid intervention was performed in 104 patients (0.6%), including 0.2% of patients with mild TR, 2% of those with moderate TR, and 31% of those with severe TR. In the propensity score-matched analysis, there was not a statistically significant difference in operative mortality between the 2 groups (18% vs 9%; P = .16), but there was significantly higher composite major morbidity (51% vs 26%; P = .006) in the tricuspid intervention group compared with those without surgical TR correction. CONCLUSIONS: Increasing severity of TR is associated with higher rates of morbidity and mortality after AVR. Correction of TR at the time of surgical AVR is not associated with increased operative mortality and has been shown to improve long-term outcomes.

Burden of Tricuspid Regurgitation in Patients Undergoing Coronary Artery Bypass Grafting.

BACKGROUND: Tricuspid regurgitation (TR) is associated with poor outcomes after cardiac surgery. Guidelines recommend correction of severe TR in patients undergoing left-sided valve surgery but not coronary artery bypass graft surgery (CABG). We sought to evaluate impact of TR on outcomes after CABG. METHODS: All patients (n = 28,027) undergoing CABG in The Society of Thoracic Surgeons (STS) regional database (2011 to 2018) were stratified by TR severity. Primary outcomes included major morbidity or mortality, which were compared using univariate analysis. RESULTS: Of patients undergoing CABG, 4837 (17%) had mild, 800 (3%) had moderate, and 81 (0.29%) had severe TR. Increased severity was associated with higher rate of preoperative heart failure (none 5162 [23.4%] vs mild 1697 [35%] vs moderate 427 [53%] vs severe 54 [67%], P < .001] and STS predicted risk of mortality (1.0 [0.6 to 1.9) vs 1.4 [0.8 to 2.9] vs 2.8 [1.4 to 5.4] vs 6.2 [2.2 to 11.4], P < .001). Increasing severity was associated with higher postoperative rate of renal failure (426 [1.9%] vs 145 [3%] vs 58 [7.3%] vs 7 [8.6%], P < .001), prolonged ventilation (1652 [7.5%] vs 495 [10.2%] vs 153 [19.1%] vs 22 [27.2%], P < .001), and mortality (344 [1.6%] vs 132 [2.7%] vs 58 [7.3%] vs 9 [11.1%], P < .001). After risk adjustment, mild, moderate, and severe TR remained associated with increased morbidity and mortality (all P < .05). CONCLUSIONS: Increasing TR severity, although independently associated with higher surgical risk, is not accounted for entirely by STS risk calculator. This highlights the importance of TR on operative risk and supports consideration of concurrent tricuspid intervention for patients with significant TR undergoing CABG.

Long-term Implications of Tracheostomy in Cardiac Surgery Patients: Decannulation and Mortality.

BACKGROUND: The long-term implications of tracheostomy in cardiac surgical patients are largely unknown. We sought to investigate outcomes including decannulation and long-term mortality in a population of post-cardiac surgery patients. METHODS: All patients undergoing cardiac surgery at a single institution between 1997 and 2016 were evaluated for postoperative tracheostomy placement, time to decannulation, and mortality. Patients were stratified by tracheostomy placement, as well as by successful decannulation for comparison. Kaplan-Meier analysis identified time to decannulation and mortality and a Fine-Gray's competing risk regression, accounting for mortality, identified predictors of time to decannulation. RESULTS: Of 14,600 total cardiac surgery patients, only 309 required tracheostomy. Patients with tracheostomy had high rates of perioperative comorbidities, including 60% with heart failure and 24% with postoperative stroke. Tracheostomy patients had high short-term and long-term mortality, with a median survival of 152 days, 1-year survival of 41%, and 5-year survival of 29.1%. Patients remained with tracheostomy in place for a median of 59 days, with a 1-year decannulation rate of 80% in living patients. Patients with older age (hazard ratio 0.98, P = .01), chronic lung disease (hazard ratio 0.66, P = .03), and preoperative or postoperative dialysis (hazard ratio 0.45, P < .01) were less likely to have their tracheostomy removed. CONCLUSIONS: Tracheostomy is associated with poor long-term survival of cardiac surgery patients. However, patients who do survive have a short duration of tracheostomy with almost all surviving patients eventually decannulated. This finding provides valuable information for pre-procedural counseling for these high-risk patients and their families.

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.

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.

How Big Is Too Big?: Donor Severe Obesity and Heart Transplant Outcomes.

BACKGROUND: As the population becomes increasingly obese, so does the pool of potential organ donors. We sought to investigate the impact of donors with body mass index ≥40 (severe obesity) on heart transplant outcomes. METHODS: Single-organ first-time adult heart transplants from 2003 to 2017 were evaluated from the United Network for Organ Sharing database and stratified by donor severe obesity status (body mass index ≥40). Demographics were compared, and univariate and risk-adjusted analyses evaluated the relationship between severe obesity and short-term outcomes and long-term mortality. Further analysis evaluated the prevalence of severe obesity within the pool of organ donation candidates. RESULTS: A total of 26 532 transplants were evaluated, of which 939 (3.5%) had donors with body mass index ≥40, with prevalence increasing over time (2.2% in 2003, 5.3% in 2017). Severely obese donors more likely had diabetes mellitus (10.4% versus 3.1%, P<0.01) and hypertension (33.3% versus 14.8%, P<0.01), and 67.4% were size mismatched (donor weight >130% of recipient). Short-term outcomes were similar, including 1-year survival (10.6% versus 10.7%), with no significant difference in unadjusted and risk-adjusted long-term survival (log-rank P=0.67, hazard ratio, 0.928, P=0.30). Organ donation candidates also exhibited an increase in severe obesity over time, from 3.5% to 6.8%, with a lower proportion of hearts from severely obese donors being transplanted (19.5% versus 31.6%, P<0.01). CONCLUSIONS: Donor severe obesity was not associated with adverse post-transplant outcomes. Increased evaluation of hearts from obese donors, even those with body mass index ≥40, has the potential to expand the critically low donor pool.

Adenosine A2A receptor agonist (regadenoson) in human lung transplantation.

BACKGROUND: Currently, there are no clinically approved treatments for ischemia-reperfusion injury after lung transplantation. Pre-clinical animal models have demonstrated a promising efficacy of adenosine 2A receptor (A2AR) agonists as a treatment option for reducing ischemia-reperfusion injury. The purpose of this human study, is to conduct a Phase I clinical trial for evaluating the safety of continuous infusion of an A2AR agonist in lung transplant recipients. METHODS: An adaptive, two-stage continual reassessment trial was designed to evaluate the safety of regadenoson (A2AR agonist) in the setting of lung transplantation. Continuous infusion of regadenoson was administered to lung transplant recipients that was started at the time of skin incision. Adverse events and dose-limiting toxicities, as pre-determined by a study team and assessed by a clinical team and an independent safety monitor, were the primary end-points for safety in this trial. RESULTS: Between January 2018 and March 2019, 14 recipients were enrolled in the trial. Of these, 10 received the maximum infused dose of 1.44 µg/kg/min for 12 hours. No dose-limiting toxicities were observed. The steady-state plasma regadenoson levels sampled before the reperfusion of the first lung were 0.98 ± 0.46 ng/ml. There were no mortalities within 30 days. CONCLUSIONS: Regadenoson, an A2AR agonist, can be safely infused in the setting of lung transplantation with no dose-limiting toxicities or drug-related mortality. Although not powered for the evaluation of secondary end-points, the results of this trial and the outcome of pre-clinical studies warrant further investigation with a Phase II randomized controlled trial.

Hospital Variability Drives Inconsistency in Antiplatelet Use After Coronary Bypass.

BACKGROUND: Continuation of dual antiplatelet therapy (DAPT) after coronary artery bypass grafting (CABG) after acute myocardial infarction is recommended by current guidelines. We sought to evaluate guideline adherence over time and factors associated with postoperative DAPT within a regional consortium. METHODS: Isolated CABG patients from 2011 to 2017 who had a myocardial infarction within 21 days prior to surgery were included. Patients were stratified by DAPT prescription at discharge and by time period, early (2011-2014) vs late (2015-2017). Hierarchical regressions were then performed to evaluate factors influencing DAPT use after CABG. RESULTS: A total of 7314 patients were included with an overall rate of DAPT utilization of 31.2% that increased from 29.6% in the early to 33.4% in the late era (P < .01). There was considerable variability in hospital rates of DAPT (range 9.5%-92.1%) and hospital level changes over time (26% increased, 11% decreased, and 63% remained stable). After adjustment for clinical factors, era was not associated with DAPT use but treating hospital remained significantly associated with DAPT use. Other clinical factors associated with increased DAPT utilization included off-pump surgery (odds ratio [OR] 4.48, P < .01) and prior percutaneous coronary intervention (OR 2.02, P < .01), and atrial fibrillation (OR 0.39, P < .01) was associated with decreased utilization. CONCLUSIONS: Dual antiplatelet use has increased between 2011 and 2017, driven primarily by evolving patient demographics. Significant hospital-level variability drives inconsistency in DAPT utilization. Efforts to promote DAPT use for patients treated with CABG after myocardial infarction in concordance with current guidelines should be targeted at the hospital level.

Outcomes of non-elective coronary artery bypass grafting performed on weekends.

OBJECTIVES: A weekend effect with increased mortality has previously been reported in surgical patients and those with acute myocardial infarction (MI). We hypothesized that a similar phenomenon may exist in coronary artery bypass grafting (CABG). METHODS: Patients undergoing non-elective isolated CABG (2011-2017) were included from a multicentre regional Society of Thoracic Surgeons database. Patients were stratified by weekend versus weekday operations and further analysed by specific day of the week. RESULTS: A total of 14 374 patients underwent urgent or emergency isolated CABG with 410 (2.9%) operated on over the weekend. Weekend operations were more often emergency (36.1% vs 5.0%, P < 0.001) and more likely to be in the setting of MI (70.0% vs 51.2%, P < 0.001). Cardiopulmonary bypass times were similar [91 min (71-114) vs 94 min (74-117), P = 0.0749] and the frequency of complete revascularization equivalent (83.4% vs 85.3%, P = 0.284) between weekend and weekday operations. In risk-adjusted analyses, there was no increased odds for mortality in patients operated on over the weekend [odds ratio (OR) 1.07, P = 0.811]; however, there was an increased odds of major morbidity (OR 1.37, P = 0.034). Furthermore, compared with Monday, morbidity increased as the operative day approached the weekend (Tuesday 0.98, P = 0.828; Wednesday 1.07, P = 0.469; Thursday 1.12, P = 0.229; Friday 1.19, P = 0.041; weekend 1.47, P = 0.014). CONCLUSIONS: While patients requiring surgery on the weekend are higher risk, there is no independent effect of weekend surgery on mortality. However, these patients are at increased risk for major morbidity, the causes of which require further investigation.