The Impact of Silent Liver Disease on Hospital Length of Stay Following Isolated Coronary Artery Bypass Grafting Surgery.

Objectives: Risk assessment models for cardiac surgery do not distinguish between degrees of liver dysfunction. We have previously shown that preoperative liver stiffness is associated with hospital length of stay following cardiac surgery. The authors hypothesized that a liver stiffness measurement (LSM) ≥ 9.5 kPa would rule out a short hospital length of stay (LOS < 6 days) following isolated coronary artery bypass grafting (CABG) surgery. Methods: A prospective observational study of one hundred sixty-four adult patients undergoing non-emergent isolated CABG surgery at a single university hospital center. Preoperative liver stiffness measured by ultrasound elastography was obtained for each participant. Multivariate logistic regression models were used to assess the adjusted relationship between LSM and a short hospital stay. Results: We performed multivariate logistic regression models using short hospital LOS (<6 days) as the dependent variable. Independent variables included LSM (< 9.5 kPa, ≥ 9.5 kPa), age, sex, STS predicted morbidity and mortality, and baseline hemoglobin. After adjusting for included variables, LSM ≥ 9.5 kPa was associated with lower odds of early discharge as compared to LSM < 9.5 kPa (OR: 0.22, 95% CI: 0.06-0.84, p = 0.03). The ROC curve and resulting AUC of 0.76 (95% CI: 0.68-0.83) suggest the final multivariate model provides good discriminatory performance when predicting early discharge. Conclusions: A preoperative LSM ≥ 9.5 kPa ruled out a short length of stay in nearly 80% of patients when compared to patients with a LSM < 9.5 kPa. Preoperative liver stiffness may be a useful metric to incorporate into preoperative risk stratification.

European Association of Cardio-Thoracic Surgery (EACTS) expert consensus statement on perioperative myocardial infarction after cardiac surgery.

Cardiac surgery may lead to myocardial damage and release of cardiac biomarkers through various mechanisms such as cardiac manipulation, systemic inflammation, myocardial hypoxia, cardioplegic arrest and ischaemia caused by coronary or graft occlusion. Defining perioperative myocardial infarction (PMI) after cardiac surgery presents challenges, and the association between the current PMI definitions and postoperative outcomes remains uncertain. To address these challenges, the European Association of Cardio-Thoracic Surgery (EACTS) facilitated collaboration among a multidisciplinary group to evaluate the existing evidence on the mechanisms, diagnosis and prognostic implications of PMI after cardiac surgery. The review found that the postoperative troponin value thresholds associated with an increased risk of mortality are markedly higher than those proposed by all the current definitions of PMI. Additionally, it was found that large postoperative increases in cardiac biomarkers are prognostically relevant even in absence of additional supportive signs of ischaemia. A new algorithm for PMI detection after cardiac surgery was also proposed, and a consensus was reached within the group that establishing a prognostically relevant definition of PMI is critically needed in the cardiovascular field and that PMI should be included in the primary composite outcome of coronary intervention trials.

Use of veno-venous extracorporeal membrane oxygenation for stabilization prior to redo sternotomy for aortic pseudoaneurysm repair.

Background: Aortic pseudoaneurysms are particularly dangerous because of the risk of rupture and compression of mediastinal structures, including the trachea, and resultant respiratory distress. If respiratory distress progresses to respiratory failure, extracorporeal membrane oxygenation may be used to provide oxygenation prior to or during pseudoaneurysm repair. Case presentation: A 62-year-old male with a history of emergent aortic ascending and arch replacement for Stanford Type A dissection 10 months prior presented to his primary care physician with dyspnea. Chest radiography revealed a widened mediastinum, and subsequent computed tomography angiogram revealed a pseudoaneurysm at the distal suture line of the aortic arch replacement. Due to the location of the pseudoaneurysm, the patient's trachea was compressed, and he was emergently placed on veno-venous (VV) extracorporeal membrane oxygenation (ECMO) following unsuccessful intubation for respiratory distress. Two days later, the patient underwent a redo sternotomy and repair of a 2-3 mm defect in the anterior aspect of the distal suture line of the prior aortic arch replacement. The patient progressed well and was discharged on postoperative day 13. What we learned: Using a combination of peripheral bypass, hypothermic circulatory arrest, delayed closure, and respiratory support, this case demonstrates how even complex patients can be successfully treated with multiple strategies.

The Society of Thoracic Surgeons Looking to the Future Scholarship Program: A 15-Year Review.

BACKGROUND: It has been postulated that a possible barrier to pursuing cardiothoracic surgery is a lack of exposure and mentorship during training. In 2006, The Society of Thoracic Surgeons began the Looking to the Future Scholarship to expand interest in the field. Undecided trainees with limited exposure were prioritized in the selection process. This report summarizes the career outcomes of general surgery resident and medical student recipients. METHODS: Scholarship recipients and nonrecipients (control) were queried in a Google search. The percentage of those who were cardiothoracic surgeons or in cardiothoracic training (%CTS) was calculated, as well as the percentage of female surgeons in cardiothoracic surgery. RESULTS: From 2006 to 2021, there were 669 awardees. The %CTS was 63.7% for resident recipients and 31.4% for students, respectively. There was no significant difference in %CTS between resident and student recipients compared to nonrecipients. Notably, the percentage of female cardiothoracic surgeons was significantly greater for both resident and student recipients. CONCLUSIONS: The majority of resident recipients are now in cardiothoracic surgery, comparable to nonrecipients. While there was no significant difference between the percentage of recipients and non-recipients in cardiothoracic surgery, these groups differed substantially as nonrecipients had greater exposure and commitment to the field at the time of application.

Impact of intraoperative blood products, fluid administration, and persistent hypothermia on bleeding leading to reexploration after cardiac surgery.

OBJECTIVE: Risk factors for severe postoperative bleeding after cardiac surgery remain multiple and incompletely elucidated. We evaluated the impact of intraoperative blood product transfusions, intravenous fluid administration, and persistently low core body temperature (CBT) at intensive care unit arrival on risk of perioperative bleeding leading to reexploration. METHODS: We retrospectively queried our tertiary care center's Society of Thoracic Surgeons Institutional Database for all index, on-pump, adult cardiac surgery patients between July 2016 and September 2022. Intraoperative fluid (crystalloid and colloid) and blood product administrations, as well as perioperative CBT data, were harvested from electronic medical records. Linear and nonlinear mixed models, treating surgeon as a random effect to account for inter-surgeon practice differences, were used to assess the association between above factors and reexploration for bleeding. RESULTS: Of 4037 patients, 151 (3.7%) underwent reexploration for bleeding. Reexplored patients experienced remarkably greater postoperative morbidity (23% vs 6%, P < .001) and 30-day mortality (14% vs 2%, P < .001). In linear models, progressively increasing IV crystalloid administration (adjusted odds ratio, 1.11, 95% confidence interval, 1.03-1.19) and decreasing CBT on intensive care unit arrival (adjusted odds ratio, 1.20; 95% confidence interval, 1.05-1.37) were associated with greater risk of bleeding leading to reexploration. Nonlinear analysis revealed increasing risk after ∼6 L of crystalloid administration and a U-shaped relationship between CBT and reexploration risk. Intraoperative blood product transfusion of any kind was not associated with reexploration. CONCLUSIONS: We found evidence of both dilution- and hypothermia-related effects associated with perioperative bleeding leading to reexploration in cardiac surgery. Interventions targeting modification of such risk factors may decrease the rate this complication.

Kir1.1 and SUR1 are not implicated as subunits of an adenosine triphosphate-sensitive potassium channel involved in diazoxide cardioprotection.

Objective: The adenosine triphosphate-sensitive potassium channel opener diazoxide mimics ischemic preconditioning and is cardioprotective. Clarification of diazoxide's site and mechanism of action could lead to targeted pharmacologic therapies for patients undergoing cardiac surgery. Several mitochondrial candidate proteins have been investigated as potential adenosine triphosphate-sensitive potassium channel components. Renal outer medullary potassium (Kir1.1) and sulfonylurea sensitive regulatory subunit 1 have been suggested as subunits of a mitochondrial adenosine triphosphate-sensitive potassium channel. We hypothesized that pharmacologic blockade or genetic deletion (knockout) of renal outer medullary potassium and sensitive regulatory subunit 1 would result in loss of diazoxide cardioprotection in models of global ischemia with cardioplegia. Methods: Myocyte volume and contractility were compared after Tyrode's physiologic solution (20 minutes), stress (hyperkalemic cardioplegia ± diazoxide, ± VU591 (Kir1.1 inhibitor), N = 9 to 23 each, 20 min), and Tyrode's (20 minutes). Isolated mouse (wild-type, sensitive regulatory subunit 1 [-/-], and cardiac knockout renal outer medullary potassium) hearts were given cardioplegia ± diazoxide (N = 9-16 each) before global ischemia (90 minutes) and 30 minutes reperfusion. Left ventricular pressures were compared before and after ischemia. Results: Stress (cardioplegia) was associated with reduced myocyte contractility that was prevented by diazoxide. Isolated myocytes were not responsive to diazoxide in the presence of VU591. In isolated hearts, diazoxide improved left ventricular function after prolonged ischemia compared with cardioplegia alone in wild-type and knockout (sensitive regulatory subunit 1 [-/-] and cardiac knockout renal outer medullary potassium) mice. Conclusions: Isolated myocyte and heart models may measure independent and separate actions of diazoxide. By definitive genetic deletion, these data indicate that sensitive regulatory subunit 1 and renal outer medullary potassium are not implicated in cardioprotection by diazoxide.

Expert systematic review on the choice of conduits for coronary artery bypass grafting: endorsed by the European Association for Cardio-Thoracic Surgery (EACTS) and The Society of Thoracic Surgeons (STS).

PREAMBLE: The finalized document was endorsed by the EACTS Council and STS Executive Committee before being simultaneously published in the European Journal of Cardio-thoracic Surgery (EJCTS) and The Annals of Thoracic Surgery (The Annals) and the Journal of Thoracic and Cardiovascular Surgery (JTCVS).

Ultrafiltration in cardiac surgery: Results of a systematic review and meta-analysis.

Background: Ultrafiltration is used with cardiopulmonary bypass to reduce the effects of hemodilution and restore electrolyte balance. We performed a systematic review and meta-analysis to analyze the effect of conventional and modified ultrafiltration on intraoperative blood transfusion.Methods: Utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement, we systematically searched MEDLINE, EMBASE, Web of Science, and Cochrane Library to perform a meta-analysis of studies of randomized controlled trials (RCTs) and observational studies evaluating conventional ultrafiltration (CUF) and modified ultrafiltration (MUF) on the primary outcome of intraoperative red cell transfusions.Results: A total of 7 RCTs (n = 928) were included, comparing modified ultrafiltration (n = 473 patients) to controls (n = 455 patients) and 2 observational studies (n = 47,007), comparing conventional ultrafiltration (n = 21,748) to controls (n = 25,427). Overall, MUF was associated with transfusion of fewer intraoperative red cell units per patient (n = 7); MD -0.73 units; 95% CI -1.12 to -0.35 p = 0.04; p for heterogeneity = 0.0001, I2 = 55%) compared to controls. CUF was no difference in intraoperative red cell transfusions compared to controls (n = 2); OR 3.09; 95% CI 0.26-36.59; p = 0.37; p for heterogeneity = 0.94, I2 = 0%. Review of the included observational studies revealed an association between larger volumes (>2.2 L in a 70 kg patient) of CUF and risk of acute kidney injury (AKI).Conclusion: The results of this systematic review and meta-analysis suggest that MUF is associated with fewer intraoperative red cell transfusions. Based on limited studies, CUF does not appear to be associated with a difference in intraoperative red cell transfusion.

Real-World Examination of Revascularization Strategies for Left Main Coronary Disease in Ontario, Canada.

BACKGROUND: Randomized trials have compared percutaneous coronary intervention and coronary artery bypass grafting (CABG) in patients with left main coronary artery disease undergoing nonemergent revascularization. However, there is a paucity of real-world contemporary observational studies comparing percutaneous coronary intervention (PCI) and CABG. OBJECTIVES: The purpose of this study was to compare the long-term clinical outcomes of CABG versus PCI in patients with left main coronary disease. METHODS: Clinical and administrative databases for Ontario, Canada, were linked to obtain records of all patients with angiographic evidence of left main coronary artery disease (≥50% stenosis) treated with either isolated CABG or PCI from 2008 to 2020. Emergent, cardiogenic shock, and ST-segment elevation myocardial infarction patients were excluded. Baseline characteristics of patients were compared and 1:1 propensity score matching was performed. Late mortality and major adverse cardiac and cerebrovascular events were compared between the matched groups using a Cox proportional hazard model. RESULTS: After exclusions, 1,299 and 21,287 patients underwent PCI and CABG, respectively. Prior to matching, PCI patients were older (age 75.2 vs 68.0 years) and more likely to be women (34.6% vs 20.1%), although they had less CAD burden. Propensity score matching on 25 baseline covariates yielded 1,128 well-matched pairs. There was no difference in early mortality between PCI and CABG (5.5% vs 3.9%; P = 0.075). Over 7-year follow-up, all-cause mortality (53.6% vs 35.2%; HR: 1.63; 95% CI: 1.42-1.87; P < 0.001) and major adverse cardiac and cerebrovascular events (66.8% vs 48.6%; HR: 1.77; 95% CI: 1.57-2.00) were significantly higher with PCI than CABG. CONCLUSIONS: CABG was the most common revascularization strategy in this real-world registry. Patients undergoing PCI were much older and of higher risk at baseline. After matching, there was no difference in early mortality but improved late survival and freedom from major adverse cardiac and cerebrovascular events with CABG.

Multiple Arterial Graft Use in Coronary Artery Bypass Surgery: Surgeon Perspective vs Practice.

BACKGROUND: Despite supportive evidence and guidelines, the use of multiple arterial grafts (MAGs) in coronary artery bypass grafting remains low. We sought to determine surgeon perception of personal MAG use and compare this with actual MAG use. METHODS: We conducted a statewide surgeon survey of MAG use, presence of a hospital MAG protocol, and barriers for MAG use, with a response rate of 78% (n = 25). Surgeon survey responses were compared with actual Society of Thoracic Surgeons patient data from January 1, 2017, to December 31, 2020 using χ2 or Fisher's exact tests. RESULTS: Of 5299 patients who had first-time, nonemergent, isolated coronary artery bypass grafting (≥2 grafts) by responding surgeons, 16% received MAG (n = 825). MAG use in patients whose surgeons self-designated as "routine" MAG users was 21% vs 7% for "nonroutine" users. Surgeons with a hospital protocol for MAG use utilized MAG more often (18% vs 14%, P = .001). Surgeons who were unconvinced by the data on the benefits of MAGs used MAGs in 11% vs 22% in surgeons who were convinced. MAG use increased over time, particularly from before to after the survey (13.1% vs 30.5%, P < .001). CONCLUSIONS: Although MAG use increased over time, barriers to routine use remain. In surgeons who reported routine use, only 21% of their patients received MAGs. Hospital protocols, education, and increased awareness may reduce barriers to use and encourage evidence-based clinical practice.