Morbidity and Mortality Associated With Blood Transfusions in Elective Adult Cardiac Surgery.

OBJECTIVES: Perioperative transfusion thresholds have garnered increasing scrutiny as restrictive strategies have been shown to be noninferior. The study authors used data from a statewide academic collaborative to test the association between transfusion and 30-day mortality. DESIGN: All adult patients undergoing coronary artery bypass grafting (CABG) and/or valve surgeries between 2013 and 2019 in the authors' Academic Cardiac Surgery Consortium were examined. The relationship between the number of overall packed red blood cell (pRBC) and coagulation product (CP) (fresh frozen plasma, cryoprecipitate, platelets) transfusions on 30-day mortality was evaluated. Multivariate regression was used to evaluate predictors of transfusion and study endpoints. Machine learning (ML) models also were developed to predict 30-day mortality and rank transfusion-related features by relative importance. SETTING: At an Academic Cardiac Surgery Consortium of 5 institutions. PARTICIPANTS: Patients ≥18 years old undergoing CABG and/or valve surgeries. MEASUREMENTS AND MAIN RESULTS: Of the 7,762 patients (median hematocrit [HCT] 39%, IQR 35%-43%) who were included in the final study cohort, >40% were transfused at least 1 unit of pRBC or CP. In adjusted analyses, higher preoperative HCT was associated with reduced odds of mortality (adjusted odds ratio [aOR] 0.95, 95% CI 0.92-0.98), renal failure (aOR 0.95, 95% CI 0.92-0.98), and prolonged mechanical ventilation (aOR 0.97, 95% CI 0.95-0.99). In contrast, perioperative transfusions were associated with increased 30-day mortality after adjustment for preoperative HCT and other baseline features. The ML models were able to predict 30-day mortality with an area under the curve of 0.814-to-0.850, with perioperative transfusions displaying the highest feature importance. CONCLUSIONS: The present analysis found increasing HCT to be associated with a lower incidence of mortality. The study authors also found a direct dose-response association between transfusions and all study endpoints examined.

Suppression of inflammation and fibrosis using soluble epoxide hydrolase inhibitors enhances cardiac stem cell-based therapy.

Stem cell replacement offers a great potential for cardiac regenerative therapy. However, one of the critical barriers to stem cell therapy is a significant loss of transplanted stem cells from ischemia and inflammation in the host environment. Here, we tested the hypothesis that inhibition of the soluble epoxide hydrolase (sEH) enzyme using sEH inhibitors (sEHIs) to decrease inflammation and fibrosis in the host myocardium may increase the survival of the transplanted human induced pluripotent stem cell derived-cardiomyocytes (hiPSC-CMs) in a murine postmyocardial infarction model. A specific sEHI (1-trifluoromethoxyphenyl-3-(1-propionylpiperidine-4-yl)urea [TPPU]) and CRISPR/Cas9 gene editing were used to test the hypothesis. TPPU results in a significant increase in the retention of transplanted cells compared with cell treatment alone. The increase in the retention of hiPSC-CMs translates into an improvement in the fractional shortening and a decrease in adverse remodeling. Mechanistically, we demonstrate a significant decrease in oxidative stress and apoptosis not only in transplanted hiPSC-CMs but also in the host environment. CRISPR/Cas9-mediated gene silencing of the sEH enzyme reduces cleaved caspase-3 in hiPSC-CMs challenged with angiotensin II, suggesting that knockdown of the sEH enzyme protects the hiPSC-CMs from undergoing apoptosis. Our findings demonstrate that suppression of inflammation and fibrosis using an sEHI represents a promising adjuvant to cardiac stem cell-based therapy. Very little is known regarding the role of this class of compounds in stem cell-based therapy. There is consequently an enormous opportunity to uncover a potentially powerful class of compounds, which may be used effectively in the clinical setting.

Perioperative use of renin-angiotensin system inhibitors and outcomes in patients undergoing cardiac surgery.

It remains disputable about perioperative use of renin-angiotensin system inhibitors (RASi) and their outcome effects. This multicenter retrospective cohort study examines association between use of perioperative RASi and outcomes in patients undergoing coronary artery bypass graft and/or valve surgery. After the exclusion, the patients are divided into 2 groups with or without preoperative RASi (PreRASi, n = 8581), or 2 groups with or without postoperative RASi (PostRASi, n = 8130). With using of propensity scores matching to reduce treatment selection bias, the study shows that PreRASi is associated with a significant reduction in postoperative 30-day mortality compared with without one (3.41% vs. 5.02%); PostRASi is associated with reduced long-term mortality rate compared with without one (6.62% vs. 7.70% at 2-year; 17.09% vs. 19.95% at 6-year). The results suggest that perioperative use of RASi has a significant benefit for the postoperative and long-term survival among patients undergoing cardiac surgery.

Perioperative aspirin and long-term survival in patients undergoing coronary artery bypass graft.

This study aimed to examine association between perioperative uses of aspirin and long-term survival in patients undergoing CABG. A retrospective cohort study was performed in 9,584 consecutive patients receiving cardiac surgery from three tertiary hospitals. Of all the patients, 4,132 patients undergoing CABG met inclusion criteria and were divided into four groups: with or without preoperative or postoperative aspirin respectively. 30-day postoperative and long-term mortality were compared with the use of propensity scores and inverse probability weighting adjustment to reduce the treatment-selection bias. The patients taking preoperative aspirin presented significantly more with comorbidities. However, the results of this study showed that preoperative aspirin (vs. no preoperative aspirin) was associated with significantly reduced the risk of 30-day mortality in the patients undergoing CABG. Further, the results of long-term mortality showed that the patients taking preoperative aspirin and postoperative aspirin (vs. not taking) were associated with significantly reduced the risk of 4-year mortality (14.8% vs. 18.1%, RR: 0.82, 95% CI: 0.75-0.89, P = 0.005; 10.7% vs. 16.2%, RR: 0.66, 95% CI: 0.50-0.82, P = 0.003). In conclusion, this cohort study showed that perioperative (before and after surgery) use of aspirin was associated with significant reduction in 30-day mortality without significant bleeding complications, also improved long-term survival in patients undergoing CABG.

The Effect of Dexmedetomidine on Outcomes of Cardiac Surgery in Elderly Patients.

OBJECTIVE: The goal of this retrospective study was to investigate the effects of perioperative use of dexmedetomidine (Dex) on outcomes for older patients undergoing cardiac surgery. DESIGN: Retrospective investigation. SETTING: Patients from a single tertiary medical center. PARTICIPANTS: A total of 505 patients (≥65 years old) who underwent coronary artery bypass graft (CABG) or valve surgery. CABG and/or valve surgery plus other procedures were divided into 2 groups: 283 received intravenous Dex infusion (Dex group) and 222 did not (Non-Dex group). INTERVENTIONS: Perioperative Dex intravenous infusion (0.24 to 0.6 µg/kg/h) initiated after cardiopulmonary bypass and continued for<24 hours postoperatively in the ICU. MEASUREMENTS AND MAIN RESULTS: Data were risk adjusted, propensity score weighted, and multivariate logistic regression was used. The primary outcome was mortality. Secondary outcomes included postoperative stroke, coma, myocardial infarction, heart block, cardiac arrest, delirium, renal failure, and sepsis. Perioperative Dex infusion significantly decreased in-hospital mortality (0.90% v 2.83%; adjusted odds ratio (OR), 0.099; 95% confidence interval (CI), 0.030-0.324; p = 0.004) and operative mortality (1.35% v 3.18%; adjusted OR, 0.251; 95% CI, 0.077-0.813; p = 0.021). Perioperative Dex treatment also reduced the risk of stroke (0.90% v 1.77%; adjusted OR, 0.15; 95% CI, 0.038-0.590; p = 0.007), and delirium (7.21% v 10.95%; adjusted OR, 0.35; 95% CI, 0.212-0.578; p < 0.0001). CONCLUSIONS: Results from this study (ClinicalTrials.gov identifier: NCT01683448) suggested perioperative use of dexmedetomidine was associated with decreases in in-hospital and operative mortality in elderly patients following cardiac surgery. It also reduced incidences of postoperative stroke and delirium in elderly patients.

Impact of Body Mass Index on Outcomes in Cardiac Surgery.

OBJECTIVES: Body mass index (BMI) commonly is used in obesity classification as a surrogate measure, and obesity is associated with a cluster of risk factors for cardiovascular disease. The aim of this study was to investigate the impact of BMI on short-term outcomes after cardiac surgery. DESIGN: A retrospective cohort study. SETTING: University teaching hospital, 2 centers. PARTICIPANTS: The study comprised 4,740 patients who underwent cardiac surgery at 2 hospitals-from July 1, 2001, to June 30, 2013, in 1 hospital and from September 1, 2003, to August 31, 2014, in a second hospital. INTERVENTIONS: No changes to standard practice were required. MEASUREMENTS AND MAIN RESULTS: Patients were assigned into 6 BMI groups as follows: underweight (BMI<18.5 kg/m(2)), normal weight (≥18.5 to<25 kg/m(2)), overweight (≥25 to<30 kg/m(2)), class I obese (≥30 to<35 kg/m(2)), class II obese (≥35 to<40 kg/m(2)), and class III obese (BMI≥40 kg/m(2)). Short-term major postoperative complications (postoperative stroke, cardiac arrest, new atrial fibrillation/flutter, permanent rhythm device insertion, deep sternal infection, sepsis, prolonged ventilation, pneumonia, renal dialysis, renal failure, intensive care unit readmission, total intensive care unit hours, and readmission in 30 days, and mortalities (in-hospital mortality, 30-day mortality, surgical mortality) were compared among various BMI groups after cardiac surgery. Age, sex, surgery type, family history of coronary artery disease, diabetes, hypertension, heart failure, and lipid-lowering medication were the risk factors for early outcomes. Multiple logistic regression analysis indicated that the underweight and class III obese BMI groups demonstrated significant, adverse differences in some short-term outcomes, including deep sternal infection, prolonged ventilation, new atrial fibrillation/flutter, and renal failure. However, being in the overweight or class I obese group demonstrated a positive effect on discharge and surgical mortality. CONCLUSIONS: The results of this study demonstrated that extreme obesity and underweight were significantly associated with early major adverse clinical outcomes. However, there was an "obese paradox" in short-term mortality after cardiac surgery.

Aortic Root Enlargement with Ascending-to-Descending Aortic Bypass in Repair of Coarctation.

Ascending-to-descending aortic bypass is a valuable technique for addressing coarctation of the aorta when additional cardiac procedures are indicated in adults. Among these, aortic valve replacement is one of the most commonly performed concomitant procedures, and there are instances in which aortic root enlargement is required. Herein, a novel technique is described for performing simultaneous ascending-to-descending aortic bypass in conjunction with aortic root enlargement which incorporates the bypass graft as part of the aortic root enlargement.

Evidence for preoperative aspirin improving major outcomes in patients with chronic kidney disease undergoing cardiac surgery: a cohort study.

BACKGROUND: Effects of aspirin on patients with chronic kidney disease (CKD) remains unclear. This study aimed to examine the effect of preoperative aspirin use on postoperative renal function and 30-day mortality in patients with CKD undergoing cardiac surgery. METHODS: A retrospective cohort study was performed on consecutive patients (n = 5175) receiving cardiac surgery in 2 tertiary hospitals. Of all patients, 3585 met the inclusion criteria and underwent the analysis to determine the association of preoperative aspirin with incidence of acute kidney injury (AKI) and death based on estimated glomerular filtration rate (eGFR). RESULTS: Of 3585 patients, 31.5% had CKD (eGFR < 60 mL/min/1.73 m2) at baseline and 27.6% had AKI postoperatively. The baseline eGFR had a nonlinear relationship with the incidence and stages of AKI. As eGFR decreased to 15 to 30 from more than or equal to 90 mL/min/1.73 m2, AKI and 30-day mortality increased to 50.5% from 23.5% and to 11.9% from 2.6%, respectively (P < 0.001). However, preoperative aspirin use was associated with a significant decrease in postoperative AKI and 30-day mortality in patients with CKD undergoing cardiac surgery, in particular, the survival benefit associated with aspirin was greater in patients with CKD (vs normal kidney function): 30-day mortality was reduced by 23.3%, 58.2%, or 70.0% for patients with baseline eGFR more than or equal to 90, 30 to 59, or 15 to 30 mL/min/1.73 m2, respectively (P trend < 0.001). CONCLUSIONS: For patients with CKD undergoing cardiac surgery, preoperative aspirin therapy was associated with renal protection and mortality decline. The magnitude of the survival benefit was greater in patients with CKD than normal kidney function.

Perioperative dexmedetomidine improves mortality in patients undergoing coronary artery bypass surgery.

OBJECTIVE: This study retrospectively investigated the effect of dexmedetomidine on outcomes of patients undergoing coronary artery bypass graft (CABG) surgery. DESIGN: Retrospective investigation. SETTING: Patients from a single tertiary medical center. PARTICIPANTS: A total of 724 patients undergoing CABG surgery met the inclusion criteria and were categorized into 2 groups: 345 in the dexmedetomidine group (DEX) and 379 in the nondexmedetomidine group (Non-DEX). INTERVENTIONS: Perioperative dexmedetomidine was used as an intravenous infusion (0.24 to 0.6 µg/kg/hour) initiated after cardiopulmonary bypass and continued for less than 24 hours postoperatively in the intensive care unit. MEASUREMENTS AND MAIN RESULTS: Major outcome measures of this study were in-hospital, 30-day and 1-year all-cause mortality, delirium and major adverse cardiocerebral events. Perioperative dexmedetomidine infusion was associated with significant reductions in in-hospital, 30-day, and 1-year mortalities, compared with the patients who did not received dexmedetomidine. In-hospital, 30-day, and 1-year mortalities were 1.5% and 4.0% (adjusted odds ratio [OR], 0.332; 95% CI, 0.155 to 0.708; p = 0.0044), 2.0% and 4.5% (adjusted OR, 0.487; 95% CI, 0.253 to 0.985; p = 0.0305), and 3.2% and 6.9% (adjusted OR 0.421; 95% CI, 0.247 to 0.718, p = 0.0015), respectively. Perioperative dexmedetomidine infusion was associated with a reduced risk of delirium from 7.9% to 4.6% (adjusted OR, 0.431; 95% CI, 0.265-0.701; p = 0.0007). CONCLUSION: Dexmedetomidine infusion during CABG surgery was more likely to achieve improved in-hospital, 30-day, and 1-year survival rates, and a significantly lower incidence of delirium.

The effects of preoperative renin-angiotensin system inhibitors on outcomes in patients undergoing cardiac surgery.

OBJECTIVE: The effects of preoperative (pre-op) renin-angiotensin system (RAS) inhibitors on outcomes in patients undergoing cardiac surgery remain uncertain. The aim of this study was to evaluate whether the use of pre-op RAS inhibitors affected major outcomes of cardiac surgery. DESIGN: A retrospective cohort study. SETTING: A university teaching hospital. PARTICIPANTS: Patients undergoing cardiac surgery between January 1, 2001 and December 31, 2011. INTERVENTIONS: One thousand two hundred thirty-nine patients who received pre-op RAS inhibitors were compared with those who did not (control group, n = 1,083). MEASUREMENTS AND MAIN RESULTS: Acute kidney injury (AKI) was defined using Acute Kidney Injury Network classification. Patients in the RAS inhibitors group presented with higher comorbidities. Pre-op RAS inhibitors therapy was associated with the reduction in the incidence of AKI (27.2% v 34.0%, p<0.001), septicemia (1.9% v 3.5%, p = 0.019), and operative mortality (2.99% v 4.62%, p = 0.039). After adjusted propensity scores and multivariate logistic regression, the pre-op RAS inhibitors were found to have protective effects against AKI (odds ratio [OR]: 0.764, 95% confidence interval [CI]: 0.670-0.873, p<0.001), septicemia (OR: 0.515, 95% CI: 0.348-0.761, p>0.001), and operative mortality (OR: 0.539, 95% CI: 0.348-0.758, p<0.001). CONCLUSION: The results suggested that pre-op RAS inhibitor therapy was associated with significant reductions in the risk of AKI, operative mortality, and septicemia.

Perioperative dexmedetomidine improves outcomes of cardiac surgery.

BACKGROUND: Cardiac surgery is associated with a high risk of cardiovascular and other complications that translate into increased mortality and healthcare costs. This retrospective study was designed to determine whether the perioperative use of dexmedetomidine could reduce the incidence of complications and mortality after cardiac surgery. METHODS AND RESULTS: A total of 1134 patients who underwent coronary artery bypass surgery and coronary artery bypass surgery plus valvular or other procedures were included. Of them, 568 received intravenous dexmedetomidine infusion and 566 did not. Data were adjusted with propensity scores, and multivariate logistic regression was used. The primary outcomes measured included mortality and postoperative major adverse cardiocerebral events (stroke, coma, perioperative myocardial infarction, heart block, or cardiac arrest). Secondary outcomes included renal failure, sepsis, delirium, postoperative ventilation hours, length of hospital stay, and 30-day readmission. Dexmedetomidine use significantly reduced postoperative in-hospital (1.23% versus 4.59%; adjusted odds ratio, 0.34; 95% confidence interval, 0.192-0.614; P<0.0001), 30-day (1.76% versus 5.12%; adjusted odds ratio, 0.39; 95% confidence interval, 0.226-0.655; P<0.0001), and 1-year (3.17% versus 7.95%; adjusted odds ratio, 0.47; 95% confidence interval, 0.312-0.701; P=0.0002) mortality. Perioperative dexmedetomidine therapy also reduced the risk of overall complications (47.18% versus 54.06%; adjusted odds ratio, 0.80; 95% confidence interval, 0.68-0.96; P=0.0136) and delirium (5.46% versus 7.42%; adjusted odds ratio, 0.53; 95% confidence interval, 0.37-0.75; P=0.0030). CONCLUSION: Perioperative dexmedetomidine use was associated with a decrease in postoperative mortality up to 1 year and decreased incidence of postoperative complications and delirium in patients undergoing cardiac surgery. CLINICAL TRIAL REGISTRATION: URL: www.clinicaltrials.gov. Unique identifier: NCT01683448.

Preoperative aspirin use and outcomes in cardiac surgery patients.

BACKGROUND: The effects of preoperative aspirin use on outcomes of cardiac surgery patients remain uncertain. This study was aimed to evaluate the effect of preoperative aspirin use on major outcomes in cardiac surgery patients. METHODS: An observational cohort study was performed on consecutive patients (n = 4256) undergoing cardiac surgery in 2 tertiary hospitals. Of all patients, 2868 patients met the inclusion criteria and were divided into 2 groups: those taking (n = 1923) or not taking (n = 945) aspirin within 5 days preceding surgery. RESULTS: Patients in the aspirin group presented significantly more with comorbidities including hypertension, diabetes, peripheral arterial disease, previous myocardial infarction, angina, cerebrovascular disease, older age, and male gender. With propensity scores adjusted and multivariate logistic regression, however, the results of this study showed that preoperative aspirin therapy (vs nonaspirin) significantly reduced the risk of 30-day mortality (3.5% vs 6.5%, OR: 0.611, 95% CI: 0.391-0.956, P = 0.031), postoperative renal failure (3.7% vs 7.1%, OR: 0.384, 95% CI: 0.254-0.579, P < 0.001), dialysis required (1.9% vs 3.6%, OR: 0.441, 95% CI: 0.254-0.579, P < 0.001), intensive care unit stay (mean 107.2 vs 136.1 h, P < 0.001) and a composite outcome-major adverse cardiocerebral events (8.7% vs 10.8%, OR: 0.662, 95% CI:: 0.482-0.909, P = 0.011) in the patients undergoing cardiac surgery. However, readmissions did not show a significant difference between the 2 groups (14.5% vs 12.8%, P = 0.944). CONCLUSIONS: Preoperative aspirin therapy is associated with a significant decrease in the risk of major cardiocerebral complications, renal failure, intensive care unit stay and 30-day mortality but does not increase the risk of readmissions in patients undergoing cardiac surgery.

Cardiac output monitoring during off-pump coronary artery bypass grafting.

OBJECTIVE: To evaluate and compare monitors of cardiac output during repositioning and stabilization of the heart for off-pump coronary artery bypass (OPCAB) surgery. DESIGN: Prospective, observational, clinical study. SETTING: University teaching hospital. PARTICIPANTS: Consecutive patients scheduled to undergo elective OPCAB (n = 19). INTERVENTIONS: Monitoring, induction, and anesthesia followed a routine protocol for coronary artery bypass patients. This included the use of transesophageal echocardiography (TEE) and pulmonary artery catheter placement. MEASUREMENTS AND MAIN RESULTS: After positioning and stabilization for OPCAB surgery, the changes in descending aortic flow velocity (VTI) times heart rate (HR) and the mixed venous oxygen saturation (SvO(2)) could be used to predict the changes in thermodilution cardiac output (TDCO) using the following model: deltaTDCO((calc))=-13.15+0.35(deltaVTI*HR)+0.61(deltaSvO(2)) where Delta indicates the percentage change from baseline values. The changes in mean arterial pressure, mean pulmonary artery pressure, and continuous cardiac output did not correlate with the changes in TDCO. CONCLUSION: The use of the VTI*HR, as determined by TEE, in addition to the SvO(2) can strengthen clinical decision making during repositioning and stabilization of the heart during OPCAB. Changes in the VTI*HR and SvO(2) can be used as surrogate markers for changes in CO during OPCAB surgery.