Postoperative kidney oxygen saturation as a novel marker for acute kidney injury after adult cardiac surgery

ObjectiveAcute kidney injury is a severe complication and one of the stronger risk factors for death in patients undergoing cardiac surgery. The relationship between postoperative brain oxygen saturation and kidney oxygen saturation with acute kidney injury in adults undergoing cardiac surgery has not been determined. We designed a single-center prospective study to determine if the continuous monitoring of postoperative brain oxygen saturation and kidney oxygen saturation could predict postoperative acute kidney injury.MethodsWe conducted a prospective open cohort study from January to September 2017. The primary outcome was postoperative acute kidney injury using the Kidney Disease: Improving Global Outcomes criteria. Brain oxygen saturation and kidney oxygen saturation, the metrics of which were area measurements (%-min), were recorded during the surgery and the first 48 hours after the cardiac procedure. Receiver operating characteristic curve analysis was used to evaluate the predictive power of kidney oxygen saturation for acute kidney injury.ResultsA total of 121 consecutive patients were enrolled. Thirty-five patients (28.9%) developed acute kidney injury. Brain oxygen saturation showed no statistical difference in both groups; however, kidney oxygen saturation was related to acute kidney injury (P = .001). Receiver operating characteristic curve analysis showed that kidney oxygen saturation could predict the risk of acute kidney injury. Kidney oxygen saturation less than 65% (area under the curve-receiver operating characteristic, 0.679 ± 0.054, 95% confidence interval, 0.573-0.785, P = .002) and 20% decrease from baseline (area under the curve-receiver operating characteristic, 0.639 ± 0.059, 95% confidence interval, 0.523-0.755, P = .019) showed the better performance, respectively.ConclusionsPostoperative kidney oxygen saturation is related to the development of cardiac surgery–associated acute kidney injury. Continuous kidney saturation monitoring might be a promising, noninvasive tool for predicting acute kidney injury during the postoperative period for adult patients after cardiac surgery.     

Urine metabolites for preoperative prediction of acute kidney injury after coronary artery bypass graft surgery

ObjectiveAcute kidney injury is a common complication after on-pump coronary artery bypass grafting. Prediction of acute kidney injury remains a challenge. Our study aims to identify a panel of urine metabolites for preoperative warning of acute kidney injury after on-pump coronary artery bypass grafting.MethodsA total of 159 patients undergoing isolated on-pump coronary artery bypass grafting were enrolled from July 7, 2017, to May 17, 2019. Preoperative urine samples were analyzed with the approach of liquid chromatography-mass spectrometry–based urine metabolomics. The study end point was the episode of acute kidney injury within 48 hours postoperatively. The predictive performance was determined by the area under the curve and calibration curve. The results were validated using bootstrap resampling.ResultsThe acute kidney injury (n = 55) and nonacute kidney injury (n = 104) groups showed significant different metabolic profiling. A total of 28 metabolites showed significant differences between the acute kidney injury and nonacute kidney injury groups. A metabolite panel of 5 metabolites (tyrosyl-gamma-glutamate, deoxycholic acid glycine conjugate, 5-acetylamino-6-amino-3-methyluracil, arginyl-arginine, and L-methionine) was discovered to have a good predicting performance (area under the curve, 0.89; 95% confidence interval, 0.82-0.93), which is higher than the clinical factor–based model (area under the curve, 0.63; 95% confidence interval, 0.53-0.72). Internal validation by bootstrap resampling showed an adjusted area under the curve of 0.88, and the calibration curve demonstrated good agreement between prediction and observation in the probability of postoperative acute kidney injury. Decision curve analysis revealed a superior net benefit of the metabolite model over the traditional clinical factor–based model.ConclusionsWe present 5 urine metabolites related to acute kidney injury after coronary artery bypass grafting. This metabolite model may serve as a preoperative warning of acute kidney injury after on-pump coronary artery bypass grafting.     

Comparison of C-C motif chemokine ligand 14 with other biomarkers for adverse kidney events after cardiac surgery

ObjectiveOutcomes after acute kidney injury are affected by both the severity and the duration of the insult. Patients with persistent acute kidney injury have higher major adverse kidney events, including 90-day mortality, renal replacement therapy, and persistent kidney dysfunction. Methods to identify these patients are urgently needed to improve outcomes. The purpose of this study was to evaluate whether biomarkers, including C-C motif chemokine ligand 14, were able to predict persistent acute kidney injury and major adverse kidney events after cardiac surgery.MethodsThis study was a single-center, prospective, observational study. Patients who developed moderate or severe acute kidney injury (Kidney Disease Improving Global Outcomes 2 or 3) within 72 hours after cardiac surgery were enrolled with a primary end point of persistent severe acute kidney injury (Kidney Disease Improving Global Outcomes 3) lasting 72 hours or more.ResultsA total of 100 patients were available for the primary analysis, and 37 met the primary end point. C-C motif chemokine ligand 14 was the most predictive biomarker for the primary end point with an area under the curve of 0.930 (95% confidence interval, 0.881-0.979). The area under the curve of C-C motif chemokine ligand 14 was significantly higher than the area under the curve for the other biomarkers analyzed. C-C motif chemokine ligand 14 was significantly higher in end point positive patients at enrollment (4.47 ng/mL [2.35-11.5] vs 0.67 ng/mL [0.38-1.07]; P = .001). Sensitivity and specificity were 78% and 95% at a cutoff value of 2.21 ng/mL, respectively. C-C motif chemokine ligand 14 was also highly accurate for predicting renal replacement therapy within 7 days (area under the curve, 0.915; 95% confidence interval, 0.858-0.972; P < .001).ConclusionsElevated C-C motif chemokine ligand 14 levels predict persistent acute kidney injury in cardiac surgery patients with moderate or severe acute kidney injury. This new biomarker may help stratify patients destined to receive renal replacement therapy and identify patients who may benefit from novel therapeutic approaches to acute kidney injury.     

Characteristics and operative outcomes for children undergoing repair of truncus arteriosus: A contemporary multicenter analysis

ObjectiveWe sought to describe characteristics and operative outcomes of children who underwent repair of truncus arteriosus and identify risk factors for the occurrence of major adverse cardiac events (MACE) in the immediate postoperative period in a contemporary multicenter cohort.MethodsWe conducted a retrospective review of children who underwent repair of truncus arteriosus between 2009 and 2016 at 15 centers within the United States. Patients with associated interrupted or obstructed aortic arch were excluded. MACE was defined as the need for postoperative extracorporeal membrane oxygenation, cardiopulmonary resuscitation, or operative mortality. Risk factors for MACE were identified using multivariable logistic regression analysis and reported as odds ratios (ORs) with 95% confidence intervals (CIs).ResultsWe reviewed 216 patients. MACE occurred in 44 patients (20%) and did not vary significantly over time. Twenty-two patients (10%) received postoperative extracorporeal membrane oxygenation, 26 (12%) received cardiopulmonary resuscitation, and 15 (7%) suffered operative mortality. With multivariable logistic regression analysis (which included adjustment for center effect), factors independently associated with MACE were failure to diagnose truncus arteriosus before discharge from the nursery (OR, 3.1; 95% CI, 1.3-7.4), cardiopulmonary bypass duration >150 minutes (OR, 3.5; 95% CI, 1.5-8.5), and right ventricle-to-pulmonary artery conduit diameter >50 mm/m² (OR, 4.7; 95% CI, 2.0-11.1).ConclusionsIn a contemporary multicenter analysis, 20% of children who underwent repair of truncus arteriosus experienced MACE. Early diagnosis, shorter duration of cardiopulmonary bypass, and use of smaller diameter right ventricle-to-pulmonary artery conduits represent potentially modifiable factors that could decrease morbidity and mortality in this fragile patient population.     

Renal perfusion with histidine-tryptophan-ketoglutarate compared with Ringer's solution in patients undergoing thoracoabdominal aortic open repair

ObjectiveThe objective of this study was to compare the efficacy of renal perfusion with Custodiol (Dr Franz-Kohler Chemie GmbH, Bensheim, Germany) versus enriched Ringer's solution for renal protection in patients undergoing open thoracoabdominal aortic aneurysm (TAAA) repair.MethodsNinety consecutive patients scheduled for elective open TAAA repair were enrolled between 2015 and 2017 in a single-center, phase IV, prospective, parallel, randomized, double-blind trial (the CUstodiol versus RInger: whaT Is the Best Agent [CURITIBA] trial), and randomized to renal arteries perfusion with 4°C Custodiol (Dr Franz-Kohler Chemie GmbH, Bensheim, Germany; n = 45) or 4°C lactated Ringer's solution (n = 45). The incidence of acute kidney injury (AKI) in patients undergoing TAAA open surgery using Custodiol renal perfusion versus an enriched Ringer's solution was the primary end point.ResultsNinety patients completed the study (45 patients in each group). The incidence of postoperative AKI was significantly lower in the Custodiol group (48.9% vs 75.6%; P = .02). In the multivariable model, only the use of Custodiol solution resulted as protective from the occurrence of any AKI (odds ratio, 0.230; 95% confidence interval, 0.086-0.614; P = .003), whereas TAAA type II extent was associated with the development of severe AKI (odds ratio, 4.277; 95% confidence interval, 1.239-14.762; P = .02). At 1-year follow-up, serum creatinine was not significantly different from the preoperative values in both groups.ConclusionsThe use of Custodiol during open TAAA repair was safe and resulted in significantly lower rates of postoperative AKI compared with Ringer's solution. These findings support safety and efficacy of Custodiol in this specific setting, which is currently off-label.     

The effect of driving pressure-guided versus conventional mechanical ventilation strategy on pulmonary complications following on-pump cardiac surgery: A randomized clinical trial

Study objectivePostoperative pulmonary complications occur frequently and are associated with worse postoperative outcomes in cardiac surgical patients. The advantage of driving pressure-guided ventilation strategy in decreasing pulmonary complications remains to be definitively established. We aimed to investigate the effect of intraoperative driving pressure-guided ventilation strategy compared with conventional lung-protective ventilation on pulmonary complications following on-pump cardiac surgery.DesignProspective, two-arm, randomized controlled trial.SettingThe West China university hospital in Sichuan, China.PatientsAdult patients who were scheduled for elective on-pump cardiac surgery were enrolled in the study.InterventionsPatients undergoing on-pump cardiac surgery were randomized to receive driving pressure-guided ventilation strategy based on positive end-expiratory pressure (PEEP) titration or conventional lung-protective ventilation strategy with fixed 5 cmH₂O of PEEP.MeasurementsThe primary outcome of pulmonary complications (including acute respiratory distress syndrome, atelectasis, pneumonia, pleural effusion, and pneumothorax) within the first 7 postoperative days were prospectively identified. Secondary outcomes included pulmonary complication severity, ICU length of stay, and in-hospital and 30-day mortality.Main resultsBetween August 2020 and July 2021, we enrolled 694 eligible patients who were included in the final analysis. Postoperative pulmonary complications occurred in 140 (40.3%) patients in the driving pressure group and 142 (40.9%) in the conventional group (relative risk, 0.99; 95% confidence interval, 0.82–1.18; P = 0.877). Intention-to-treat analysis showed no significant difference between study groups regarding the incidence of primary outcome. The driving pressure group had less atelectasis than the conventional group (11.5% vs 17.0%; relative risk, 0.68; 95% confidence interval, 0.47–0.98; P = 0.039). Secondary outcomes did not differ between groups.ConclusionAmong patients who underwent on-pump cardiac surgery, the use of driving pressure-guided ventilation strategy did not reduce the risk of postoperative pulmonary complications when compared with conventional lung-protective ventilation strategy.     

A novel predictive model for poor in-hospital outcomes in patients with acute kidney injury after cardiac surgery

ObjectivePatients with cardiac surgery–associated acute kidney injury are at risk of renal replacement therapy and in-hospital death. We aimed to develop and validate a novel predictive model for poor in-hospital outcomes among patients with cardiac surgery–associated acute kidney injury.MethodsA total of 196 patients diagnosed with cardiac surgery–associated acute kidney injury were enrolled in this study as the training cohort, and 32 blood cytokines were measured. Least absolute shrinkage and selection operator regression and random forest quantile-classifier were performed to identify the key blood predictors for in-hospital composite outcomes (requiring renal replacement therapy or in-hospital death). The logistic regression model incorporating the selected predictors was validated internally using bootstrapping and externally in an independent cohort (n = 52).ResultsA change in serum creatinine (delta serum creatinine) and interleukin 16 and interleukin 8 were selected as key predictors for composite outcomes. The logistic regression model incorporating interleukin 16, interleukin 8, and delta serum creatinine yielded the optimal performance, with decent discrimination (area under the receiver operating characteristic curve: 0.947; area under the precision-recall curve: 0.809) and excellent calibration (Brier score: 0.056, Hosmer–Lemeshow test P = .651). Application of the model in the validation cohort yielded good discrimination. A nomogram was generated for clinical use, and decision curve analysis demonstrated that the new model adds more net benefit than delta serum creatinine.ConclusionsWe developed and validated a promising predictive model for in-hospital composite outcomes among patients with cardiac surgery–associated acute kidney injury and demonstrated interleukin-16 and interleukin-8 as useful predictors to improve risk stratification for poor in-hospital outcomes among those with cardiac surgery–associated acute kidney injury.     

Intravenous amino acid therapy for kidney protection in cardiac surgery patients: A pilot randomized controlled trial

ObjectiveTo determine whether a continuous intravenous infusion of standard amino acids could preserve kidney function after on-pump cardiac surgery.MethodsAdult patients scheduled to receive cardiac surgery lasting longer than 1 hour on-pump were randomized to standard care (n = 36) or an infusion of amino acids initiated immediately after induction of anesthesia (n = 33). The study's primary outcome measurements assessed renal function. These assessments included duration of renal dysfunction, duration and severity of acute kidney injury (AKI), estimated glomerular filtration rate (eGFR) over time, urine output, and use of renal-replacement therapy. Complications and other measures of morbidity were also assessed.ResultsSixty-nine patients (mean age 71.5 [standard deviation 9.2] years; 19 of 69 women) were enrolled and randomized. Patients received coronary artery bypass graft surgery (37/69), valve surgery (24/69), coronary artery bypass graft and valve surgery (6/69), or other procedures (2/69). Mean on-pump time was 268 [standard deviation 136] minutes. Duration of renal dysfunction did not differ between the groups (relative risk, 0.86; 95% confidence interval [CI], 0.19-3.79, P = .84). However, patients who received the amino acid infusion had a reduced duration of AKI (relative risk, 0.02; 95% CI, 0.005-0.11, P < .0001) and greater eGFR (+10.8%; 95% CI, 1.0%-20.8%, P = .033). Daily mean urine output was also significantly greater in patients who received the amino acid infusion (1.4 ± 0.5 vs 1.7 ± 0.9 L/d; P = .046).ConclusionsCommencing an infusion of standard amino acids immediately after the induction of anesthesia did not alter duration of renal dysfunction; however, other key measures of renal function (duration of AKI, eGFR and urine output) were significantly improved. These results warrant replication in multicenter clinical trials.     

Open surgery for descending thoracic aorta in an endovascular era

BackgroundThoracic endovascular aortic repair has become the preferred treatment for a variety of descending thoracic aortic pathologies. However, there are unresolved issues such as morphologic appearance of chronic dissection, persistent false lumen perfusion, and adequacy of landing zone. Enthusiasm for improving the technique of open aortic repair and perioperative management is fading. In this study, we would like to demonstrate how we improve our surgical outcomes by establishing a dedicated aortic multidisciplinary team at the Kawasaki Aortic Center.MethodWe performed a single-center retrospective study from January 2015 to December 2016. All patients with open descending thoracic aortic replacement were recruited. Preoperative patient demographic data, bypass strategies, operative details, and postoperative outcomes were reviewed.ResultFrom January 2015 to December 2016, we treated 168 cases of descending thoracic aortic repair using a left thoracotomy. Median age was 69.0 ± 21.8 years old, and 63.1% were aortic dissection (acute, 4.8%; chronic, 58.3%); 81.3% patients underwent elective operations. Left heart bypass, deep hypothermic circulatory arrest, and partial cardiopulmonary bypass were performed in 88.6%, 9.0%, and 2.4% of patients, respectively. Mean operative time was 312 ± 94 minutes. In-hospital mortality in total was 0.6%. The rate of transient spinal cord injury was 4.7%.ConclusionsUnder a dedicated aortic multidisciplinary team, we demonstrated that open descending thoracic aorta replacement can be performed with excellent early outcomes with low reintervention rates, regardless of the nature of the aortic pathologies.     

The impact of long-term corticosteroid use on acute postoperative complications following lumbar decompression surgery

BackgroundCorticosteroids have a negative impact on the human immune system’s ability to function at an optimal level. Studies have shown that patients on long-term corticosteroids have higher infection rates. However, the rates of infection and other complications following lumbar decompression surgery remains under-investigated. The aim of our study was to determine the impact of preoperative long-term corticosteroid usage on acute, 30-day postoperative complications in a subset of patients undergoing lumbar spine decompression surgery, without fusion or instrumentation. We hypothesize that patients on long-term corticosteroids will have higher rates of infection and other postoperative complications after undergoing lumbar decompression surgery of the spine.MethodsA retrospective cohort study was conducted using data collected from the National Surgical Quality Improvement Program database data from 2005 to 2016. Lumbar decompression surgeries, including discectomies, laminectomies, and others were identified using CPT codes. Chi-square analysis was used to evaluate differences among the corticosteroid and non-corticosteroid groups for demographics, preoperative comorbidities, and postoperative complications. Logistic regression analysis was done to determine if long-term corticosteroid use predicts incidence of postoperative infections following adjustment.Results26,734 subjects met inclusion criteria. A total of 1044 patients (3.9%) were on long-term corticosteroids prior to surgical intervention, and 25,690 patients (96.1%) were not on long-term corticosteroids. Patients on long-term corticosteroids were more likely to be older (p < 0.001), female (p < 0.001), nonsmokers (p < 0.001), and have a higher American Society of Anesthesiologist class (p < 0.001). Multivariate analysis demonstrated that long-term corticosteroid usage was associated with increased overall complications (odds ratio [OR]: 1.543; p < 0.001), and an independent risk factor for the development of minor complications (OR: 1.808; p < 0.001), urinary tract infection (OR: 2.033; p = 0.002), extended length of stay (OR: 1.244; p = 0.039), thromboembolic complications (OR: 1.919; p = 0.023), and sepsis complications (OR: 2.032; p = 0.024).ConclusionLong-term corticosteroid usage is associated with a significant increased risk of acute postoperative complication development, including urinary tract infection, sepsis and septic shock, thromboembolic complications, and extended length of hospital stay, but not with superficial or deep infection in patients undergoing lumbar decompression procedures. Spine surgeons should remain vigilant regarding postoperative complications in patients on long-term corticosteroids, especially as it relates to UTI and propensity to decompensate into sepsis or septic shock. Thromboembolic risk attenuation is also imperative in this patient group during the postoperative period and the surgeon should weigh the risks and benefits of more intensive anticoagulation measures.     

The fate of aortic valve after rheumatic mitral valve surgery

ObjectiveDeterioration of the native aortic valve function by a late progression of rheumatic disease is not infrequent in patients who underwent rheumatic mitral valve surgery; however, this phenomenon has not been clearly quantified.MethodsA total of 1155 consecutive patients (age 52.0 ± 12.9 years; 807 female) who underwent rheumatic mitral valve surgery without concomitant aortic valve surgery from 1997 to 2015 were enrolled. The primary end point was the composite of progression to severe aortic valve dysfunction or a requirement of subsequent aortic valve replacements during follow-up. To determine the risk factors of the primary outcome, we performed the generalized linear mixed model.ResultsThe baseline severities of aortic valve were none to trivial in 880 patients (76.2%), mild in 256 patients (22.2%), and moderate in 19 patients (1.6%). The latest 1062 echocardiographic assessments (91.9%; median, 81.2 postoperative months; interquartile range, 37.3-132.1 months) demonstrated 26 cases (0.33%/patient-year) meeting the primary end point during follow-up. Cumulative incidence of the primary end point at 10 years was 0.4% ± 0.3% and 7.4% ± 2.5% depending on the presence of mild or greater aortic valve dysfunction at baseline (P < .01). In multivariable analyses, aortic valve peak pressure gradient (odds ratio, 1.14; 95% confidence interval, 1.10-1.20), aortic regurgitation degree (mild over none: odds ratio, 3.26; 95% confidence interval, 1.15-9.23), and time (odds ratio, 1.30; 95% confidence interval 1.19-1.41) were significantly associated with the occurrence of the primary end point.ConclusionsProgression of severe aortic valve dysfunction and the need for aortic valve replacement are uncommon in patients undergoing rheumatic mitral valve surgery. However, such events were relatively common among those with mild or greater aortic valve dysfunction at the time of mitral valve surgery.     

Myeloperoxidase in the pericardial fluid improves the performance of prediction rules for postoperative atrial fibrillation

ObjectivesAfter surgery, inflammation is a prominent factor influencing postoperative atrial fibrillation. Myeloperoxidase is a major contributor to inflammatory responses after surgical tissue damage. We evaluated whether myeloperoxidase is associated with postoperative atrial fibrillation clinically and in an animal model.MethodsThis prospective cohort study included patients undergoing isolated coronary artery bypass grafting. Myeloperoxidase concentrations in blood and pericardial fluid were determined at baseline and 6, 12, and 18 hours after coronary artery bypass grafting. Myeloperoxidase activity in blood, pericardial fluid, and atrium were also evaluated in a canine coronary artery bypass grafting model. Electrophysiologic, histologic, and immunohistochemistry analyses were performed to explore underlying mechanisms.ResultsPostoperative atrial fibrillation occurred in 45 of 137 patients (32.8%). Patients with postoperative atrial fibrillation had significantly higher serum and pericardial myeloperoxidase levels. Individual clinical and surgical factors had moderate predictive value (area under the curve, 0.760) for postoperative atrial fibrillation. Discrimination improved remarkably when myeloperoxidase was combined with other parameters (area under the curve, 0.901). Pericardial myeloperoxidase at 6 hours postoperatively was the strongest independent predictor of postoperative atrial fibrillation (odds ratio, 19.215). The rate of postoperative atrial fibrillation increased exponentially across pericardial myeloperoxidase grades. Compared with controls, coronary artery bypass grafting–treated dogs showed higher atrial fibrillation vulnerability and maintenance, shorter atrial effective refractory period, attenuated connexin 43 expression, and increased myocardial and pericardial myeloperoxidase activity. Connexin 43 expression and atrial effective refractory period were strongly negatively correlated with myocardial and pericardial myeloperoxidase activity.ConclusionsMyeloperoxidase is linked to postoperative atrial fibrillation, and the ability to predict postoperative atrial fibrillation was remarkably improved by adding pericardial myeloperoxidase. Myeloperoxidase-related atrial structural and electrical remodeling is a physiologic substrate for this arrhythmia.     

Differences among sexes in presentation and outcomes in acute type A aortic dissection repair

ObjectiveFemale sex is a known risk factor in most cardiac surgery, including coronary and valve surgery, but unknown in acute type A aortic dissection repair.MethodsFrom 1996 to 2018, 650 patients underwent acute type A aortic dissection repair; 206 (32%) were female, and 444 (68%) were male. Data were collected through the Cardiac Surgery Data Warehouse, medical record review, and National Death Index database.ResultsCompared with men, women were significantly older (65 vs 57 years, P < .0001). The proportion of women and men inverted with increasing age, with 23% of patients aged less than 50 years and 65% of patients aged 80 years or older being female. Women had significantly less chronic renal failure (2.0% vs 5.4%, P = .04), acute myocardial infarction (1.0% vs 3.8%, P = .04), and severe aortic insufficiency. Women underwent significantly fewer aortic root replacements with similar aortic arch procedures, shorter cardiopulmonary bypass times (211 vs 229 minutes, P = .0001), and aortic crossclamp times (132 vs 164 minutes, P < .0001), but required more intraoperative blood transfusion (4 vs 3 units) compared with men. Women had significantly lower operative mortality (4.9% vs 9.5%, P = .04), especially in those aged more than 70 years (4.4% vs 16%, P = .02). The significant risk factors for operative mortality were male sex (odds ratio, 2.2), chronic renal failure (odds ratio, 3.4), and cardiogenic shock (odds ratio, 6.8). The 10-year survival was similar between sexes.ConclusionsPhysicians and women should be cognizant of the risk of acute type A aortic dissection later in life in women. Surgeons should strongly consider operations for acute type A aortic dissection in women, especially in patients aged 70 years or more.     

Coronary artery bypass grafting after acute ST-elevation myocardial infarction

ObjectivesThe study objectives were to describe the trends and outcomes of isolated coronary artery bypass grafting after ST-elevation myocardial infarction using a nationwide database.MethodsWe queried the 2002-2016 National Inpatient Sample database for hospitalized patients with ST-elevation myocardial infarction who underwent isolated coronary artery bypass grafting. We report temporal trends, predictors, and outcomes of coronary artery bypass grafting in the early (2002-2010) and recent (2011-2016) cohorts.ResultsOf 3,347,470 patients hospitalized for ST-elevation myocardial infarction, 7.7% underwent isolated coronary artery bypass grafting. The incidence of isolated coronary artery bypass grafting after ST-elevation myocardial infarction decreased over time (9.2% in 2002 vs 5.5% in 2016, P_trend < .001), whereas perioperative crude in-hospital mortality did not change (5.1% in 2002 vs 4.2% in 2016, P_trend = .66), coinciding with an increase in the burden of comorbidities. There was an increase in performing isolated coronary artery bypass grafting on hospitalization day 3 or more, as well as an increase in the use of mechanical support devices and precoronary artery bypass grafting percutaneous coronary intervention. In the early cohort, isolated coronary artery bypass grafting on days 1 and 2 was associated with higher in-hospital mortality. In the recent cohort, coronary artery bypass grafting on day 2 had similar in-hospital mortality compared with day 3 or more and lower rates of acute kidney injury, ischemic stroke, ventricular arrhythmia, and length of hospital stay.ConclusionsIn this nationwide analysis, there has been a decline in the use of isolated coronary artery bypass grafting after ST-elevation myocardial infarction. Isolated coronary artery bypass grafting on day 1 was performed in sicker patients and was associated with higher in-hospital mortality than coronary artery bypass grafting performed on day 3 or more. In the recent cohort, isolated coronary artery bypass grafting on day 2 had similar in-hospital mortality compared with day 3 or more.     

Stage 1 acute kidney injury is independently associated with infection following cardiac surgery

ObjectivesSevere acute kidney injury (AKI) is a known risk factor for infection and mortality. However, whether stage 1 AKI is a risk factor for infection has not been evaluated in adults. We hypothesized that stage 1 AKI following cardiac surgery would independently associate with infection and mortality.MethodsIn this retrospective propensity score–matched study, we evaluated 1620 adult patients who underwent nonemergent cardiac surgery at the University of Colorado Hospital from 2011 to 2017. Patients who developed stage 1 AKI by Kidney Disease Improving Global Outcomes creatinine criteria within 72 hours of surgery were matched to patients who did not develop AKI. The primary outcome was an infection, defined as a new surgical-site infection, positive blood or urine culture, or development of pneumonia. Secondary outcomes included in-hospital mortality, stroke, and intensive care unit (ICU) and hospital length of stay (LOS).ResultsStage 1 AKI occurred in 293 patients (18.3%). Infection occurred in 20.9% of patients with stage 1 AKI compared with 8.1% in the no-AKI group (P < .001). In propensity-score matched analysis, stage 1 AKI independently associated with increased infection (odds ratio [OR]; 2.24, 95% confidence interval [CI], 1.37-3.17), ICU LOS (OR, 2.38; 95% CI, 1.71–3.31), and hospital LOS (OR, 1.30; 95% CI, 1.17-1.45).ConclusionsStage 1 AKI is independently associated with postoperative infection, ICU LOS, and hospital LOS. Treatment strategies focused on prevention, early recognition, and optimal medical management of AKI may decrease significant postoperative morbidity.     

Goal-directed fluid therapy guided by Plethysmographic Variability Index (PVI) versus conventional liberal fluid administration in children during elective abdominal surgery: A randomized controlled trial

BackgroundPVI has been shown to be an accurate predictor of fluid responsiveness in paediatric patients. Evidence regarding the role of PVI to guide intraoperative fluid therapy in paediatric abdominal surgery is lacking. We aimed to assess the effect of PVI-guided fluid therapy on the volume of intraoperative fluids administered and post-operative biochemical and recovery profile in children undergoing elective abdominal surgery.Methods42 children, 6 months-3 years scheduled for elective open bowel surgery were randomised to receive either ‘conventional liberal intraoperative fluids’ (liberal group) or ‘goal-directed intraoperative fluids’ (GDT group). PVI <13 was targeted in the GDT group. The primary outcome was the volume of intraoperative fluids administered. Postoperative serum lactate, base excess, hematocrit, recovery of bowel function and duration of postoperative hospital stay were the secondary outcomes.ResultsThe mean fluid administered intra-operatively was significantly lower in the GDT group as compared to the liberal group (24.1 ± 9.6 mL/kg vs 37.0 ± 8.9 mL/kg, p < 0.001). The postoperative hemoglobin concentration (g%) was significantly lower in the liberal group as compared to the GDT group (8.1 ± 1.3 vs 9.2 ± 1.4, p = 0.008). Recovery of bowel function (hours) was significantly delayed in the liberal group as compared to the GDT group (58.2 ± 17.9 vs 36.5 ± 14.1, p < 0.001).ConclusionIntraoperative PVI-guided fluid therapy significantly reduces the volume of intravenous crystalloids administered to children undergoing open bowel surgery. These children also had faster recovery of bowel function and less hemodilution in the immediate postoperative period, compared to those who received liberal intraoperative fluid therapy.Type of study: Randomized Clinical Trial.Level of evidence: Treatment Study (LEVEL 1).     

Is anterior mitral valve leaflet length important in outcome of septal myectomy for obstructive hypertrophic cardiomyopathy?

ObjectivesElongation of mitral valve leaflets is a phenotypic feature of hypertrophic cardiomyopathy, and some surgeons advocate plication of the anterior leaflet at the time of septal myectomy. The present study investigates mitral valve leaflet length and outcomes of patients undergoing septal myectomy for obstructive hypertrophic cardiomyopathy.MethodsWe reviewed the records and echocardiograms of 564 patients who underwent transaortic septal myectomy for obstructive hypertrophic cardiomyopathy between February 2015 and April 2018. Extended septal myectomy without plication of the anterior leaflet was the standard procedure. From intraoperative prebypass transesophageal echocardiograms, we measured anterior and posterior mitral valve leaflets and their coaptation length. For comparison, we performed these mitral valve leaflet measurements in 90 patients who underwent isolated coronary artery bypass grafting and 92 patients undergoing aortic valve replacement in the same period. Among patients with hypertrophic cardiomyopathy undergoing septal myectomy, we assessed left ventricular outflow tract gradient relief and 1-year survival in relation to leaflet length.ResultsMedian patient age (interquartile range) was 60.3 (50.2-67.7) years, and 54.1% were male. Concomitant mitral valve repair was performed in 36 patients (6.4%), and mitral valve replacement was performed in 8 patients (1.4%), primarily for intrinsic mitral valve disease. Patients in the hypertrophic cardiomyopathy cohort had significantly longer mitral valve leaflet measurements compared with patients undergoing coronary artery bypass grafting or aortic valve replacement (P < .001 for all 3 measurements). Preoperative resting left ventricular outflow tract gradients were not related to leaflet length (<30 mm, median 49 [21, 81.5] mm Hg vs ≥30 mm, 50.5 [21, 77] mm Hg; P = .76). Further, gradient reduction after myectomy was not related to leaflet length; patients with less than 30 mm anterior leaflet length had a median gradient reduction of 33 (69, 6) mm Hg compared with 36.5 (62, 6) mm Hg for patients with leaflet length 30 mm or more (P = .36). Anterior mitral valve leaflet length was not associated with increased 1-year mortality (P = .758).ConclusionsOur study confirms previous findings that patients with hypertrophic cardiomyopathy have slight (5 mm) elongation of mitral valve leaflets. In contrast to other reports, increased anterior mitral valve leaflet length was not associated with higher left ventricular outflow tract gradients. Importantly, we found no significant relationship between anterior mitral valve leaflet length and postoperative left ventricular outflow tract resting gradients or gradient relief. Thus, in the absence of intrinsic mitral valve disease, transaortic septal myectomy with focus on extending the excision beyond the point of septal contact is sufficient for almost all patients.     

Should concomitant surgical ablation for atrial fibrillation be performed in elderly patients?

ObjectiveThe incidence of atrial fibrillation increases with age, and therefore many elderly patients presenting for cardiac surgery have atrial fibrillation. In recent publications, increasing age has been recognized as a predictor for ablation failure. Furthermore, many surgeons are reluctant to perform a surgical ablation in elderly patients. We investigated the safety and efficacy of concomitant surgical atrial fibrillation ablation in elderly patients.MethodsBetween 2003 and 2013, 556 patients underwent concomitant surgical atrial fibrillation ablation at the University Heart Center Hamburg and served as our primary study cohort. During follow-up, rhythm monitoring was established by 24-hour Holter electrocardiogram (70.5%) or an implantable loop recorder (29.5%) at 3, 6, and 12 months postoperatively. The primary end point of the study was freedom from atrial fibrillation at 12 months follow-up and the detection of deviations from a linear association between age and risk of atrial fibrillation recurrence. A multiple logistic regression model including age as a linear term was used to identify predictors for rhythm outcome.ResultsMean patients’ age was 68.4 ± 9.07 years, and 67.3% of the patients were male. Mean duration of atrial fibrillation was 3.5 ± 3.3 years, and mean left atrium diameters were enlarged with 50.5 ± 8.8 mm. There were no major ablation-related complications. The 30-day and 1-year survivals were 97.7% and 95.8%, respectively. The overall rate of freedom from atrial fibrillation ranged from 62% to 72% and was independent of age. The age-dependent risk of atrial fibrillation at 12 months was significantly increased in elderly patients undergoing a concomitant coronary artery bypass grafting surgery. Multiple logistic regression model revealed double valve procedures (odds ratio, 3.48; P = .020), preoperative persistent atrial fibrillation (odds ratio, 2.43; P = .001), and coronary artery bypass grafting surgery in elderly patients (odds ratio, 2.03; P = .009) as risk factors for recurrence of atrial fibrillation. Sinus rhythm at discharge (odds ratio, 0.39; P < .001) and bipolar ablation (odds ratio, 0.32; P < .001) were significant predictors for successful ablation.ConclusionsSurgical atrial fibrillation ablation was safe and effective independently of age. Sinus rhythm at discharge and bipolar ablation were significant predictors for successful ablation, whereas double valve procedures, preoperative persistent atrial fibrillation, and coronary artery bypass grafting surgery in elderly patients were risk factors for recurrence of atrial fibrillation.     

Reducing delirium and cognitive dysfunction after off-pump coronary bypass: A randomized trial

BackgroundNeuropsychiatric complications of surgical coronary revascularization are inconspicuous but frequent and clinically relevant. So far, attempts to reduce their occurrence, such as the introduction of off-pump coronary artery bypass (OPCAB) grafting method, have not brought the desired results. The aim of this trial was to determine whether using any of the 2 selected modifications of OPCAB could decrease the incidence of these undesired sequelae.MethodsIn this single-center, assessor- and patient-blinded, superiority, randomized controlled trial, 192 patients scheduled for elective isolated OPCAB were randomized to 3 parallel arms. The control arm underwent “conventional” OPCAB with vein grafts. The first study arm underwent anaortic OPCAB (ANA) with total arterial revascularization. The second study arm underwent OPCAB with vein grafts using carbon dioxide surgical field flooding (CO₂FF). Outcomes included the incidence of postoperative delirium (PD) and early postoperative cognitive dysfunction (ePOCD).ResultsThe incidence of PD was 35.9% in the control (OPCAB) arm, 32.8% in the CO₂FF arm, and 12.5% in the ANA arm (χ² [2, N = 191] = 10.17; P = .006). Post hoc tests revealed that the incidence of PD in the ANA arm differed from that in the OPCAB arm (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.09-0.68; P = .002). The incidence of ePOCD was 34.4% in the OPCAB arm, 28.1% in the CO₂FF arm, and 9.5% in the ANA arm (χ² [2, N = 191] = 11.58; P = .003). Post hoc tests revealed that the incidence of ePOCD differed between the ANA and OPCAB arms (OR, 0.20; 95% CI, 0.06-0.58; P < .001).ConclusionsPerforming ANA significantly decreases the incidence of PD and ePOCD compared with “conventional” OPCAB with vein grafts, whereas CO₂FF is inconsequential in this regard. These results, which probably reflect decreased delivery of embolic load to the brain in ANA, may have practical applicability in daily practice to improve clinical outcomes.     

Derivation and Validation of a Machine Learning Algorithm for Predicting Venous Thromboembolism in Injured Children

BackgroundVenous thromboembolism (VTE) causes significant morbidity in pediatric trauma patients. We applied machine learning algorithms to the Trauma Quality Improvement Program (TQIP) database to develop and validate a risk prediction model for VTE in injured children.MethodsPatients ≤18 years were identified from TQIP (2017–2019, n = 383,814). Those administered VTE prophylaxis ≤24 h and missing the outcome (VTE) were removed (n = 347,576). Feature selection identified 15 predictors: intubation, need for supplemental oxygen, spinal injury, pelvic fractures, multiple long bone fractures, major surgery (neurosurgery, thoracic, orthopedic, vascular), age, transfusion requirement, intracranial pressure monitor or external ventricular drain placement, and low Glasgow Coma Scale score. Data was split into training (n = 251,409) and testing (n = 118,175) subsets. Machine learning algorithms were trained, tested, and compared.ResultsLow-risk prediction: For the testing subset, all models outperformed the baseline rate of VTE (0.15%) with a predicted rate of 0.01–0.02% (p < 2.2e⁻¹⁶). 88.4–89.4% of patients were classified as low risk by the models.High-risk predictionAll models outperformed baseline with a predicted rate of VTE ranging from 1.13 to 1.32% (p < 2.2e⁻¹⁶). The performance of the 3 models was not significantly different.ConclusionWe developed a predictive model that differentiates injured children for development of VTE with high discrimination and can guide prophylaxis use.Level of EvidencePrognostic, Level II.Type of StudyRetrospective, Cross-sectional.