Stroke prevention strategies for cardiac surgery: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Stroke is a much-feared complication of cardiac surgery, but existing literature on preventive strategies is fragmented. Hence, a systematic review and meta-analysis of stroke prevention strategies for cardiac surgery was conducted. METHODS: An electronic literature search was conducted to retrieve randomized controlled trials (RCTs) investigating perioperative interventions for cardiac surgery, with stroke as an outcome. Random-effects meta-analyses were conducted to generate risk ratios (RRs), 95% confidence intervals (95% CI), and forest plots. Descriptive analysis and synthesis of literature was conducted for interventions not amenable to meta-analysis, focusing on risks of stroke, myocardial infarction and study-defined major adverse cardiovascular events (MACE). RESULTS: Fifty-six RCTs (61 894 patients) were retrieved. Many included trials were underpowered to detect differences in stroke risk. Among pharmacological therapies, only preoperative amiodarone was shown to reduce stroke risk in one trial. Concomitant left atrial appendage closure (LAAC) significantly reduced stroke risk (RR = 0.55, 95% CI = 0.36-0.84, P = 0.006) in patients with preoperative atrial fibrillation, and there was no difference in on-pump versus off-pump coronary artery bypass grafting (CABG) (RR = 0.94, 95% CI = 0.64-1.37, P = 0.735). Much controversy exists in literature on the timing of carotid endarterectomy relative to CABG in patients with severe carotid stenosis. The use of preoperative remote ischemic preconditioning was not found to reduce rates of stroke or MACE. CONCLUSION: This review presents a comprehensive synthesis of existing interventions for stroke prevention in cardiac surgery, and identifies gaps in research which may benefit from future, large-scale RCTs. LAAC should be considered to reduce stroke incidence in patients with preoperative atrial fibrillation.

Association between HbA1c and deep sternal wound infection after coronary artery bypass: a systematic review and meta-analysis.

BACKGROUND: Deep sternal wound infection (DSWI) constitutes a serious complication after coronary artery bypass grafting (CABG) surgery. The aim of this study is to evaluate the dose-response relationship between glycated hemoglobin (HbA1c) level and the risk of DSWI after CABG. METHODS: PubMed, Scopus, and Cochrane Library databases were searched to identify potentially relevant articles. According to rigorous inclusion and exclusion criteria, fourteen studies including 15,570 patients were enrolled in our meta-analysis. Odds ratio (OR) with 95% confidence intervals (CIs) was used as the summary statistic. The robust-error meta-regression model was used to synthesize the dose-response relationship. RESULTS: Our meta-analysis shows that among patients undergoing CABG, preoperative elevated HbA1c was associated with the risk of developing DSWI (OR = 2.67, 95% CI 2.00-3.58) but with low prognostic accuracy (diagnostic OR = 2.70, 95% CI 1.96-3.73; area under the curve = 0.66, 95% CI 0.62-0.70) for predicting postoperative DSWI. Subgroup analyses showed the relationship became nonsignificant in patients without diabetes and studies adopting lower HbA1c thresholds. Dose-response analysis showed a significant nonlinear (p = 0.03) relationship between HbA1c and DSWI, with a significantly increased risk of DSWI when HbA1c was > 5.7%. CONCLUSIONS: An elevated HbA1c level of > 5.7% was related to a higher risk of developing DSWI after CABG, and the risk increased as the HbA1c level grew. The association between HbA1c and DSWI was nonsignificant among nondiabetic patients while significant among diabetic patients.

Rational design of Bi2Sn2O7/Bi5O7I S-scheme heterojunction for visible photocatalytic oxidation of emerging pollutants.

The construction of an S-scheme heterostructure is considered as a promising strategy for enhancing photocatalytic performance. Herein, a three-dimensional Bi5O7I (BOI) microsphere decorated with Bi2Sn2O7 (BSO) nanoparticles was prepared for the first time via a simple ultrasonic-assisted electrostatic self-assembly strategy and used for the degradation of 2,4-dinitrophenylhydrazine. 3 wt% Bi2Sn2O7/Bi5O7I has the highest degradation activity (93.7 %), with an apparent rate constant of 0.0848 min-1, which is 2.55 times that of the original Bi5O7I (0.0333 min-1). Moreover, the optimal binary heterojunction photocatalyst has good reusability and universal applicability. The results of cyclic voltammetry tests clarify that the optimal photocatalyst can provide more surface reactive sites. The results of radical trapping experiments and electron spin resonance indicate that holes (h+) and superoxide radicals are the main active radicals in the degradation process of 2,4-dinitrophenylhydrazine. Photoelectrochemical and photoluminescence confirm that 3 wt% Bi2Sn2O7/Bi5O7I composites exhibit the highest separation rate of photogenerated carriers. Finally, based on the results of experimental studies and theoretical calculations, the S-scheme charge transfer path on Bi2Sn2O7/Bi5O7I composite is determined. This work provides a new perspective on how to design high-performance S-scheme bismuth oxyhalide-based heterojunction photocatalysts for solar energy conversion.

Efficacy of mesh coverage in surgical bullectomy for primary spontaneous pneumothorax: A systematic review and meta-analysis.

BACKGROUND AND PURPOSE: Thoracic surgeons are now adopting a new method of using a mesh covering to reduce recurrence in surgical pleurodesis for pneumothorax. We aimed to review the literature and compare the outcomes of using mesh covering as an additional procedure during surgical pleurodesis. METHODS: A comprehensive search was performed from inception to October 2022 on PubMed, Embase, Cochrane and Scopus. Randomised controlled trials (RCTs) and observational cohort studies (OCSs) comparing the use of mesh coverage, and different materials were included. Data were extracted to compare recurrence and other outcomes using a random effect model. RESULTS: 23 studies consisting of 2 RCTs and 21 OCSs totalling 5092 patients were included. Patients with a mesh had a significantly lower recurrence (OR = 0.22, 95% CI 0.12-0.42, p < 0.0001) and a shorter duration of chest tube drainage (SMD = -0.74 days, 95% CI -0.28 to -1.20, p < 0.0001) but no significant difference in the length of operation. The use of polyglycolic acid (PGA) and vicryl mesh was associated with a significantly shorter duration of chest tube drainage [(PGA, SMD = 0.83 days, 95% CI 0.14-1.52, p < 0.0001), (vicryl, SMD = 1.06 days, 95% CI 0.71-2.82, p = 0.0005)]. They also had a shorter post-operative length of stay than oxidized regenerative cellulose (ORC) but this was not statistically significant. CONCLUSION: The use of a mesh material reduced the incidence of post-operative air leaks in the short term and the recurrence rate in the long term. Some mesh materials such as PGA and vicryl performed better than other materials.

Impact of restrictive red blood cell transfusion strategy on thrombosis-related events: A meta-analysis and systematic review.

BACKGROUND AND OBJECTIVES: There is an ongoing controversy regarding the risks of restrictive and liberal red blood cell (RBC) transfusion strategies. This meta-analysis assessed whether transfusion at a lower threshold was superior to transfusion at a higher threshold, with regard to thrombosis-related events, that is, whether these outcomes can benefit from a restrictive transfusion strategy is debated. MATERIALS AND METHODS: We searched PubMed, Cochrane Central Register of Controlled Trials and Scopus from inception up to 31 July 2021. We included randomized controlled trials (RCTs) in any clinical setting that evaluated the effects of restrictive versus liberal RBC transfusion in adults. We used random-effects models to calculate the risk ratios (RRs) and 95% confidence intervals (CIs) based on pooled data. RESULTS: Thirty RCTs involving 17,334 participants were included. The pooled RR for thromboembolic events was 0.65 (95% CI 0.44-0.94; p = 0.020; I2  = 0.0%, very low-quality evidence), favouring the restrictive strategy. There were no significant differences in cerebrovascular accidents (RR = 0.83; 95% CI 0.64-1.09; p = 0.180; I2  = 0.0%, very low-quality evidence) or myocardial infarction (RR = 1.05; 95% CI 0.87-1.26; p = 0.620; I2  = 0.0%, low-quality evidence). Subgroup analyses showed that a restrictive (relative to liberal) strategy reduced (1) thromboembolic events in RCTs conducted in North America and (2) myocardial infarctions in the subgroup of RCTs where the restrictive transfusion threshold was 7 g/dl but not in the 8 g/dl subgroup (with a liberal transfusion threshold of 10 g/dl in both subgroups). CONCLUSIONS: A restrictive (relative to liberal) transfusion strategy may be effective in reducing venous thrombosis but not arterial thrombosis.

N-Acetylcysteine's Renoprotective Effect in Cardiac Surgery: A Systematic Review and Meta-Analysis.

OBJECTIVE: To examine N-acetylcysteine's (NAC's) renoprotective effect in adult cardiac surgeryMethods: PubMed, Ovid Medline, and Embase were searched for randomized controlled trials published between January 1990 and May 2021 that investigated the effect of NAC in preventing acute kidney injury (AKI) in patients undergoing cardiac surgery. The inclusion criterion was studies that assessed the effect of NAC in comparison to placebo by measuring the incidence of AKI. RESULTS: Overall meta-analytic estimates of all 10 included trials showed that NAC did not have a significant effect (odds ratio [OR]: 0.84, 95% confidence interval [CI]: 0.64-1.10) on AKI. Further subgroup analysis did not show a significant benefit of NAC in preventing AKI. CONCLUSION: This meta-analysis suggests that NAC does not have a significant effect in reducing the incidence of AKI. However, there is notable heterogeneity among the included studies that could possibly account for the non-significant effect observed. It is worth noting that only one trial administered NAC high dosages perioperatively, and it is the only included trial to show a significant benefit in reducing the incidence of AKI (OR: 0.30, 95% CI: 0.11-0.81). Further studies on this dosage and duration of administration should be conducted to best elucidate the effect of administering NAC.

Comparison of the safety and efficacy between minimally invasive cardiac surgery and median sternotomy in a low-risk mixed Asian population in Singapore.

Introduction: Minimally invasive cardiac surgery (MICS) has attracted increasing attention, with institutions increasingly adopting this approach over conventional median sternotomy (MS). This study aimed to describe the outcomes of minimally invasive cardiac surgery in our institution as the only centre with an established MICS programme in Singapore. Methods: Patients who had undergone cardiac procedures such as heart valve replacement or repair, coronary artery bypass grafting or atrial septal defect repair were included in the study. We analysed 4063 patients who had undergone MS and 390 patients who had undergone MICS between January 2009 and February 2020. Results: Over the years, the number of MICS procedures performed increased, along with an increase in MICS operations with two or more concomitant cardiac procedures and a decrease in postoperative length of stay. Compared with patients who underwent MS, those who underwent MICS had shorter length of postoperative hospital stay (P < 0.001). On multivariate analysis, patients who underwent MICS had lower rates of atrial fibrillation (P = 0.021), reoperation (P = 0.028) and prolonged ventilation (P < 0.001). However, the rates of other postoperative complications were comparable between patients who underwent MICS and those who underwent MS. Conclusion: In our institution, MICS is a safe, reproducible and efficacious technique that yields superior outcomes compared with conventional MS procedures, in some aspects. The results of this study provide further evidence and support towards adopting the minimally invasive approach to cardiac surgery in a carefully selected group of cardiac patients in Singapore.

The moderating effect of solar radiation on the association between human mobility and COVID-19 infection in Europe.

The novel coronavirus disease 2019 (COVID-19) has caused a global pandemic. Some studies have suggested a negative association between sunlight intensity and COVID-19 infection, alluding to the belief that it might be safe to go out on sunny days. This paper examined whether solar radiation mitigated the association between human mobility and COVID-19 infection in Europe using a dynamic panel data model to investigate the effect of human mobility, solar radiation, and their interaction on COVID-19 infection. The results revealed that outgoing mobility was positively correlated and solar radiation was negatively correlated with COVID-19 infection at lag levels of 1, 2, and 3 weeks. The coefficients of the interaction items indicated that solar radiation negatively moderated the relationship between outgoing mobility and the number of daily new confirmed cases at 2- and 3-week lag levels. However, the moderating effect was limited and unable to eliminate the positive effect of outgoing mobility on COVID-19 infection. Thus, these results suggested that solar radiation only weakly mitigated the relationship between human mobility and COVID-19 infection, providing policy implications that mobility should still be restricted on sunny days during the COVID-19 pandemic.

Partial Versus Complete Thymectomy in Non-Myasthenic Patients With Thymoma: A Systematic Review and Meta-Analysis of Clinical Outcomes.

OBJECTIVE: The optimal extent of surgical resection for non-myasthenic patients with thymoma is controversial. The objective of this meta-analysis was to compare complete to partial thymectomy in non-myasthenic patients for oncological and postoperative clinical outcomes. METHODS: We performed a PubMed and EMBASE search (from inception to January 2020) for English-language studies directly comparing partial thymectomy (thymomectomy) to complete thymectomy for thymoma resection. Clinical endpoints studied included overall and disease-free survival, Masaoka and World Health Organization staging, adjuvant therapy, postoperative complications, postoperative drainage, length of hospital stay, thymoma-related deaths, postresection development of myasthenia gravis, incomplete resection, and recurrence. Random effects meta-analyses across all clinical endpoints was done. RESULTS: There was no statistically significant difference between the two approaches with regard to recurrence (odds ratio [OR], 1.22; 95% confidence interval [CI], 0.78-1.92), completeness of resection (OR, 1.17; 95% CI, 0.66-2.10), adjuvant therapy (OR, 0.71; 95% CI, 0.40-1.26), or thymoma-related deaths (OR, 0.76; 95% CI, 0.12-4.66). There was a statistically significant decrease in postoperative complications (OR, 0.61; 95% CI, 0.39-0.97), drainage (mean difference [MD], -0.99; 95% CI, -1.98 to -0.01), and length of hospital length (MD, -1.88; 95% CI, -3.39 to -0.36) with partial thymectomy. CONCLUSIONS: The evidence appeared to suggest that partial thymectomy is oncologically equivalent to complete thymectomy for non-myasthenic patients with early-stage thymoma. There is an additional advantage of reduced postoperative complications and decreased length of hospital stay with partial thymectomy.

Effect of Renin-Angiotensin System Inhibitors on Acute Kidney Injury Among Patients Undergoing Cardiac Surgery: A Review and Meta-Analysis.

Acute kidney injury (AKI) is a frequent complication of cardiac surgery, which can lead to higher mortality and long-term renal function impairment. The effect of perioperative renin-angiotensin system inhibitors (RASi) therapy on AKI incidence in patients undergoing cardiac surgery remains controversial. We reviewed related studies in PubMed, Scopus, and Cochrane Library from inception to February 2020. Two randomized controlled trials and 21 cohort studies were included in the meta-analysis, involving 76,321 participants. The pooled odds ratio and 95% confidence interval were calculated using the DerSimonian and Laird random-effects model. The results showed no significant association between perioperative RASi therapy and postoperative AKI in patients undergoing cardiac surgery. We highlighted the limitations of existing studies and called for well-designed large-scale randomized controlled trials to verify the conclusion.

Validation of prognostic accuracy of the SOFA score, SIRS criteria, and qSOFA score for in-hospital mortality among cardiac-, thoracic-, and vascular-surgery patients admitted to a cardiothoracic intensive care unit.

SEPSIS-3 DEFINITION: Sepsis is defined as life-threatening organ dysfunction due to a dysregulated host response to infection. The clinical criteria of sepsis include organ dysfunction, which is defined as an increase of two points or more on the sequential organ failure assessment (SOFA). For patients with infection, an increase of 2 SOFA points yields an overall mortality rate of 10%. Patients with suspected infection who are likely to have a prolonged intensive care unit (ICU) stay or to have in-hospital mortality can be promptly identified at the bedside with a quick SOFA (qSOFA) score of 2 or higher. IMPORTANCE: The sepsis-3 criteria have emphasized the value of a change of two or more points on the SOFA, introduced the qSOFA, and removed the systemic inflammatory response syndrome (SIRS) criteria from the sepsis definition. OBJECTIVE: To externally validate and assess the discriminatory capacities of an increase in the SOFA score by two or more points, the presence of two or more SIRS criteria, or a qSOFA score of 2 or more points for outcomes in 5109 patients, the vast majority of whom were postcardiac surgery patients who were admitted to a Cardiothoracic Surgical ICU in Singapore. DESIGN, SETTING, AND PARTICIPANTS: A retrospective cohort analysis of 5109 patients with an infection-related primary admission diagnosis in the cardiothoracic intensive care unit (CTICU) at the National University Hospital (NUH) in Singapore from 2010 to 2016. EXPOSURES: The SOFA, qSOFA, and SIRS criteria were applied to the data representing the worst condition within 24 hours of ICU admission. MAIN OUTCOMES AND MEASURES: The primary outcome was in-hospital mortality. Discrimination was assessed using the area under the receiver operating characteristic curve (AUROC). RESULTS: In 5109 patients, the average mortality of patients with an increase in the SOFA scores of less than 2 points was 3.5% (n = 64), and it was 6% (n = 199) for those with an increase in the SOFA scores of 2 or more points. The mortality of patients with an increase in the qSOFA scores of less than 2 points was 2.6% (n = 7), and it was 5.3% (n = 256) for those with an increase in the qSOFA scores of 2 or more points. The mortality of patients with an increase in the SIRS criteria of less than 2 points was 3.6% (n = 30), and it was 5.4% (n = 233) for those with an increase in the SIRS criteria of 2 or more points. The AUROC of in-hospital mortality of patients with an increase in the SOFA, qSOFA, and SIRS criteria of 2 or more points was 0.96, 0.95, and 0.95, respectively. CONCLUSIONS AND RELEVANCE: In adults with suspected infection admitted to the CTICU in NUH, the change in in-hospital mortality between patients with an increase in SOFA scores of less than 2 and those with an increase of 2 or more was 2.5 percentage points. In contrast to other studies, the absolute change in mortality was nearly the same compared to the qSOFA and SIRS criteria, and the qSOFA score had the greatest percentage increase of 104%, compared to 71% for the SOFA score and 50% for the SIRS criteria. Besides, from the perspective of discriminatory capacities, an increase in SOFA scores of 2 or more did not demonstrate significantly greater prognostic accuracy for in-hospital mortality than equivalent increases in qSOFA scores or SIRS criteria. These findings suggest distinctive characteristics of the study population in the CTICU that are different from the general population.

To extubate or not to extubate: Risk factors for extubation failure and deterioration with further mechanical ventilation.

BACKGROUND: Extubation is a critical step in the intensive care unit (ICU). In this study, we aim to investigate the risk factors for both extubation failure and deterioration with further mechanical ventilation (MV). METHODS: Data were collected from a cardiothoracic ICU in a tertiary hospital. The risk factors for extubation failure and deterioration with further MV were investigated by multivariate logistic regression. RESULTS: A total of 676 patients were enrolled in the study. Patients with extubation failure had a longer ICU length of stay and a higher mortality rate than patients without extubation failure. An age greater than 65 years, abnormal heart rate, respiratory rate exceeding 20 times/min, arterial pH lower than 7.35, pressure of oxygen in arterial blood (PaO2)/fraction of inspired oxygen (FiO2) ratio lower than 300 mmHg, mean arterial pressure lower than 70 mmHg, duration of MV longer than 12 hours, and high quick Sequential Organ Failure Assessment (qSOFA) score were independent risk factors for extubation failure. Furthermore, we found that a respiratory rate greater than 20 times/min and a PaO2/fraction of Inspired Oxygen FiO2 ratio less than 300 mmHg were protective factors, while a mean arterial pressure lower than 70 mmHg, arterial pH lower than 7.35, and high qSOFA score were risk factors for deterioration on continued MV. CONCLUSIONS: Since the duration of MV increases the risk of extubation failure, physicians should consider not only the risk of extubation failure but also the risk of deterioration with further MV.

Cardiopulmonary bypass time: every minute counts.

BACKGROUND: This study was conducted to examine the impact of CPB times on postoperative outcomes. We sought to determine the optimum cut-offs of CPB per graft time and cumulative CPB time and their predictive accuracy for mortality in conjunction with EuroSCORE II. METHODS: The de-identified data of 1960 patients who had undergone isolated on-pump CABG from 2009 to 2014 were analyzed. The risk strata of cardiopulmonary bypass (CPB)/graft and cumulative CPB times, identified with a decision tree, were added into an augmented model for predicting short- and intermediate-term postoperative clinical events. RESULTS: Prolonged cumulative CPB time (>180 minutes) was significant in predicting mortality while adjusting for EuroSCORE II, postoperative complications, prolonged ICU stay and prolonged mechanical ventilation. Whereas prolonged CPB/graft time (>56 minutes) was marginally non-significant in terms of its direct effects, its indirect effect on mortality could be manifested through enhanced risks of complications, prolonged ICU stay (>48 hours) and prolonged mechanical ventilation (>24 hours). CONCLUSIONS: Prolonged CPB times could predict postoperative clinical events, in particular mortality. To minimize the occurrence of unfavorable adverse outcomes, it is recommended that the CPB/graft time and cumulative CPB time be kept below 56 minutes and 180 minutes respectively.

Myopia, axial length, and OCT characteristics of the macula in Singaporean children.

PURPOSE: The purpose of this study was to evaluate the associations between macular volume and thickness, as assessed by optic coherence tomography (OCT), with refraction and axial length (AL) in children. METHODS: A total of 104 Chinese school children (51 girls and 53 boys) 11 to 12 years of age were randomly selected from one school during the 2005 examination in the Singapore Cohort Study of the Risk Factors for Myopia (SCORM). Cycloplegic autorefraction was performed to obtain refraction (defined as spherical equivalent [SE]) and ultrasound biometry performed to obtain the AL. Macular volume and thickness were then measured (StratusOCT3; Carl Zeiss Meditec, Dublin, CA). RESULTS: Children with moderate myopia (SE at least -3.0 D) tended to have smaller total macular volume and thinner quadrant-specific macular thickness (except in the inferior and superior inner quadrants), followed by children with low myopia (-0.5-0.5 D). Total macular volume was positively associated with SE (beta=1.58, 95% CI, 0.84 to 2.32, standardized beta=0.14, P<0.001) and negatively associated with AL (beta=-1.20, 95% CI, -1.62 to -0.79, standardized beta=0.45, P<0.001) in multiple linear regression models controlling for age and gender. CONCLUSIONS: In children, increasing axial myopia was associated with reduced macular volume and thickness. These findings suggest that early anatomic changes may be present in the retinas of children with axial myopia.