Epicardial left atrial appendage clipping versus direct oral anticoagulant to reduce stroke risk in non-paroxysmal atrial fibrillation (LAA-CLIP): rationale, design and study protocol for a multicentre randomised controlled trial.

INTRODUCTION: The prevalence of atrial fibrillation (AF) is increasing globally, and stroke prevention is the key to reduce the morbidity and mortality related to AF. Currently, direct oral anticoagulants (DOACs) are the primary options for stroke prevention, while it increases risk of bleeding. Left atrial appendage (LAA) is suspected as a vital source of cerebral emboli and may lead to ischaemic stroke, and thoracoscopic LAA clipping procedure provides an alternative option for stroke prevention in high-risk patients. However, high-quality evidence comparing LAA clipping to DOACs in terms of stroke prevention is lacking. This trial is designed to assess whether the efficacy of thoracoscopic LAA clipping is superior to DOACs for stroke prevention in AF patients at high risk of thrombosis (CHA2DS2-VASc≥2 in men and ≥3 in women)[CHA2DS2-VASc stands for "congestive heart failure, hypertension, age ≥75 (doubled), diabetes, stroke (doubled), vascular disease, age 65 to 74 and sex category (female)"]. METHODS AND ANALYSIS: This is a prospective, multicentre, open-labelled, randomised controlled study. This trial will randomly assign 290 patients with non-paroxysmal AF to thoracoscopic LAA clipping group or DOAC therapy group in a 1:1 randomisation. The primary endpoint is defined as a composite endpoint event consisting of stroke, systemic embolism, all-cause mortality, major bleeding events and clinically relevant non-major bleeding events at 24 months after randomisation. The secondary endpoints consist of the components of the primary composite endpoint, surgery-related adverse events and minor bleeding events. ETHICS AND DISSEMINATION: The central ethics committee at Fuwai Hospital approved the trial entitled "Epicardial left atrial appendage clipping versus direct oral anticoagulant to reduce stroke risk in non-paroxysmal atrial fibrillation (LAA-CLIP trial)". The results of this study will be disseminated through publications in peer-reviewed journals and conference presentations. TRIAL REGISTRATION NUMBER: NCT06021808.

Association of carotid duplex ultrasonography screening with stroke and mortality among patients undergoing coronary artery bypass grafting.

OBJECTIVE: Selection criteria for carotid duplex ultrasonography screening (DUS) before coronary artery bypass grafting (CABG) is primarily based on limited observational analysis, and the risks associated with carotid artery stenosis (CAS) detected by this approach to preoperative DUS are uncertain. This study aimed to determine the association of carotid DUS with stroke and mortality among patients undergoing CABG. METHODS: Adult patients with coronary artery disease who underwent isolated CABG or CABG with concomitant valvular or congenital procedure were identified. CHA2DS2-VASc score was assessed before CABG, and patients were recorded as high risk if they had a score of 3 or higher. The primary outcomes were stroke and all-cause mortality. Secondary outcomes included ischemic stroke, non-ischemic stroke, transient ischemic attack, and cardiovascular mortality. RESULTS: Among 8958 patients who underwent CABG, 70.9% (n = 6347) received carotid DUS preoperatively (low-risk, 57.3%; high-risk, 42.7%). In the low-risk cohort, there was no significant difference in the risk of stroke (20.7 per 1000 patient-years for CAS vs 13.1 per 1000 patient-years for no CAS; adjusted hazard ratio [aHR], 1.14; 95% confidence interval [CI], 0.78-1.68) or mortality (20.5 per 1000 patient-years for CAS vs 16.8 per 1000 patient-years for no CAS; aHR, 1.33; 95% CI, 0.97-1.83) at 15 years. In the high-risk cohort, CAS was associated with significantly higher risks of stroke at 30 days (433.2 vs 279.5 per 1000 patient-years; aHR, 1.92; 95% CI, 1.00-3.70) and mortality at 15 years (38.4 vs 32.7 per 1000 patient-years; aHR, 1.25; 95% CI, 1.01-1.57) compared with no CAS. CONCLUSIONS: CAS did not impact the incidence of stroke or mortality in the low-risk cohort who underwent CABG. However, in the high-risk cohort, CAS was associated with a significant increase in the risks of 30-day stroke and 15-year mortality, indicating selective carotid DUS is necessarily recommended for these patients.

Administrative Model for Profiling Hospital Performance on Coronary Artery Bypass Graft Surgery: Based on the Chinese Hospital Quality Monitoring System.

BACKGROUND: We aimed to develop an administrative model to profile the performance on the outcomes of coronary artery bypass grafting across hospitals in China. METHODS AND RESULTS: This retrospective study was based on the Chinese Hospital Quality Monitoring System (HQMS) from 2016 to 2020. The coronary artery bypass grafting cases were identified by procedure code, and those of 2016 to 2017 were randomly divided into modeling and validation cohorts, while those in other years were used to ensure the model stability across years. The outcome was discharge status as "death or withdrawal," and that withdrawal referred to discharge without medical advice when patients were in the terminal stage but reluctant to die in the hospital. Candidate covariates were mainly identified by diagnoses or procedures codes. Patient-level logistic models and hospital-level hierarchical models were established. A total of 203 010 coronary artery bypass grafts in 699 hospitals were included, with 60 704 and 20 233 cases in the modeling and validation cohorts and 40 423, 42 698, and 38 952 in the years 2018, 2019, and 2020, respectively. The death or withdrawal rate was 3.4%. The areas under the curve were 0.746 and 0.729 in the patient-level models of modeling and validation cohorts, respectively, with good calibration and stability across years. Hospital-specific risk-standardized death or withdrawal rates were 2.61% (interquartile range, 1.87%-3.99%) and 2.63% (interquartile range, 1.97%-3.44%) in the modeling and validation cohorts, which were highly correlated (correlation coefficient, 0.96; P<0.001). Between-hospital variations were distinguished among hospitals of different volumes and across years. CONCLUSIONS: The administrative model based on Hospital Quality Monitoring System could profile hospital performance on coronary artery bypass grafting in China.

Outcome differences between surgeons performing first and subsequent coronary artery bypass grafting procedures in a day: a retrospective comparative cohort study.

BACKGROUND: With increasing surgical workload, it is common for cardiac surgeons to perform coronary artery bypass grafting (CABG) after other procedures in a workday. To investigate whether prior procedures performed by the surgeon impact the outcomes, we compared the outcomes between CABGs performed first versus those performed after prior procedures, separately for on-pump and off-pump CABGs as they differed in technical complexity. METHODS: We conducted a retrospective cohort study of patients undergoing isolated CABG in China from January 2013 to December 2018. Patients were categorised as undergoing on-pump and off-pump CABGs. Outcomes of the procedures performed first in primary surgeons' daily schedule (first procedure) were compared with subsequent ones (non-first procedure). The primary outcome was an adverse events composite (AEC) defined as the number of adverse events, including in-hospital mortality, myocardial infarction, stroke, acute kidney injury and reoperation. Secondary outcomes were the individual components of the primary outcome, presented as binary variables. Mixed-effects models were used, adjusting for patient and surgeon-level characteristics and year of surgery. RESULTS: Among 21 866 patients, 10 109 (16.1% as non-first) underwent on-pump and 11 757 (29.6% as non-first) off-pump CABG. In the on-pump cohort, there was no significant association between procedure order and the outcomes (all p>0.05). In the off-pump cohort, non-first procedures were associated with an increased number of AEC (adjusted rate ratio 1.29, 95% CI 1.13 to 1.47, p<0.001), myocardial infarction (adjusted OR (ORadj) 1.43, 95% CI 1.13 to 1.81, p=0.003) and stroke (ORadj 1.73, 95% CI 1.18 to 2.53, p=0.005) compared with first procedures. These increases were only found to be statistically significant when the procedure was performed by surgeons with <20 years' practice or surgeons with a preindex volume <700 cases. CONCLUSIONS: For a technically challenging surgical procedure like off-pump CABG, prior workload adversely affected patient outcomes.

Bi-atrial versus left atrial ablation for patients with rheumatic mitral valve disease and non-paroxysmal atrial fibrillation (ABLATION): rationale, design and study protocol for a multicentre randomised controlled trial.

INTRODUCTION: Atrial fibrillation (AF) is common in patients with rheumatic mitral valve disease (RMVD) and increase the risk of stroke and death. Bi-atrial or left atrial ablation remains controversial for treatment of AF during mitral valve surgery. The study aims to compare the efficacy and safety of bi-atrial ablation with those of left atrial ablation among patients with RMVD and persistent or long-standing persistent AF. METHODS AND ANALYSIS: The ABLATION trial (Bi-atrial vs Left Atrial Ablation for Patients with RMVD and Non-paroxysmal AF) is a prospective, multicentre, randomised controlled study. The trial will randomly assign 320 patients with RMVD and persistent or long-standing persistent AF to bi-atrial ablation procedure or left atrial ablation procedure in a 1:1 randomisation. The primary end point is freedom from documented AF, atrial flutter or atrial tachycardia of >30 s at 12 months after surgery off antiarrhythmic drugs. Key secondary end point is the probability of freedom from permanent pacemaker implantation at 12 months after surgery. Secondary outcomes include the probability of freedom from any recurrence of atrial tachyarrhythmias with antiarrhythmic drugs, AF burden, incidence of adverse events and cardiac function documented by echocardiography at 12 months after operation. ETHICS AND DISSEMINATION: The central ethics committee at Fuwai Hospital approved the ABLATION trial. The results of this study will be disseminated through publications in peer-reviewed journals and conference presentations. TRIAL REGISTRATION NUMBER: NCT05021601.

Efficient extraction of biodiesel feedstock and dehydration of kitchen waste: A method based on co-dissolution of liquefied dimethyl ether and water.

In the context of low-carbon development, as a waste rich in lipids, kitchen waste (KW) has received increasing attention for resource utilization and low-carbon utilization. In this study, we explored a method for efficient extraction of lipids and dehydration using liquefied dimethyl ether (L-DME) to address the problem of high lipids and the difficulty of dewatering of KW. A closed DME reaction vessel was used to conduct experiments on the effects of lipids extraction and dehydration of KW under different reaction times, mass ratios, temperatures and moisture contents. It was found that DME could extract more than 90% of the lipids and the dehydration rate could reach approximately 80%. The main components of the lipids in the liquid phase extract were fatty acids (C18:2, C18:1, C16:0, and C18:0) whose good thermal properties made them suitable for use as a feedstock for biodiesel production. Moreover, the greatly increased heating value of the solid residue facilitated low-carbon utilization. This study also demonstrated a promotion effect of the co-dissolution system of L-DME and water on the extraction of lipids and explored the related mechanism.

Transformation mechanism of polycyclic aromatic hydrocarbons and hydrogen production during the gasification of coking sludge in supercritical water.

In this study, the characteristic of hydrogen production and polycyclic aromatic hydrocarbons (PAHs) transformation during supercritical water gasification (SCWG) of coking sludge (400 °C - 450 °C, 1 min-30 min) were explored. The total gas yield was between 0.62 mol/kg OM and 1.05 mol/kg OM (on dry basis), and the proportion of CH4 and H2 was only between 5.41% and 6.44%. PAH content were increased from 194.92 mg/kg to 326.04 mg/kg, and mainly high molecular weight PAHs, which were formed from the Diels-Adler reaction of single aromatic hydrocarbon and the addition reaction of low molecular weight PAHs. High reaction temperature favored more active PAH formation than reaction time. The possible control methods for PAH formation during SCWG of coking sludge was proposed. H2O2 and KOH addition effectively reduce PAHs amount in solid residues by 46.67% and 38.33%, and KOH performed positive effect on hydrogen production. The work revealed that the inhibition of PAHs and hydrogen production were achieved from SCWG of coking sludge with KOH addition.

Coronary Artery Bypass Grafting and Percutaneous Coronary Intervention in Patients With Chronic Total Occlusion and Multivessel Disease.

BACKGROUND: Percutaneous coronary intervention (PCI) has been used increasingly as an alternative means of revascularization for patients with chronic total occlusion and multivessel disease. We investigated 5-year clinical outcomes following coronary artery bypass grafting (CABG) and PCI in patients with chronic total occlusion and multivessel disease. METHODS: In this single-center, retrospective cohort study, 4324 consecutive patients with ≥1 chronic total occlusion and multivessel disease were treated with either CABG (n=2264) or PCI (n=2060) between 2010 and 2013. The primary outcome was 5-year composite of death, myocardial infarction, or stroke. An inverse-probability-of-treatment weighting method was used adjusting for both patient and lesion characteristics. RESULTS: The unadjusted 5-year composite outcomes were similar between CABG group and PCI group (12.1% [258/2264] versus 11.4% [218/2060]; P=0.52). After adjustment for baseline variables, PCI was associated with significantly higher risk of composite outcomes (adjusted hazard ratio: 1.21 [95% CI, 1.02-1.44]; P=0.03). The inferiority of PCI in 5-year composite outcome was significant in patients with CABG recommendation according to SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score II (adjusted hazard ratio: 1.55 [95% CI, 1.14-2.09]; P=0.005) but not evident in patients with PCI or PCI/CABG equipoise recommendation according to SYNTAX score II (adjusted hazard ratio: 0.94 [95% CI, 0.75-1.17]; P=0.56). A similar risk of 5-year composite outcomes was observed between CABG and PCI with residual SYNTAX score ≤8. CONCLUSIONS: In this single-center retrospective study among patients with chronic total occlusion and multivessel disease, PCI was associated with higher risk of 5-year composite death, myocardial infarction, or stroke.

Preoperative clopidogrel and outcomes in patients with acute coronary syndrome undergoing coronary artery bypass surgery.

OBJECTIVE: The optimal preoperative antiplatelet strategy for patients with acute coronary syndrome (ACS) requiring surgical revascularization remains unclear because of competing risks of bleeding and ischemic events. We evaluated the effect of clopidogrel within 5 days before coronary artery bypass grafting (CABG) on outcomes in patients with ACS. METHODS: Consecutive patients with ACS who underwent isolated CABG at a single center were included in this retrospective study. The primary outcome was a composite of death, myocardial infarction, and stroke within 30 days after surgery. Secondary outcomes were CABG-related major bleeding and perioperative transfusion. Inverse probability weighting using propensity score was performed to evaluate the risk-adjusted effect of preoperative clopidogrel on outcomes. RESULTS: Of 5543 patients with ACS, 820 (14.8%) patients continued clopidogrel within 5 days before CABG. After adjustment for differences in baseline factors, clopidogrel use ≤5 days before CABG was associated with significantly increased odds of the primary composite outcome (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.16-2.29; P = .005), stroke (OR, 3.13; 95% CI, 1.82-5.39; P < .001), major bleeding (OR, 2.01; 95% CI, 1.56-2.58; P < .001), and transfusion (OR, 2.05; 95% CI, 1.82-2.30; P < .001). The effects of preoperative clopidogrel use ≤5 days on primary outcome and major bleeding were greater in patients older than 65 years. CONCLUSIONS: Among patients with ACS undergoing CABG, clopidogrel therapy within 5 days before surgery was associated with increased odds of major cardiac and cerebrovascular events and bleeding complications than discontinuing clopidogrel for >5 days.

Outcomes After Isolated Aortic Valve Replacement in Patients with Bicuspid vs Tricuspid Aortic Valve.

To compare the outcomes in patients undergoing isolated aortic valve replacement with bicuspid (BAV) vs tricuspid aortic valves (TAV). A total of 1204 consecutive patients (BAV, n = 454; TAV, n = 750) underwent isolated aortic valve replacement (AVR) between 2002 and 2009 at a single institution. Adverse aortic events were defined as the occurrence of aortic dissection or the ascending aorta diameter greater than 50 mm or sudden death during follow-up. Propensity score matching yielded 318 patient pairs. Follow-up was obtained on 1156 patients. The mean length of follow up was 10.4 ± 3.9 years. A total of 155 (13.4%) patients died, and adverse aortic events occurred in 44 (3.8%) patients. After propensity score matching, the 12-year survivals was 85.5% in the BAV group and 89.2% in the TAV group; hazard ratio (HR) 1.6; 95% confidence interval (CI) 1.0-2.5; P = 0.057. The 12-year cumulative incidence of late adverse aortic events was 14.6% in the BAV group and 10.8% in the TAV group; subdistribution hazard ratio (sHR) 1.1; 95% CI 0.6-2.0; P = 0.758. In the isolated aortic regurgitation subgroup, the rate of adverse aortic events was significantly higher in the BAV group than in the TAV group (sHR, 2.1; 95% CI, 1.1-4.0; P = 0.021). The long-term survival after isolated AVR was similar in both BAV and TAV patients. BAV does not increase the adverse aortic events after isolated AVR compared with the TAV.

Dual Antiplatelet Therapy with Clopidogrel and Aspirin Versus Aspirin Monotherapy in Patients Undergoing Coronary Artery Bypass Graft Surgery.

Background The optimal antiplatelet therapy after coronary artery bypass grafting remains unclear. We evaluated the association of dual antiplatelet therapy (DAPT) with clopidogrel plus aspirin and clinical outcomes among patients undergoing coronary artery bypass grafting. Methods and Results A total of 18 069 consecutive patients who underwent primary isolated coronary artery bypass grafting between 2013 and 2017 were identified from a contemporary registry, and 10 854 (60.1%) received DAPT with clopidogrel plus aspirin as determined by claimed prescriptions after surgery. Cox regression models with inverse probability of treatment weighting were used to examine the associations between DAPT and outcomes. Patients who received DAPT, compared with those who received aspirin monotherapy, had a lower incidence of a composite of all-cause death, myocardial infarction, stroke, or repeat revascularization at 6 months (2.9% versus 4.2%; inverse probability of treatment weighting-adjusted hazard ratio [HR], 0.65; 95% CI, 0.55-0.77; P<0.001) as well as death (HR, 0.61; 95% CI, 0.41-0.90), myocardial infarction (HR, 0.55; 95% CI, 0.40-0.74), and stroke (HR, 0.58; 95% CI, 0.46-0.74). The incidence of major bleeding did not differ significantly between the 2 groups (HR, 1.11; 95% CI, 0.69-1.78). Similar results were noted across multiple subgroups as well as when using different analytic methods. Conclusions Among patients undergoing coronary artery bypass grafting, DAPT with clopidogrel plus aspirin as secondary prevention was associated with reduced risk of major adverse cardiovascular and cerebrovascular events within 6 months as compared with aspirin monotherapy, and there was no significant increase in major bleeding.

Mechanism of separation and removal of water from oily sludge using liquid dimethyl ether to dissolve hydrocarbons.

The effective disposal of oily sludge generated from the petroleum industry has received increasing concern. The primary difficulty for the reduction and resource utilization of oily sludge is dewatering. Therefore, finding an efficient and energy-saving dewatering technology is an urgent need for the treatment of oily sludge. In this study, an innovative developed method using liquefied dimethyl ether (L-DME) for dewatering is employed to deal with oily sludge for the first time. Oily sludge from a refinery was used to conduct experiments in sequencing dissolution-separation reactors. Changes in the dehydration rate, oil recovery, group components (hydrocarbon series of petroleum, including saturates, aromatics, resins and asphaltenes) at different extraction time, temperatures and L-DME additions were measured. The results revealed that L-DME removed 90% of the water and recovered 40% of the oil, which was an amazing dehydration effect for oily sludge. The water-binding form of oily sludge is different from sewage sludge and other biomass and the water in oily sludge is in a stable water-in-oil (W/O) suspension emulsified state. L-DME was mixed with semi-colloidal like oily sludge to break the structure of the water-in-oil emulsion, making the mixture into a solid-liquid two phase substances that were easy to separate, thus achieving a high degree of separation of water. The dissolution of saturated hydrocarbons, aromatic hydrocarbons, and small amounts of colloid by L-DME played an important auxiliary role in water removal.

Trends of Coronary Artery Bypass Grafting Performance in a Cohort of Hospitals in China Between 2013 and 2018.

BACKGROUND: China has witnessed a rapid increase in the volume of coronary artery bypass grafting (CABG) but substantial gaps in the performance for CABG across the nation. The present study aimed to investigate the change in CABG performance after years of quality improvement measures in a national registry in China. METHODS: The study included 66 971 patients who underwent isolated CABG in a cohort of 74 tertiary hospitals in China between January 2013 and December 2018. Data were collected from the Chinese Cardiac Surgery Registry. Outcomes were in-hospital mortality and postoperative length of stay. Five process measures for surgical technique and secondary prevention were also analyzed. We described the changes in the overall performance and interhospital heterogeneity across the years. RESULTS: The in-hospital mortality declined from 0.9% in 2013 to 0.6 in 2018, with a risk-adjusted odds ratio of 0.66 (95% CI, 0.46-0.93; P<0.001). The standard mean difference for risk-standardized mortality rate between hospitals in the lowest and highest quartile narrowed from 1.63 in 2013 to 1.35 in 2018. The median (interquartile range) hospital-level rate of using arterial graft increased from 93.9% (86.0%-97.8%) to 94.6% (83.3%-99.2%), but the difference was not statistically significant. Meanwhile, the rate of free from blood transfusion increased from 17.0% (2.6%-32.0%) to 34.1% (8.8%-52.9%). The hospital-level rate of prescribing ß-blockers at discharge significantly increased from 82.8% (66.7%-90.3%) to 91.1% (82.1%-97.1%), statin from 75.8% (55.7%-88.9%) to 88.9% (75.0%-96.0%), and aspirin from 90.3% (83.9%-95.2%) to 95.3% (88.9%-98.1%). CONCLUSIONS: In the Chinese Cardiac Surgery Registry, there were notable improvements in the treatment process related to CABG and decline of in-hospital mortality with reduced interhospital heterogeneity.

Clinical Outcomes in Chronic Total Occlusion Revascularization Versus No Chronic Total Occlusion Revascularization: Variability by Target Vessel.

We aimed to investigate the impact of target vessel on clinical outcomes in chronic total occlusion (CTO) revascularization versus no CTO revascularization. This multicenter, retrospective, cohort study involves patients with ≥1 CTO. After classification based on different CTO target vessels or multiple CTOs, patients were further categorized as the CTO revascularization group and the no CTO revascularization group based on treatment received. The primary outcome was a composite of death, myocardial infarction, stroke, repeated revascularization, and hospital admission due to ischemic symptoms. From August 2016 to August 2017, 1712 eligible patients were consecutively enrolled. Chronic total occlusion revascularization was associated with lower risk of 1-year major adverse cardiovascular and cerebrovascular events (MACCEs; adjusted hazard ratio [HR]: 0.36; 95% CI: 0.20-0.67; P = .001) compared with no CTO revascularization in left anterior descending (LAD) CTO patients. The benefit of CTO revascularization was not evident among those with left circumflex (LCX; adjusted HR: 0.51; 95% CI: 0.23-1.10; P = .087), right coronary artery (RCA; adjusted HR: 1.17; 95% CI: 0.59-2.33; P = .648), and multiple CTOs (adjusted HR: 1.00; 95% CI: 0.41-2.44; P = .994). Revascularization for LAD CTO, but not LCX, RCA, or multiple CTOs, was associated with lower risk of 1-year MACCEs compared with no CTO revascularization.

Effect of a smartphone-based intervention on secondary prevention medication prescriptions after coronary artery bypass graft surgery: The MISSION-1 randomized controlled trial.

BACKGROUND: Studies found that patients who underwent coronary artery bypass grafting (CABG) often fail to receive optimal evidence-based secondary prevention medications. We evaluated the effectiveness of a smartphone-based quality improvement effort on improving the prescription of medical therapies. METHODS: In this cluster-randomized controlled trial, 60 hospitals were randomized to a control arm (n = 30) or to an intervention arm using smartphone-based multifaceted quality improvement interventions (n = 30). The primary outcome was the prescription of statin. The secondary outcomes were prescription of beta-blocker, angiotensin-converting enzyme inhibitor, or angiotensin receptor blocker (ACE inhibitor or ARB), and optimal medical therapy for eligible patients. RESULTS: Between June 1, 2015 and September 15, 2016, a total of 10,006 CABG patients were enrolled (5,653 in 26 intervention and 4,353 in 29 control hospitals, 5 hospitals withdrew). Statin prescribing rate was 87.8% in the intervention arm and 84.4% in the control arm. We saw no evidence of an effect of intervention on statin prescribing in the intention-to-treat analysis (odds ratio [OR], 1.31; 95% confidence interval (CI), 0.68-2.54; P = .43) or in key patient subsets. The prescription rates of ACE inhibitor or ARB and optimal medical therapy were comparable between study groups, while beta-blocker was more often prescribed in the intervention arm. Post hoc analysis demonstrated a greater increase in statin prescribing rate over time in the intervention arm. CONCLUSIONS: A smartphone-based quality improvement intervention compared with usual care did not increase statin prescribing for patients who received CABG. New studies focusing on the best practice of this technique may be warranted.

Influence of operator volume on early outcomes of septal myectomy for isolated hypertrophic obstructive cardiomyopathy.

BACKGROUND: Guidelines on the diagnosis and management of hypertrophic cardiomyopathy (HCM) recommend that septal myectomy be performed by experienced operators. However, the impact of operator volume on surgical treatment outcomes for isolated HCM has been poorly investigated. METHODS: From 2002 to 2014, 435 consecutive patients with isolated HCM undergoing myectomy at the Fuwai Hospital were retrospectively enrolled. All 29 surgeons were divided into beginner surgeons (operator volume ≤20) and experienced surgeons (operator volume >20) according to the guidelines for the diagnosis and treatment of HCM. Propensity score matching of patients in the two groups was performed. RESULTS: Baseline differences included advanced New York Heart Association classification and older age in the experienced surgeon group. After matching, in the beginner surgeon group (107 cases), residual obstruction (18.7% vs. 0.9%, P<0.001) was more common, and the postoperative left ventricular outflow tract pressure gradient (20.7±15.1 vs. 14.3±7.4 mmHg, P<0.001) was higher than that of the experienced surgeon group. In the experienced surgeon group (107 cases), the incidence of mitral valve replacement (1.9% vs. 11.2%, P<0.001) and permanent pacemaker implantation (1.9% vs. 3.7%, P<0.001) was significantly lower than that in the beginner surgeon group. However, there was no difference in procedural mortality (1.9% vs. 1.9%) between the two groups. CONCLUSIONS: Operator volume is an important factor in achieving better obstruction obliteration after septal myectomy in patients with isolated HCM.

Elevated postoperative serum uric acid is associated with major adverse events following coronary artery bypass grafting.

BACKGROUND: Few data are available on the association between postoperative serum uric acid (SUA) level and poor survival in patients undergoing coronary artery bypass grafting (CABG). We evaluated the relationship between postoperative SUA and major adverse cardiac and cerebrovascular events (MACCE) among patients undergoing CABG. METHODS: This study used data from 1614 consecutive patients undergoing CAGB at Fuwai Hospital (Beijing, China) from 2011 to 2015. Patients were stratified into statistical quartiles of postoperative SUA (between 6 and 18 hours after cardiac surgery): less than 203.7, 203.7 to 254.1, 254.1 to 316.6, and ≥316.6 µmol/L. The association of postoperative SUA with MACCE (ie, death, myocardial infarction [MI], stroke, or repeat revascularization) and the composite endpoint of mortality/MI were assessed. RESULTS: Patients had a mean age of 60.3 ± 8.4 years, and 79.3% were male. During mean follow-up of 2.5 ± 0.7 years, MACCE occurred in 201 (12.5%) patients. In separate multivariable regression models, postoperative SUA level was positively associated with in-hospital MACCE (highest vs lowest SUA quartile: odds ratio [OR]: 2.40; 95% confidence interval [CI]: 1.29, 4.48; P = .006) and in-hospital composite endpoint of mortality/MI (OR: 2.88; 95% CI: 1.45, 5.72; P = .003), respectively. And elevated postoperative SUA level was independently associated with MACCE (Hazard ratio [HR]: 1.70; 95% CI: 1.12, 2.57; P = .01) and the composite endpoint of mortality/MI (HR: 2.42; 95% CI: 1.32, 4.43; P = .004) respectively within 3 years after CABG. CONCLUSIONS: Elevated postoperative SUA level is associated with poor clinical outcomes after CABG. Patients with high postoperative SUA levels after CABG might require to be closely monitored.

Surgical left atrial appendage occlusion in patients with atrial fibrillation undergoing mechanical heart valve replacement.

BACKGROUND: Surgical left atrial appendage occlusion (SLAAO) may be associated with a lower risk of thromboembolism in patients with atrial fibrillation undergoing cardiac surgery. However, evidence regarding the effectiveness of SLAAO in patients undergoing mechanical heart valve replacement (MHVR) is lacking. Therefore, we aimed to evaluate the association between SLAAO and the cardiovascular outcomes in patients with atrial fibrillation undergoing MHVR. METHODS: We retrospectively analyzed data for 497 patients with atrial fibrillation; 27.6% of the patients underwent SLAAO, and the remainder of the patients did not (No-SLAAO group). The primary outcome was a composite of ischemic stroke, systemic embolism, and all-cause mortality. Cumulative event-free survival rates were estimated using Kaplan-Meier curves, and we performed multivariate Cox analyses to evaluate the association between SLAAO and outcomes. We used one-to-one propensity score matching to balance patients' baseline characteristics, and analyzed 120 matching pairs. RESULTS: Five patients died within 30 days postoperatively, and there were no significant differences between the two groups regarding in-hospital complications (all P > 0.05). After a median follow-up of 14 months, 14 primary events occurred. Kaplan-Meier curves showed no difference in the cumulative incidence of freedom from the primary outcome (log-rank P = 0.830), hemorrhagic events (log-rank P = 0.870), and the secondary outcome (log-rank P = 0.730), between the two groups. Multivariable Cox proportional hazards regression analysis showed no association between SLAAO and any outcome (all P > 0.05). After propensity score matching, cardiopulmonary bypass time and aortic cross-clamp time, and the postoperative length of stay were significantly longer in the SLAAO group (all P < 0.05); results were similar to the unadjusted analyses. CONCLUSIONS: Concomitant SLAAO and MHVR was associated with longer length of stay, and cardiopulmonary bypass time and aortic cross-clamp time, but was not associated with additional protective effects against thromboembolic events and mortality during the 14-month follow-up.