Obesity is a risk factor for preoperative hypoxemia in Stanford A acute aortic dissection

Influence of false lumen status on systemic inflammatory response triggered by acute aortic dissection

We investigated the influence of false lumen (FL) status on the systemic inflammatory response triggered by acute aortic dissection (AAD) using cytokine profiling. The study included 44 patients with AAD. Patients were divided between those with a thrombosed FL (Group T, n = 21) and those with a non-thrombosed FL (Group P, n = 23). On-admission serum concentrations of 29 cytokines were compared between unmatched and propensity-score matched (n = 10 pairs) FL groups and a control group (non-ruptured thoracic aortic aneurysm, Group C, n = 20). Unmatched analysis showed 12 cytokines differed between groups and fell into three categories: Category A (increased expression in both FL groups: IL-6, IL-10, IL-15, G-CSF); Category B (increased expression only in Group P: IL-1Ra, IL-1β, IL-8, IL-12p70, GM-CSF); and Category C (others: IP-10, VEGF-A, eotaxin). The increases in Category A and Category B cytokines in Group T were attenuated, but not significantly, compared to their increases in Group P. Propensity-score matching analysis revealed a similar expression pattern with respect to all four Category A cytokines, four Category B cytokines (IL-1β, IL-1Ra, IL-12p70, and GM-CSF), and two Category C cytokines (IP-10 and VEGF-A). A robust inflammatory response occurs in patients with AAD, but the response is attenuated when the FL is thrombosed.

Perioperative oxygenation impairment related to type a aortic dissection

Type A aortic dissection (TAAD) is a life-threatening disease with high mortality and poor prognosis, usually treated by surgery. There are many complications in its perioperative period, one of which is oxygenation impairment (OI). As a common complication of TAAD, OI usually occurs throughout the perioperative period of TAAD and requires prolonged mechanical ventilation (MV) and other supportive measures. The purpose of this article is to review the risk factors, mechanisms, and treatments of type A aortic dissection-related oxygenation impairment (TAAD-OI) so as to improve clinicians' knowledge about it. Among risk factors, elevated body mass index (BMI), prolonged extracorporeal circulation (ECC) duration, higher inflammatory cells and stored blood transfusion stand out. A reduced occurrence of TAAD-OI can be achieved by controlling these risk factors such as suppressing inflammatory response by drugs. As for its mechanism, it is currently believed that inflammatory signaling pathways play a major role in this process, including the HMGB1/RAGE signaling pathway, gut-lung axis and macrophage, which have been gradually explored and are expected to provide evidences revealing the specific mechanism of TAAD-OI. Numerous treatments have been investigated for TAAD-OI, such as nitric oxide (NO), continuous pulmonary perfusion/inflation, ulinastatin and sivelestat sodium, immunomodulation intervention and mechanical support. However, these measures are all aimed at postoperative TAAD-OI, and not all of the therapies have shown satisfactory effects. Treatments for preoperative TAAD-OI are not currently available because it is difficult to correct OI without correcting the dissection. Therefore, the best solution for preoperative TAAD-OI is to operate as soon as possible. At present, there is no specific method for clinical application, and it relies more on the experience of clinicians or learns from treatments of other diseases related to oxygenation disorders. More efforts should be made to understand its pathogenesis to better improve its treatments in the future.

Study on risk factors and treatment strategies of hypoxemia after acute type a aortic dissection surgery

Acute type A aortic dissection is a life-threatening cardiovascular disease characterized by rapid onset and high mortality. Emergency surgery is the preferred and reliable treatment option. However, postoperative complications significantly impact patient prognosis. Hypoxemia, a common complication, poses challenges in clinical treatment, negatively affecting patient outcomes and increasing the risk of mortality. Therefore, it is crucial to study and comprehend the risk factors and treatment strategies for hypoxemia following acute type A aortic dissection to facilitate early intervention.

The effect of obesity on the outcome of thoracic endovascular aortic repair: a systematic review and meta-analysis

Background

Obesity is a well-known predictor for poor postoperative outcomes of vascular surgery. However, the association between obesity and outcomes of thoracic endovascular aortic repair (TEVAR) is still unclear. This systematic review and meta-analysis was performed to assess the roles of obesity in the outcomes of TEVAR.

Methods

We systematically searched the Web of Science and PubMed databases to obtain articles regarding obesity and TEVAR that were published before July 2023. The odds ratio (OR) or hazard ratio (HR) was used to assess the effect of obesity on TEVAR outcomes. Body mass index (BMI) was also compared between patients experiencing adverse events after TEVAR and those not experiencing adverse events. The Newcastle-Ottawa Scale was used to evaluate the quality of the enrolled studies.

Results

A total of 7,849 patients from 10 studies were included. All enrolled studies were high-quality. Overall, the risk of overall mortality (OR = 1.49, 95% CI [1.02-2.17], p = 0.04) was increased in obese patients receiving TEVAR. However, the associations between obesity and overall complications (OR = 2.41, 95% CI [0.84-6.93], p = 0.10) and specific complications were all insignificant, including stroke (OR = 1.39, 95% CI [0.56-3.45], p = 0.48), spinal ischemia (OR = 0.97, 95% CI [0.64-1.47], p = 0.89), neurological complications (OR = 0.13, 95% CI [0.01-2.37], p = 0.17), endoleaks (OR = 1.02, 95% CI [0.46-2.29], p = 0.96), wound complications (OR = 0.91, 95% CI [0.28-2.96], p = 0.88), and renal failure (OR = 2.98, 95% CI [0.92-9.69], p = 0.07). In addition, the patients who suffered from postoperative overall complications (p < 0.001) and acute kidney injury (p = 0.006) were found to have a higher BMI. In conclusion, obesity is closely associated with higher risk of mortality after TEVAR. However, TEVAR may still be suitable for obese patients. Physicians should pay more attention to the perioperative management of obese patients.

Investigation of the Association between Bilateral Selective Anterograde Cerebral Perfusion and Postoperative Ischemic Stroke in Obese Patients with Emergency Surgery for Acute Type A Aortic Dissection

Background and objectives: The relationship between cerebral perfusion and new postoperative ischemic stroke in obese patients is not well defined. The aim of this study was to investigate the association between selective bilateral anterograde cerebral perfusion and new postoperative ischemic stroke in obese patients with emergency surgery for acute type A aortic dissection. Materials and methods: A total of 292 patients with emergency surgery for acute type A aortic dissection were included in this study. Patients with hemorrhagic stroke or ischemic stroke with severe neurological dysfunction at admission that were not candidates for surgery; patients who died in the first 48 h after intensive care admission and patients with incomplete medical records were excluded. Results: The mean age was 59.42 ± 10.68 years and the mean Euroscore was 9.12 ± 1.63. Obesity was present in 76.4%, the incidence of new postoperative ischemic stroke was 27.5%, and the postoperative mortality rate was 26.7%. The mean cardiopulmonary bypass time was 206.81 ± 75.48 min, the aortic cross-clamp time was 118.2 ± 46.42 min, and 90% of cases required cerebral perfusion. The mean cerebral perfusion time was 30.8 ± 24.41 min. Obese patients had a higher frequency of in-hospital death (p = 0.009), smoking (p = 0.036), hypertension (p = 0.023), left common carotid artery dissection (p < 0.001), right common carotid artery dissection (p = 0.029), femoral artery cannulation (p = 0.026), aortic root replacement (p = 0.009), aortic valve replacement (p = 0.005) and early reintervention for bleeding (p = 0.004). Using logistic regression, selective bilateral anterograde cerebral perfusion over 40 min in obese patients was independently associated with new postoperative ischemic stroke (OR = 2.35; 95%CI = 1.36-4.86; p = 0.021). Conclusions: A patient-tailored strategy for cerebral perfusion should be considered in obese patients, considering the high atheromatous burden of the supra-aortic vessels in these patients and the potential risk of atheromatous embolization associated with this technique.

Analysis of clinical characteristics and imagological features of the aortic dissection patients with negative D-dimer results

Background

D-dimer (DD) is a vital biomarker to rule out the diagnosis of aortic dissection (AD). However, the DD level in some patients with AD is not high in clinical practice, which often leads to missed diagnosis; therefore, understanding the characteristics of patients with AD and negative DD is of great clinical value.

Methods

From May 2015 to October 2020, 286 patients with AD who visited the first medical contact (FMC) within 24 h of symptom onset and were hospitalized in the Xiamen Cardiovascular Hospital of Xiamen University were enrolled in this study. Clinical characteristics and outcomes of patients were assessed.

Results

Among them, 13 cases (approximately 4.5%) had negative DD results. Compared to patients with positive DD results, patients with negative DD results had significantly higher platelet counts and lower aortic dissection detection risk scores (ADD-RS). The imagological analysis showed that patients with AD and negative DD had lower extension scores and milder damage to the mesenteric artery and three branches of the aortic arch. Furthermore, the results of the multivariable analysis showed that white blood cell count (WBC) [odds ratio (OR): 1.379, P = 0.028], FMC (OR: 0.904, P = 0.028), and extension score (OR: 1.623, P = 0.046) were associated with negative DD result.

Conclusions

Patients with AD and negative DD results had longer FMC and lower WBC. Imaging showed a smaller tear extension range and less damage to the mesenteric artery and three branches of the aortic arch. A negative DD result could not completely rule out AD even if the ADD-RS was zero.

Impact of body mass index on perioperative mortality of acute stanford type A aortic dissection: a systematic review and meta-analysis

BACKGROUND

Obesity may increase perioperative mortality of acute Stanford type A aortic dissection (ATAAD). However, the available evidence was limited. This study aimed to systematically review published literatures about body mass index (BMI) and perioperative mortality of ATAAD.

METHODS

Electronic literature search was conducted in PubMed, Medline, Embase and Cochrane Library databases. All observational studies that investigated BMI and perioperative mortality of ATAAD were included. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effects model. Meta-regression analysis was performed to assess the effects of different clinical variables on BMI and perioperative mortality of ATAAD. Sensitivity analysis was performed to determine the sources of heterogeneity. Egger's linear regression method and funnel plot were used to determine the publication bias.

RESULTS

A total of 12 studies with 5,522 patients were eligible and included in this meta-analysis. Pooled analysis showed that perioperative mortality of ATAAD increased by 22% for each 1 kg/m2 increase in BMI (OR = 1.22, 95% CI: 1.10-1.35). Univariable meta-regression analysis indicated that age and female gender significantly modified the association between BMI and perioperative mortality of ATAAD in a positive manner (meta-regression on age: coefficient = 0.04, P = 0.04; meta-regression on female gender: coefficient = 0.02, P = 0.03). Neither significant heterogeneity nor publication bias were found among included studies.

CONCLUSIONS

BMI is closely associated with perioperative mortality of ATAAD. Optimal perioperative management needs to be further explored and individualized for obese patient with ATAAD, especially in elderly and female populations.

TRIAL REGISTRATION

PROSPERO (CRD42022358619). BMI and perioperative mortality of ATAAD.

Risk Factors for Aortic Dissection

Aortic dissection is a critical condition, which can affect the aorta over its entire length. Characterized by a split between the tunica intima and the tunica media of the aorta, aortic dissection is seen in both sexes, and diagnosis and treatment are decisive for the survival of the patient. Aortic dissection has a wide range of risk factors that contribute to it being one of the most serious of cardiovascular conditions. Diagnosis is based on a thorough knowledge of the condition and its risk factors. This review describes the patient characteristics, drugs, and medical procedures that may contribute to an increased risk of aortic dissection, raising awareness of this life-threatening condition.

Postoperative pulmonary complications in patients undergoing aortic surgery: A single-center retrospective study

Postoperative pulmonary complications (PPCs) are among the most common complications after cardiovascular surgery. This study aimed to explore the real incidence of and risk factors for PPC in patients with acute type A aortic dissection (ATAAD) who underwent total aortic arch replacement combined with the frozen elephant trunk (TAR + FET). In total, 305 ATAAD patients undergoing TAR + FET from January 2021 to August 2022 in a single-center were divided into PPCs or non-PPCs group. The incidence of PPCs was calculated, risk factors of PPCs were analyzed, and postoperative outcomes were compared between these 2 groups. The incidence of any PPC was 29.2%. And the incidence of respiratory infection, respiratory failure, pleural effusion, atelectasis, pneumothorax, acute respiratory distress syndrome, aspiration pneumonitis, pulmonary edema and bronchospasm was 23.0%, 12.5%, 10.5%, 1.0%, 0.7%, 1.0%, 0%, 0.7%, 0%, respectively. The logistic regression analysis revealed that the history of diabetes, history of renal dysfunction, preoperative SpO2 <90%, cardiopulmonary bypass duration, fresh frozen plasma volume and platelet concentrates volume were independent risk factors for PPCs. Among 2 groups, postoperative ventilation duration, postoperative length of stay in intensive care unit and hospital were (73.5 ± 79.0 vs 24.8 ± 35.2 hours; P < .001), (228.3 ± 151.2 vs 95.2 ± 72.0 hours; P < .001) and (17.9 ± 8.8 vs 11.5 ± 6.2 days; P < .001). There was no difference between 2 groups of in-hospital mortality rate. Additionally, other short-term outcomes were also significantly poorer in patients with PPCs. PPCs are common in ATAAD patients undergoing TAR + FET, and could be multifactorial. PPCs occurrence are associated with poor patient outcomes postoperatively and worth further investigation.

The risk factors of postoperative hypoxemia in patients with Stanford type A acute aortic dissection

Hypoxemia is one of the most common complications in patients after Stanford type A acute aortic dissection surgery. The aim of this study was to investigate the association of circulating ANG II level with postoperative hypoxemia and to identify the risk factors for postoperative hypoxemia in Stanford type A acute aortic dissection patients. In this study, 88 patients who underwent Stanford type A acute aortic dissection surgery were enrolled. Postoperative hypoxemia is defined by the oxygenation index (OI). Perioperative clinical data were collected and the serum ANG II and sACE2 levels were measured. The differences in the basic characteristics, intraoperative details, biochemical parameters, laboratory test data and clinical outcomes were compared between the hypoxemia group and the non-hypoxemia group by univariate analysis. Multivariate logistic regression analysis was performed on the variables with P < .1 in univariate analysis or that were considered clinically important to identify risk factors for postoperative hypoxemia. Twenty-five patients (28.4%) were considered to have postoperative hypoxemia (OI ≤ 200 mm Hg). The ANG II concentration remained a risk factor associated with postoperative hypoxemia [OR = 1.018, 95% CI (1.003-1.034), P = .022]. The other risk factors remaining in the logistic regression model were BMI [OR = 1.417, 95% CI (1.159-1.733), P = .001] and cTnI [OR = 1.003, 95% CI (1.000-1.005), P = .032]. Elevated levels of ANG II, BMI and cTnI are risk factors for postoperative hypoxemia in patients with Stanford type A acute aortic dissection.

Postoperative hypoxemia for patients undergoing Stanford type A aortic dissection

Clinically, it is widely recognized that surgical treatment is the preferred and reliable option for Stanford type A aortic dissection. Stanford type A aortic dissection is an emergent and serious cardiovascular disease characterized with an acute onset, poor prognosis, and high mortality. However, the incidences of postoperative complications are relatively higher due to the complexity of the disease and its intricate procedure. It has been considered that hypoxemia, one of the most common postoperative complications, plays an important role in having a worse clinical prognosis. Therefore, the effective intervention of postoperative hypoxemia is significant for the improved prognosis of patients with Stanford type A aortic dissection.

Acute Lung Injury in aortic dissection : new insights in anesthetic management strategies

Acute aortic dissection (AAD) is a severe cardiovascular disease characterized by rapid progress and a high mortality rate. The incidence of acute aortic dissection is approximately 5 to 30 per 1 million people worldwide. In clinical practice, about 35% of AAD patients are complicated with acute lung injury (ALI). AAD complicated with ALI can seriously affect patients' prognosis and even increase mortality. However, the pathogenesis of AAD combined with ALI remains largely unknown. Given the public health burden of AAD combined with ALI, we reviewed the anesthetic management advances and highlighted potential areas for clinical practice.

Morbid obesity impacts mortality among inpatients with type a aortic dissection: an analysis of the national inpatient sample

BACKGROUND

Stanford type A aortic dissection (T(A)AD) is one of the most dangerous cardiovascular diseases and morbid obesity is associated with the prognosis of many cardiovascular diseases. The aim of this study is to investigate the impact of morbid obesity on in-hospital mortality, total hospital costs and discover the prevalence of morbid obesity among inpatients with T(A)AD.

METHODS

Patients with a primary diagnosis of T(A)AD were identified from the National Inpatient Sample database (NIS) from 2008 to 2017. These patients were categorized into non-obesity, obesity and morbid obesity. Multivariable regression models were utilized to assess the association between obesity/morbid obesity and in-hospital mortality, total cost and other clinical factors. The temporal trend in prevalence of obesity/morbid obesity in T(A)ADs and the trend of in-hospital mortality among different weight categories were also explored.

RESULTS

From the NIS database 8489 T(A)AD inpatients were identified, of which 7230 (85.2%) patients were non-obese, 822 (9.7%) were obese and 437 (5.1%) were morbid obese. Morbid obesity was associated with increased risk of in-hospital mortality (odds ratio [OR] 1.39; 95% confidence interval [CI] 1.03-1.86), 8% higher total cost compared with the non-obese patients. From 2008 to 2017, the rate of obesity and morbid obesity in patients with T(A)AD have significantly increased from 7.36 to 11.33% (P < 0.001) and from 1.95 to 7.37% (P < 0.001). Factors associated with morbid obesity in T(A)ADs included age, female, elective admission, hospital region, dyslipidemia, smoking, rheumatoid arthritis/collagen vascular diseases, chronic pulmonary disease, diabetes and hypertension.

CONCLUSIONS

Morbid obesity are connected with worse clinical outcomes and more health resource utilization in T(A)AD patients. Appropriate medical resource orientation and weight management education for T(A)AD patients may be necessary.

The relation of aortic dimensions and obesity in adults with Marfan or Loeys-Dietz syndrome

Background

Aortic aneurysm and aortic dissection can have a major impact on the life expectancy of Marfan syndrome (MFS) or Loeys-Dietz syndrome (LDS) patients. Although obesity can influence the development of aortic complications, evidence on whether obesity influences the development of aortic aneurysm or dissection in MFS and LDS is limited. The aim of the present study was to elucidate the relationship between aortic size and body composition, assessed by modern bioelectrical impedance analysis (BIA) in MFS/LDS-patients.

Methods

In this exploratory cross-sectional study in MFS or LDS patients, enrolled between June 2020 and May 2022, 34 patients received modern BIA and magnetic resonance imaging (MRI) (n=32) or computed tomography (CT) imaging (n=2) of the entire aorta. A P value of <0.05 was considered significant.

Results

Fifty-one patients (66% female; mean age: 37.7±11.7; range, 17-68 years) with MFS or LDS were enrolled; 34 patients, 27 with MFS and 7 with LDS, underwent aortic MRI or CT scanning. The mean aortic length was 503.7±58.7 mm, and the mean thoracic aortic length and abdominal aortic length were 351.5±52.4 and 152.2±27.4 mm, respectively. The aortic bulb and the ascending aorta were measured only in the non-surgically repaired patients. Fifteen MFS (88.2%) and two LDS (40.0%) patients had an aortic aneurysm. In these, the aortic bulb tended to be larger in MFS than in LDS patients [42.6×41.9×41.2 vs. 37.8×37.4×36.8 mm; P=0.07 (-1.1; 9.1); P=0.07 (-1.2; 8.4); P=0.07 (-1.5; 7.9)]. BIA revealed mean body fat levels of 31.6%±8.7% (range, 9.5-53.5%), indicating that 18 patients (52.9%) were obese. There was a significant correlation between body fat content and thoracic aortic length (R=-0.377; P=0.02), muscle mass and total aortic length (R=0.359; P=0.03), thoracic aortic length (R=0.399; P=0.02), extracellular mass (ECM), and total aortic length (R=0.354; P=0.04), and connective tissue and aortic diameters at the aortic arch (R=0.511; P=0.002), aortic isthmus (R=0.565; P<0.001), and abdominal aorta (R=0.486; P=0.004). Older age was correlated with wider aortic arch, isthmus, and abdominal aorta. Male patients had a longer aorta.

Conclusions

While a slender habitus is commonly known for MFS and LDS patients, our data show that many MFS and LDS patients (especially female) do not fit this phenotypic characteristic and are obese, which is associated with a more severe aortic phenotype. This topic should be included in the clinical assessment of affected MFS and LDS patients, in addition to measurement of the aortic diameters. Physicians should systematically screen MFS and LDS patients for obesity, educate them about the potential risk of resulting aortic complications, and encourage them to adopt a healthy lifestyle, that includes (mild) exercise and a balanced diet.

A Cohort Study of Surgical Indexes, Postoperative Complications, Recovery Speed, and Prognosis of Stanford Type A Aortic Dissection Compared with Traditional Sun's Operation

Objective

The objective is to explore the surgical index, postoperative complications, recovery speed, and prognosis of Stanford type A aortic dissection (AD) compared with traditional 'Sun's operation.

Methods

One hundred patients with Stanford type A AD treated from February 2018 to February 2021 were enrolled in our hospital. Patients were randomly divided into control and research group. The former group underwent traditional Sun's surgery, and the latter group underwent combined debranching surgery. The general data, surgical indexes, total amount of blood transfusion, renal function 72 hours after operation, postoperative indexes during hospitalization, and follow-up results after discharge were compared between the two groups.

Results

The CPB time, ACC time, operation time, and postoperative total drainage volume of the study group were all lower than those of the control group, and the intraoperative urine volume of the study group was higher than that of the control group (P < 0.05). The total amount of RBC infused in the study group was higher than that in the control group, while the total amount of PLT, cryoprecipitate, and plasma infusion in the study group was lower than that in the control group (P < 0.05). At 72 hours after operation, BUN, Scr, and UA in the study group were significantly lower than those in the control group (P < 0.05). The number of the secondary intubation, hemodialysis, neurological complications, and deaths in the study group was significantly lower than that in the control group (P < 0.05).

Conclusion

Both Sun's operation and branch removal are more effective treatment methods, and the two different surgical methods have different indications, advantages, and disadvantages, so different surgical methods can be chosen according to different conditions for Stanford AD. The possible postoperative complications should be comprehensively analyzed in the clinical work in order to reduce the occurrence of postoperative complications and improve the cure rate.

Impact of body mass index on postoperative oxygenation impairment in patients with acute aortic syndrome

Objective: Oxygenation impairment is a common complication of acute aortic syndrome (AAS) patients after surgical repair. The aim of this study is to identify the relationship between body mass index (BMI) and the risk of postoperative oxygenation impairment in AAS patients.

Methods: A total of 227 consecutive patients who were diagnosed as AAS and underwent surgical repair were recruited. They were divided into two groups based on the postoperative oxygenation impairment (non-oxygenation impairment group and oxygenation impairment group). Logistic regression was conducted to evaluate the association between BMI and the risk of oxygenation impairment after surgery. Dose-response curve and subgroup analysis were used to test the reliability of the results of regression analysis. A meta-analysis was then performed to further confirm these results using Pubmed, Embase, and Web of Science databases.

Results: For the retrospective study, a significant association was observed after adjusting for a series of variables. BMI was significantly correlated with postoperative oxygenation impairment in patients with AAS (OR, 95% CI, P: 1.27, 1.17–1.46, 0.001). Compared with the normal weight group (18.5 kg/m² ≤ BMI <23.0 kg/m²), patients with excessive BMI were at a higher risk of oxygenation impairment for the overweight group (23.0 kg/m² ≤ BMI <25 kg/m²) and obesity group (BMI ≥25 kg/m²) (OR, 95% CI, P: 4.96, 1.62–15.15, 0.005; 9.51, 3.06–29.57, <0.001). The dose-response curve showed that the risk of oxygenation impairment after surgery increased with the increased BMI. Besides, subgroup analysis showed that AAS patients who have an excess weight with a TNF-α ≥ 8.1 pg/ml carried an excess risk of postoperative oxygenation impairment. For the meta-analysis, the pooled result also indicated that AAS patients with high BMI had a significantly increased risk of oxygenation impairment after surgery (OR, 95% CI, P: 1.40, 1.18–1.66, 0.001).

Conclusion: Excessive BMI was an independent risk factor for AAS with postoperative oxygenation impairment.

Nomogram and risk calculator for severe hypoxemia after heart valve surgery

Background

Hypoxemia is a very common issue in patients undergoing heart valve surgery (HVS), related to poor clinical outcomes. However, studies on severe hypoxemia (SH) after HVS have not been reported. The aims of this study were to identify predictors for SH in patients undergoing HVS and to develop and validate a risk prediction model.

Methods

Patients undergoing HVS between 2016 and 2019 in a cardiovascular center were enrolled and were assigned to training and validation sets by a 7:3 ratio. Based on whether patients developed SH, they were divided into two groups. By univariate and multivariate analysis, predictors for SH were identified. Based on the predictors and logistic rule, a nomogram and a risk calculator were generated. The model was evaluated using calibration, discrimination and clinical utility.

Results

The incidence rates of SH, moderate hypoxemia and mild hypoxemia were respectively 2.4, 23.9, and 58.2%. By multivariate analysis, seven independent risk factors for SH after HVS were identified, including body mass index, chronic obstructive pulmonary disease, renal insufficiency, white blood cell count, serum globulin, cardiopulmonary bypass time, and surgical types. The logistic model demonstrated satisfactory discrimination, calibration and clinical utility in both the training and validation sets. A nomogram and a risk calculator based on the logistic model were generated for easy application. Risk stratification was performed and three risk intervals were defined according to the nomogram and clinical practice. In addition, compared to patients without SH, patients with SH had significantly poorer clinical outcomes.

Conclusions

Postoperative hypoxemia was prevalent after HVS, related to poor clinical outcomes. A logistic model including seven independent predictors for SH after HVS were established and validated, which demonstrated satisfactory discrimination, calibration and clinical utility. The results of this study may provide help to individualized risk assessment, early prevention and perioperative management.

Differential expression profile of plasma exosomal microRNAs in acute type A aortic dissection with acute lung injury

MicroRNAs (miRNAs) packaged into exosomes mediate cell communication and contribute to the pathogenesis of acute type A aortic dissection (ATAAD) with acute lung injury (ALI). The expression profile of plasma exosomal miRNAs in ATAAD patients with ALI hasn’t been identified. We performed a miRNA-sequencing to analyze the differentially expressed miRNAs (DE-miRNAs) of circulating exosomes in ATAAD patients with ALI compared to patients without ALI, founding 283 specific miRNAs in two groups. We respectively selected the top 10 downregulated and upregulated DE-miRNAs for further studies. The predicted transcription factors (TFs) of these DE-miRNAs were SMAD2, SRSF1, USF1, etc. The Gene Ontology (GO) and Kyoto Encyclopedia Genes and Genomes (KEGG) analysis predicted their target genes mainly involved acute inflammatory response, cell junction, cytoskeleton, NF-κB signaling pathway, etc. Construction and analysis of the PPI network revealed that RHOA and INSR were considered hub genes with the highest connectivity degrees. Moreover, we confirmed two exosomal miRNAs (hsa-miR-485-5p and hsa-miR-206) by real-time quantitative polymerase chain reaction (RT-qPCR) in a validation cohort. Our study identified a plasma exosomal miRNAs signature related to ATAAD with ALI. Certain DE-miRNAs may contribute to the progression of this disease, which help us better understand the pathogenesis of ATAAD with ALI.

Incidence, Risk Factors, and Outcomes of Severe Hypoxemia After Cardiac Surgery

Background

Hypoxemia is common in patients undergoing cardiac surgery, however, few studies about severe hypoxemia (SH) after cardiac surgery exist. The objectives of this study were to clarify the incidence, risk factors, and outcomes of SH after cardiac surgery.

Methods

Patients undergoing cardiac surgery from 2016 to 2019 in a single center were enrolled and were divided into two groups based on whether postoperative SH developed. Independent risk factors for SH were identified by univariate and multivariate analysis. Model selection statistics were applied to help determine the most parsimonious final model.

Results

Severe hypoxemia developed in 222 of the 5,323 included patients (4.2%), was associated with poorer clinical outcomes. Six independent risk factors for SH after cardiac surgery were identified by multivariate analysis, such as surgical types, white blood cell (WBC) count, body mass index (BMI), serum albumin, cardiopulmonary bypass (CPB) time, and intraoperative transfusion of red blood cells (RBCs). After comprehensively considering the discrimination, calibration, and simplicity, the most appropriate and parsimonious model was finally established using four predictors, such as WBC count, BMI, CPB time, and intraoperative transfusion of RBCs. A nomogram and a web-based risk calculator based on the final model were constructed to facilitate clinical practice. Patients were stratified into three risk groups based on the nomogram and clinical practice.

Conclusion

Severe hypoxemia was common after cardiac surgery and was associated with poorer clinical outcomes. A parsimonious final model with good discrimination, calibration, and clinical utility was constructed, which may be helpful for personalized risk assessment and targeted intervention.

Metabolic syndrome and its components are associated with hypoxemia after surgery for acute type A aortic dissection: an observational study

Background

The aim of this study was to explore whether or to what extent metabolic syndrome (METs) and its components were associated with hypoxemia in acute type A aortic dissection (ATAAD) patients after surgery.

Methods

This study involved 271 inpatients who underwent surgery. Demographic and clinical data were collected. Subgroup analysis, mixed model regression analysis, and receiver operating characteristic (ROC) curve analysis were performed, and a scoring system was evaluated.

Results

The 271 inpatients were assigned to the hypoxemia group (n = 48) or no hypoxemia group (n = 223) regardless of METs status. Compared to the no hypoxemia group, the hypoxemia group had a higher incidence of METs. Hypoxemia was present in 0%, 3.7%, 19.8%, 51.5%, 90.0% and 100% in the groups of individuals who met the diagnostic criteria of MetS 0, 1, 2, 3, 4 and 5 times, respectively. In the multivariable logistic regression analysis, BMI quartile was still a risk factor for hypoxemia after adjustment for other risk factors. After adjustment for potential confounding factors, METs was an independent risk factor for hypoxemia in several models. After assigning a score for each METs component present, the AUCs were 0.852 (95% CI 0.789–0.914) in all patients, 0.728 (95% CI 0.573–0.882) in patients with METs and 0.744 (95% CI 0.636–0.853) in patients without METs according to receiver operating characteristic analysis.

Conclusions

METs, especially body mass index, confers a greater risk of hypoxemia in ATAAD after surgery.

Preoperative Nomogram and Risk Calculator for Postoperative Hypoxemia and Related Clinical Outcomes Following Stanford Type A Acute Aortic Dissection Surgery

Background

Hypoxemia is a common complication after Stanford type A acute aortic dissection surgery (AADS), however, few studies about hypoxemia after AADS exist. The aims of this study were to identify independent risk factors for hypoxemia after AADS and to clarify its association with clinical outcomes.

Methods

Patients undergoing AADS from 2016 to 2019 in our hospital were identified and used as a training set. Preoperative variables were first screened by univariate analysis and then entered into a multivariate logistic regression analysis to identify independent risk factors. A nomogram and an online risk calculator were constructed based on the logistic model to facilitate clinical practice and was externally validated in an independent dataset.

Results

Severe hypoxemia developed in 119 of the 492 included patients (24.2%) and poorer clinical outcomes were observed in these patients. Five independent risk factors for severe hypoxemia after AADS were identified by multivariate analysis, including older age, smoking history, renal insufficiency, higher body mass index, and white blood cell count. The model showed good calibration, discrimination, and clinical utility in the training set, and was well validated in the validation set. Risk stratification was performed and three risk groups were defined as low, medium, and high risk groups. Hypertension was identified as an independent risk factor for moderate hypoxemia besides the five predictors mentioned above, and renal insufficiency was not significant for mild hypoxemia by multivariate analysis. In addition, although frozen elephant trunk was associated with increased risk of postoperative hypoxemia in the univariate analysis, frozen elephant trunk was also not identified as an independent risk factor for postoperative hypoxemia in the multivariate analysis.

Conclusion

Hypoxemia was frequent following AADS, related to poorer clinical outcomes. Predictors were identified and a nomogram as well as an online risk calculator predicting severe hypoxemia after AADS was developed and validated, which may be helpful for risk estimation and perioperative management.

Factors Associated with Postoperative Lipiduria and Hypoxemia in Patients Undergoing Surgery for Orthopedic Fractures

We investigated factors associated with postoperative lipiduria and hypoxemia in patients undergoing surgery for orthopedic fractures. We enrolled patients who presented to our emergency department due to traumatic fractures between 2016 and 2017. We collected urine samples within 24 h after the patients had undergone surgery to determine the presence of lipiduria. Hypoxemia was defined as an SpO2 &lt;95% determined with a pulse oximeter during the hospitalization. Patients’ anthropometric data, medical history, and laboratory test results were collected from the electronic medical record. Logistic regression analyses were used to determine the associations of clinical factors with postoperative lipiduria and hypoxemia with multivariate adjustments. A total of 144 patients were analyzed (mean age 51.3 ± 22.9 years, male 50.7%). Diabetes (odd ratio 3.684, 95% CI, 1.256–10.810, p = 0.018) and operation time (odd ratio 1.005, 95% CI, 1.000–1.009, p = 0.029) were independently associated with postoperative lipiduria, while age (odd ratio 1.034, 95% CI, 1.003–1.066, p = 0.029), body mass index (odd ratio 1.100, 95% CI, 1.007–1.203, p = 0.035), and operation time (odd ratio 1.005, 95% CI, 1.000–1.010, p = 0.033) were independently associated with postoperative hypoxemia. We identified several factors independently associated with postoperative lipiduria and hypoxemia in patients with fracture undergoing surgical intervention. Operation time was associated with both postoperative lipiduria and hypoxemia, and we recommend that patients with prolonged operation for fractures should be carefully monitored for clinical signs related to fat embolism syndrome.

Preoperative acute lung injury and oxygenation impairment occurred in the patients with acute aortic dissection

Acute lung injury (ALI) and oxygenation impairment (OI) frequently occur in the patients with acute aortic dissection (AAD), which may necessitate mechanical ventilation and result in adverse outcomes. This paper aims to increase clinicians’ awareness of the severe respiratory complications in the patients with AAD, and provide the overview of the epidemiology, adverse outcomes, pathogenesis, predictive markers and therapeutic modalities of the concurrent conditions. Currently, it is considered that inflammatory response plays a great role in the pathogenesis of ALI and OI in the patients with AAD, but the definite pathogenesis remains unclear. Given the great importance of the prediction of the occurrence of the severe respiratory complication at a very early stage, some inflammatory biomarkers have been investigated to predict the occurrence of ALI and OI in several studies. C-reactive protein was found to have a significant predictive effect for the development of ALI and OI. Early use of beta-blockers and the use of bindarit could prevent the occurrence of OI and ALI. Ulinastatin could also improve oxygenation in the patients with type-A AAD. Prevention and management of ALI and OI in AAD remain a great challenge. The definite pathogenesis should be clearly clarified and further studies should be performed to look for potential effective way to predict and manage the severe respiratory conditions.

The association between body mass index and risk of preoperative oxygenation impairment in patients with the acute aortic syndrome

OBJECTIVE

The study aimed to determine the relationship between body mass index (BMI) and the risk of acute aortic syndrome (AAS) with preoperative oxygenation impairment.

METHODS

A meta-analysis of published observational studies involving BMI and AAS with preoperative oxygenation impairment was conducted. A total of 230 patients with AAS were enrolled for retrospective analysis. All patients were divided into 2 groups (Non-oxygenation impairment group and Oxygenation impairment group). Logistic regression analysis was performed to assess the relation between BMI and the risk of preoperative oxygenation impairment after the onset of AAS. Dose-response relationship curve and subgroup analysis were conducted to test the reliability of BMI as an independent factor of it.

RESULTS

For the meta-analysis, the quantitative synthesis indicated that excessive BMI increased the risk of preoperative oxygenation impairment (OR: 1.30, 95% CI: 1.05-1.60, P _{heterogeneity} = 0.001). For the retrospective analysis, a significant association was observed after adjusting for a series of variables. BMI was significantly related to preoperative oxygenation impairment after the onset of AAS (OR: 1.34, 95% CI: 1.15-1.56, p <0.001), and compared with normal weight group (18.5 kg/m² ≤ BMI < 23.0 kg/m²), the individuals with excessive BMI were at higher risk of preoperative oxygenation impairment for the obese group (BMI ≥ 25 kg/m²) (OR: 17.32, 95% CI: 4.03-74.48, p <0.001). A J-shape curve in dose-response relationship analysis further confirmed their positive correlation. Subgroup analysis showed that diastolic blood pressure (DBP) ≥ 90mmHg carried an excess risk of preoperative oxygenation impairment in obese patients.

CONCLUSION

Excessive BMI was an independent risk factor for AAS with preoperative oxygenation impairment.

Predictors of hypoxemia in type-B acute aortic syndrome: a retrospective study

Acute aortic syndrome (AAS) can be life-threatening owing to a variety of complications, and it is managed in the intensive care unit (ICU). Although Stanford type-B AAS may involve hypoxemia, its predictors are not yet clearly understood. We studied clinical factors and imaging parameters for predicting hypoxemia after the onset of type-B AAS. We retrospectively analyzed patients diagnosed with type-B AAS in our hospital between January 2012 and April 2020. We defined hypoxemia as PaO₂/FiO₂ ≤ 200 within 7 days after AAS onset and used logistic regression analysis to evaluate prognostic factors for hypoxemia. We analyzed 224 consecutive patients (140 males, mean age 70 ± 14 years) from a total cohort of 267 patients. Among these, 53 (23.7%) had hypoxemia. The hypoxemia group had longer ICU and hospital stays compared with the non-hypoxemia group (median 20 vs. 16 days, respectively; p = 0.039 and median 7 vs. 5 days, respectively; p < 0.001). Male sex (odds ratio [OR] 2.87; 95% confidence interval [CI] 1.24–6.63; p = 0.014), obesity (OR 2.36; 95% CI 1.13–4.97; p = 0.023), patent false lumen (OR 2.33; 95% CI 1.09–4.99; p = 0.029), and high D-dimer level (OR 1.01; 95% CI 1.00–1.02; p = 0.047) were independently associated with hypoxemia by multivariate logistic analysis. This study showed a significant difference in duration of ICU and hospital stays between patients with and without hypoxemia. Furthermore, male sex, obesity, patent false lumen, and high D-dimer level may be significantly associated with hypoxemia in patients with type-B AAS.

Association of body mass index with outcomes after thoracic endovascular aortic repair in the vascular quality initiative

OBJECTIVE

Although several studies have evaluated the impact of obesity on outcomes after abdominal aortic aneurysm repair, literature examining this association in thoracic endovascular aortic repair (TEVAR) is sparse. Here, we use a multi-institutional, international database to assess the role of body mass index (BMI) on adverse outcomes in patients who underwent TEVAR for descending thoracic aortic aneurysms (DTAA) and type B dissections (TBD).

METHODS

A retrospective review of all patients who underwent TEVAR for DTAA or TBD from August 2014 to August 2020 was performed. Patients who were underweight (BMI <18.5 kg/m²) or obese (BMI ≥30 kg/m²) were compared with those of normal weight (≥18.5 to <30 kg/m²). Adjustment for confounding was done with multivariable logistic regression or Cox proportional hazards regression as appropriate for studying postoperative or 1-year outcomes. Primary outcomes were 30-day and 1-year mortality. Other outcomes included any postoperative complication, stroke, and spinal cord ischemia.

RESULTS

A total of 3423 participants were included in the study, of whom 3.3% (n = 113) were underweight, 65.9% (n = 2253) had normal weight, and 30.8% (n = 1053) were obese. Compared with normal weight, there was no significant difference in 30-day mortality in underweight patients (odds ratio [OR], 1.81; 95% confidence interval [CI], 0.80-4.14; P = .156). Obese patients who underwent TEVAR for TBD had a 2.7-fold increase in the odds of 30-day mortality compared with normal weight (OR, 2.67; 95% CI, 1.52-4.68; P = .001). Obese and normal weight patients with DTAA had equivalent odds of 30-day mortality (OR, 1.32; 95% CI, 0.79-2.23; P = .292). The adjusted hazard of 1-year mortality was 2-fold higher in underweight patients compared with normal weight (hazard ratio, 2.15; 95% CI, 1.41-3.29; P < .001), driven by a higher risk of mortality among patients with thoracic aortic aneurysm (OR, 2.62; 95% CI, 1.63-4.21; P < .001). There was no significant difference in 1-year mortality risk between normal weight and obesity in both DTAA (OR, 0.77; 95% CI, 0.54-1.09; P = .146) and TBD (OR, 1.26; 95% CI, 0.85-1.86; P = .248).

CONCLUSIONS

In this study, obese patients who underwent TEVAR for DTAA had comparable 30-day and 1-year mortality risk as normal weight individuals. Obese patients who underwent TEVAR for TBD demonstrated a 2.7-fold increase in the odds of 30-day mortality, but equivalent mortality risk as normal weight patients at 1 year. TEVAR represents a safe minimally invasive option for treatment of DTAA in obese patients. Future work should be directed toward minimizing perioperative mortality among patients with TBD to optimize TEVAR outcomes.

The risk factors for postoperative acute respiratory distress syndrome in Stanford type a acute aortic dissection patients

OBJECTIVE

To explore the risk factors for postoperative acute respiratory distress syndrome (ARDS) in Stanford type A acute aortic dissection (AAD) patients.

METHODS

This study included 64 patients with Stanford type A AAD who underwent Sun's procedure. The patients were divided into an ARDS group (PaO₂/FiO₂ < 200 mmHg) and a non-ARDS group (PaO₂/FiO₂ ≥ 200 mmHg). We compared the patients' perioperative clinical features in the two groups. A multivariate binary logistic regression was used to analyze the risk factors for ARDS in the Stanford type A AAD patients.

RESULTS

The incidence of postoperative ARDS was 56.25%. There were 13 deaths in the 6-month follow-up, including 8 in the ARDS group and 5 in the non-ARDS group. There were differences in the body mass index (BMI) levels, the times from onset to operation, the preoperative white blood cell counts, the preoperative hemoglobin levels, the preoperative alanine aminotransferase levels, the preoperative blood creatinine levels, the preoperative PaO₂/FiO₂, intraoperative blood transfusion volumes, the assisted mechanical ventilation times, and the durations of the intensive care unit stays between the two groups (all P < 0.05). The logistic regression analysis revealed that a BMI ≥ 25 kg/m², a time from onset to operation ≥ 24 hours, a preoperative white blood cell count ≥ 10×10⁹/L, and a preoperative PaO₂/FiO₂ < 300 mmHg were the independent risk factors for postoperative ARDS in patients with Stanford type A AAD.

CONCLUSIONS

ARDS occurs often in Stanford type A AAD patients. A BMI ≥ 25 kg/m², a time from onset to operation ≥ 24 hours, a preoperative white blood cell count ≥ 10×10⁹/L, and a preoperative PaO₂/FiO₂ < 300 mmHg are the independent risk factors for postoperative ARDS in these patients.

Identification of Molecular Regulatory Features and Markers for Acute Type A Aortic Dissection

BACKGROUND

Acute type A aortic dissection (ATAAD) is one of the most lethal cardiovascular diseases, and its molecular mechanism remains unclear.

METHODS

Differentially expressed genes (DEGs) between ATAAD and control were detected by limma R package in GSE52093, GSE153434, GSE98770, and GSE84827, respectively. The coexpression network of DEGs was identified by the WGCNA package. Enrichment analysis was performed for module genes that were positively correlated with ATAAD using clusterProfiler R package. In addition, differentially methylated markers between aortic dissection and control were identified by ChAMP package. After comparing with ATAAD-related genes, a protein-protein interaction (PPI) network was established based on the STRING database. The genes with the highest connectivity were identified as hub genes. Finally, differential immune cell infiltration between ATAAD and control was identified by ssGSEA.

RESULTS

From GSE52093 and GSE153434, 268 module genes were obtained with consistent direction of differential expression and high correlation with ATAAD. They were significantly enriched in T cell activation, HIF-1 signaling pathway, and cell cycle. In addition, 2060 differentially methylated markers were obtained from GSE84827. Among them, 77 methylation markers were ATAAD-related DEGs. Using the PPI network, we identified MYC, ITGA2, RND3, BCL2, and PHLPP2 as hub genes. Finally, we identified significantly differentially infiltrated immune cells in ATAAD.

CONCLUSION

The hub genes we identified may be regulated by methylation and participate in the development of ATAAD through immune inflammation and oxidative stress response. The findings may provide new insights into the molecular mechanisms and therapeutic targets for ATAAD.

Effects of Obesity on Outcomes of Acute Type A Aortic Dissection Repair in Japan

Background: The prevalence of obesity among Japanese acute type A aortic dissection (ATAAD) patients and its effect on repair outcomes remain to be elucidated.

Methods and Results: The prevalence of obesity (body mass index [BMI] ≥30.0 kg/m²) among 1,059 patients (mean [±SD] age 64.3±12.7 years) who underwent ATAAD repair between 1990 and 2018 was compared with that among the general Japanese population (National Health and Nutrition Survey data). The prevalence of obesity among male patients (17.1% [6/35], 20.0% [18/90], and 14.4% [20/139] for those aged 20–39, 40–49, and 50–59 years, respectively) was significantly higher than that among the age- and sex-matched general population. The 1,059 patients were divided into groups according to weight (normal [BMI <25.0 kg/m²; n=742], overweight [BMI 25.0–29.9 kg/m²; n=248], or obese [BMI ≥30.0 kg/m²; n=69]). Comparing the normal weight, overweight, and obese groups revealed significant differences among the 3 groups in median cardiopulmonary bypass time (143, 167, and 183 min, respectively), ventilation >48 h (44.5%, 60.1%, and 78.3%, respectively), and in-hospital mortality (7.0%, 7.3%, and 17.4%, respectively), but not in 30-day survival. Shock, visceral malperfusion, operation time >360 min, obesity, and coronary malperfusion were identified as predictors of in-hospital mortality.

Conclusions: The prevalence of obesity is increased among Japanese male patients with ATAAD aged ≤59 years. Obesity may increase these patients’ operative risk; overweight does not.