Predictors of oxygenation impairment in medical treatment for type B acute aortic dissection

Value of C-reactive protein/albumin ratio in predicting the development of preoperative oxygenation impairment in patients with Stanford type-B acute aortic dissection

Objectives

We aimed to assess the predicting value of C-reactive protein (CRP)/albumin ratio (CAR) in the development of Oxygenation impairment (OI) in the patients with Stanford type-B acute aortic dissection (AAD).

Methods

This study included 133 patients (age = 58.8 ± 12.0 years, median age = 61 years, Male/Female = 117/16) diagnosed as Stanford type-B AAD accompanied by hypertension from July 2012 to May 2020. Clinical data were retrospectively extracted from the database. The patients in this study were divided into OI group (oxygenation index ≤ 200) and non-OI group (oxygenation index > 200). Clinical characteristics in both groups were compared, and predicting value of CAR in the development of OI was assessed.

Results

Patients in OI group had higher peak body temperature (37.94 ± 0.62 vs. 37.67 ± 0.51 ℃, P =.010), higher levels of serum CRP (41.74 ± 27.71 vs 15.21 ± 19.66 mg/L, P =.000) and plasma B-type natriuretic peptide (292.14 ± 251.11 vs 179.80 ± 241.27 ng/L, P =.016), lower levels of albumin (34.00 ± 5.14 vs 37.72 ± 5.24 g/L, P =.000), and higher CAR (1.27 ± 0.89 vs 0.41 ± 0.53, P =.000). In multivariate regression analysis, CAR (odds ratio: 5.215, 95 % CI: 2.682; 10.137, P =.000) and the peak body temperature (odds ratio: 2.905, 95 % CI: 1.255; 6.724, P =.013) could significantly predict the OI development. The AUC for CAR was 0.831 (95 % CI: 0.756-0.907). An optimal cutoff value for CAR for predicting OI was ≥ 0.70, with a sensitivity of 67.5 % and a specificity of 88.2 %.

Conclusions

Compared with CRP or albumin alone, the CAR might be a more accurate marker in predicting OI development in Stanford type-B AAD.

Risk profile analysis of uncomplicated type B aortic dissection patients undergoing thoracic endovascular aortic repair: Laboratory and radiographic predictors

BACKGROUND

There is emerging evidence to support pre-emptive thoracic endovascular aortic repair (TEVAR) intervention for uncomplicated type B aortic dissection (unTBAD). Pre-emptive intervention would be particularly beneficial in patients that have a higher baseline risk of progressing to complicated TBAD (coTBAD). There remain debate on the optimal clinical, laboratory, morphological, and radiological parameters, which would identify the highest-risk patients that would benefit most from pre-emptive TEVAR.

AIM

This review summarizes evidence on the clinical, laboratory, and morphological parameters that increase the risk profiles of unTBAD patients.

METHODS

A comprehensive literature search was carried out on multiple electronic databases including PubMed, EMBASE, Ovid, and Scopus to collate all research evidence on the clinical, laboratory, and morphological parameters that increase the risk profiles of unTBAD patients RESULTS: At present, there are no clear clinical guidelines using risk-stratification to inform the selection of unTBAD patients for TEVAR. However, there are noticeable literature trends that can assist with the identification of the most at-risk unTBAD patients. Patients are at particular risk when they have refractory pain and/or hypertension, elevated C-reactive protein (CRP), larger aortic diameter, and larger entry tears. These risks should be considered alongside factors that increase the procedural risk of TEVAR to create a well-balanced approach. Advances in biomarkers and imaging are likely to identify more pertinent parameters in the future to optimize the development of balanced, risk-stratified treatment protocols.

CONCLUSION

There are a variety of risk profiling parameters that can be used to identify the high-risk unTBAD patient, with novel biomarkers and imaging parameters emerging. Longer-term evidence verifying these parameters would be ideal. Further randomized controlled trials and multicentre registry analyses are also warranted to guide risk-stratified selection protocols.

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.

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.

Venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome due to an acute type B aortic dissection: a case report

Acute type B aortic dissection is sometimes complicated by acute respiratory failure requiring mechanical ventilation. Herein, we describe our experience in a rare acute type B aortic dissection-associated respiratory failure case culminating in acute respiratory distress syndrome. The patient was a 45-year-old man admitted with a complaint of sudden chest pain radiating to his back. On computed tomography, an acute type B aortic dissection was diagnosed. He had no dyspnea on admission, but his respiratory function subsequently deteriorated, and severe acute respiratory distress syndrome was diagnosed on Day 4. Venovenous extracorporeal membrane oxygenation with anticoagulation plus continuous renal replacement therapy for oliguria improved the oxygenation, and the patient was weaned from the extracorporeal membrane oxygenation on Day 8. This patient fully recovered without worsening the aortic dissection, using venovenous extracorporeal membrane oxygenation with anticoagulation plus a continuous renal replacement therapy.

Predictors for the development of preoperative oxygenation impairment in acute aortic dissection in hypertensive patients

BACKGROUND

Acute aortic dissection (AAD) is an acute life-threatening cardiovascular disease, which is frequently complicated with oxygenation impairment (OI). We aim to investigate predictors of the development of OI in the patients with AAD.

METHODS

We retrospectively collected clinical data of AAD in hypertensive patients from July 2012 to March 2020. The patients included in this study were divided into OI (+) group (oxygenation index≤200) and OI (-) group (oxygenation index> 200). Both groups were compared according to demographic and clinical characteristics, and laboratory findings. Characteristics of hypertension in the patients with AAD were described. Predictors for the development of OI were assessed. And cutoff values were determined by receiver operating characteristics (ROC) curve.

RESULTS

A total of 208 patients were included in this study and the incidence of OI was 32.2%. In OI (+) group, patients had significantly higher peak body temperature (37.85 ± 0.60 vs 37.64 ± 0.44 °C, P = .005), higher levels of CRP (42.70 ± 28.27 vs 13.90 ± 18.70 mg/L, P = .000) and procalcitonin (1.07 ± 3.92 vs 0.31 ± 0.77μg/L, P = .027), and lower levels of albumin (34.21 ± 5.65 vs 37.73 ± 4.70 g/L, P = .000). Spearman's rank correlation test showed that the minimum oxygenation index was positively correlated with albumin, and was negatively correlated with the peak body temperature, serum CRP, procalcitonin, BNP and troponin. The stepwise multiple linear regression analysis showed that the peak body temperature, serum CRP and albumin were independently associated with development of OI. An optimal cutoff value for CRP for predicting OI was ≥9.20 mg/L, with a sensitivity of 91.0% and a specificity of 61.0%.

CONCLUSIONS

The peak body temperature, serum CRP and albumin were independent predictors of OI development in the patients with AAD. The serum CRP on admission≥9.20 mg/L might be a valuable and reliable indicator in predicting the development of OI.

miR-27a regulates vascular remodeling by targeting endothelial cells' apoptosis and interaction with vascular smooth muscle cells in aortic dissection

Rationale: Aortic dissection (AD) is caused by functional disorder of cells in the aortic wall, which is largely attributed to vascular remodeling. Therapeutic strategies for AD remain limited due to our incomplete understanding of the role of endothelial cells (ECs) in AD pathogenesis. This study aimed to identify the regulatory role of miR-27a in AD and provide a mechanistic basis for a non-invasive treatment of AD.

Methods: We harvested aortas from normal and AD patients to explore the expression of miR-27a. In vitro and in vivo assays were preformed to explore the biological effects of differential expression of miR-27a in ECs and its regulatory effect on AD.

Results: MiR-27a was lower in intima of AD samples than in healthy individuals. Downregulation of miR-27a in EC was due to up-regulated expression of fas-associated protein with death domain (FADD) and the activation of apoptosis pathway, which led to apoptosis of ECs. Migration of vascular smooth muscle cells was promoted by EC after downregulation of miR-27a due to enhancement of growth/differentiation factor 8 (GDF8) and repression of matrix metalloproteinase-20 (MMP20) in the co-culture system supernatants. Increase in FADD and apoptosis of ECs to induce AD was shown using mouse models of AD in which miR-27a was stably knocked-down by antagomir. Up-regulation of miR-27a by agomir led to a protective effect on AD.

Conclusion: Treatment with miR-27a activator that targets apoptosis of ECs strongly diminished occurrence of AD, providing a new strategy for this disease.