Clinical dilemma in the surgical treatment of organ malperfusion caused by acute type A aortic dissection

Early Prediction Model of Acute Aortic Syndrome Mortality in Emergency Departments

Purpose

Acute aortic syndrome is a constellation of life-threatening medical conditions for which rapid assessment and targeted intervention are important for the prognosis of patients who are at high risk of in-hospital death. The current study aims to develop and externally validate an early prediction mortality model that can be used to identify high-risk patients with acute aortic syndrome in the emergency department.

Patients and Methods

This retrospective multi-center observational study enrolled 1088 patients with acute aortic syndrome admitted to the emergency departments of two hospitals in China between January 2017 and March 2021 for model development. A total of 210 patients with acute aortic syndrome admitted to the emergency departments of Peking University Third Hospital between January 2007 and December 2021 was enrolled for model validation. Demographics and clinical factors were collected at the time of emergency department admission. The predictive variables were determined by referring to the results of previous studies and the baseline analysis of this study. The study’s endpoint was in-hospital death. To assess internal validity, we used a fivefold cross-validation method. Model performance was validated internally and externally by evaluating model discrimination using the area under the receiver-operating characteristic curve (AUC). A nomogram was developed based on the binary regression results.

Results

In the development cohort, 1088 patients with acute aortic syndromes were included, and 88 (8.1%) patients died during hospitalization. In the validation cohort, 210 patients were included, and 20 (9.5%) patients died during hospitalization. The final model included the following variables: digestive system symptoms (OR=2.25; P=0.024), any pulse deficit (OR=7.78; P<0.001), creatinine (µmol/L)(OR=1.00; P=0.018), lesion extension to iliac vessels (OR=4.49; P<0.001), pericardial effusion (OR=2.67; P=0.008), and Stanford type A (OR=10.46; P<0.001). The model’s AUC was 0.838 (95% CI 0.784–0.892) in the development cohort and 0.821 (95% CI 0.750–0.891) in the validation cohort, and the Hosmer–Lemeshow test showed p=0.597. The fivefold cross-validation demonstrated a mean accuracy of 0.94, a mean precision of 0.67, and a mean recall of 0.13.

Conclusion

This risk prediction tool uses simple variables to provide robust prediction of the risk of in-hospital death from acute aortic syndrome and validated well in an independent cohort. The tool can help emergency clinicians quickly identify high-risk acute aortic syndrome patients, although further studies are needed for verifying the prospective data and the results of our study.

Percutaneous coronary intervention for left main coronary artery malperfusion in acute type A aortic dissection

The clinical outcomes of patients undergoing percutaneous coronary intervention (PCI) for left main coronary artery (LMCA) malperfusion caused by acute type A aortic dissection (AAAD) remains largely unexplored. The aim of this study was to determine the clinical outcomes of patients undergoing PCI for LMCA malperfusion caused by AAAD. We examined nine consecutive patients undergoing PCI for LMCA malperfusion caused by AAAD between 1995 and 2020. The mean age was 55.4 ± 7.7 years. Eight patients presented cardiogenic shock, and five patients cardiopulmonary arrest. Two patients were diagnosed with AAAD before coronary angiography using computed tomography and transthoracic echocardiography, respectively, and in the other seven patients after coronary angiography using other modalities. Four patients underwent PCI on intra-aortic balloon pumping support, and four patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO) support, including one patient on both. PCI was successful in eight patients, with final thrombolysis in myocardial infarction grade 2 or 3. The four patients on VA-ECMO did not undergo aortic dissection repair due to poor recovery of cardiac function and died during the hospital stay, and the other five patients had successful PCI, underwent aortic dissection repair, and remained alive at 5 year follow-up. In conclusion, LMCA malperfusion caused by AAAD seemed to have clinical presentations and electrocardiogram changes similar to acute coronary syndrome. PCI and subsequent surgical aortic repair saved the lives of all AAAD patients with LMCA malperfusion who had not required VA-ECMO.

Perioperative Hyperlactemia Is a Poor Predictor of Outcome in Patients Undergoing Surgery for Acute Type-A Aortic Dissection

OBJECTIVE

In patients presenting with acute type-A aortic dissection (aTAAD), lactic acid measurement is a frequently used analysis for diagnosis of acute ischemia, which may have a dismal prognosis. The aim of the current study was to determine the performance of perioperative arterial lactic acid measurements in predicting outcome in aTAAD patients.

DESIGN

Retrospective, observational study.

SETTING

Cardiothoracic surgery unit at a tertiary-level hospital.

PARTICIPANTS

The study involved 285 consecutive patients undergoing surgery for aTAAD.

INTERVENTIONS

Preoperative and postoperative lactic acid levels were measured and evaluated together with clinical data related to outcome, including in-hospital and 1-year mortality.

MEASUREMENTS AND MAIN RESULTS

Altogether, 37 patients (13%) died during the index hospital admission, and survival was 84.4 ± 2.2 at 1 year. Preoperative cardiac malperfusion (odds ratio [OR] 3.1; 95% confidence interval [CI] 1.3-7.3) and cerebral malperfusion (OR 2.6; 95% CI 1.2-5.6) were associated significantly with poorer 1-year survival. The area under the curve (AUC) for in-hospital and 1-year mortality in relation to preoperative lactic acid levels was 0.684 and 0.673, respectively, corresponding to a lactic acid cut-off for in-hospital mortality of 2.75 mmol/L (sensitivity 56%; specificity 72%) and a cut-off for 1-year mortality of 2.85 mmol/L (sensitivity 48%; specificity 74%). The AUC for in-hospital and 1-year mortality in relation to lactic acid levels measured postoperatively on arrival at the intensive care unit was 0.582 and 0.498, respectively.

CONCLUSION

Although hyperlactemia in aTAAD indicates an increased risk of postoperative mortality, the sole use of lactic acid levels as a tool for accurate assessment of postoperative mortality is inadvisable due to its poor discriminatory performance.

Hyperlactemia Predicts Surgical Mortality in Patients Presenting With Acute Stanford Type-A Aortic Dissection

OBJECTIVE

Inspired by the limited facility of the Penn classification, the authors aimed to determine a rapid and optimal preoperative assessment tool to predict surgical mortality after acute Stanford type-A aortic dissection (AAAD) repair.

DESIGN

Patients who underwent an attempted surgical repair of AAAD were determined using a de-identified single institution database. The charts of 144 patients were reviewed retrospectively for preoperative demographics and surrogates for disease severity and malperfusion. Bivariate analysis was used to determine significant (p≤0.05) predictors of in-hospital and 1-year mortality, the primary endpoints. Receiver operating characteristic curve generation was used to define optimal cut-off values for continuous predictors.

SETTING

Single center, level 1 trauma, university teaching hospital.

PARTICIPANTS

The study included 144 cardiac surgical patients with acute type-A aortic dissection presenting for surgical correction.

INTERVENTIONS

Surgical repair of aortic dissection with preoperative laboratory samples drawn before patient transfer to the operating room or immediately after arterial catheter placement intraoperatively.

MEASUREMENTS AND MAIN RESULTS

The study cohort comprised 144 patients. In-hospital mortality was 9%, and the 1-year mortality rate was 17%. Variables that demonstrated a correlation with in-hospital mortality included an elevated serum lactic acid level (odds ratio [OR] 1.5 [1.3-1.9], p<0.001), a depressed ejection fraction (OR 0.91 [0.86-0.96], p = .001), effusion (OR 4.8 [1.02-22.5], p = 0.04), neurologic change (OR 5.3 [1.6-17.4], p = 0.006), severe aortic regurgitation (OR 8.2 [2.0-33.9], p = 0.006), and cardiopulmonary resuscitation (OR 6.8 [1.7-26.9], p = 0.01). Only an increased serum lactic acid level demonstrated a trend with 1-year mortality using univariate Cox regression (hazard ratio 1.1 [1.0-1.1], p = 0.006). Receiver operating characteristic analysis revealed optimal cut-off lactic acid levels of 6.0 mmol/L and 6.9 mmol/L for in-hospital and 1-year mortality, respectively.

CONCLUSION

Lactic acidosis, ostensibly as a surrogate for systemic malperfusion, represents a novel, accurate, and easily obtainable preoperative predictor of short-term mortality after attempted AAAD repair. These data may improve identification of patients who would not benefit from surgery.

Mesenteric ischemia: Pathogenesis and challenging diagnostic and therapeutic modalities

Mesenteric ischemia (MI) is an uncommon medical condition with high mortality rates. ΜΙ includes inadequate blood supply, inflammatory injury and eventually necrosis of the bowel wall. The disease can be divided into acute and chronic MI (CMI), with the first being subdivided into four categories. Therefore, acute MI (AMI) can occur as a result of arterial embolism, arterial thrombosis, mesenteric venous thrombosis and non-occlusive causes. Bowel damage is in proportion to the mesenteric blood flow decrease and may vary from minimum lesions, due to reversible ischemia, to transmural injury, with subsequent necrosis and perforation. CMI is associated to diffuse atherosclerotic disease in more than 95% of cases, with all major mesenteric arteries presenting stenosis or occlusion. Because of a lack of specific signs or due to its sometime quiet presentation, this condition is frequently diagnosed only at an advanced stage. Computed tomography (CT) imaging and CT angiography contribute to differential diagnosis and management of AMI. Angiography is also the criterion standard for CMI, with mesenteric duplex ultrasonography and magnetic resonance angiography also being of great importance. Therapeutic approach of MI includes both medical and surgical treatment. Surgical procedures include restoration of the blood flow with arteriotomy, endarterectomy or anterograde bypass, while resection of necrotic bowel is always implemented. The aim of this review was to evaluate the results of surgical treatment for MI and to present the recent literature in order to provide an update on the current concepts of surgical management of the disease. Mesh words selected include MI, diagnostic approach and therapeutic management.