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.

The effect of postoperative anticoagulation on false lumen patency after surgery for acute type A aortic dissection

Background Patent false lumen has been shown to have a negative impact on prognosis after surgery for acute type A aortic dissection (ATAAD). We aimed to assess the effect of postoperative anticoagulation on false lumen patency and clinical outcomes in relation to false lumen status. Methods Postoperative computed tomographies of 156 patients undergoing ATAAD DeBakey type I surgery were retrospectively evaluated for false lumen patency. The patients were divided into groups determined by anticoagulation treatment at discharge. Uni- and multivariable logistic regression was used for analysing the effect of anticoagulation on the false lumen, and Kaplan–Meier estimates were used to assess the association of a patent false lumen with the incidence of reoperation and long-term survival. Results A patent false lumen was present in 81% of the patients. Postoperative anticoagulants were not associated with a patent false lumen (p = 0.48) in univariable analysis. In multivariable analysis, both hemiarch replacement (OR 0.15, CI95% 0.05–0.49, p = 0.001) and the use of betablockers had a protective effect (OR 0.29, CI95% 0.10–0.85, p = 0.023). The Kaplan–Meier estimates for survival and the composite endpoint of survival and freedom from distal reintervention indicated no difference in outcome between patients in regard to anticoagulation treatment (survival p = 0.43, composite p = 0.82) or false lumen status (survival p = 0.21, composite p = 0.09). Conclusion This study could not show negative effects from the postoperative use of anticoagulants on false lumen status, nor that false lumen patency was associated with poorer prognosis. A hemiarch procedure was shown to be associated with reduced risk of false lumen patency.