Lactate-Based Difference as a Determinant of Outcomes following Surgery for Type A Acute Aortic Dissection: A Multi-Centre Study.

Type A acute aortic dissection (TAAAD) is a serious condition within the acute aortic syndromes that demands immediate treatment. Despite advancements in diagnostic and referral pathways, the survival rate post-surgery currently sits at almost 20%. Our objective was to pinpoint clinical indicators for mortality and morbidity, particularly raised arterial lactate as a key factor for negative outcomes. METHODS: All patients referred to the three cardiovascular centres between January 2005 and December 2022 were included in the study. The inclusion criteria required the presence of a lesion involving the ascending aorta, symptoms within 7 days of surgery, and referral for primary surgical repair of TAAAD based on recommendations, with consideration for other concomitant major cardiac surgical procedures needed during TAAAD and retrograde extension of TAAAD. We conducted an analysis of both continuous and categorical variables and utilised predictive mean matching to fill in missing numeric features. For missing binary variables, we used logistic regression to impute values. We specifically targeted early postoperative mortality and employed LASSO regression to minimise potential collinearity of over-fitting variables and variables measured from the same patient. RESULTS: A total of 633 patients were recruited for the study, out of which 449 patients had complete preoperative arterial lactate data. The average age of the patients was 64 years, and 304 patients were male (67.6%). The crude early postoperative mortality rate was 24.5% (110 out of 449 patients). The mortality rate did not show any significant difference when comparing conservative and extensive surgeries. However, malperfusion had a significant impact on mortality [48/131 (36.6%) vs. 62/318 (19.5%), p < 0.001]. Preoperative arterial lactates were significantly elevated in patients with malperfusion. The optimal prognostic threshold of arterial lactate for predicting early postoperative mortality in our cohort was ≥2.6 mmol/L. CONCLUSION: The arterial lactate concentration in patients referred for TAAAD is an independent factor for both operative mortality and postoperative complications. In addition to mortality, patients with an upper arterial lactate cut-off of ≥2.6 mmol/L face significant risks of VA ECMO and the need for dialysis within the first 48 h after surgery. To improve recognition and facilitate rapid transfer and surgical treatment protocol, more diligent efforts are required in the management of malperfusion in TAAAD.

Current Knowledge on the Interaction of Human Cytomegalovirus Infection, Encoded miRNAs, and Acute Aortic Syndrome.

Aortic dissection is a clinicopathological entity caused by rupture of the intima, leading to a high mortality if not treated. Over time, diagnostic and investigative methods, antihypertensive therapy, and early referrals have resulted in improved outcomes according to registry data. Some data have also emerged from recent studies suggesting a link between Human Cytomegalovirus (HCMV) infection and aortic dissection. Furthermore, the use of microRNAs has also become increasingly widespread in the literature. These have been noted to play a role in aortic dissections with elevated levels noted in studies as early as 2017. This review aims to provide a broad and holistic overview of the role of miRNAs, while studying the role of HCMV infection in the context of aortic dissections. The roles of long non-coding RNAs, circular RNAs, and microRNAs are explored to identify changes in expression during aortic dissections. The use of such biomarkers may one day be translated into clinical practice to allow early detection and prognostication of outcomes and drive preventative and therapeutic options in the future.

The Roles of microRNAs in the Cardiovascular System.

The discovery of miRNAs and their role in disease represent a significant breakthrough that has stimulated and propelled research on miRNAs as targets for diagnosis and therapy. Cardiovascular disease is an area where the restrictions of early diagnosis and conventional pharmacotherapy are evident and deserve attention. Therefore, miRNA-based drugs have significant potential for development. Research and its application can make considerable progress, as seen in preclinical and clinical trials. The use of miRNAs is still experimental but has a promising role in diagnosing and predicting a variety of acute coronary syndrome presentations. Its use, either alone or in combination with currently available biomarkers, might be adopted soon, particularly if there is diagnostic ambiguity. In this review, we examine the current understanding of miRNAs as possible targets for diagnosis and treatment in the cardiovascular system. We report on recent advances in recognising and characterising miRNAs with a focus on clinical translation. The latest challenges and perspectives towards clinical application are discussed.

Surgical Strategy for the Repair of Acute Type A Aortic Dissection: A Multicenter Study.

Type A acute aortic dissection is associated with significant morbidity and mortality, with prompt referral imaging and management to tertiary referral centers needed urgently. Surgery is usually needed emergently, but the choice of surgery often varies depending on the patient and the presentation. Staff and center expertise also play a major role in determining the surgical strategy employed. The aim of this study was to compare the early- and medium-term outcomes of patients undergoing a conservative approach extended only to the ascending aorta and the hemiarch to those of patients subjected to extensive surgery (total arch reconstruction and root replacement) across three European referral centers. A retrospective study was conducted across three sites between January 2008 and December 2021. In total, 601 patients were included within the study, of which 30% were female, and the median age was 64.4 years. The most common operation was ascending aorta replacement (n = 246, 40.9%). The aortic repair was extended proximally (i.e., root n = 105; 17.5%) and distally (i.e., arch n = 250; 41.6%). A more extensive approach, extending from the root to the arch, was employed in 24 patients (4.0%). Operative mortality occurred in 146 patients (24.3%), and the most common morbidity was stroke (75, 12.6%). An increased length of ICU admission was noted in the extensive surgery group, which comprised younger and more frequently male patients. No significant differences were noted in surgical mortality between patients managed with extensive surgery and those managed conservatively. However, age, arterial lactate levels, "intubated/sedated" status on arrival, and "emergency or salvage" status at presentation were independent predictors of mortality both within the index hospitalization and during the follow-up. The overall survival was similar between the groups.

A Decrease in Hypoxic Pulmonary Vasoconstriction Correlates With Increased Inflammation During Extended Normothermic Ex Vivo Lung Perfusion.

Normothermic ex vivo lung perfusion (EVLP) is an evolving technology to evaluate function of donor lungs to determine suitability for transplantation. We hypothesize that hypoxic pulmonary vasoconstriction (HPV) during EVLP will provide a more sensitive parameter of lung function to determine donor lung quality for lung transplantation. Eight porcine lungs were procured, and subsequently underwent EVLP with autologous blood and STEEN solution for 10 h. Standard physiologic parameters including dynamic compliance, peak airway pressure, and pulmonary vascular resistance (PVR) remained stable (P = 0.055), mean oxygenation (PO2 /FiO2 ) was 400 ± 18 mm Hg on average throughout perfusion. Response to hypoxia resulted in a robust increase in PVR (ΔPVR) up to 4 h of perfusion, however the HPV response then blunted beyond T6 (P < 0.01). The decrease in HPV response inversely correlated to cytokine concentrations of Interleukin-6 and tumor necrosis factor-α (P < 0.01). Despite acceptable lung oxygenation and standard physiologic parameters during 10 h of EVLP, there is a subclinical deterioration of lung function. HPV challenges can be performed during EVLP as a simple and more sensitive index of pulmonary vascular reactivity.