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.

Prevalence, clinical characteristics and outcomes of high-risk patients treated for severe aortic stenosis prior to and after transcatheter aortic valve implantation availability.

OBJECTIVES: Transcatheter aortic valve implantation (TAVI) has emerged as an effective treatment for high-risk patients with severe aortic stenosis (AS). The aim of our study was to compare the prevalence, characteristics and outcomes of high-risk patients treated prior to and after the availability of TAVI in our high-volume surgical institution. METHODS: Among 879 consecutive patients treated 2 years before ('pre-TAVI era') and after ('modern era') the availability of TAVI in our institution, 83 patients were at high risk [defined by logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) >20%]. RESULTS: Among all patients treated for severe AS, the prevalence of high-risk patients was higher in the modern era (12.7 vs 4.9%, P < 0.0001). In the modern era, high-risk patients were treated by TAVI in 89% of cases. Despite similar logistic EuroSCORE (34.9 vs 34%, P = 0.96), the clinical characteristics of these patients have evolved: high-risk patients in the modern era were older (85.3 ± 5.9 vs 78.5 ± 6.5 years, P = 0.0005) and presented more frequently with New York Heart Association class III-IV (92.3 vs 61.1%, P = 0.003), while high-risk patients treated by surgical aortic valve replacement in the pre-TAVI era presented more frequently with a critical preoperative status (33.3 vs 7.7%, P = 0.01), lower left ventricular ejection fraction (41 ± 14 vs 49 ± 15%, P = 0.05) and a history of recent myocardial infarction (27.8 vs 6.1%, P = 0.02). The overall 1-year survival was not different for high-risk patients treated in the pre-TAVI era or in the modern era (61 ± 11 vs 68 ± 6%, P = 0.52). CONCLUSIONS: The availability of TAVI has increased the prevalence of high-risk patients treated for severe AS and changed the clinical features of this kind of patients who were rarely surgically treated before. The 1-year survival was similar between pre-TAVI and modern eras.

Preoperative carriage and postoperative same-species sternal wound infection after cardiac surgery.

Sternal wound infection (SWI) after cardiac surgery remains an important problem. Prediction of pathogens involved in such infection could guide antibiotics. From April 1, 2006 to December 31, 2008, retrospectively, we evaluated the diagnostic value of preoperative methicillin-sensible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA) or multi-drug resistant Gram-negative bacillus (MDRGNB) carriage to predict same-pathogens involved in postoperative SWI. All patients referred for elective cardiac surgery were screened using multisite (nares, axillae, rectal) sampling at admission to detect MSSA, MRSA, and MDRGNB. Of the 1895 patients addressed, 425 patients (22.4%) were colonized at admission. Preoperative carriers more frequently developed SWI than non-carriers, respectively, 11% vs. 5.5% (P<0.05). Because of the small sample, MDRGNB carriers could not be analyzed. For prediction of MSSA SWI with preoperative MSSA carriage, the area under the receiver operating characteristic (ROC) curve was 0.720 (95% confidence interval (CI), 0.364-0.796) and 0.710 (95% CI, 0.623-0.787) for prediction of MRSA SWI with preoperative MRSA carriage. Preoperative MSSA carriage is frequent but preoperative MRSA or MDRGNB carriage remains infrequent. The ability of preoperative carriage to predict a same-pathogen-postoperative SWI was low and should not be used to guide empirical antibiotherapy.