Dynamic Lactate Level: An Effective Predictor of Short-Term Mortality After Type A Aortic Dissection Surgery.

Background: Type A aortic dissection (TAAD) is a life-threatening cardiovascular emergency frequently accompanied by elevated lactate (Lac) levels during surgery. This study investigated the relationship between early postoperative changes in Lac levels and short-term mortality in patients with TAAD. Methods: A retrospective analysis was conducted on TAAD patients who underwent surgery at our institution. Lac levels were measured immediately after surgery and on postoperative days (PODs) 1 and 3. Logistic regression was used to analyze patient demographics and clinical outcomes, and to identify short-term mortality risk factors. Receiver operating characteristic (ROC) curves were constructed to assess the association between Lac levels, lactate clearance (LC), and short-term mortality. Results: A total of 146 patients were included; 101 survived, and 45 died. Non-survivors had significantly higher Lac levels at intensive care unit (ICU) admission and on PODs 1 and 3. Time-dependent multivariate Cox regression analysis revealed that the trend in Lac levels during the first 3 days in the ICU was an independent risk factor for short-term mortality (hazard ratio = 1.33). On POD3, the area under the curve (AUC) for predicting short-term mortality was 0.838 for Lac and 0.667 for LC. Kaplan-Meier analysis showed an increased mortality risk with Lac >1.75 mmol/L or LC ≤37.23%. Age, sex, and liver and kidney function did not significantly affect the predictive value of Lac and LC for mortality. Conclusion: Dynamic postoperative changes in Lac levels are significantly associated with adverse clinical outcomes in patients with TAAD. Lac and LC measured on POD3 may serve as reliable indicators for predicting short-term mortality in these patients.