Serum Lactate Predicts Early Outcome and Long-term Survival after Aortic Type A Dissection: A Single-Center Experience over 16 Years

Objectives: Acute Aortic Dissection Type A (AADA) represents a life-threatening emergency that requires immediate surgery. Despite huge progress of surgical care in the last decades, an accurate risk scoring remains mandatory. Serum lactate is easy to measure and provides information about the patient's general condition apart from the exact surgical entity, and could be an additional tool to assess postoperative mortality. The current study aims to analyze the impact of serum lactate on short and long-term survival in such patients.

Methods: Between 2000 and 2016, 330 patients underwent surgery for AADA at our institution. Predictors for 30-day mortality and long-term survival were tested by multivariate regression analysis. Included parameters were lactate levels at the introduction of surgery, time on cardiopulmonary bypass (CPB) and kind of surgery (i.e., aortic valve involvement, arch involvement, aorta descendens stenting, additional surgery).

Results: Mean age was 59.7 ± 14.1 years. Follow-up could be obtained in 99.7% of the patients. Mean follow-up was 4.4 ± 4.6 years (range: 0–16 years). CPB time had an independent impact on short-term mortality (OR = 1.01, p < 0.0001). Mean preoperative lactate serum levels were 1.9 ± 2.2 mmol/L (range: 0.3–19.3 mmol/L, median: 1.3 mmol/L). 125 (37.9%) patients had a lactate level > 1.5 mmol/l. Multiple regression analysis revealed the initial lactate level as the strongest independent predictor for 30-day mortality (OR = 1.17, p < 0.0001) and long-term mortality (OR = 1.14, p < 0.0001). A stepwise testing showed a cut-off lactate level of more than 1.5 mmol/l as an independent prognostic factor for 30-day mortality (OR = 2.70, p < 0.0001,) and long-term survival (OR = 1.47, p < 0.0001)

Conclusion: Serum lactate levels represent an independent predictor for survival independently from the extension of disease. Lactate levels > 1.5 mmol/l strongly indicates impaired survival during the 30 day period as well as in the long-term outcome.