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

Abstract

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.

Baseline risk factors of in-hospital mortality after surgery for acute type A aortic dissection: an ERTAAD study

“…A recent study by Nappi et al ( 19 ) showed that preoperative arterial lactate was an independent risk factor for early postoperative mortality (OR, 1.378, 95% CI, 1.176–1.616) along with eGFR (OR, 0.978, 95% CI, 0.991–0.997) after surgery for TAAD. The authors identified a cutoff of 2.6 mmol/L for arterial lactate, which was associated with a significantly higher rate of early mortality (44.6% vs. 17.8%, OR, 4.07, 95% CI, 2.43–7.78) ( 19 ). Ghoreishi et al ( 18 ) identified preoperative lactic acid level (OR, 1.39, 95%CI, 1.45–20.0) along with serum creatinine and increased liver enzymes (aspartate aminotransferase >50 mmol/L, alanine aminotransferase >55 mmol/L, bilirubin >1.2 mg/dl) as independent risk factors for early mortality in patients who underwent surgical repair for TAAD.…”

“…In fact, after excluding these risk factors from the regression model of the derivation dataset, the AUC of the probabilities of in-hospital mortality was 0.708 (95% CI, 0.680–0.736) with a Brier score of 0.135. Recent studies showed that biomarkers may be helpful in stratifying the operative risk of TAAD patients ( 6 , 18 , 19 ). In particular, preoperative levels of creatinine and arterial lactate have been shown to be significant predictors of early postoperative mortality ( 6 , 18 , 19 ).…”

“…Recent studies showed that biomarkers may be helpful in stratifying the operative risk of TAAD patients ( 6 , 18 , 19 ). In particular, preoperative levels of creatinine and arterial lactate have been shown to be significant predictors of early postoperative mortality ( 6 , 18 , 19 ). The prognostic impact of eGFR on adverse events after cardiac surgery has been largely demonstrated ( 20 ), while the value of arterial lactate in predicting the outcome of critically ill cardiac surgery patients is rather novel ( 6 , 18 , 19 , 21 ).…”

“…In particular, preoperative levels of creatinine and arterial lactate have been shown to be significant predictors of early postoperative mortality ( 6 , 18 , 19 ). The prognostic impact of eGFR on adverse events after cardiac surgery has been largely demonstrated ( 20 ), while the value of arterial lactate in predicting the outcome of critically ill cardiac surgery patients is rather novel ( 6 , 18 , 19 , 21 ). A recent study by Nappi et al ( 19 ) showed that preoperative arterial lactate was an independent risk factor for early postoperative mortality (OR, 1.378, 95% CI, 1.176–1.616) along with eGFR (OR, 0.978, 95% CI, 0.991–0.997) after surgery for TAAD.…”

“…The prognostic impact of eGFR on adverse events after cardiac surgery has been largely demonstrated ( 20 ), while the value of arterial lactate in predicting the outcome of critically ill cardiac surgery patients is rather novel ( 6 , 18 , 19 , 21 ). A recent study by Nappi et al ( 19 ) showed that preoperative arterial lactate was an independent risk factor for early postoperative mortality (OR, 1.378, 95% CI, 1.176–1.616) along with eGFR (OR, 0.978, 95% CI, 0.991–0.997) after surgery for TAAD. The authors identified a cutoff of 2.6 mmol/L for arterial lactate, which was associated with a significantly higher rate of early mortality (44.6% vs. 17.8%, OR, 4.07, 95% CI, 2.43–7.78) ( 19 ).…”