Arterial Lactate for Mortality Prediction After Cardiogenic Shock

Arterial lactate levels 8 hours after cardiogenic shock (CS) were found to be a better parameter for mortality risk prediction than lactate clearance or baseline lactate, according to a study published in the Journal of the American College of Cardiologists: Cardiovascular interventions.

This was a subanalysis of data from 666 patients included in a randomized, open-label trial and registry, the Intraaortic Balloon Pump in Cardiogenic Shock II study (ClinicalTrials.gov Identifier: NCT00491036) conducted at 37 centers in Germany, beginning in 2009. In this study, patients who had undergone CS were randomly assigned at a 1:1 ratio to receive an intraaortic balloon pump counterpulsation or not (control condition). CS was defined by the occurrence of systemic hypotension, pulmonary congestion, and impaired end-organ perfusion. Patients were assessed at 30 days, and at 1 and 6 years.

The 30-day mortality rate in this cohort was 38.4%. Patients who survived vs died in the 30 days following CS differed in: average age (67 vs 73 years, respectively; P <.001), serum creatinine (106 vs 135 mmol/l, respectively; P <.001), serum creatine kinase (5.6 vs 8.4 mkat/l, respectively; P =.007), hemoglobin (8.3 vs 8.1 mmol/l, respectively; P =.04), rates of diabetes mellitus (31% vs 40%, respectively; P =.02), peripheral artery disease (10% vs 17%, respectively; P =.01), prior stroke (4% vs 9, respectively P =.01), and coronary 3-vessel disease (49% vs 59%, respectively; P =.02).

Patients who died vs survived within 30 days of index event also differed in: average arterial lactate at baseline (5.8 vs 3.2 mmol/l, respectively; P <.001) and at 8 hours (5.1 vs 1.7 mmol/l, respectively; P <.001), as well as lactate clearance between baseline and 8 hours (-0.4% vs 1.4%, respectively; P <.001). Lactate levels differed between the 2 intervention groups for up to 48 hours.

Baseline lactate levels ³5.0 mmol/L (hazard ratio [HR], 1.35; 95% CI, 0.99-1.83; P =.06), lactate levels 8 hours after CS ³3.1 mmol/L (HR, 2.89; 95% CI, 2.10-3.97; P <.001), and lactate clearance <3.45%/hour (HR, 0.53; 95% CI, 0.40-0.70; P <.001) were found to be the best predictors of 30-day mortality, and need for mechanical circulatory and catecholamine support.

Baseline lactate levels predicted survival after 30 days with an area under the receiving operator characteristic curve (AUC) of 0.71 (95% CI, 0.67-0.75). Lactate levels at 8 hours were found to best predict 30-day survival (AUC, 0.76; 95% CI, 0.72-0.80).

Study limitations include the absence of an independent cohort, and the fact that lactate values were not collected at other time points.

“A cutoff value of 3.1 mmol/l for lactate after 8 h showed the best discrimination for assessing early prognosis in CS and may serve as new treatment goal,” concluded the study authors.

Reference

Fuernau G, Desch S, de Waha-Thiele S, et al. Arterial Lactate in Cardiogenic Shock: Prognostic Value of Clearance Versus Single Values. JACC Cardiovasc Interv. 2020;13(9):2208.2216. doi:10.1016/j.jcin.2020.06.037