Dynamic arterial lactate values are associated with 30-day mortality in patients with acute myocardial infarction and cardiogenic shock on intra-aortic balloon pump circulatory support.

Abstract

Introduction: In patients with acute myocardial infarction and cardiogenic shock (AMICS), the intra-aortic balloon pump (IABP) remains the most commonly used form of mechanical circulatory support (MCS). However, information on the characteristics of non-responders is limited. This study evaluated the risk factors associated with 30-day mortality in a cohort of patients with AMICS, on IABP support.

Methods: The medical records of patients admitted for AMICS, who underwent IABP insertion over a period of five years, were extracted from the electronic database of a tertiary cardiovascular disease center. The primary end-point was 30-day all-cause mortality.

Results: A cohort of 62 patients was included in the analysis. Mechanical complications were diagnosed in 54.8% of the patients. At 30 days follow-up, mortality reached 69.3%. High arterial lactate at the time of IABP insertion (OR 1.04; 95%CI 1.01-1.09; p=0.04), high arterial lactate after 24h of circulatory support (OR 1.07; 95%CI 1.02-1.17; p=0.03), and low lactate clearance at 24h (OR 0.51; 95%CI 0.22-0.83; p=0.03) were associated with 30-day mortality independent of infarct type, mechanical complications, baseline SCAI stage, creatinine, and bicarbonate value at the time of support initiation. Lactate at the time of IABP insertion and lactate at 24h predicted 30-day mortality at a cutoff value >50mg/dl and >27mg/dl, respectively.

Conclusion: In a cohort of patients with AMICS who underwent IABP therapy, dynamic arterial lactate values both pre- and post-IABP insertion were independently associated with increased 30-day all-cause mortality. The dynamic changes in arterial lactate could help establish the optimal timing of circulatory support initiation and guide treatment escalation in patients at risk for adverse outcomes.