Prognostic value of arterial lactate index in ST-elevation myocardial infarction treated with primary percutaneous coronary intervention: a prospective cohort study.

Aim: Limited knowledge exists on the pathophysiological cascade beyond serum lactate's association with myocardial injury. Method: Assessed the prognostic value of lactate index on periprocedural variables and its impact on 30-day major adverse cardiovascular events (MACE) in 300 prospective ST-elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (pPCI). Results: Significant correlations were observed between admission lactate and Killip class, periprocedural time intervals, postprocedure thrombolysis in myocardial infarction (TIMI) flow and myocardial blush grade (MBG; p < 0.01). Lactate levels correlated with diminished ST-deviation resolution, cardiac enzymes (CK-MB, troponin; p < 0.001; 0.004), and lower ejection fraction (p < 0.001). This relationship impacted 30-day MACE (p < 0.001). Conclusion: Hyperlactatemia in STEMI patients undergoing pPCI is associated with worse Killip class, unsatisfactory TIMI flow, MBG, larger infarct size and higher 30-day MACE. Serum lactate aids risk stratification in pPCI for STEMI patients.