Prognostic accuracy of mean arterial pressure and serum lactate level in patients with acute myocardial infarction.

Background: Mean arterial pressure (MAP) can be used to evaluate macro-circulatory perfusion while serum lactate concentration is a marker of tissue perfusion. It is important to note that the primary objective of initial medical interventions is to restore microcirculatory perfusion rather than focusing solely on macro-hemodynamics.

Aims: We aimed to investigate the prognostic value of the combination of MAP and serum lactate levels measured on admission to the hospital in relation to patients' 30-day survival rate in patients with acute myocardial infarction (MI).

Methods: Data from 532 consecutive patients with acute MI treated with percutaneous coronary intervention were analyzed. The study endpoint was 30-day all-cause mortality.

Results: We found that both MAP and lactate levels were relevant predictors of the 30-day mortality in multivariable Cox regression analysis (HR, 0.83; 95% CI, 0.71-0.97; P = 0.02 and HR, 1.16; 95% CI, 1.06-1.16; P = 0.01, respectively). There was a significant increase in the prognostic performance in relation to 30-day mortality for the combination of both MAP and lactate levels in comparison to MAP alone (P = 0.03 for comparison between areas under the curve). Conversely, the combination of MAP and lactates did not add a significant prognostic value in comparison to lactates alone (P = 0.53 for comparison between areas under the curve).

Conclusions: In patients with acute MI, serum lactate level seems to have a higher prognostic value in comparison to MAP. Our data suggest that on initial assessment of patients with acute myocardial infarction, we should move toward a tissue perfusion-based approach instead of focusing on a blood pressure-oriented strategy alone.