['we investigated the relationship between sublingual perfused capillary density (PCD) as a measure of tissue perfusion and outcome (i.e. occurrence of organ failure and mortality) in patients with cardiogenic shock from acute myocardial infarction.', 'we performed a prospective study in 68 patients. Using Sidestream Dark Field imaging, PCD was measured after hospital admission (T0, baseline) and 24 h later (T1). We compared patients with baseline PCD ≤ median to patients with baseline PCD > median. Sequential organ failure assessment (SOFA) scores were calculated at both time points. The Kaplan-Meier 30-day survival analyses were performed and predictors of 30-day mortality were identified. The baseline PCD was a predictor of the change in the SOFA score between T0 and T1 (ΔSOFA; ρ = -0.25, P = 0.04). Organ failure recovered more frequently in patients with PCD > median (>10.3 mm mm(-2); n = 33) than in patients with PCD ≤ median (n = 35; 52 vs. 29%, P < 0.05). Twenty-two patients (32%) died: 17 patients (49%) with PCD ≤ median vs. 5 patients (15%) with PCD > median (P = 0.004). After adjustment, the cardiac power index [odds ratio (OR): 0.48, 95% CI: 0.24-0.94) and PCD (OR: 0.65, 95% CI: 0.45-0.92) remained significant predictors of 30-day outcome. Patients with baseline sublingual PCD ≤ median that improved at T1 had a considerable better prognosis relative to patients who had a persistently low PCD.'] Does impaired microcirculation predict poor outcome of patients with acute myocardial infarction complicated by cardiogenic shock?