Clinical significance of lactate in acute cardiac patients

Lactate, as a metabolite of easy and quick assessment, has been studied over time in critically ill patients in order to evaluate its prognostic ability. The present review is focused on the prognostic role of lactate levels in acute cardiac patients(that is with acute coronary syndrome, cardiogenic shock, cardiac arrest, non including post cardiac surgery patients). In patients with STelevation myocardial infarction treated with mechanical revascularization, hyperlactatemia identified a subset of patients at higher risk for early death and in-hospital complications, being strictly related mainly to hemodynamic derangement. The prognostic impact of hyperlactatemia on mortality has been documented in patients with cardiogenic shock and in those with cardiac arrest even if there is no cut-off value of lactate to be associated with worse outcome or to guide resuscitation or hemodynamic management. Therapeutic hypothermia seems to affect per se lactate values which have been shown to progressively decrease during hypothermia. The mechanism(s) accounting for lactate levels during hypothemia seem to be multiple ranging from the metabolic effects of reduced temperatures to the hemodynamic effects of hypothermia(i.e., reduced need of vasopressor agents). Serial lactate measurements over time, or lactate clearance, have been reported to be clinically more reliable than lactate absolute value also in acute cardiac patients. Despite differences in study design, timing of lactate measurements and type of acute cardiac conditions(i.e., cardiogenic shock, cardiac arrest, refractory cardiac arrest), available evidence strongly suggests that higher lactate levels can be observed on admission in non-survivors and that higher lactate clearance is associated with better outcome.

Clinical significance of glycated hemoglobin in the acute phase of ST elevation myocardial infarction

In population-based studies,including diabetic and nondiabetic cohorts,glycated hemoglobin A1c(HbA1c) has been reported as an independent predictor of allcause and cardiovascular disease mortality.Data on the prognostic role of HbA1c in patients with acute myocardial infarction(MI) are not univocal since they stem from studies which mainly differ in patients' selection criteria,therapy(thrombolysis vs mechanical revascularization) and number consistency.The present review is focused on available evidence on the prognostic significance of HbA1c measured in the acute phase in patients with ST-elevation myocardial infarction(STEMI) submitted to primary percutaneous coronary intervention(PCI).We furthermore highlighted the role of HbA1c as a screening tool for glucose intolerance in patients with STEMI.According to available evidence,in contemporary cohorts of STEMI patients submitted to mechanical revascularization,HbA1c does not seem to be associated with short and long term mortality rates.However,HbA1c may represent a screening tool for glucose intolerance from the early phase on in STEMI patients.On a pragmatic ground,an HbA1c testhas several advantages over fasting plasma glucose or an oral glucose tolerance test in an acute setting.The test can be performed in the non-fasting state and reflects average glucose concentration over the preceding 2-3 mo.We therefore proposed an algorithm based on pragmatic grounds which could be applied in STEMI patients without known diabetes in order to detect glucose intolerance abnormalities from the early phase.The main advantage of this algorithm is that it may help in tailoring the follow-up program,by helping in identifying patients at risk for the development of glucose intolerance after MI.Further validation of this algorithm in prospective studies may be required in the contemporary STEMI population to resolve some of these uncertainties around HbA1c screening cutoff points.

Hemodynamic changes acutely determined by primary PCI in STEMI patients evaluated with a minimally invasive method

Objective: Few studies are available on the hemodynamic changes acutely determined by Primary Percutaneous Coronary Intervention (PCI) in ST-Elevation Myocardial Infarction (STEMI) patients, probably for the difficult evaluation of hemodynamic variables in this acute setting. Therefore, the paper is to evaluate the variations of several hemodynamic parameters determined by PCI using PRAM (Pressure Recording Analytical Method), minimally invasive hemodynamic monitoring. Methods: We analyzed in 20 STEMI patients submitted to PCI several hemodynamic variables, assessed with PRAM from radial/ femoral artery, 3-minute before PCI and at endprocedure. Variables measures were: systolic, diastolic, dicrotic and mean arterial pressures;heart rate (HR);stroke volume (SV);systemic vascular resistance (SVR);dP/dtmax;cardiac cycle efficiency (CCE). Results: In our patients HR, SVR and dP/dtmax decreased significantly (85 ± 6.3 to 77 ± 4.5, p = 0.002;1738 ± 241 to 1450 ± 253, p = 0.022;1.22 ± 0.11 to 1.11 ± 0.12, p = 0.007, respectively) while CCE and SV increased significantly (?0.25 ± 0.23 to ?0.01 ± 0.12,