The predictive value of cardiac troponin T measurements in subjects on regular haemodialysis.

BACKGROUND: Cardiac troponin T (cTnT) is a subunit of the cardiac actin-myosin complex, which leaks into the circulation when myocardial necrosis is present. Detection of cTnT is associated with a poor outcome in patients with unstable angina, and is a useful tool for risk stratification. The value of cTnT determination in patients with renal failure has been questioned, and the specificity of cTnT in this particular group has not been established. METHODS: In the present study, 94 patients at a single centre were followed prospectively after three determinations of cTNT, at 1-month intervals. The outcome after 12 months was chosen as the end-point. cTnT was measured using both a quantitative chemiluminiscence immunoassay and a qualitative rapid bedside immunoassay on a test strip. The maximum of three measurements was used and was correlated with different parameters and outcome. The following statistical tests were performed: Kaplan-Meier analysis, Cox's proportional regression analysis for measuring survival and logistic regression for analysing factors influencing cTnT. RESULTS: Forty seven of the 94 patients had a positive cTnT by test strip defined as >0.10 ng/ml. Twenty four patients died in the follow-up period (14 from cardiovascular causes). Twenty of the 24 non-survivors had an increased cTnT by test strip and 23 had increased cTnT by laboratory immunoassay. The outcome analysed by a Cox's proportional regression analysis showed that the factors which influenced survival significantly were cTnT, the presence of ischaemic heart disease, C-reactive protein (CRP) and prealbumin. A logistic multivariate analysis revealed that age and CRP significantly influenced cTnT. A good correlation was found between cTnT determined by test strip and in the laboratory. CONCLUSION: cTnT is elevated in a large number of patients on regular haemodialysis and is a significant independent predictor of outcome. Increased cTnT is significantly predicted by age and CRP.

[Hemodynamic repercussions and clinical tolerance of 6 class I anti-arrhythmia agents in acute myocardial infarction]. / Répercussions hémodynamiques et tolérance clinique de six agents antiarythmiques de la classe I dans l'infarctus aigu du myocarde.

Clinical safety and hemodynamic repercussions were studied after administration of six class I antiarrhythmics (xylocaine, ajmaline, mexiletine, lorcainide, indecainide and tocainide) to patients presenting acute myocardial infarction without complications. The hemodynamic parameters monitored generally followed the same trends. A significant decrease of more than 10 per cent of the initial value was seen in systolic blood flow after injection of lorcainide, indecainide and tocainide. Peripheral vascular resistance increased moderately. Pulmonary capillary pressure increased by more than 40 per cent of the starting value after administration of mexiletine, indecainide and tocainide (significant increase in case of mexiletine). These changes in patients presenting infarction without complications are not of clinical importance. There were, however, two very severe cases of hemodynamic reaction after administration of mexiletine. Other signs of intolerance were seen, but they were of minor importance and administration of the drugs was not interrupted. Xylocaine and ajmaline produced the smallest depression of left ventricular functional activity in these patients.

Haemodynamic reactions after intravenous injection of lorcainide hydrochloride in acute myocardial infarction.

Lorcainide hydrochloride given at the doses of 150 mg i.v. proved to be well tolerated at the acute stage of a myocardial infarction; the subjective signs were benign and never prevented us from completing the injection. The haemodynamic changes reflect some depressive effects on the myocardial function. Most of the observed changes are transient, and when significant from the statistical point of view, they remain very mild: the cardiac output decreased from 3.4 to 3.2 l/min per m2, the stroke index from 46 to 41 ml/m2, the pulmonary wedge pressure increases from 6.6 to 8.4 mm Hg (mean values). Lorcainide hydrochloride may thus be used as an antiarrhythmic drug in acute myocardial infarction.