Direct percutaneous transluminal coronary angioplasty in acute myocardial infarction. Predictors of short-term outcome and the impact of coronary stenting

Background Direct percutaneous transluminal coronary angioplasty (PTCA)is widely accepted in the treatment of acute myocardial infarctionsince excellent results had been reported from several smallrandomized trials. Less favourable results were observed inlarge-scale registries. In particular, the use of stents inacute myocardial infarction has become common practice withoutdocumented evidence of clinical efficacy. Methods Data were analysed from a registry of all consecutive percutaneoustransluminal coronary angioplasty procedures from 62centresin Germany, including 2331 direct percutaneous transluminalcoronary angioplasty in acute myocardial infarction from July1994 to April 1997. Results The overall angiographic success rate of percutaneous transluminalcoronary angioplasty, defined as complete antegrade perfusionof the infarct vessel, was 87%. In-hospital mortality was 11·2%.The most important predictor of death was the presence of cardiogenicshock in 15% of patients, of whom 52% died. Mortality in patientswithout shock was 3·9%. Failed percutaneous transluminalcoronary angioplasty was associated with a mortality of 36%.Further independent predictors of death were older age, multivesseldisease, and anterior myocardial infarction. Stents were usedin 4·1% of the procedures in 1994, increasing to 53%in 1997. However, this was not accompanied by improved clinicaloutcome. Mortality with coronary stenting was 9·9% vs11·6% without stents (ns). Conclusions Direct percutaneous transluminal coronary angioplasty is a valuabletreatment strategy in acute myocardial infarction, althoughthe results are less exceptional than reported from some highlyspecialized centres. Failed percutaneous transluminal coronaryangioplasty seems to be harmful, thus outweighing much of thebenefit from successful procedures. Stents did not improve theclinical outcome significantly, despite technically successfulplacement in 98%. Mortality from cardiogenic shock continuesto be excessively high despite direct PTCA.     

Transfer of cryopreserved-thawed pre-embryos in a cycle using exogenous steroids without prior gonadotrophin-releasing hormone agonist suppression yields favourable pregnancy results

We have analysed the use of a programmed cycle of administration of exogenous steroids without prior suppression with a gonadotrophin- releasing hormone agonist (GnRHa) for the transfer of cryopreserved- thawed pre-embryos. From July 1992 to June 1994, 199 cycles (162 patients) were studied. Pre-embryos had been previously cryopreserved at the pronuclear stage using 1.5 M 1,2-propanediol as a cryoprotectant. Preparation of the endometrium was achieved in a step- up regime with transdermal oestradiol patches (0.1 to 0.4 mg). Progesterone in oil (50 mg i.m.) was started on cycle day 13. Pre- embryos were thawed on day 14 and transferred on day 15 after evidence of survival and cleavage. The mean (+/- SD) age of patients undergoing transfer was 35.4 +/- 4.3 years. The mean number of pre-embryos thawed was 4.7 +/- 1.8 with a mean of 3.3 +/- 1.4 pre-embryos being transferred. Eight of the cycles demonstrated follicular development >16 mm prior to thaw and transfer; however, these patients did not demonstrate a luteinizing hormone surge. Mean endometrial thickness on day 13 was 10.8 +/- 2.1 mm. Overall pregnancy rate was 29.2% (57/195). The ongoing or delivery rate was 16.1% (32/195). The rate of preclinical losses per transfer was 6.2% (12/195). Overall, the implantation rate was 6.2% (47/757). Thus, the use of a programmed cycle for cryopreserved embryo transfer yields favourable pregnancy outcome and offers practical advantages to patients. Prior suppression with a GnRHa is not necessary for endometrial preparation.      

Hepatocyte Culture between Woven Capillary Networks: A Microscopy Study

Abstract: A multi-compartment capillary membrane culture model with independently perfused three-dimensionally woven capillaries was developed for immobilization of hepatocytes in bioreactors. This enables spatial restructuring of cells and enhanced mass transfer performance with more efficient oxygenation and metabolite exchange. Seeding density defines cell behaviour in this model. With low densities cells attach to the membranes and flatten. Increasing density leads to spontaneous formation of aggregates which are immobilized between the capillaries.