[Transradial approach for coronary angiography and angioplasty: the gold standard]. / Les coronarographies et les angioplasties coronaires par voie radiale: l'approche de choix?

Transradial approach in interventional cardiology is performed heterogenously around the world. Nevertheless, this technique allows to decrease access site complications and major bleeding, and increases patient's comfort. All patient subgroups beneficiate from this approach, especially in the case of acute coronary syndromes in which the bleeding risk is the highest, in relation to aggressive anticoagulation and platelet antiaggregation treatment. Transradial approach requires a longer learning curve than transfemoral approach due to specific technical challenges that are often overcome with experience. Because of its clear benefits, transradial access should become the gold standard approach for coronary diagnostic and interventional procedures.

[Patent foramen ovale in the adult: state of the art in 2010]. / Le foramen ovale perméable chez l'adulte: le point en 2010.

A patent foramen ovale (PFO) can be found in 25% of the normal population. Several pathologies have been related to PFO as paradoxical embolism, migraine with aura and decompression illness in divers. Finding a PFO in a young patient suffering a stroke and/or TIA is the most common situation in daily practice and where the therapeutic attitude is most controversial. Should we treat the patient with aspirin, with coumadin or should we proceed to a percutaneous closure? We think that only an open discussion with the patient explaining the pros and contras of each strategy is reasonable, because the only randomised study, CLOSURE I, comparing medical treatment with percutaneous closure has shown no difference between these two strategies in terms of clinical events at two years.

A wavelet approach for on-line spike sorting in tetrode recordings.

A new method for spike sorting of tetrode recordings during data acquisition is introduced. For each tetrode channel, putative spikes are detected by means of a threshold, and then convolved with a cascade of wavelet filters. These transformed putative spikes are averaged and this average is used as a matched filter to find portions of signals that are likely to contain a spike. A collection of vectors containing the correlation coefficients between putative spikes and the matched filters is then clustered using K-Means. Centroids of the resulting clusters contain enough information to sort spikes recorded by all tetrode channels simultaneously. On-line sorting is achieved by measuring euclidean distance between putative new spikes and the cluster centroids.

[CT coronary angiogram: state of the art in 2009]. / Coronarographie par CT-scan en 2009.

Thanks to 64 multi-detector CT-scan it is nowadays possible to visualise non invasively the coronary arteries: the recently published series have shown excellent sensitivity and specificity in the detection of coronary artery disease. Actually, the principal interest of the technique is the excellent negative predictive value which is very useful to rule out a significant coronary artery stenosis. For the time being, the angio CT is recommended for symptomatic patients with low to intermediate probability of coronary artery disease with inconclusive functional test. Despite some technical ameliorations, the irradiation doses delivered by multi-detector CT are significant and should restrict its indications specifically in women and young patients, in whom a late radio-induced cancer may be a concern.

[Anti-platelet treatment in cardiology]. / Utilisation des antiagrégants plaquettaires en cardiologie.

Antiplatelets are today one of the pivotal treatment in cardiovascular disease. Aspirin, used for more than 100 years, continue to be the most used drug in the treatment of athe rosclerosis. However, new antiplatelet molecules such as clopidogrel and antibodies against glycoprotein IIb-IIIa are now part of the daily treatment for the general as well for the interventional cardiologist. This paper is a review of these different compounds in the light of the huge data available in the literature.

[Out of hours coronary angiography: changing indications]. / Coronarographies en dehors des heures ouvrables: évolution des indications.

The authors have recently demonstrated that 13% of indications for cardiac catheterisation performed "after hours" (week ends, holidays or from 6 pm to 7 am) are Class III of the AHA/ACC recommendations (i.e. indications not based on recognised medical evidence). In order to limit procedures performed for these unrecognised indications, a consensus of experts has defined a number of local recommendations. The aim of this paper was to study the impact of these recommendations on the indications of "out of hours" cardiac catheterisation. Two patient populations were identified and compared with respect to these recommendations. The first group comprised 157 consecutive patients treated between 1993 and 1994 (average age 58 +/- 13 years; 35% females) and the second one of 148 consecutive patients treated from 1998 to 1999 (average age 57 +/- 13 years; 25% females). The local recommendations were respected in 61% of cases and not applied in 39% of cases. This was a satisfactory result in view of the fact that the local recommendations are more restrictive than international guidelines as they cover emergency indications. In the second group of patients, there were no AHA/ACC Class III indications (30% Class I, 6% Class IIa and 3% Class IIb). There was a significant increase in the number of primary angioplasties for acute myocardial infarction (27 vs 2%; p < 0.001) and an expected reduction in salvage angioplasties (17 vs 7%; p < 0.01). There was no significant change in the indications in patients with unstable angina, the European and American guidelines having been published at the end of data collection. Therefore, the introduction of recommendations for out of hours cardiac catheterisation has limited the number performed for unrecognised indications in favour of evidence based procedures.

Differential expression of matrix metalloproteinases after stent implantation and balloon angioplasty in the hypercholesterolemic rabbit.

BACKGROUND: Intimal hyperplasia is the principal mechanism of in-stent restenosis. Matrix metalloproteinases (MMPs) play a key role in intimal growth after balloon angioplasty (BA). Little is known, however, about MMP expression after stent implantation (ST). We investigated whether MMP9 and MMP2 are differentially expressed after ST and BA. METHODS AND RESULTS: Hypercholesterolemic rabbits underwent ST and BA in the right and left iliac arteries, respectively. The expression of MMPs and their inhibitors (TIMPs) was studied at various time points in the injured arteries by use of zymography, reverse transcription-polymerase chain reaction, and immunohistochemistry. MMP2, but not MMP9, was constitutively expressed in uninjured arteries. MMP9 expression was rapidly induced after injury, whereas the increase in MMP2 expression was delayed. At all time points, pro-MMP9 activity and MMP9 mRNA levels were >/=2-fold (ANOVA, P=0.002) and >/=3-fold (P<0.0001) higher after ST than after BA, respectively. Active MMP9 was detected only after ST. Although the increases in MMP2 mRNA levels were of similar magnitudes after ST and BA, pro-MMP2 activity was slightly higher 7 and 30 days after ST, and MMP2 activity was >/=2-fold higher 7 to 60 days after ST (P=0.002). No difference in TIMP expression was observed between stented and balloon-injured arteries. Cellular distributions of MMPs and TIMP1 were similar after ST and BA. Early inflammatory cell recruitment and 30-day intimal growth were more severe after ST. CONCLUSIONS: Stent implantation results in more intense and sustained expression of MMP9 and activation of MMP2 than balloon angioplasty.

Beta-radiation for coronary in-stent restenosis.

To determine the feasibility and safety of an intracoronary beta-radiation device in preventing the recurrence of in-stent restenosis (ISR) after successful angioplasty, we studied 37 patients treated with beta-radiation (30-mm strontium-90 source) after angioplasty. The mean reference diameter was 2.9 +/- 0.5 mm, and 62% of lesions were diffuse, including four total occlusions. Beta-radiation was successfully delivered in 36 of 37 (97%) cases. Over the course of 7.1 +/- 4.5 mo follow-up, there were no myocardial infarctions and three deaths: one from preexisting malignancy, one from progressive cardiac failure, and one from sudden cardiac death. Target vessel revascularization (TVR) was performed in seven of 36 (19%) patients. Thirty patients underwent angiography at 6 mo; three (10%) experienced restenosis (diameter stenosis > 50%) at the target site, four (13%) had edge stenoses, and two (7%) had late (> 1 mo) thrombotic occlusions. Beta-radiation for ISR is associated with encouragingly low rates of target lesion restenosis and TVR. Further improvements are needed to solve the limitations of the edge effect and late occlusion.

In-vivo measurements of wall shear stress in human coronary arteries.

BACKGROUND: Wall shear stress (WSS) is closely associated with arteriosclerosis. WSS values for various vessels and species are available, but fully in-vivo measurements in human coronary arteries have not yet been reported. OBJECTIVE: To measure WSS in undiseased coronary arteries of adult patients at rest. METHODS: We recorded the temporal average value (APV) of the instantaneous maximal blood velocity in the three vessel segments of angiographically normal coronary artery bifurcations in 21 patients undergoing cardiac catheterization to treat various diseases by means of a 0.036 cm Doppler wire (FloWire). In total, 36 bifurcations were examined. The 36 x 3 cross-sectional areas (CSA) were determined by means of a three-dimensional angiographic technique. The three flows, Q1 (inflow), Q2, and Q3 of each bifurcation were calculated according to Q=0.5 x APV x CSA. For each segment, WSS was calculated as WSS=32 eta Q/(pi D3) (where blood viscosity eta=3.5 mPa s and D is vessel diameter). Only the 54 WSS values obtained from the 18 flow triplets which satisfied the equation Q1/(Q2+Q3)=1 better than did the 18 other ones were retained. RESULTS: The 54 WSS values ranged from 0.33 to 1.24 Pa (mean 0.68 Pa, SEM, 0.027 Pa). They did not depend significantly on Q (r=0.07; P=0.60) and the CSA (r=0.24, P=0.08) but the second relationship approached significance. CONCLUSION: The obtained mean WSS value (0.68 Pa) is half the value predicted for coronary arteries from optimality principles. It is also smaller than many values reported for human carotid, renal, and femoral arteries.

[Thrombolysis in acute myocardial infarct in everyday clinical practice]. / Thrombolyse dans l'infarctus aigu du myocarde en pratique clinique courante.

We prospectively included in a database all thrombolyzed acute transmural myocardial infarction patients admitted to our hospital from November 1986 to September 1995. Six hundred and twenty-seven patients (497 males) with a mean age of 61 +/- 12 years (range 26-88 years) were included. 87% were having their first acute myocardial infarction. Different thrombolytic regimens were applied in the emergency room but the vast majority (92%) received t-PA. The median delay between the onset of pain and admission was 2 h 0 min (10 min-22 h). The median admission to treatment time was 40 min (5 min-6 h 20 min). The latter has been shortened (median 55 min from 1986 to 1989 versus 35 min from 1990 to 1995, p < 0.05) during the study period. The rate of intracerebral hemorrhage was 2.4% (confidence interval 1.1-3.5%) and no significant predictor could be found, although patients with cerebral bleeding tended to be slightly older (66 +/- 9 years vs 61 +/- 13 years, p = ns). The rate of false diagnosis was only 4.6%, even when patients with a final diagnosis of unstable angina and/or aborted acute myocardial infarction were included. The in-hospital mortality was 8.8%, a rate similar to those reported in the literature. Using multivariate analysis, negative prognostic factors were higher age (p < 0.001), advanced Killip class at admission (p < 0.001) and elevated peak CPK levels (p < 0.001). These results confirm that thrombolysis for acute myocardial infarction in the emergency room can be done with a short admission-to-treatment time and with an acceptably low rate of false diagnosis. However, our intracerebral hemorrhage rate was clearly higher than generally reported in the literature and may be explained by a different patient selection from that in large randomized studies.

Procoagulant and fibrinolytic activities in bronchoalveolar fluid of HIV-positive and HIV-negative patients.

Imbalance between intra-alveolar procoagulant activity (PCA) and fibrinolytic activity may lead to fibrin deposition, as described in several pneumopathies, and may eventually contribute to fibrotic changes as observed in Pneumocystis carinii pneumonia (PCP). The aim of our study was to compare these activities in bronchoalveolar lavages of human immunodeficiency virus (HIV)-positive and HIV-negative patients. The material comprised: a) controls (n = 7); b) HIV-positive patients subdivided into PCP (n = 11), bacterial pneumonia (n = 8) and other pneumopathies (n = 22); and c) HIV-negative patients with bacterial pneumonia (n = 8). PCA was significantly increased (p less than 0.05) in all patient groups compared to controls. The urokinase-type plasminogen activator (u-PA) antigen levels were highest during bacterial pneumonia. Regardless of the HIV status, in bacterial pneumonia there was a marked elevation of plasminogen activator inhibitor antigens with little residual fibrinolytic activity. In contrast, the fibrinolytic activity was not decreased in PCP. D-dimer were elevated during PCP compared to controls; the highest levels were found in HIV-negative bacterial pneumonia. These data indicate that transient fibrotic changes seen in PCP may be favoured by increased PCA, but not by a depressed fibrinolytic activity. In bacterial pneumonia PCA is increased and fibrinolysis decreased independently of the HIV status.

Procoagulant activity in bronchoalveolar fluids: no relationship with tissue factor pathway inhibitor activity.

Abnormalities in local coagulation may explain alveolar fibrin deposition which often accompanies human lung injuries. The purpose of this study was to investigate the generation of procoagulant activity (PCA) and tissue factor pathway inhibitor (TFPI) in selected bronchoalveolar lavage fluids (BAL) from controls (n = 7) and from patients with interstitial lung diseases (n = 9), Pneumocystis carinii (PCP) pneumonia (n = 11) and bacterial pneumonia (n = 8). As compared with controls a significant increase of PCA was observed in the three groups with lung diseases. PCA in BAL from patients with untreated interstitial lung diseases (PC Units mean of 162 +/- 48) was significantly higher than PCA of treated patients (PC Units 36 +/- 10; p less than 0.05). Increases of PCA paralleled protein levels in BAL and the protein/albumin ratios were comparable in the four groups. TFPI was significantly increased in PCP (p less than 0.02) and bacterial pneumonia (p less than 0.03), but only marginally increased in interstitial lung diseases when compared with controls. No correlation was found between TFPI and PCA in any of the four groups. These data indicate that increased procoagulant activity observed in various lung diseases is not counterbalanced by TFPI.

On the estimation of proton gradient and osmotic volume in chloroplast membranes.

The dependence of thylakoid osmotic volume on NH4Cl uncoupling and on phosphorylation substrates is determined by the centrifuge filtration method. The values obtained are used to evaluate the transmembrane proton gradient in conjunction with either the 9-aminoacridine fluorescence quenching method or the [14C]methylamine uptake method. The DeltapH values obtained with the two methods are compared and a linear relationship is demonstrated in the DeltapH range from 1.4 to 2.7 ([14C]methylamine values). Different linear relationships are obtained depending on the presence or absence of electron acceptor. We conclude that the 9-aminoacridine method can be used for DeltapH determination after calibration with other methods.