Luis Azcona

Hospital Clínico San Carlos, Madrid, Madrid, Spain

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Publications (30)92.96 Total impact

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    ABSTRACT: Several mechanisms have been proposed to explain why some platelets have a reduced response to aspirin (ASA). Among them, it was reported an increased circulating level of vitamin-D binding protein (DBP). In addition, nitric oxide (NO) released from mononuclear cells was involved in the antiplatelet effects of ASA. The aim was to analyze the relationship between platelet response to aspirin and both nitric oxide generation and vitamin D-binding protein content in mononuclear cells. Mononuclear cells were obtained from patients with stable coronary artery disease that were divided by a platelet functionality test (PFA-100) as ASA-sensitive (n=23) and ASA-resistant (n=27). Both the release of NO (determined by nitrite+nitrate concentration) and the expression of endothelial-type NO synthase (eNOS) were higher in mononuclear cells from ASA-sensitive as compared with those from ASA-resistant patients. There was a positive correlation between either the release of NO and the expression of eNOS protein in mononuclear cells with the ability of ASA to inhibit platelet activity. DBP content in mononuclear cells was higher in ASA-resistant than in ASA-sensitive. The level of DBP content in mononuclear cells was negatively associated with the ability of ASA to inhibit platelets. However, in vitro experiments suggested that there was no association between DBP and NO production by mononuclear cells. Mononuclear cells from patients with platelets with lower responsiveness to ASA showed a reduced ability to produce NO. This article is protected by copyright. All rights reserved.
    European Journal of Clinical Investigation 02/2014; · 3.37 Impact Factor
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    ABSTRACT: To analyse if platelet responsiveness to aspirin (ASA) may be associated with a different ability of platelets to generate nitric oxide (NO). Platelets were obtained from 50 patients with stable coronary ischemia and were divided into ASA-sensitive (n = 26) and ASA-resistant (n = 24) using a platelet functionality test (PFA-100). ASA-sensitive platelets tended to release more NO (determined as nitrite + nitrate) than ASA-resistant platelets but it did not reach statistical significance. Protein expression of nitric oxide synthase 3 (NOS3) was higher in ASA-sensitive than in ASA-resistant platelets but there were no differences in the platelet expression of nitric oxide synthase 2 (NOS2) isoform. The highest NOS3 expression in ASA-sensitive platelets was independent of the presence of T-to-C mutation at nucleotide position -786 (T(-786)→C) in the NOS3-coding gene. However, platelet content of phosphorylated NOS3 at Serine (Ser)(1177), an active form of NOS3, was higher in ASA-sensitive than in ASA-resistant platelets. The level of platelet NOS3 Ser(1177) phosphorylation was positively associated with the closure time in the PFA-100 test. In vitro, collagen failed to stimulate the aggregation of ASA-sensitive platelets, determined by lumiaggregometry, and it was associated with a significant increase (p = 0.018) of NOS3 phosphorylation at Ser(1177). On the contrary, collagen stimulated the aggregation of ASA-resistant platelets but did not significantly modify the platelet content of phosphorylated NOS3 Ser(1177). During collagen stimulation the release of NO from ASA-sensitive platelets was significantly enhanced but it was not modified in ASA-resistant platelets. Functional platelet responsiveness to ASA was associated with the platelet content of phosphorylated NOS3 at Ser(1177).
    PLoS ONE 01/2013; 8(12):e82574. · 3.73 Impact Factor
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    ABSTRACT: The purpose of this study was to compare the effect of dual antiplatelet therapy [clopidogrel + aspirin (ASA)] with respect to ASA on the protein expression of platelets from controlled type-2 diabetic patients with stable coronary ischemia. Patients had been taking ASA (100 mg day) and they were randomized to receive (n = 29) or not (n = 28) 75 mg day clopidogrel for 12 ± 2 weeks in a blind form. Protein expression was analyzed by two-dimensional electrophoresis and mass spectrometry. The protein expression of a limited number of proteins such as actin-binding protein isotypes 2 and 5, lactate dehydrogenase, serotransferrin isotype 4, protein disulfide isomerase-A3 isotype 1, fibrinogen beta chain isotype 5, Ras-related protein Rab-7b isotypes 1 and 6, and immunoglobulin heavy chain was changed after dual antiplatelet therapy. Plasma level of platelet factor 4 (PF4), an in vivo marker of platelet activity, was not different between both groups. These changes suggest lower platelet reactivity after dual antiplatelet therapy in the studied patients. However, the variation in platelet proteome was lower than it would be initially expected, taking into account the apparent clinical beneficial effects of dual antiplatelet therapy. PF4 plasma level was not further decreased in the platelets treated for a longer time than 9-12 months with ASA + clopidogrel, as compared with ASA alone.
    Journal of Pharmaceutical Sciences 05/2012; 101(8):2821-32. · 3.13 Impact Factor
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    ABSTRACT: Acute coronary syndromes (ACS) are associated with platelet activation. The aim of the present study was to study the protein expression level associated with glycolysis, oxidative stress, cytoskeleton and cell survival in platelets obtained during an ACS. Platelets from 42 coronary ischemic patients, divided into patients admitted within 24 h after the onset of chest pain (ACS group; n=16) and patients with stable coronary ischemic disease (CAD, n=26), were analyzed using proteomics. The expression levels of proteins involved in cellular cytoskeleton (F-actin capping, β-tubulin, α-tubulin isotypes 1 and 2, vinculin, vimentin and two Ras-related protein Rab-7b isotypes), glycolysis pathway (glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase and two pyruvate kinase isotypes) and cellular-related antioxidant system (manganese superoxide dismutase) and even the expression and activity of glutathione-S-transferase were significantly reduced in platelets from ACS patients compared to CAD patients. Moreover, reduction in the expression of proteins associated with cell survival such as proteasome subunit β type 1 was also observed in ACS platelets compared with CAD platelets. Principal component and logistic regression analysis suggested the existence of factors (proteins) expressed in the platelets inversely associated with acute coronary ischemia. In summary, these results suggest the existence of circulating antioxidant, cytoskeleton and glycolytic-"bewildered" platelets during the acute phase of a coronary event.
    Proteomics 08/2011; 11(16):3335-48. · 4.43 Impact Factor
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    ABSTRACT: Aspirin resistance or aspirin non-responsiveness is a recently described phenomenon which has been consistently associated with an increased risk of cardiovascular events. This study was designed to determine the effects of an additional dose of 100 mg of aspirin on platelet function and proportion of aspirin non-responders using the platelet function analyzer-100 (PFA-100), in a well characterized population of stable coronary heart disease patients already on long-term aspirin treatment. Platelet function was assessed using PFA-100 in 141 patients (64.8 ± 10.1 years, 87.9% men) on long-term aspirin treatment (100 mg/day) before and 1 h after "in site" oral aspirin administration (100 mg). Prevalence of aspirin non-responders using PFA-100 was 50.7% (95% confidence interval 42.4-59). One hour after 100 mg of oral aspirin, reassessment of aspirin effects showed a prevalence of non-responders using PFA of 35.0% (95% CI 27.3-43.2) (P < 0.001 vs. pre-dose proportion). Using the PFA-100 system, reassessment of platelet function following oral administration of daily aspirin dosage significantly reduces the number of stable coronary disease patients considered to be non-responders to such treatment.
    Journal of Thrombosis and Thrombolysis 05/2011; 32(3):356-61. · 1.99 Impact Factor
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    ABSTRACT: Current available data show that about 5 to 40% of coronary patients treated with conventional doses of antithrombotic drugs do not display adequate antiplatelet response. Nowadays, aspirin remains the main antiplatelet therapy. However, a significant number of patients show platelet resistance to aspirin therapy, and recurrent thrombotic events occur. Combined antithrombotic therapies with thienopyridines, such as clopidogrel have been used to resolve this problem. However, clopidogrel treatment has been also associated with wide response variability, and non-responsiveness to clopidogrel also occurs in some patients. Therefore, the main question arising about the antithrombotic therapy is why particular patients do not benefit from the therapy and how they might be identified to improve their treatment. Different hypotheses have been suggested, including genetic factors, platelet heterogeneity, non-compliance and others. However, it is probably that many molecular mechanisms involved in platelet resistance to antithrombotic therapies still remains unknown. New technologies, such as proteomics and genetic, are beginning to show new unknown biological biomarkers and molecular mechanisms which may be associated with platelet antithrombotic drug resistance.
    Pharmaceutical Research 11/2010; 27(11):2365-73. · 4.74 Impact Factor
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    ABSTRACT: Proteomics and Atrial Appendages. Introduction: The objective was to compare by proteomics the expression of proteins associated with the cytoskeleton, energetic metabolism, and cardiac cytoprotection between left atrial appendages (LAA) and right atrial appendages (RAA) obtained from patients with mitral valve disease both in sinus rhythm (SR, n = 6) and in permanent atrial fibrillation (AF, n = 11).Methods and Results: Samples from RAA and LAA were obtained from the same patient. Proteins were separated in 2-dimensional electrophoresis and identified by mass spectrometry. LAA from SR patients upexpressed -actin isotype 1 and desmin isotypes 3 and 5 with respect to RAA. In LAA from AF patients were upexpressed cardiac -actin isotypes 1 and 2, tropomyosin - and β-chains, and myosin light chain embryonic muscle/atrial isoform with respect to LAA from SR patients. In RAA from AF patients also upexpressed different cytoskeleton associated proteins with respect to RAA from SR patients. Different energetic metabolism-associated proteins were upexpressed in LAA and RAA from AF with respect those from SR patients. In AF patients, the expression of proteins associated with cardiac cytoprotection such as gluthatione-S-transferase, heat shock protein (Hsp) 27, and different Hsp60 isotypes, were higher in RAA but not in LAA with respect to the corresponding appendages in SR patients.Conclusions: For each individual patient RAA and LAA showed a similar level of proteins expressed associated with cytoskeleton, energetic metabolism, and cardiac cytoprotection. There were more differences in the level of proteins associated with the above-mentioned mechanisms between the atrial appendages from AF with respect to SR patients, which may open new targets for drugs. (J Cardiovasc Electrophysiol, Vol. 21, pp. 859-868, August 2010)
    Journal of Cardiovascular Electrophysiology 07/2010; 21(8):859 - 868. · 3.48 Impact Factor
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    ABSTRACT: The aim of the present study was to analyse differences in the protein expression profile between platelets from aspirin (ASA)-resistant patients and ASA-sensitive patients. We analysed platelets from 51 clinically stable coronary ischaemic patients taking ASA (100 mg/day) divided into ASA-resistant (n=25) and ASA-sensitive (n=26) based on a platelet functionality test (PFA-100). Proteins associated with cytoskeleton, energetic metabolism, oxidative stress, inflammation and cell survival were analysed by two-dimensional electrophoresis and mass spectrometry. The expression of two gelsolin precursor isotypes and one F-acting capping protein isotype was decreased in ASA-resistant platelets (p<0.05). The expression of glyceraldehyde 3-phosphate dehydrogenase was increased in the ASA-resistant platelets (1751.1 + or - 220.6 vs. 4273.3 + or - 971.7, 95% confidence interval [CI] 1815.11 to 4061.2, p=0.001). It was accompanied by a reduced expression and activity of 1,6-bisphosphate aldolase in platelets without changes in the content of pyruvate. A reduced expression of gluthathione-S-transferase and the protein disulfide isomerase isotype 1 was found in ASA-resistant platelets. The protein expression of the chloride intracellular channel isotype 1 was increased in ASA-resistant platelets (21.3 + or - 3.8 vs. 48.8 + or - 6.0, CI 29.5 to 45.95, p=0.03) while the expression of two HSP60 and two HSP71 isotypes was decreased. No changes were observed in proteins associated with inflammation. In conclusion, ASA-resistant and ASA-sensitive platelets are different in terms of the level of expression of proteins associated with mechanisms such as energetic metabolism, cytoskeleton, oxidative stress and cell survival which may be associated with their different ability to respond to ASA.
    Thrombosis and Haemostasis 01/2010; 103(1):160-70. · 5.76 Impact Factor
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    ABSTRACT: The aim of this study was to analyze the effect of 2 antiplatelet regimens on the inhibition of GP IIb/IIIa-dependent platelet activation and their association with the poststenting inflammatory response. Seventeen patients with acute myocardial infarction were divided into 2 groups: (A) clopidogrel plus tirofiban infusion administered together during inclusion (n = 10); (B) clopidogrel administered at inclusion and followed 2 hours after by tirofiban (n = 7). Blood samples were obtained at inclusion and at 24 and 48 hours after stenting. Before stenting, a greater reduction of GP IIb/IIIa-dependent platelet activation was found in both groups, although it was greater in group A than in group B. This statistical difference was not observed at 24 and 48 hours after the procedure. At 48 hours after stenting, interleukin-6, interleukin-10, soluble intracellular adhesion molecule-1, and soluble CD40 ligand plasma values were not different between experimental groups. By proteomics, different isoforms of the following proteins were identified: alpha 1-antitrypsin (ATT-1), fibrinogen gamma chain, apolipoprotein A-IV, apolipoprotein A-I, vitamin D binding protein, haptoglobin, and serotransferrin. At 48 hours after stenting, only the plasma expression of the ATT-1 isoform 5 was significantly increased in group A compared with group B. In conclusion, a greater inhibition of GP IIb/IIIa-dependent platelet activation before stenting was not correlated with a different inflammatory activity early after stenting.
    Journal of Cardiovascular Pharmacology 04/2008; 51(3):286-92. · 2.38 Impact Factor
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    ABSTRACT: Our aim was to analyze the plasma proteome in aspirin (acetylsalicylic acid [ASA])-sensitive and ASA-resistant coronary ischemic patients. Plasma from 19 ASA-sensitive and 19 ASA-resistant patients was analyzed. For the proteomic study, two-dimensional electrophoresis was performed. The expression of one isotype of the fibrinogen gamma chain and three isotypes of haptoglobin was increased in ASA-resistant patients. Three vitamin D binding protein isotypes were increased in ASA-resistant patients. In vitro incubation of vitamin D binding protein (DBP) with blood from healthy volunteers reduced the inhibitory effect of ASA on thromboxane A2 production. DBP may be a new regulator of the inhibitory effect of ASA on platelets.
    Journal of Proteome Research 08/2007; 6(7):2481-7. · 5.06 Impact Factor
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    ABSTRACT: La reestenosis intrastent (RIS) tiene una incidencia del 20 al 30% cuando se utilizan stents convencionales. El fenómeno de regresión tardía de (RTRIS) ha sido descrito previamente, pero no se han identificado variables relacionadas con dicho fenómeno. El objetivo del estudio fue identificar variables relacionadas con la RTRIS.
    Archivos de cardiología de México 12/2006; 76(4):390-396.
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    ABSTRACT: Patients with cardiac arrest have been excluded from most randomized trials on percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). The aim of the study was to evaluate the outcome of patients undergoing primary PCI for acute myocardial infarction who suffered from cardiac arrest prior to the procedure, focusing the study on the influence of immediate paramedical-medical assistance on the outcome. Sixty-three patients with ST-elevation AMI and previous cardiac arrest underwent primary PCI within 12 hours after symptom onset. Three groups of patients were defined: Group 1: Cardiac arrest before hospital admission, without immediate (< 1 minute) initiation of resuscitation maneuvers (n = 13); Group 2: Pre-hospital cardiac arrest with immediate initiation of resuscitation maneuvers (n = 14); Group 3: Cardiac arrest after hospital admission. The proportion of patients with ventricular tachycardia or fibrillation as documented initial rhythm was similar among the groups (77%, 79% and 83%, respectively), as well as the rate of angiographic success (92%, 93% and 86%, respectively). However, the incidence of cardiac events at 30 days was significantly higher in Group 1 than in Groups 2 or 3 (54%, 29% and 17%, respectively; p = 0.03), as well as the mortality rate at 30 days (46%, 21% and 18%, respectively; p = 0.06). Interestingly, the outcomes were not statistically different between Groups 2 and 3. In multivariate analysis, the independent predictors for mortality at 30 days for Group 1 were: multivessel disease, angiographic failure and cardiogenic shock. Combining immediate initiation of resuscitation maneuvers and primary PCI yields a very good clinical outcome in patients with AMI suffering from cardiac arrest.
    The Journal of invasive cardiology 06/2006; 18(6):269-72. · 1.57 Impact Factor
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    ABSTRACT: Objetivo: El objetivo fue evaluar el grado de compromiso de las ramas que son enjauladas durante la implantación directa de stent.
    Archivos de cardiología de México 09/2005; 75(3):252-259.
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    ABSTRACT: Myocardial contrast echocardiography (MCE) is useful for predicting the functional recovery of akinetic segments in patients undergoing primary angioplasty after acute myocardial infraction (AMI). Recently, parametric imaging-based quantitative MCE has been developed for measuring perfusion. Our aims were: a) to measure perfusion in akinetic myocardial segments in patients undergoing primary angioplasty using parametric imaging-based quantitative MCE; and b) to assess the usefulness of these measurements in predicting functional recovery of these segments. The study group comprised 49 consecutive patients undergoing primary angioplasty. Both MCE and standard echocardiography were performed between 2 and 5 days after AMI. Six months later, additional standard echocardiography and coronary angiography were performed. Perfusion was quantified independently off-line from parametric images. The patients' mean age was 62.3+/-14.5 years (39 men; 79.2%). Some 170 akinetic segments were detected. Of these, 105 (62.1%) recovered function. The quantitative MCE parameter that best predicted functional recovery was myocardial blood flow velocity (beta): the area under the receiver operating characteristic (ROC) curve was 0.96 (95% CI, 0.92-0.99). For a cut-off point of 31 dB/s, the sensitivity was 87.62%, the specificity was 95.31%, the positive predictive value was 96.8%, and the negative predictive value was 82.43%. These results were better than those obtained using qualitative methods for assessing myocardial perfusion. Perfusion measurement by parametric imaging-based quantitative MCE is useful for predicting the functional recovery of akinetic segments in patients undergoing primary angioplasty after AMI. The technique provides superior information to older qualitative methods.
    Revista Espa de Cardiologia 07/2005; 58(6):649-56. · 3.20 Impact Factor
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    ABSTRACT: Patients with in-stent restenosis involving the proximal segment of the left anterior descending coronary artery are frequently sent for surgical revascularization. We studied the long-term (3.3 +/- 2.8 years) outcome of 123 patients with in-stent restenosis involving the proximal left anterior descending coronary artery who were treated with a second percutaneous procedure. Cumulative survival rate, probability of being alive and free from surgical revascularization, and probability of being alive and free from new revascularization procedures was 98.3 +/- 1.2%, 92.8 +/- 2.5%, and 82.2 +/- 3.6% at 1 year, and 95.2 +/- 2.5%, 88.5 +/- 3.4%, and 76.9 +/- 4.3% at 3 years, respectively. Thus, in patients with in-stent restenosis involving the proximal left anterior descending artery, a second percutaneous procedure is a feasible and safe long-term strategy, with few patients ultimately requiring surgical revascularization.
    The Journal of invasive cardiology 05/2005; 17(4):218-21. · 1.57 Impact Factor
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    ABSTRACT: Introducción y objetivos. La ecocardiografía de contraste miocárdico (ECM) es útil para predecir la recuperación funcional de los segmentos acinéticos en pacientes que reciben una angioplastia coronaria transluminal percutánea primaria. Se ha desarrollado recientemente la imagen paramétrica para la cuantificación de la perfusión. Los objetivos son: a) valorar de forma cuantitativa la perfusión de los segmentos acinéticos en pacientes que reciben angioplastia primaria, y b) evaluar la utilidad de la cuantificación con imagen paramétrica para predecir la recuperación funcional de los segmentos acinéticos. Pacientes y método. Se analizó a 49 pacientes con infarto agudo de miocardio (IAM) que recibieron angioplastia primaria. Se realizó ecocardiograma estándar y ECM entre los 2 y 5 días posteriores al IAM. Se realizaron ecocardiograma estándar y cateterismo a los 6 meses. La evaluación cualitativa y cuantitativa fue realizada off-line por 2 investigadores independientes. Resultados. La edad media fue de 62,3 ± 14,5 años (39 varones). En el estudio basal se detectaron 170 segmentos acinéticos. La recuperación funcional fue observada en 105 segmentos. El mejor parámetro cuantitativo para predecir la recuperación funcional fue la velocidad del flujo sanguíneo (ß): el área bajo la curva ROC fue 0,96 (intervalo de confianza del 95%, 0,92-0,99). Para un punto de corte de 31dB/s, la sensibilidad fue del 87,62%, la especificidad del 95,31%, el valor predictivo positivo del 96,8% y el valor predictivo negativo del 82,43%. Estos resultados son mejores que los obtenidos con el método cualitativo. Conclusiones. La cuantificación de la perfusión con imagen paramétrica es una herramienta útil para predecir la recuperación funcional de los segmentos acinéticos en pacientes que reciben angioplastia coronaria transluminal percutánea primaria y es mejor que la valoración cualitativa.
    Revista española de cardiología, ISSN 0300-8932, Vol. 58, Nº. 6, 2005, pags. 649-656. 01/2005;
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    ABSTRACT: The aim of the study was to evaluate the compromise of side branches when jailed by a coronary stent implanted without balloon predilation. 56 patients in which at least a coronary stent was implanted without balloon predilation and covering a side brach (58 stents, 1.04 +/- 0.19 per patient) were studied. The effect of direct coronary stent implantation over side branch flow, as well as the characteristics associated were studied. The main vessel was left anterior descending in 63%, left circumflex in 21%, right coronary in 14%, and left main in one case. An angiographic successful result in the main vessel was obtained in all cases. Coronary flow was TIMI 3, 2, 1, and 0 in 95%, 3%, 0%, and 2% before the procedure, in comparison with 86%, 2%, 3%, and 9% after stent implantation (p = 0.204). The incidence of side branch occlusion was 12% (7/58). In one case, the side branch was dilated across the stent struts, and thus the rate of side branch loss at the end of the procedure was 10% (6/58). In cases of side branch occlusion, there was a more severe stenosis at its origin before stent implantation (30.2 +/-31.3% vs 16.8 +/- 11.1%, p = 0.028). Fifty percent of side branches occluded after direct coronary stent implantation and angiographically re-evaluated at follow-up became patent, and 88% of side branches not affected after stent implantation remained patent at 6.2+/-1.9 months. The rate of side branch occlusion after direct stent implantation in our series was 12%, that is not different from that reported for conventional stent implantation. Thus, the decision of using direct or conventional coronary stenting should not be conditioned by the presence of side branches arising from the target lesion.
    Archivos de cardiología de México 01/2005; 75(3):252-9.
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    ABSTRACT: Data on percutaneous coronary intervention (PCI) in nonagenarians are very scarce. The investigators present a series of 26 nonagenarians who underwent PCI (29 lesions, 1.1 +/- 0.3 per patient). Most (96%) had acute coronary syndrome at presentation, 27% underwent primary PCI for acute myocardial infarctions, and 54% had multivessel disease. Angiographically successful results were obtained in 24 patients (92%), and coronary stents were used in 81%. Five patients (19%) died during hospitalization. In-hospital mortality was significantly greater in patients with Killip class III or IV at presentation (100% vs 9%, p = 0.001), in those in whom the procedure was a primary PCI for acute myocardial infarction (57% vs 5%, p = 0.010), and in the presence of angiographic failure (100% vs 13%, p = 0.031). In-hospital mortality was 0% after excluding patients in cardiogenic shock and those with primary PCI. Thus, most nonagenarians who undergo PCI have a high-risk profile. However, PCI achieves a successful angiographic result in most patients. Mortality is high but concentrated in patients in cardiogenic shock and with primary angioplasty as PCI.
    The American Journal of Cardiology 11/2004; 94(8):1058-60. · 3.21 Impact Factor
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    ABSTRACT: A meta-analysis of 11 randomized trials was done to compare stenting versus balloon angioplasty (BA) in small coronary vessels. Randomized studies on coronary stenting (CS) in small vessels have yielded controversial results. Eleven randomized trials on CS versus BA in small vessels, including angiographic re-evaluation at six months, were analyzed. The BeStent (Medtronic Instent, Minneapolis, Minnesota) was used in four studies, the Multi-Link (Guidant, Advanced Cardiovascular Systems Inc., Santa Clara, California) in three trials, and the NIR (Boston Scientific Corp., Boston, Massachusetts), JoStent (Jomed International AB, Helsingborg, Sweden), Tenax (Biotronik, Berlin, Germany), and BioDivysio (Abbott Vascular Devices, Redwood City, California) in the remaining four trials. Overall, 3,541 patients were included (1,672 allocated to BA and 1,869 to stent). The rate of cross-over from balloon to stent in the pooled population was 19%, and unsuccessful stent deployment occurred in 2% of the patients allocated to stent. The pooled rates of restenosis were 25.8% and 34.2% in patients allocated to stent and balloon, respectively (p = 0.003) (risk ratio [RR] 0.77; 95% confidence interval [CI] 0.65 to 0.92). A smaller reference vessel diameter at baseline was associated with a higher risk reduction in the restenosis rate (y = -3.551 + 1.826 [x]; p = 0.012). Patients allocated to stent had lower rates of major adverse cardiac events (15.0% vs. 21.8%, p = 0.002; RR 0.70; 95% CI 0.57 to 0.87) and new target vessel revascularizations (12.5% vs. 17.0%, p = 0.004; RR 0.75, 95% CI 0.61 to 0.91). Elective stenting is superior to provisional stenting in small coronary arteries. This benefit is more evident in smaller coronary arteries.
    Journal of the American College of Cardiology 07/2004; 43(11):1964-72. · 14.09 Impact Factor
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    ABSTRACT: Stent implantation without predilation simplifies a large proportion of coronary intervention procedures, with a significant reduction in costs and procedure time. To determine the variables associated with a higher probability of failure in direct stent implantation in daily practice in a wide range of clinical contexts and types of lesions. Over a period of 28 months, direct implantation of 931 stents was attempted in our Center (811 patients, 83% male, mean age 62 +/- 12 years; 1.1 stent per patient). In 59 patients (7.3%), balloon predilation was necessary, and the factors associated with direct implant failure were determined. The vessels treated were: anterior descending (373 lesions: 40.1%), right coronary artery (306 lesions: 32.9%, circumflex (210 lesions: 22.6%), saphenous vein (35 lesions: 3.8%), left main (5 lesions: 0.4%) and internal mammary artery (2 lesions: 0.2%). 54% of the lesions were of type B2/C (ACC/AHA classification). The characteristics significantly associated with, or with statistical tendency towards, a lower success rate in direct stent implantation were: Lesion in the circumflex (11% vs. 5.5%, p = 0.012); reference vessel diameter less than 3.0 mm (9.8% vs. 6.2%, p = 0.097); age over 65 years (8.5% vs. 4.5%, p = 0.017); left main disease, irrespective of the vessel treated (23.5%% vs. 6.5%, p = 0.023); B2/C lesion (7.8%, vs. 4.8%, p = 0.086); calcification (9.9% vs. 4.9%, p = 0.012); vessel angulation greater than 45 degrees (9.9% vs. 4.9%, p = 0.009); and Express stent implant (19.6% vs. 6.0%, p < 0.001). On multivariate analysis, independent predictors of failure in direct stent implantation were: left main lesion (RR 6.6; 95% CI 1.73-24.93; p = 0.013), presence of calcium (RR 1.9; 95% CI 1.02-3.37; p = 0.049), vessel curvature (RR 2.0; 95% CI 1.13-3.64; p = 0.018), reference vessel diameter less than 3 mm (RR 2.2; 95% CI 1.15-4.32; p = 0.023), lesion type B2/C (RR 1.9; 95% CI 1.0-3.52; p = 0.044) and Express stent (RR 2.7; 95% CI 1.07-6.79; p = 0.05). In a large and heterogeneous series of patients, direct stenting was not possible in 7.3% of cases, which required balloon predilation. Certain clinical and angiographic features can predict when this is more like to occur.
    Revista portuguesa de cardiologia: orgao oficial da Sociedade Portuguesa de Cardiologia = Portuguese journal of cardiology: an official journal of the Portuguese Society of Cardiology 01/2004; 23(7-8):951-60. · 0.59 Impact Factor