Rosa Maria Rahmi Garcia

Impact of diabetes on 10-year outcomes of patients with multivessel coronary artery disease in the Medicine, Angioplasty, or Surgery Study II (MASS II) trial

INTRODUCTION Diabetes mellitus is a major cause of coronary artery disease (CAD). Despite improvement in the management of patients with stable CAD, diabetes remains a major cause of increased morbidity and mortality. There is no conclusive evidence that either modality is better than medical therapy alone for the treatment of stable multivessel CAD in patients with diabetes in a very long-term follow-up. Our aim was to compare 3 therapeutic strategies for stable multivessel CAD in a diabetic population and non-diabetic population. METHODS It was compared medical therapy (MT), percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG) in 232 diabetic patients and 379 nondiabetic patients with multivessel CAD. Endpoints evaluated were overall and cardiac mortality. RESULTS Patients (n = 611) were randomized to CABG (n = 203), PCI (n = 205), or MT (n = 203). In a 10-year follow-up, more deaths occurred among patients with diabetes than among patients without diabetes (P = .001) for overall mortality. In this follow-up, 10-year mortality rates were 32.3% and 23.2% for diabetics and non-diabetics respectively (P = .024). Regarding cardiac mortality, 10-year cardiac mortality rates were 19.4% and 12.7% respectively (P = .031).Considering only diabetic patients and stratifying this population by treatment option, we found mortality rates of 31.3% for PCI, 27.5% for CABG and 37.5% for MT (P = .015 for CABG vs MT) and cardiac mortality rates of 18.8%, 12.5% and 26.1% respectively (P = .005 for CABG vs MT). CONCLUSIONS/INTERPRETATION Among patients with stable multivessel CAD and preserved left ventricular ejection fraction, the 3 therapeutic regimens had high rates of overall and cardiac-related deaths among diabetic compared with non-diabetic patients. Moreover, better outcomes were observed in diabetic patients undergoing CABG compared to MT in relation to overall and cardiac mortality in a 10-year follow-up.

Nitric oxide production by neutrophils obtained from patients during acute coronary syndromes: expression of the nitric oxide synthase isoforms.

OBJECTIVES To analyze the differences in the nitric oxide (NO) forming system between neutrophils obtained from patients during unstable angina (UA) and during acute myocardial infarction (AMI). BACKGROUND Neutrophils are involved in the regulation of thrombus formation through the release of active substances such as NO. Acute myocardial infarction is the result of an occlusive thrombus; unstable angina is attributed to intermittent thrombus formation. METHODS We studied 49 patients admitted to hospital within 24 h after the onset of chest pain: 31 experienced AMI and 18 experienced UA. Acute myocardial infarction was defined as CK greater than two-fold the upper limit of normal value of biochemical laboratory, with CK-MB >10% total CK. Unstable angina was defined as transient ST segment changes without significant increases in CK and CK-MB. RESULTS The amount of NO generated by neutrophils from AMI patients was significantly higher than that generated by neutrophils from UA patients. Neutrophils from UA and AMI patients showed low levels of endothelial-like NO synthase protein expression and a marked expression of the inducible NO synthase (iNOS) isoform. Although neutrophils from patients during acute coronary syndromes generated high amounts of NO, they did not demonstrate an increased ability to stimulate cyclic guanosine monophosphate (cGMP) synthesis in platelets. This lack of activity to release NO by neutrophils from patients during AMI was unrelated to a defect in the platelet cGMP-forming system; sodium nitroprusside, an exogenous NO donor, similarly increased cGMP levels in platelets from AMI patients and healthy donors. CONCLUSIONS Neutrophils from patients during AMI and UA showed an increased production of NO and a marked expression of the iNOS isoform. However, NO released from these neutrophils showed a deficient functionality. These findings could have clinical implications because they show differences in thrombus growth in patients with UA versus patients with AMI.

Inhibition of platelet activation in stroke-prone spontaneously hypertensive rats: comparison of losartan, candesartan, and valsartan.

In vitro studies have suggested that losartan interacts with the thromboxane (TxA2)/ prostaglandin H2 (PGH2) receptor in human platelets, reducing TxA2-dependent platelet activation. The aim of this study was to evaluate the effect of different angiotensin II type 1 receptor antagonists in stroke-prone spontaneously hypertensive rats (SHRSP). The level of platelet activation was assessed by determining P-selectin expression in platelets by flow cytometry. The ex vivo adhesion of platelets was also analyzed. The number of platelets that expressed P-selectin in SPSHR was significantly increased (% P-selectin expression: WKY 4 ± 0, 4%; SHRSP 15.5 ± 0, 8% [n = 8], p < 0.05). In SHRSP receiving losartan (20 mg/kg body weight per day) the percentage of platelets expressing P-selectin fell to levels close to that observed in WKY. The number of platelets from SHRSP treated with valsartan and candesartan (20 mg/kg body weight per day for 14 days) that expressed P-selectin was not significantly different from those from untreated SPRHR. Only losartan treatment reduced ex vivo platelet adhesion to a synthetic surface. The antiplatelet effect of losartan does not appear to be related to the level of blood pressure reduction. In ex vivo experiments, losartan significantly reduced the binding of the radiolabeled TxA2 agonist U46619 to platelets obtained from SHRSP in a dose-dependent manner. Treatment with losartan reduced the number of activated platelets in SHRSP independently of its blood pressure effects. TxA2-receptor blockade is proposed as a mechanism by which losartan can prevent platelet activation.

Circulating immune complexes from HIV‐1+ patients induces apoptosis on‘qc normal lymphocytes

Isolated immune complexes from sera of 49 out of 67 human immunodeficiency virus‐1‐positive (HIV‐1+) patients (CIC–HIV+), composed of anti‐HIV–HIV‐Ag, could induce apoptosis on normal phytohaemagglutinin (PHA)‐activated lymphocytes. DNA degradation was detected by propidium iodide staining. This activity is directed against CD4+ lymphocytes as demonstrated by double binding of CIC–HIV+ and anti‐CD4 on apoptotic cells. Expression of Fas antigen is prior to apoptotic phenomena. CIC–HIV+ apoptosis inducers belong mainly to asymptomatic HIV‐infected patients, indicating that immune complexes from these patients can destroy CD4+ lymphocytes.

Do CD8(+)CD25(+) cells predict immune reconstitution syndrome in HIV-positive patients who begin HAART?

Although undesirable, immune reconstitution syndrome (IRS) indicates a favourable effect of HAART and it should be differentiated from an opportunistic infection because of their distinct implications and management. Our group analysed different immunological parameters with the aim of identifying IRS predictors in patients who begin HAART. We found that CD8+CD25+ cell pretreatment values in patients who developed IRS were four times higher than in those patients who did not develop IRS.

Avaliação da prevalência do diabetes e da hiperglicemia de estresse no infarto agudo do miocárdio

OBJECTIVES: To evaluate in our population the real prevalence of diabetes (DM) and stress hyperglycemia (HE) in patients with myocardial infarction (IAM) admitted in a cardiologic emergency unit. METHODS: A retrospective analysis of 2262 patients with AMI evaluating the prevalence of DM (referred and diagnosed) and stress hyperglycemia. RESULTS: Besides 12,1% of subjects were previously referred to be diabetic (men: 10.7% and women: 15.8%), diabetes was effectively diagnosed in 24,8% (M: 22,9%, W: 29,7%) and stress hyperglycemia in 13,6% HE of the patients (M: 14,3%, W: 11,7%) indicating that glycemic alterations were effectively observed in 37.2.% of the patients with IAM (M: 37,2%, W: 41,4%). In DM subjects IAM events occurred earlier, total intra-hospital mortality was higher (DM: 20.7%, ND: 13,8%, HE: 13,4%) and less surgical procedures were performed (ND 33.8%, DM: 21.7%, HE: 18.0%). CONCLUSION: The elevated DM and stress hyperglycemia prevalence observed in our study indicates that glycemic alterations is one of the most important risk factors for IAM.

Impact of hypoglycemic agents on myocardial ischemic preconditioning

Murry et al in 1986 discovered the intrinsic mechanism of profound protection called ischemic preconditioning. The complex cellular signaling cascades underlying this phenomenon remain controversial and are only partially understood. However, evidence suggests that adenosine, released during the initial ischemic insult, activates a variety of G protein-coupled agonists, such as opioids, bradykinin, and catecholamines, resulting in the activation of protein kinases, especially protein kinase C (PKC). This leads to the translocation of PKC from the cytoplasm to the sarcolemma, where it stimulates the opening of the ATP-sensitive K(+) channel, which confers resistance to ischemia. It is known that a range of different hypoglycemic agents that activate the same signaling cascades at various cellular levels can interfere with protection from ischemic preconditioning. This review examines the effects of several hypoglycemic agents on myocardial ischemic preconditioning in animal studies and clinical trials.

Role of antiretroviral regimes in HIV‐1 patients in reducing immune activation

We assessed whether antiretroviral regimes are able to diminish apoptosis and markers of lymphocyte activation and restore lymphocyte proliferation. T‐cell subset, spontaneous and induced apoptosis, CD95 and soluble Fas antigen and cell proliferation were analysed in 41 human immunodeficiency virus type 1‐positive patients. Twenty‐five were in asymptomatic stage A and 16 were in stage B/C. Thirty‐five received antiretroviral treatment: 18 received two inhibitors of reverse transcriptase and one protease inhibitor and 17 received three inhibitors of reverse transcriptase. Six patients did not receive treatment, for different reasons, but continued to participate in the study. Studies were performed at baseline, 3, 6 and 12 months. Levels of CD4 increased slightly until 6 months of antiretroviral treatment, as a whole, in all the patients treated. Naïve CD4 lymphocytes, as well as memory CD4 lymphocytes, remained constant. Spontaneous apoptosis of lymphocytes, after 72 hr of culture, decreased in all patients treated, but to a much smaller extent than phytohaemagglutinin‐induced apoptosis. In both groups treated, levels of soluble Fas decreased until 6 months of treatment and then increased again. Lymphocyte proliferation reached normal levels after 1 year of treatment. In patients without treatment CD4 cells decreased slowly and no modification in activation markers was found. Antiretroviral regimes decrease immune activation as well as viral load and this deactivation restores lymphocyte proliferation.

Hypotheses, rationale, design, and methods for prognostic evaluation of cardiac biomarker elevation after percutaneous and surgical revascularization in the absence of manifest myocardial infarction. A comparative analysis of biomarkers and cardiac magnetic resonance. The MASS-V Trial

BackgroundAlthough the release of cardiac biomarkers after percutaneous (PCI) or surgical revascularization (CABG) is common, its prognostic significance is not known. Questions remain about the mechanisms and degree of correlation between the release, the volume of myocardial tissue loss, and the long-term significance. Delayed-enhancement of cardiac magnetic resonance (CMR) consistently quantifies areas of irreversible myocardial injury. To investigate the quantitative relationship between irreversible injury and cardiac biomarkers, we will evaluate the extent of irreversible injury in patients undergoing PCI and CABG and relate it to postprocedural modifications in cardiac biomarkers and long-term prognosis.Methods/DesignThe study will include 150 patients with multivessel coronary artery disease (CAD) with left ventricle ejection fraction (LVEF) and a formal indication for CABG; 50 patients will undergo CABG with cardiopulmonary bypass (CPB); 50 patients with the same arterial and ventricular condition indicated for myocardial revascularization will undergo CABG without CPB; and another 50 patients with CAD and preserved ventricular function will undergo PCI using stents. All patients will undergo CMR before and after surgery or PCI. We will also evaluate the release of cardiac markers of necrosis immediately before and after each procedure. Primary outcome considered is overall death in a 5-year follow-up. Secondary outcomes are levels of CK-MB isoenzyme and I-Troponin in association with presence of myocardial fibrosis and systolic left ventricle dysfunction assessed by CMR.DiscussionThe MASS-V Trial aims to establish reliable values for parameters of enzyme markers of myocardial necrosis in the absence of manifest myocardial infarction after mechanical interventions. The establishments of these indices have diagnostic value and clinical prognosis and therefore require relevant and different therapeutic measures. In daily practice, the inappropriate use of these necrosis markers has led to misdiagnosis and therefore wrong treatment. The appearance of a more sensitive tool such as CMR provides an unprecedented diagnostic accuracy of myocardial damage when correlated with necrosis enzyme markers. We aim to correlate laboratory data with imaging, thereby establishing more refined data on the presence or absence of irreversible myocardial injury after the procedure, either percutaneous or surgical, and this, with or without the use of cardiopulmonary bypass.

HCV coinfection contributes to HIV pathogenesis by increasing immune exhaustion in CD8 T-cells.

Background There are several contributors to HIV-pathogenesis or insufficient control of the infection. However, whether HIV/HCV-coinfected population exhibits worst evolution of HIV-pathogenesis remains unclear. Recently, some markers of immune exhaustion have been proposed as preferentially upregulated on T-cells during HIV-infection. Herein, we have analyzed T-cell exhaustion together with several other contributors to HIV-pathogenesis that could be affected by HCV-coinfection. Patients and methods Ninety-six patients with chronic HIV-infection (60 HIV-monoinfected and 36 HIV/HCV-coinfected), and 20 healthy controls were included in the study. All patients were untreated for both infections. Several CD4 and CD8 T-cell subsets involved in HIV-pathogenesis were investigated. Non-parametric tests were used to establish differences between groups and associations between variables. Multivariate linear regression was used to ascertain the variables independently associated with CD4 counts. Results HIV-patients presented significant differences compared to healthy controls in most of the parameters analyzed. Both HIV and HIV/HCV groups were comparable in terms of age, CD4 counts and HIV-viremia. Compared to HIV group, HIV/HCV group presented significantly higher levels of exhaustion (Tim3+PD1- subset) in total CD8+ T-cells (p = 0.003), and higher levels of exhaustion in CD8+HLADR+CD38+ (p = 0.04), CD8+HLADR-CD38+ (p = 0.009) and CD8+HLADR-CD38- (p = 0.006) subsets of CD8+ T-cells. Interestingly these differences were maintained after adjusting by CD4 counts and HIV-viremia. Conclusions We show a significant impact of HCV-coinfection on CD8 T-cells exhaustion, an important parameter associated with CD8 T-cell dysfunction in the setting of chronic HIV-infection. The relevance of this phenomenon on immunological and/or clinical HIV progression prompts HCV treatment to improve management of coinfected patients.