Increased Abdominal Perimeter Differently Affects Respiratory Function in Men and Women.

Obesity is a worldwide epidemic being the main cause of cardiovascular, metabolic disturbances and chronic pulmonary diseases. The increase in body weight may affect the respiratory system due to fat deposition and systemic inflammation. Herein, we evaluated the sex differences in the impact of obesity and high abdominal circumference on basal ventilation. Thirty-five subjects, 23 women and 12 men with a median age of 61 and 67, respectively, were studied and classified as overweight and obese according to body mass index (BMI) and were also divided by the abdominal circumference. Basal ventilation, namely, respiratory frequency, tidal volume, and minute ventilation, was evaluated. In normal and overweight women, basal ventilation did not change, but obese women exhibited a decrease in tidal volume. In men, overweight and obese subjects did not exhibit altered basal ventilation. In contrast, when subjects were subdivided based on the abdominal perimeter, a higher circumference did not change the respiratory frequency but induced a decrease in tidal volume and minute ventilation in women, while in men these two parameters increased. In conclusion, higher abdominal circumference rather than BMI is associated with alterations in basal ventilation in women and men.

Microvascular Dysfunction Is Associated With Impaired Myocardial Work in Obstructive and Nonobstructive Hypertrophic Cardiomyopathy: A Multimodality Study.

Background Two-dimensional speckle tracking echocardiography has been shown to correlate with microvascular dysfunction, a hallmark of hypertrophic cardiomyopathy (HCM). We hypothesized that there is an association between myocardial work and left ventricular ischemia, with incremental value to global longitudinal strain, in patients with HCM. Methods and Results We performed a prospective assessment of patients with HCM, undergoing 2-dimensional speckle tracking echocardiography and stress perfusion cardiac magnetic resonance. Results were stratified according to obstructive or nonobstructive HCM and the presence of significant replacement fibrosis (late gadolinium enhancement ≥15% of left ventricular mass). Seventy-five patients with HCM (63% men, age 55±15 years) were evaluated, 28% with obstructive HCM (mean gradient 89±60 mm Hg). Perfusion defects were found in 90.7%, involving 22.5±16.9% of left ventricular mass, and 38.7% had late gadolinium enhancement ≥15%. In a multivariable analysis, a lower global work index (r=-0.519, ß-estimate -10.822; P=0.001), lower global work efficiency (r=-0.379, ß-estimate -0.123; P=0.041), and impaired global constructive work (r=-0.532, ß-estimate -13.788; P<0.001) significantly correlated with ischemia. A segmental analysis supported these findings, albeit with lower correlation coefficients. A global work index cutoff ≤1755 mm Hg% was associated with hypoperfusion with a sensitivity of 88% and a specificity of 71%, while the best cutoff for global longitudinal strain (>-15.5%) had a sensitivity of 64% and a specificity of 57%. The association between myocardial work and perfusion defects was significant independently of late gadolinium enhancement ≥15% and obstructive HCM. Conclusions Impaired myocardial work was significantly correlated with the extent of ischemia in cardiac magnetic resonance, independently of the degree of left ventricular hypertrophy or fibrosis, with a higher predictive power than global longitudinal strain.

Blunted coronary flow velocity reserve is associated with impairment in systolic function and functional capacity in hypertrophic cardiomyopathy.

BACKGROUND: Coronary microvascular dysfunction constitutes an important pathophysiological feature in hypertrophic cardiomyopathy (HCM). We aimed to assess the association between impaired coronary flow velocity reserve (CFVR) and ventricular systolic function and functional capacity. METHODS: Eighty-three patients with HCM were enrolled in this prospective cohort study. Patients underwent echocardiogram to evaluate ventricular performance and CFVR in the left anterior descending artery (LAD) and posterior descending artery (PD). Diastolic coronary flow velocity was measured in basal conditions and in hyperemia. CFVR was calculated as the ratio of hyperemic and basal peak diastolic flow velocities. Functional capacity was evaluated by cardiopulmonary exercise testing (CPET). The link between CFVR and biventricular systolic function and peak VO2 was studied. RESULTS: Age was 55.0(14.4)years, 50 patients (60%) were male; 59 patients (71%) had nonobstructive HCM. Mean CFVR LAD was 1.81(0.49) and CFVR PD was 1.73(0.55). Lower CFVR PD was associated with impaired global longitudinal strain (GLS) 2D (ß-estimate:-3.240,95%CI:-4.634;-1.846, p < 0.001), GLS 3D (ß-estimate:-2.559,95%CI:-3.932;-1.186, p < 0.001) and area strain (ß-estimate:-3.044,95%CI:-5.373;-0.716, p = 0.011). Lower values of CFVR PD related to worse global work index (ß-estimate:267.824,95%CI:75.964;459.683, p = 0.007), global constructive work (ß-estimate:217.300,95%CI:38.750;395.850, p = 0.018) and global work efficiency (ß-estimate:5.656,95%CI:2.229;9.084, p = 0.002). Impaired CFVR LAD (ß-estimate:2.826, 95%CI:0.913;4.739, p = 0.004) and CFVR PD (ß-estimate:2.801,95%CI:0.657;4.945, p = 0.011) were associated with lower TAPSE. Lower values of CFVR LAD (ß-estimate:2.580, 95%CI:0.169;4.991, p = 0.036) and CFVR PD (ß-estimate:3.163, 95%CI: 0.721;5.606, p = 0.012) were associated with worse peak VO2. CONCLUSION: Lower CFVR was associated with impairment in biventricular systolic function parameters and functional capacity assessed by pVO2.

Association between miR-146a and Tumor Necrosis Factor Alpha (TNF-α) in Stable Coronary Artery Disease.

Background and Objectives: Tumor necrosis factor alpha (TNF-α) is proatherogenic and associated with the risk of acute ischemic events, although the mechanisms that regulate TNF-α expression in stable coronary artery disease (SCAD) are not fully understood. We investigated whether metabolic, inflammatory, and epigenetic (microRNA (miRNA)) markers are associated with TNF-α expression in SCAD. Materials and Methods: Patients with SCAD were prospectively recruited and their metabolic and inflammatory profiles were assessed. TNF-α levels were assessed using an enzyme-linked immunosorbent assay. The relative expression of six circulating miRNAs associated with the regulation of inflammation and/or atherosclerosis was determined. Results: Of the 24 included patients with the mean age of 65 (9) years, 88% were male, and 54% were diabetic. The TNF-α levels were (median (interquartile range)) 1.0 (0.7-1.1) pg/mL. The percentage of glycosylated hemoglobin (r = 0.418, p = 0.042), serum triglyceride levels (r = 0.429, p = 0.037), and C-reactive protein levels (r = 0.407, p = 0.048) were positively correlated with TNF-α levels. Of the candidate miRNAs, miR-146a expression levels were negatively correlated with TNF-α levels (as indicated by r = 0.500, p = 0.035 for correlation between delta cycle threshold (ΔCt) miR-146a and TNF-α levels). In multivariate analysis, serum triglyceride levels and miR-146a expression levels were independently associated with TNF-α levels. miR-146 expression levels were not associated with metabolic or other inflammatory parameters and were negatively correlated with the number of coronary vessels with obstructive disease (as indicated by r = 0.556, p = 0.017 for correlation between ΔCt miR-146a and number of diseased vessels). Conclusions: miR-146a expression levels were negatively correlated with TNF-α levels in patients with SCAD, irrespective of other metabolic or inflammatory markers, and with the severity of coronary artery disease. The results add to the knowledge on the role of miR-146a in TNF-α-based inflammation in SCAD and support future research on the potential therapeutic use of miR-146a in such a clinical scenario.

Cigarette Smoking, miR-27b Downregulation, and Peripheral Artery Disease: Insights into the Mechanisms of Smoking Toxicity.

Cigarette smoking is a risk factor for the development of peripheral artery disease (PAD), although the proatherosclerotic mediators of cigarette smoking are not entirely known. We explored whether circulating microRNAs (miRNAs) are dysregulated in cigarette smokers and associated with the presence of PAD. Ninety-four participants were recruited, including 58 individuals without and 36 with PAD, 51 never smokers, 28 prior smokers, and 15 active smokers. The relative expression of six circulating miRNAs with distinct biological roles (miR-21, miR-27b, miR-29a, miR-126, miR-146, and miR-218) was assessed. Cigarette smoking was associated with the presence of PAD in multivariate analysis. Active smokers, but not prior smokers, presented miR-27b downregulation and higher leukocyte, neutrophil, and lymphocyte counts; miR-27b expression levels were independently associated with active smoking. Considering the metabolic and/or inflammatory abnormalities induced by cigarette smoking, miR-27b was independently associated with the presence of PAD and downregulated in patients with more extensive PAD. In conclusion, the atheroprotective miR-27b was downregulated in active smokers, but not in prior smokers, and miR-27b expression was independently associated with the presence of PAD. These unreported data suggest that the proatherogenic properties of cigarette smoking are mediated by a downregulation of miR-27b, which may be attenuated by smoking cessation.

Circulating miRNAs Are Associated with the Systemic Extent of Atherosclerosis: Novel Observations for miR-27b and miR-146.

The mechanisms that regulate the systemic extent of atherosclerosis are not fully understood. We investigated whether the expression of circulating miRNAs is associated with the extent of stable atherosclerosis to a single territory or multiple territories (polyvascular) and with the severity of atherosclerosis in each territory. Ninety-four participants were prospectively recruited and divided into five age- and sex-matched groups: presenting no atherosclerosis, isolated coronary atherosclerosis, coronary and lower extremity atherosclerosis, coronary and carotid atherosclerosis, and atherosclerosis of the coronary, lower extremity, and carotid territories. The expression of six circulating miRNAs with distinct biological roles was assessed. The expression of miR-27b and miR-146 differed across groups (p < 0.05), showing a decrease in the presence of atherosclerosis, particularly in the three territories. miR-27b and miR-146 expression decreased in association with a higher severity of coronary, lower extremity, and carotid atherosclerosis. Polyvascular atherosclerosis involving the three territories was independently associated with a decreased miR-27b and miR-146 expression. Both miRNAs presented an area under the curve of ≥0.75 for predicting polyvascular atherosclerosis involving the three territories. To conclude, miR-27b and miR-146 were associated with the presence of severe polyvascular atherosclerosis and with the atherosclerosis severity in each territory. Both are potential biomarkers of severe systemic atherosclerosis.

The Proinflammatory Soluble CD40 Ligand Is Associated with the Systemic Extent of Stable Atherosclerosis.

Background and objectives: Polyvascular atherosclerosis is frequent and associated with a high cardiovascular risk, although the mechanisms regulating the atherosclerosis extent to single or multiple arterial territories are still poorly understood. Inflammation regulates atherogenesis and soluble CD40 ligand (sCD40L) is an inflammatory mediator associated with the presence of single-territorial atherosclerosis. We assessed whether the sCD40L expression is associated with the atherosclerosis extent to single or multiple arterial territories and with the atherosclerosis severity in different territories. Materials and Methods: We prospectively enrolled 94 participants with no atherosclerosis (controls, n = 26); isolated coronary atherosclerosis (group 1, n = 20); coronary and lower extremity (LE) atherosclerosis (group 2, n = 18); coronary and carotid atherosclerosis (group 3, n = 12); and coronary, LE, and carotid atherosclerosis (group 4, n = 18). Serum sCD40L levels were quantified. Results: The sCD40L levels (ng/mL, mean (standard deviation)) were 4.0 (1.5), 5.6 (2.6), 7.2 (4.2), 5.9 (3.7), and 5.1 (2.4) in controls and groups 1 to 4, respectively (ANOVA p = 0.012). In nonrevascularized patients, the sCD40L levels were significantly higher in group 2 than in group 1 and were correlated with the number of LE diseased segments. Prior LE bypass surgery was associated with lower sCD40L levels. Coexistence of coronary and LE atherosclerosis was independently associated with the sCD40L levels. Conclusions: The sCD40L levels were increased in stable atherosclerosis, particularly in polyvascular coronary and LE atherosclerosis. The number of LE diseased segments and prior LE revascularization were associated with sCD40L expression. To our knowledge, these are novel data, which provide insights into the mechanisms underlying multi-territorial atherosclerosis expression. sCD40L may be a promising noninvasive tool for refining the stratification of the systemic atherosclerotic burden.

Inflammation is associated with the presence and severity of chronic coronary syndrome through soluble CD40 ligand.

INTRODUCTION: Inflammation contributes to the initiation and progression of atherosclerosis, although the underlying inflammatory pathways are not entirely known. Specifically, the role of the proinflammatory soluble CD40 ligand (sCD40L) on the expression of chronic coronary syndrome (CCS) is not completely understood. We evaluated whether sCD40L expression is associated with the presence of CCS and with the clinical and anatomical severity of CCS. METHODS: We prospectively recruited 94 participants, assigned to two groups matched by age and sex, without coronary artery disease (n=26) and with CCS (n=68). Clinical, laboratory and anatomical data were prospectively collected, and serum levels of sCD40L were measured. RESULTS: In patients with CCS, classic cardiovascular risk factors were more prevalent, and the sCD40L levels, leukocyte and neutrophil counts, and neutrophil/lymphocyte ratio, but not the C-reactive protein levels, were significantly higher than those in controls. sCD40L was independently associated with the presence of obstructive coronary artery disease in multivariate analysis. Regarding CCS severity, sCD40L levels showed a significant stepwise increase with increasing angina severity (ANOVA P=0.001). In addition, sCD40L was independently associated with the anatomical severity of coronary artery disease, as assessed by the Gensini score. Among patients with CCS, those with previous coronary artery bypass grafting (n=23) had lower sCD40L levels than patients waiting for revascularization (n=45) [4.3 (2.1) ng/mL vs. 6.8 (3.5) ng/mL, P=0.001]. CONCLUSIONS: The expression of the proinflammatory sCD40L was associated with the presence of CCS and reflected the clinical and anatomical severity of CCS. In addition, we describe for the first time the association between prior CABG and reduced sCD40L levels in patients with CCS.

Carotid body chemosensitivity: early biomarker of dysmetabolism in humans.

OBJECTIVE: The carotid bodies (CBs) are peripheral chemoreceptor organs classically described as being O2 sensors, which are increasingly emerging as core players in metabolic control. Herein we evaluated CB activity in prediabetes patients and determined its correlation with dysmetabolism clinical features. DESIGN AND METHODS: Prediabetes patients were recruited at the Cardiology Service, Hospital Santa Marta, Centro Hospitalar Lisboa Central, EPE (CHLC-EPE). The study was approved by CHLC-EPE and NOVA Medical School Ethics Committee. Thirty-three prediabetic and 14 age-matched, non-prediabetic, volunteers had their peripheral chemosensitivity evaluated by the Dejours test. Serum biomarkers of metabolic disease, insulin sensitivity (HOMA-IR), blood pressure, carotid intima-media thickness (cIMT) and glucose tolerance were assessed. RESULTS: CB chemosensitivity was significantly increased in prediabetic group (P < 0.01). Fasting blood, glucose intolerance, fasting insulin and HOMA-IR were significantly higher in prediabetes patients. Insulin resistance correlated both with peripheral chemosensitivity, assessed by the Dejours test (P < 0.05) and with abdominal circumference (P < 0.01). HbA1c correlated with HOMA-IR (P < 0.05) and left cIMT (P < 0.05) in prediabetes patients. CONCLUSIONS: We conclude that CB is overactive in prediabetes subjects and that peripheral chemosensitivity correlates with fasting insulin and insulin resistance representing a novel non-invasive functional biomarker to forecast early metabolic disease.

Does permanent atrial fibrillation modify response to cardiac resynchronization therapy in heart failure patients?

INTRODUCTION: The benefits of cardiac resynchronization therapy (CRT) documented in heart failure (HF) may be influenced by atrial fibrillation (AF). We aimed to compare CRT response in patients in AF and in sinus rhythm (SR). METHODS: We prospectively studied 101 HF patients treated by CRT. Rates of clinical, echocardiographic and functional response, baseline NYHA class and variation, left ventricular ejection fraction, volumes and mass, atrial volumes, cardiopulmonary exercise test (CPET) duration (CPET dur), peak oxygen consumption (VO2max) and ventilatory efficiency (VE/VCO2 slope) were compared between AF and SR patients, before and at three and six months after implantation of a CRT device. RESULTS: All patients achieved ≥95% biventricular pacing, and 5.7% underwent atrioventricular junction ablation. Patients were divided into AF (n=35) and SR (n=66) groups; AF patients were older, with larger atrial volumes and lower CPET dur and VO2max before CRT. The percentages of clinical and echocardiographic responders were similar in the two groups, but there were more functional responders in the AF group (71% vs. 39% in SR patients; p=0.012). In SR patients, left atrial volume and left ventricular mass were significantly reduced (p=0.015 and p=0.021, respectively), whereas in AF patients, CPET dur (p=0.003) and VO2max (p=0.001; 0.083 age-adjusted) showed larger increases. CONCLUSION: Clinical and echocardiographic response rates were similar in SR and AF patients, with a better functional response in AF. Improvement in left ventricular function and volumes occurred in both groups, but left ventricular mass reduction and left atrial reverse remodeling were seen exclusively in SR patients (ClinicalTrials.gov identifier: NCT02413151; FCT code: PTDC/DES/120249/2010).

Stratification of ST-elevation myocardial infarction patients based on soluble CD40L longitudinal changes.

Involvement of soluble CD40 ligand (sCD40L) in thrombosis and inflammation on the context of coronary artery disease is currently being revised. In that perspective, we had studied the association of sCD40L with markers of platelet activation and markers of endothelial and vascular function. On that cohort, a stratification of patients with acute myocardial infarction (AMI) 1 month after percutaneous coronary intervention (PCI) was observed based on concentrations of sCD40L. The study intended to identify the groups of AMI patients with different profiles of sCD40L concentrations and verify how medication, clinical evolution, biochemical data, and markers of regulation of endothelial function at genetic (endothelial nitric oxide synthase polymorphisms) and post-transcriptional levels (circulating microRNAs) affect sCD40L serum levels. Lower quartiles of sCD40L (<2.3 ng/mL) were associated with higher concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP), high frequency of G894T polymorphism, and altered expression of a set of microRNAs assumed to be involved in the regulation of endothelial and cardiac function and myocardium hypertrophy, relative to patients in sCD40L upper quartiles. A characteristic sCD40L variation pattern in STEMI patients was identified. Low levels of sCD40L 1 month after PCI distinguish STEMI patients with worse prognosis, a compromised cardiac healing, and a persistent endothelial dysfunction, as given by the association between sCD40L, NT-proBNP, G894T polymorphism, and specific profile of miRNA expression. These results suggest sCD40L could have a prognostic value in STEMI patients.

Intracoronary Delivery of Human Mesenchymal/Stromal Stem Cells: Insights from Coronary Microcirculation Invasive Assessment in a Swine Model.

BACKGROUND: Mesenchymal stem/stromal cells have unique properties favorable to their use in clinical practice and have been studied for cardiac repair. However, these cells are larger than coronary microvessels and there is controversy about the risk of embolization and microinfarctions, which could jeopardize the safety and efficacy of intracoronary route for their delivery. The index of microcirculatory resistance (IMR) is an invasive method for quantitatively assessing the coronary microcirculation status. OBJECTIVES: To examine heart microcirculation after intracoronary injection of mesenchymal stem/stromal cells with the index of microcirculatory resistance. METHODS: Healthy swine were randomized to receive by intracoronary route either 30x106 MSC or the same solution with no cells (1% human albumin/PBS) (placebo). Blinded operators took coronary pressure and flow measurements, prior to intracoronary infusion and at 5 and 30 minutes post-delivery. Coronary flow reserve (CFR) and the IMR were compared between groups. RESULTS: CFR and IMR were done with a variance within the 3 transit time measurements of 6% at rest and 11% at maximal hyperemia. After intracoronary infusion there were no significant differences in CFR. The IMR was significantly higher in MSC-injected animals (at 30 minutes, 14.2U vs. 8.8U, p = 0.02) and intragroup analysis showed a significant increase of 112% from baseline to 30 minutes after cell infusion, although no electrocardiographic changes or clinical deterioration were noted. CONCLUSION: Overall, this study provides definitive evidence of microcirculatory disruption upon intracoronary administration of mesenchymal stem/stromal cells, in a large animal model closely resembling human cardiac physiology, function and anatomy.

Changes of soluble CD40 ligand in the progression of acute myocardial infarction associate to endothelial nitric oxide synthase polymorphisms and vascular endothelial growth factor but not to platelet CD62P expression.

Reported in vitro data implicated soluble CD40 ligand (sCD40L) in endothelial dysfunction and angiogenesis. However, whether sCD40L could exert that influence in endothelial dysfunction and angiogenesis after injury in acute myocardial infarction (AMI) patients remains unclear. In the present study, we evaluated the association of sCD40L with markers of platelet activation, endothelial, and vascular function during a recovery period early after AMI. To achieve this goal, the time changes of soluble, platelet-bound, and microparticle-bound CD40L levels over 1 month were assessed in AMI patients and correlated with endothelial nitric oxide synthase (eNOS) polymorphisms, vascular endothelial growth factor (VEGF) concentrations, and platelet expression of P-selectin (CD62P). The association of soluble form, platelet-bound, and microparticle-bound CD40L with CD62P expression on platelets, a marker of platelet activation, was also assessed to evaluate the role of CD40L in the thrombosis, whereas the association with eNOS and VEGF was to evaluate the role of CD40L in vascular dysfunction. This work shows for the first time that time changes of sCD40L over 1 month after myocardial infarct onset were associated with G894T eNOS polymorphism and with the VEGF concentrations, but not to the platelet CD62P expression. These results indicate that, in terms of AMI pathophysiology, the sCD40L cannot be consider just as being involved in thrombosis and inflammation but also as having a relevant role in vascular and endothelial dysfunction.

[Percutaneous treatment of mitral valve regurgitation: Initial experience with the MitraClip device]. / Terapêutica percutânea da insuficiência mitral: experiência inicial com o dispositivo MitraClip.

INTRODUCTION: Mitral regurgitation (MR) is the most common valvular disease and has recently become the target of a number of percutaneous approaches. The MitraClip is virtually the only device for which there is considerable experience, with more than 20,000 procedures performed worldwide. OBJECTIVE: To describe our initial experience of the percutaneous treatment of MR with the MitraClip device. METHODS: We describe the first six MitraClip cases performed in this institution (mean age 58.5 ± 13.1 years), with functional MR grade 4+ and New York Heart Association (NYHA) heart failure class III or IV (n=3), with a mean follow-up of 290 ± 145 days. RESULTS: Procedural success (MR ≤ 2+) was 100%. Total procedure time was 115.8 ± 23.7 min, with no in-hospital adverse events and discharge between the fourth and eighth day, and consistent improvement in the six-minute walk test (329.8 ± 98.42 vs. 385.33 ± 106.95 m) and in NYHA class (three patients improved by two NYHA classes). During follow-up there were two deaths, in two of the four patients who had been initially considered for heart transplantation. CONCLUSION: In patients with functional MR the MitraClip procedure is safe, with both a high implantation and immediate in-hospital success rate. A longer follow-up suggests that the clinical benefit decreases or disappears completely in patients with more advanced heart disease, namely those denied transplantation or on the heart transplant waiting list.

Prognostic value of VEGF in patients submitted to percutaneous coronary intervention.

We examined the longitudinal changes of VEGF levels after percutaneous coronary intervention for predicting major adverse cardiac events (MACE) in coronary artery disease (CAD) patients. VEGF was measured in 94 CAD patients' serum before revascularization, 1-month and 1-year after. Independently of clinical presentation, patients had lower VEGF concentration than a cohort of healthy subjects (median, IQ: 15.9, 9.0-264 pg/mL versus 419, 212-758 pg/mL; P < 0.001) at baseline. VEGF increased to 1-month (median, IQ: 276, 167-498 pg/mL; P < 0.001) and remained steady to 1-year (median, IQ: 320, 173-497 pg/mL; P < 0.001) approaching control levels. Drug eluting stent apposition and previous medication intake produced a less steep VEGF evolution after intervention (P < 0.05). Baseline VEGF concentration <40.8 pg/mL conveyed increased risk for MACE in a 5-year follow-up. Results reflect a positive role of VEGF in recovery and support its importance in CAD prognosis.

Invasive assessment of the coronary microcirculation using the index of microcirculatory resistance: description and validation of an animal model.

INTRODUCTION: The index of microcirculatory resistance (IMR) enables/provides quantitative, invasive, and real-time assessment of coronary microcirculation status. AIMS: The primary aim of this study was to validate the assessment of IMR in a large animal model, and the secondary aim was to compare two doses of intracoronary papaverine, 5 and 10 mg, for induction of maximal hyperemia and its evolution over time. METHODS: Measurements of IMR were performed in eight pigs. Mean distal pressure (Pd) and mean transit time (Tmn) were measured at rest and at maximal hyperemia induced with intracoronary papaverine, 5 and 10 mg, and after 2, 5, 8 and 10 minutes. Disruption of the microcirculation was achieved by selective injection of 40-µm microspheres via a microcatheter in the left anterior descending artery. RESULTS: In each animal 14 IMR measurements were made. There were no differences between the two doses of papaverine regarding Pd response and IMR values - 11 ± 4.5 U with 5 mg and 10.6 ± 3 U with 10 mg (p=0.612). The evolution of IMR over time was also similar with the two doses, with significant differences from resting values disappearing after five minutes of intracoronary papaverine administration. IMR increased with disrupted microcirculation in all animals (41 ± 16 U, p=0.001). CONCLUSIONS: IMR provides invasive and real-time assessment of coronary microcirculation. Disruption of the microvascular bed is associated with a significant increase in IMR. A 5-mg dose of intracoronary papaverine is as effective as a 10-mg dose in inducing maximal hyperemia. After five minutes of papaverine administration there is no significant difference from resting hemodynamic status.

T lymphocytes alterations are associated with oxidized LDL, troponin T, white blood cells and C-reactive protein during acute myocardial infarction.

BACKGROUND: Auto-immune responses are associated with oxidized LDL (ox-LDL) release, a key factor in plaque destabilization. Data on the relationship between ox-LDL and T lymphocytes in human populations remains scarce. T cells also react with other molecules from the lesion and/or damage the myocardium. OBJECTIVE: The objective of the present study was to examine the relationship between circulating T lymphocytes, ox-LDL, markers of myocardial necrosis (cTnT), myocardial dysfunction (N-terminal pro-brain natriuretic peptide - NT-proBNP) and inflammation (C-reactive protein - CRP) in the setting of acute myocardial infarction. METHODS: A longitudinal study of 55 patients with ST-elevation myocardial infarction (STEMI) were evaluated at three time points: admission, 2 and 40 days following admission, together with 30 patients with stable angina (SA) and 56 subjects without coronary artery disease serving as controls (CTR). RESULTS: STEMI patients had maximal ox-LDL values and minimal levels of CD3+ T lymphocytes at admission, which was normalized during the recovery period. The increasing trend of CD3+ T cells was positively associated with an ox-LDL decline over time. CRP and cTnT longitudinal variations were negatively associated with the CD3+ T-cell increasing trend. These associations were not found in SA patients or controls. CONCLUSIONS: The associations found between CD3+ T lymphocytes, ox-LDL and cTnT suggest a specificity of the immune response in AMI towards arterial and myocardial inflammation and remodelling.

Serial changes in oxidized low-density lipoprotein associated with culprit vessel in ST-elevation myocardial infarction--a promising marker?

The aim of the present study was to investigate variations in oxidized LDL (oxLDL) at the onset of acute myocardial infarction (AMI) and over the recovery period, exploring their relationship with coronary disease severity. A follow-up of 50 AMI patients was evaluated against 25 healthy volunteers (reference group). The AMI patients were evaluated at three time points: at admission before the administration of IIb/IIIa inhibitors and angioplasty, and two and 40 days after intervention. Plasma oxLDL concentrations were measured by ELISA. oxLDL was found to be significantly higher in AMI patients in the acute phase relative to reference levels, decreasing progressively over the recovery period. The results also demonstrated that oxLDL levels were decreased in patients with the left circumflex artery (LCX) as culprit vessel compared to the left anterior descending coronary (LAD) or right coronary artery (RCA). The results highlight a significant increase in oxLDL concentration related to coronary artery disease severity, as conditions such as LCX lesions are usually associated with a favorable prognosis, contrasting with LAD-associated conditions that can compromise large areas of myocardium. The results thus suggest that oxLDL may constitute a promising marker in assessment of AMI evolution.

Variations in inflammatory markers in acute myocardial infarction: a longitudinal study.

Inflammation is now considered a key component of atherosclerosis, from fatty streak formation to plaque rupture, subsequent thrombosis, and progressive mechanical and dynamic obstruction. Rupture of the arterial plaque's fibrous cap exposes tissue factors present in the necrotic core, triggering inflammatory signaling, cell adhesion, and the coagulation cascade that eventually leads to thrombus. Cytokines and adhesion molecules are key components of these events that contribute to the development of an atherosclerotic plaque. The cytokine TNF-alpha and intercellular adhesion molecule-1 (ICAM-1) are indicators of basal inflammation, while the soluble forms of adhesion molecules such as CD40L and P-selectin indicate the extent of platelet activation. This study reports on the follow-up of 17 patients with confirmed acute myocardial infarction (AMI group) undergoing angioplasty and a matched control group of 16 patients without coronary artery disease as verified by coronary angiography. Patients from the AMI group were assessed at the onset of the acute coronary syndrome, within 24 h, before the administration of glycoprotein IIb/IIIa inhibitors and coronary angioplasty, and during the recovery period, two and 40 days after intervention. For both groups, clinical characteristics were documented and serum concentrations of soluble CD40L, P-selectin, ICAM-1, TNF-alpha, and conventional biochemical indicators were analyzed. For AMI patients, these indicators were recorded at study entry and during follow-up. Concentrations of cytokines and adhesion molecules were measured using commercial immunoassay (ELISA) kits. Significant variations in sP-selectin were observed relative to the control group. Immediately after myocardial infarction, sP-selectin levels rose markedly, followed by a sharp decrease two days later. After 40 days of recovery, sP-selectin levels rose again, returning to the initial values. Variations in sCD40L levels were not significant relative to controls. However, sCD40L concentrations tended to fall until the second day after infarction, followed by a rise, and by the 40th day of recovery levels were slightly higher than controls. Unlike sCD40L and sP-selectin, consistently higher levels of TNF-alpha relative to controls were observed, which were only significant after 40 days of recovery. No significant variations were observed for ICAM-1 serum concentrations in the AMI group. The variations observed demonstrate the role of inflammatory markers in AMI progression and highlight the importance of systemic inflammation in disease evolution. The increased concentration of sP-selectin at infarction onset is evidence of thrombosis and platelet activation. Later, during the recovery period when hemodynamic variables are returning to stability in part due to medication, rises in circulating levels of sCD40L and cytokines such as TNF-alpha may reflect the role of these molecules in the recovery of endothelial and myocardial tissues.