The Impact of Sonothrombolysis on Left Ventricular Diastolic Function and Left Atrial Mechanics Preventing Left Atrial Remodeling in Patients With ST Elevation Acute Myocardial Infarction.

BACKGROUND: The diagnostic ultrasound-guided high mechanical index impulses during an intravenous microbubble infusion (sonothrombolysis) improve myocardial perfusion in acute ST segment elevation myocardial infarction, but its effect on left ventricular diastolic dysfunction (DD), left atrial (LA) mechanics and remodeling is unknown. We assessed the effect of sonothrombolysis on DD grade and LA mechanics. METHODS: One hundred patients (59 ± 10 years; 34% women) were randomized to receive either high mechanical index impulses plus percutaneous coronary intervention (PCI) (therapy group) or PCI only (control group) (n = 50 in each group). Diastolic dysfunction grade and LA mechanics were assessed immediately before and after PCI and at 48 to 72 hours, 1 month, and 6 months of follow-up. Diastolic dysfunction grades were classified as grades I, II, and III. The LA mechanics was obtained by two-dimensional speckle-tracking echocardiography-derived global longitudinal strain (GLS). RESULTS: As follow-up time progressed, increased DD grade was observed more frequently in the control group than in the therapy group at 1 month and 6 months of follow-up (all P < .05). The LA-GLS values were incrementally higher in the therapy group when compared with the control group at 48 to 72 hours, 24.0% ± 7.3% in the therapy group versus 19.6% ± 7.2% in the control group, P = .005; at 1 month, 25.3% ± 6.3% in the therapy group versus 21.5% ± 8.3% in the control group, P = .020; and at 6 months, 26.2% ± 8.7% in the therapy group versus 21.6% ± 8.5% in the control group, P = .015. The therapy group was less likely to experience LA remodeling (odds ratio, 2.91 [1.10-7.73]; P = .03). LA-GLS was the sole predictor of LA remodeling (odds ratio, 0.79 [0.67-0.94]; P = .006). CONCLUSION: Sonothrombolysis is associated with better DD grade and LA mechanics, reducing LA remodeling.

Coronary atherosclerotic burden assessed by SYNTAX scores and outcomes in surgical, percutaneous or medical strategies: a retrospective cohort study.

INTRODUCTION: Coronary atherosclerotic burden and SYNTAX Score (SS) are predictors of cardiovascular events. OBJECTIVES: To investigate the value of SYNTAX scores (SS, SYNTAX Score II (SSII) and residual SYNTAX Score (rSS)) for predicting cardiovascular events in patients with coronary artery disease (CAD). DESIGN: Retrospective cohort study. SETTING: Single tertiary centre. PARTICIPANTS: Medicine, Angioplasty or Surgery Study database patients with stable multivessel CAD and preserved ejection fraction. INTERVENTIONS: Patients with CAD undergoing coronary artery bypass graft (CABG), percutaneous coronary intervention (PCI) or medical treatment (MT) alone from January 2002 to December 2015. PRIMARY AND SECONDARY OUTCOMES: Primary: 5-year all-cause mortality. Secondary: composite of all-cause death, myocardial infarction, stroke and subsequent coronary revascularisation at 5 years. RESULTS: A total of 1719 patients underwent PCI (n=573), CABG (n=572) or MT (n=574) alone. The SS was not considered an independent predictor of 5-year mortality in the PCI (low, intermediate and high SS at 6.5%, 6.8% and 4.3%, respectively, p=0.745), CABG (low, intermediate and high SS at 5.7%, 8.0% and 12.1%, respectively, p=0.194) and MT (low, intermediate and high SS at 6.8%, 6.9% and 6.5%, respectively, p=0.993) cohorts. The SSII (low, intermediate and high SSII at 3.6% vs 7.9% vs 10.5%, respectively, p<0.001) was associated with a higher mortality risk in the overall population. Within each treatment strategy, SSII was associated with a significant 5-year mortality rate, especially in CABG patients with higher SSII (low, intermediate and high SSII at 1.8%, 9.7% and 10.0%, respectively, p=0.004) and in MT patients with high SSII (low, intermediate and high SSII at 5.0%, 4.7% and 10.8%, respectively, p=0.031). SSII demonstrated a better predictive accuracy for mortality compared with SS and rSS (c-index=0.62). CONCLUSIONS: Coronary atherosclerotic burden alone was not associated with significantly increased risk of all-cause mortality. The SSII better discriminates the risk of death. TRIAL REGISTRATION NUMBER: ISRCTN66068876.

Influence of Direct Thrombin Inhibitor and Low Molecular Weight Heparin on Platelet Function in Patients with Coronary Artery Disease: A Prospective Interventional Trial.

INTRODUCTION: The interaction between anticoagulants and platelet function is complex. Previous publications showed mixed results regarding the role of heparins in platelet aggregation. On the other hand, the direct thrombin inhibitor (DTI) dabigatran might enhance the risk of myocardial infarction in patients with atrial fibrillation, which could be related to increased platelet aggregability. METHODS: This was a prospective, interventional study of patients with chronic coronary artery disease (CAD) taking low-dose aspirin. The objective of the current study was to compare the effects of dabigatran versus enoxaparin on platelet aggregability. Subjects initially were on orally administered dabigatran for 5 days followed by subcutaneously administered enoxaparin after a 30-day washout period. Platelet function was assessed at baseline and after each intervention by multiple electrode aggregometry (MEA-ASPI) (primary endpoint), serum thromboxane B2 (TXB2), VerifyNow Aspirin™, and coagulation tests (secondary endpoints). RESULTS: Compared to baseline MEA-ASPI values, dabigatran increased platelet aggregation while enoxaparin decreased platelet aggregation (+ 5 U ± 24.1 vs - 6 U ± 22.2, respectively, p = 0.012). The TXB2 assay showed the same pattern (+ 2 pg/ml for dabigatran vs - 13 pg/ml for enoxaparin, p = 0.011). None of the additional tests showed significant differences between the groups. Individually, compared to baseline TXB2 results, enoxaparin significantly decreased platelet activation [33 (16.5-95) pg/mL vs 20 (10-52) pg/mL, respectively, p = 0.026], but no significant differences were observed with dabigatran. CONCLUSIONS: DTI and anti-Xa drugs exert opposite effects on platelet function. A significant decrease in platelet activation through COX1 (also known as prostaglandin G/H synthase 1) was observed with enoxaparin, but no significant differences in platelet function were observed with dabigatran. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02389582.

Lipid transfer to high-density lipoproteins in coronary artery disease patients with and without previous cerebrovascular ischemic events.

BACKGROUND: Patients with coronary artery disease (CAD) and previous ischemic cerebrovascular events (ICVE, ischemic stroke, or transitory ischemic attack) constitute a high-risk subgroup for cardiovascular outcomes. High-density lipoprotein cholesterol (HDL-C) levels are correlated with cardiovascular events. Lipid transfer to HDL affects structure size and HDL subclass profile. Impairment of this transfer could influence ischemic risk seen in patients with CAD + ICVE. The objective was to evaluate the HDL ability to receive the lipids in patients with CAD with or without ICVE. METHODS: Patients with CAD + ICVE (n = 60) and patients with CAD only (n = 60) were matched by age, sex, acute coronary syndromes (ACS) event type, and time elapsed between the ACS event and inclusion in the study. Lipid transfer to HDL was evaluated by incubating donor lipid nanoparticles labeled with radioactive unesterified cholesterol (UC) and esterified cholesterol (EC), phospholipid (PL), and triglyceride (TG) with whole plasma. After the chemical precipitation of non-HDL fractions and nanoparticles, the supernatant was counted for HDL radioactivity. RESULTS: CAD + ICVE group presented with impaired lipid transfer to HDL for PL (CAD + ICVE: 21.14 ± 2.7% vs CAD: 21.67 ± 3.1%, P = .03), TG (CAD + ICVE: 4.88 ± 0.97% vs CAD: 5.63 ± 0.92%, P = .002), and UC (CAD + ICVE: 5.55 ± 1.19% vs CAD: 6.16 ± 1.14%, P = .009). Lipid transfer to HDL was similar in both groups for EC. Adjusted models showed similar results. CONCLUSION: Patients with CAD and ICVE have reduced lipid transfer to HDL compared to those with CAD only. Dysfunctional HDL may account for the higher incidence of ischemic outcomes observed in this population.

Effect of ischemic preconditioning on cardiovascular outcomes in patients with symptomatic coronary artery disease: a cohort study.

BACKGROUND: Despite the powerful myocardial protection of ischemic preconditioning (IP) observed in experimental studies, it remains a challenge to observe such protection in humans. Thus, the aim of this study was to evaluate the possible effects of IP on clinical outcomes in patients with coronary artery disease (CAD). PATIENTS AND METHODS: In this cohort study, patients with multivessel CAD, preserved systolic ventricular function, and stable angina were prospectively selected. They underwent two sequential exercise stress tests (EST) to evaluate IP presence. IP was considered present if patients had an improvement in the time to the onset of 1.0-mm STsegment deviation in the second EST. The primary end point was the composite rate of cardiac death, nonfatal myocardial infarction, or revascularization during 1-year follow-up. Patients with (IP+) and without (IP-) the cardioprotective mechanism were compared regarding clinical end points. RESULTS: A total of 229 patients completed EST and had IP evaluated: 165 (72%) were IP+ and 64 (28%) were IP - patients. Of these, 218 patients had complete follow-up. At 1-year, event-free survival regarding the primary end point was 95.5 versus 83.6% (P = 0.0024) and event-free survival regarding cardiac death or myocardial infarction was 99.4 versus 91.7% (P=0.0020), respectively, in IP + and IP - groups. The unadjusted hazard ratio (IP + /IP-) for the primary end point was 4.63 (1.52-14.08). After multivariate analysis, IP was still significantly associated with better clinical outcomes (P = 0.0025). CONCLUSION: This data suggest that IP may contribute to better clinical outcomes in patients with ischemic heart disease.

Chagas' heart disease: gender differences in myocardial damage assessed by cardiovascular magnetic resonance.

BACKGROUND: Since a male-related higher cardiovascular morbidity and mortality in patients with Chagas' heart disease has been reported, we aimed to investigate gender differences in myocardial damage assessed by cardiovascular magnetic resonance (CMR). METHODS AND RESULTS: Retrospectively, 62 seropositive Chagas' heart disease patients referred to CMR (1.5 T) and with low probability of having significant coronary artery disease were included in this analysis. Amongst both sexes, there was a strong negative correlation between LV ejection fraction and myocardial fibrosis (male r = 0.64, female r = 0.73, both P < 0.001), with males showing significantly greater myocardial fibrosis (P = 0.002) and lower LV ejection fraction (P < 0.001) than females. After adjustment for potential confounders, gender remained associated with myocardial dysfunction, and 53% of the effect was mediated by myocardial fibrosis (P for mediation = 0.004). Also, the transmural pattern was more prevalent among male patients (23.7 vs. 9.9%, P < 0.001) as well as the myocardial heterogeneity or gray zone (2.2 vs. 1.3 g, P = 0.003). CONCLUSIONS: We observed gender-related differences in myocardial damage assessed by CMR in patients with Chagas' heart disease. As myocardial fibrosis and myocardial dysfunction are associated to cardiovascular outcomes, our findings might help to understand the poorer prognosis observed in males in Chagas' disease.

Diagnostic Ultrasound Impulses Improve Microvascular Flow in Patients With STEMI Receiving Intravenous Microbubbles.

BACKGROUND: Pre-clinical trials have demonstrated that, during intravenous microbubble infusion, high mechanical index (HMI) impulses from a diagnostic ultrasound (DUS) transducer might restore epicardial and microvascular flow in acute ST-segment elevation myocardial infarction (STEMI). OBJECTIVES: The purpose of this study was to test the safety and efficacy of this adjunctive approach in humans. METHODS: From May 2014 through September 2015, patients arriving with their first STEMI were randomized to either DUS intermittent HMI impulses (n = 20) just prior to emergent percutaneous coronary intervention (PCI) and for an additional 30 min post-PCI (HMI + PCI), or low mechanical index (LMI) imaging only (n = 10) for perfusion assessments before and after PCI (LMI + PCI). All studies were conducted during an intravenous perflutren lipid microsphere infusion. A control reference group (n = 70) arrived outside of the time window of ultrasound availability and received emergent PCI alone (PCI only). Initial epicardial recanalization rates prior to emergent PCI and improvements in microvascular flow were compared between ultrasound-treated groups. RESULTS: Median door-to-dilation times were 82 ± 26 min in the LMI + PCI group, 72 ± 15 min in the HMI + PCI group, and 103 ± 42 min in the PCI-only group (p = NS). Angiographic recanalization prior to PCI was seen in 12 of 20 HMI + PCI patients (60%) compared with 10% of LMI + PCI and 23% of PCI-only patients (p = 0.002). There were no differences in microvascular obstructed segments prior to treatment, but there were significantly smaller proportions of obstructed segments in the HMI + PCI group at 1 month (p = 0.001) and significant improvements in left ventricular ejection fraction (p < 0.005). CONCLUSIONS: HMI impulses from a diagnostic transducer, combined with a commercial microbubble infusion, can prevent microvascular obstruction and improve functional outcome when added to the contemporary PCI management of acute STEMI. (Therapeutic Use of Ultrasound in Acute Coronary Artery Disease; NCT02410330).

Myocardial tissue characterization in Chagas' heart disease by cardiovascular magnetic resonance.

BACKGROUND: Chagas' heart disease is an important public health problem in South America. Several aspects of the pathogenesis are not fully understood, especially in its subclinical phases. On pathology Chagas' heart disease is characterized by chronic myocardial inflammation and extensive myocardial fibrosis. The latter has also been demonstrated by late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR). In three clinical phases of this disease, we sought to investigate the presence of LGE, myocardial increase in signal intensity in T2-weighted images (T2W) and in T1-weighted myocardial early gadolinium enhancement (MEGE), previously described CMR surrogates for myocardial fibrosis, myocardial edema and hyperemia, respectively. METHODS: Fifty-four patients were analyzed. Sixteen patients with the indeterminate phase (IND), seventeen patients with the cardiac phase with no left ventricular systolic dysfunction (CPND), and twenty-one patients with the cardiac phase with left ventricular systolic dysfunction (CPD). All patients underwent 1.5 T CMR scan including LGE, T2W and MEGE image sequences to evaluate myocardial abnormalities. RESULTS: Late gadolinium enhancement was present in 72.2 % of all patients, in 12.5 % of IND, 94.1 % of the CPND and 100 % of the CPD patients (p < 0.0001). Myocardial increase in signal intensity in T2-weighted images (T2W) was present in 77.8 % of all patients, in 31.3 % of the IND, 94.1 % of the CPND and 100 % of the CPD patients (p < 0.0001). T1-weighted myocardial early gadolinium enhancement (MEGE) was present in 73.8 % of all patients, in 25.0 % of the IND, 92.3 % of the CPND and 94.1 % of the CPD (p < 0.0001). A good correlation between LGE and T2W was observed (r = 0.72, and p < 0.001). CONCLUSIONS: Increase in T2-weighted (T2W) myocardial signal intensity and T1-weighted myocardial early gadolinium enhancement (MEGE) can be detected by CMR in patients throughout all phases of Chagas' heart disease, including its subclinical presentation (IND). Moreover, those findings were parallel to myocardial fibrosis (LGE) in extent and location and also correlated with the degree of Chagas' heart disease clinical severity. These findings contribute to further the knowledge on pathophysiology of Chagas' heart disease, and might have therapeutic and prognostic usefulness in the future.

Alterations in lipid transfers to HDL associated with the presence of coronary artery disease in patients with type 2 diabetes mellitus.

BACKGROUND: We previously showed that unesterified-cholesterol transfer to high-density lipoprotein (HDL), a crucial step in cholesterol esterification and role in reverse cholesterol transport, was diminished in non-diabetic patients with coronary artery disease (CAD). The aim was to investigate whether, in patients with type 2 diabetes mellitus (T2DM), the occurrence of CAD was also associated with alterations in lipid transfers and other parameters of plasma lipid metabolism. METHODS: Seventy-nine T2DM with CAD and 76 T2DM without CAD, confirmed by cineangiography, paired for sex, age (40-80 years), BMI and without statin use, were studied. In vitro transfer of four lipids to HDL was performed by incubating plasma of each patient with a donor emulsion containing radioactive lipids during 1 h at 37 °C. Lipids transferred to HDL were measured after chemical precipitation of non-HDL fractions and the emulsion. Results are expressed as % of total radioactivity of each lipid in HDL. RESULTS: In T2DM + CAD, LDL-cholesterol and apo B were higher than in T2DM. T2DM + CAD also showed diminished transfer to HDL of unesterified cholesterol (T2DM + CAD = 7.6 ± 1.2; T2DM = 8.2 ± 1.5%, p < 0.01) and of cholesteryl-esters (4.0 ± 0.6 vs 4.3 ± 0.7, p < 0.01). Unesterified cholesterol in the non-HDL serum fraction was higher in T2DM + CAD (0.93 ± 0.20 vs 0.85 ± 0.15, p = 0.02) and CETP concentration was diminished (2.1 ± 1.0 vs 2.5 ± 1.1, p = 0.02). Lecithin-cholesterol acyltransferase activity, HDL size and lipid composition were equal. CONCLUSION: Reduction in T2DM + CAD of cholesterol transfer to HDL may impair cholesterol esterification and reverse cholesterol transport and altogether with simultaneous increased plasma unesterified cholesterol may facilitate CAD development in T2DM.

Late Outcome of a Randomized Study on Oral Magnesium for Premature Complexes / Evolução Tardia de Estudo Randomizado com Uso de Magnésio Via Oral em Extrassístoles Sintomáticas

Background: Ventricular and supraventricular premature complexes (PC) are frequent and usually symptomatic. According to a previous study, magnesium pidolate (MgP) administration to symptomatic patients can improve the PC density and symptoms. Objective: To assess the late follow-up of that clinical intervention in patients treated with MgP or placebo. Methods: In the first phase of the study, 90 symptomatic and consecutive patients with PC were randomized (double-blind) to receive either MgP or placebo for 30 days. Monthly follow-up visits were conducted for 15 months to assess symptoms and control electrolytes. 24-hour Holter was performed twice, regardless of symptoms, or whenever symptoms were present. In the second phase of the study, relapsing patients, who had received MgP or placebo (crossing-over) in the first phase, were treated with MgP according to the same protocol. Results: Of the 45 patients initially treated with MgP, 17 (37.8%) relapsed during the 15-month follow-up, and the relapse time varied. Relapsing patients treated again had a statistically significant reduction in the PC density of 138.25/hour (p < 0.001). The crossing-over patients reduced it by 247/hour (p < 0.001). Patients who did not relapse, had a low PC frequency (3 PC/hour). Retreated patients had a 76.5% improvement in symptom, and crossing-over patients, 71.4%. Conclusion: Some patients on MgP had relapse of symptoms and PC, indicating that MgP is neither a definitive nor a curative treatment for late follow-up. However, improvement in the PC frequency and symptoms was observed in the second phase of treatment, similar to the response in the first phase of treatment. .

Fundamento: Extrassístoles (ES) ventriculares e supraventriculares são frequentes e muitas vezes sintomáticas. Segundo estudo prévio, a administração de pidolato de magnésio (PMg) a pacientes sintomáticos pode resultar na melhora da densidade das ES e dos sintomas relacionados. Objetivo: Avaliar os resultados dessa intervenção clínica inicial no seguimento tardio de pacientes recebendo PMg ou placebo. Métodos: Noventa pacientes com ES, sintomáticos e consecutivos foram randomizados (duplo-cego) para receber PMg ou placebo por 30 dias. Visitas mensais de seguimento (15 meses) foram realizadas para avaliar a sintomatologia e controlar eletrólitos. O Holter de 24 horas foi realizado sempre que sintomáticos, ou duas vezes, independentemente dos sintomas. Na segunda fase do estudo, os pacientes cujos sintomas recidivassem, seja do grupo PMg ou placebo (crossing over), receberam PMg seguindo-se o mesmo protocolo. Resultados: Dos 45 pacientes que receberam inicialmente o PMg, 17 (37,8%) apresentaram recidiva dos sintomas em tempo variável nos 15 meses. Os pacientes com recidiva e tratados uma segunda vez apresentaram redução estatisticamente significante na densidade de ES de 138,25/hora (p < 0,001). Os pacientes de crossing reduziram em 247/hora (p < 0,001). Nos pacientes que não apresentaram recidiva, a frequência de ES foi baixa (3 ES/hora). A melhora dos sintomas foi de 76,5% nos retratados e de 71,4% nos de crossing. Conclusão: Houve recorrência de sintomas e das ES em alguns pacientes que usaram PMg, deixando claro não ser essa uma forma de tratamento definitivo ou curativo no seguimento tardio. Contudo, houve também melhora na frequência de ES e de sintomas em uma segunda etapa de tratamento, semelhante à resposta na primeira etapa. .

Long-term follow-up of a randomized, controlled clinical trial of three therapeutic strategies for multivessel stable coronary artery disease in women.

OBJECTIVES: Coronary artery disease is the leading cause of death in women. The proposed treatments for women are similar to those for men. However, in women with multivessel stable coronary artery disease and normal left ventricular function, the best treatment is unknown. METHODS: A post hoc analysis of the MASS II study with 10 years of follow-up, mean (standard deviation) 6.8 (3.7) years, enrolled between May 1995 and May 2000, evaluated 188 women with chronic stable multivessel coronary artery disease who underwent medical treatment, percutaneous coronary intervention or coronary artery bypass graft surgery. Primary end-points were incidence of total mortality, Q-wave myocardial infarction, or refractory angina. Data were analysed according to the intention-to-treat principle. RESULTS: Women treated with percutaneous coronary intervention and medical treatment had more primary events than those treated with coronary artery bypass graft surgery, respectively, of 34, 44 and 22% (P = 0.003). Survival rates at 10 years were 72% for coronary artery bypass graft surgery, 72% for percutaneous coronary intervention and 56% for medical treatment (P = 0.156). For the composite end-point, Cox regression analysis adjusted for age, diabetes, hypertension, treatment allocation, prior myocardial infarction, smoking, number of vessels affected and total cholesterol, had a higher incidence of primary events with medical treatment than with coronary artery bypass graft surgery [hazard ratio (HR) = 2.38 (95% confidence interval (CI): 1.40-4.05); P = 0.001], a lower incidence with percutaneous coronary intervention than with medical treatment [HR = 0.60 (95% CI: 0.38-0.95); P = 0.031] but no differences between coronary artery bypass graft surgery and percutaneous coronary intervention. Regarding death, a protective effect was observed with percutaneous coronary intervention compared with medical treatment [HR = 0.44 (95% CI: 0.21-0.90); P = 0.025]. CONCLUSIONS: Percutaneous coronary intervention and coronary artery bypass graft surgery compared with medical treatment had better results after 10 years of follow-up.

Monitor intracardíaco implantável (AngelMed Guardian) para detectação de isquemia miocárdica / Implantable intracardiac monitor (AngelMed Guardian) for the detection of myocardial ischemia

A maioria das mortes por infarto agudo do miocárdio (IAM) ocorre nas primeiras horas da manifestação da oclusão coronariana; portanto, em geral, acontece fora do ambiente hospitalar. O tempo decorrido entre o início da oclusão coronariana até o tratamento ser realizado é diretamente proporcional à morbidade e mortalidade cardiovascular. O prognóstico dos pacientes depende da rapidez em chegar a um hospital e quão rápido o hospital possa diagnosticar o IAM e realizar reperfusão coronariana. Estudos indicam que o tempo médio decorrido entre o início da apresentação de sintomas de IAM e a chegada do paciente ao hospital permanece entre 2 e 3 horas; no entanto, sabe-se que um terço dos IAMs é assintomático e, nesses casos, o diagnóstico é realizado posteriormente por achados clínicos através de exames complementares. Para tanto, o diagnóstico precoce é essencial para melhorar os resultados terapêuticos. Um dispositivo que monitore o coração, continuamente, via uma conexão intracardíaca, pode ser benéfico para indivíduos com doença arterial coronária (DAC) e alto risco cardiovascular, por alertá-los em tempo real quando alterações eletrocardiográficas agudas no segmento ST são detectadas (indicando oclusão coronariana aguda). Estudos nos EUA e no Brasil demonstraram que indivíduos que receberam o monitor intracardíaco implantável (MICI) apresentaram tempo médio de resposta, entre o início de um evento coronariano oclusivo e a chegada ao hospital, de 19,5 minutos, mostrando redução substancial no tempo habitual de resposta de 2-3 horas. Outros estudos demonstraram a segurança, a viabilidade e o potencial benefício de se utilizar um dispositivo de monitoramento intracardíaco para alertar o paciente de eventos coronarianos, mesmo que eles eventos sejam assintomáticos. Dessa forma, um sistema com capacidade de alertar em tempo real poderia antecipar a terapia de reperfusão e potencialmente prevenir, em vez de interromper, IAM em pacientes com DAC...

Effects of cardiac resynchronization therapy on muscle sympathetic nerve activity.

INTRODUCTION: Muscle sympathetic nerve activity (MSNA) is an independent prognostic marker in patients with heart failure (HF). Therefore, its relevance to the treatment of HF patients is unquestionable. OBJECTIVES: In this study, we investigated the effects of cardiac resynchronization therapy (CRT) on MSNA response at rest and during exercise in patients with advanced HF. METHODS: We assessed 11 HF patients (51 ± 3.4 years; New York Heart Association class III-IV; left ventricular ejection fraction 27.8 ± 2.2%; optimal medical therapy) submitted to CRT. Evaluations were made prior to and 3 months after CRT. MSNA was performed at rest and during moderate static exercise (handgrip). Peak oxygen consumption (VO2 ) was evaluated by means of cardiopulmonary exercise test. HF patients with advanced NYHA class without CRT and healthy individuals were also studied. RESULTS: CRT reduced MSNA at rest (48.9 ± 11.1 bursts/min vs 33.7 ± 15.3 bursts/min, P < 0.05) and during handgrip exercise (MSNA 62.3 ± 13.1 bursts/min vs 46.9 ± 14.3 bursts/min, P < 0.05). Among HF patients submitted to CRT, the peak VO2 increased (12.9 ± 2.8 mL/kg/min vs 16.5 ± 3.9 mL/kg/min, P < 0.05) and an inverse correlation between peak VO2 and resting MSNA (r = -0.74, P = 0.01) was observed. CONCLUSIONS: In patients with advanced HF and severe systolic dysfunction: (1) a significant reduction of MSNA (at rest and during handgrip) occurred after CRT, and this behavior was significantly superior to HF patients receiving only medical therapy; (2) MSNA reduction after CRT had an inverse correlation with O2 consumption outcomes.

Late outcome of a randomized study on oral magnesium for premature complexes.

BACKGROUND: Ventricular and supraventricular premature complexes (PC) are frequent and usually symptomatic. According to a previous study, magnesium pidolate (MgP) administration to symptomatic patients can improve the PC density and symptoms. OBJECTIVE: To assess the late follow-up of that clinical intervention in patients treated with MgP or placebo. METHODS: In the first phase of the study, 90 symptomatic and consecutive patients with PC were randomized (double-blind) to receive either MgP or placebo for 30 days. Monthly follow-up visits were conducted for 15 months to assess symptoms and control electrolytes. 24-hour Holter was performed twice, regardless of symptoms, or whenever symptoms were present. In the second phase of the study, relapsing patients, who had received MgP or placebo (crossing-over) in the first phase, were treated with MgP according to the same protocol. RESULTS: Of the 45 patients initially treated with MgP, 17 (37.8%) relapsed during the 15-month follow-up, and the relapse time varied. Relapsing patients treated again had a statistically significant reduction in the PC density of 138.25/hour (p < 0.001). The crossing-over patients reduced it by 247/hour (p < 0.001). Patients who did not relapse, had a low PC frequency (3 PC/hour). Retreated patients had a 76.5% improvement in symptom, and crossing-over patients, 71.4%. CONCLUSION: Some patients on MgP had relapse of symptoms and PC, indicating that MgP is neither a definitive nor a curative treatment for late follow-up. However, improvement in the PC frequency and symptoms was observed in the second phase of treatment, similar to the response in the first phase of treatment.

The involvement of multiple thrombogenic and atherogenic markers in premature coronary artery disease

OBJECTIVE: To examine the association of atherogenic and thrombogenic markers and lymphotoxin-alfa gene mutations with the risk of premature coronary disease. METHODS: This cross-sectional, case-control, age-adjusted study was conducted in 336 patients with premature coronary disease (<50 years old) and 189 healthy controls. The control subjects had normal clinical, resting, and exercise stress electrocardiographic assessments. The coronary disease group patients had either angiographically documented disease (>50% luminal reduction) or a previous myocardial infarction. The laboratory data evaluated included thrombogenic factors (fibrinogen, protein C, protein S, and antithrombin III), atherogenic factors (glucose and lipid profiles, lipoprotein(a), and apolipoproteins AI and B), and lymphotoxin-alfa mutations. Genetic variability of lymphotoxin-alfa was determined by polymerase chain reaction analysis. RESULTS: Coronary disease patients exhibited lower concentrations of HDL-cholesterol and higher levels of glucose, lipoprotein(a), and protein S. The frequencies of AA, AG, and GG lymphotoxin-alfa mutation genotypes were 55.0%, 37.6%, and 7.4% for controls and 42.7%, 46.0%, and 11.3% for coronary disease patients (p = 0.02), respectively. Smoking, dyslipidemia, family history, and lipoprotein(a) and lymphotoxin-alfa mutations in men were independent variables associated with coronary disease. The area under the curve (C-statistic) increased from 0.779 to 0.802 (p<0.05) with the inclusion of lipoprotein(a) and lymphotoxin-alfa mutations in the set of conventional risk factors. CONCLUSIONS: The inclusion of lipoprotein(a) and lymphotoxin-alfa mutations in the set of conventional risk factors showed an additive but small increase in the risk prediction of premature coronary disease. .

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.

Prognostic value of qualitative and quantitative vasodilator stress myocardial perfusion echocardiography in patients with known or suspected coronary artery disease.

BACKGROUND: Quantification of myocardial blood flow reserve in patients with coronary artery disease using real-time myocardial perfusion echocardiography (RTMPE) has been demonstrated to further improve accuracy over the analysis of wall motion and qualitative analysis of myocardial perfusion. The aim of this study was to determine the prognostic value of qualitative and quantitative analyses obtained by RTMPE in patients with known or suspected coronary artery disease. METHODS: From March 2003 to December 2008, 227 consecutive patients with normal left ventricular function who underwent RTMPE were prospectively studied. Replenishment velocity reserve (ß) and myocardial blood flow reserve were derived from RTMPE. Primary outcomes were cardiac death, myocardial infarction and unstable angina with need for urgent coronary revascularization, and secondary outcomes were coronary bypass graft surgery or angioplasty. RESULTS: During a median follow-up period of 32 months (range, 5 days to 6.9 years), 19 major events (two deaths, six myocardial infarctions, and 11 episodes of unstable angina) and 46 total events occurred. Wall motion (hazard ratio [HR], 2.8; 95% confidence interval [CI], 1.4-5.6; P = .003) and qualitative myocardial perfusion analysis (HR, 4.3; 95% CI, 2.1-8.5; P < .001) were predictors of total events but not primary events. Abnormal myocardial blood flow reserve and abnormal ß reserve were predictors of total events (HR, 8.1; 95% CI, 3-21; P < .001; and HR, 16.5; 95% CI, 5.5-49; P < .001) and primary events (HR, 3.8; 95% CI, 1-15; P = .048; and HR, 8.7; 95% CI, 1.8-40; P = .005). On multivariate analysis, only abnormal ß reserve was an independent predictor of total (HR, 10.6; 95% CI, 2.5-43; P = .001) and primary (HR, 10.5; 95% CI, 1.5-6; P = .015) events. Abnormal ß reserve added incremental value in predicting primary events (χ(2) = 2.0-13.2; P = .014). CONCLUSIONS: Quantitative adenosine stress RTMPE added independent and additional prognostic information over wall motion and qualitative myocardial perfusion analysis in patients with known or suspected coronary artery disease and normal left ventricular function.

Prognostic value of coronary and microvascular flow reserve in patients with nonischemic dilated cardiomyopathy.

BACKGROUND: Coronary and microvascular blood flow reserve have been established as important predictors of prognosis in patients with cardiovascular disease. The aim of this study was to assess the value of coronary flow velocity reserve (CFVR) and real-time myocardial perfusion echocardiography (RTMPE) for predicting events in patients with nonischemic dilated cardiomyopathy. METHODS: One hundred ninety-five patients (mean age 54 ± 12 years; 66% men) with dilated cardiomyopathy (left ventricular ejection fraction < 35% and no obstructive coronary disease on invasive angiography or multidetector computed tomography) who underwent dipyridamole stress (0.84 mg/kg over 10 min) RTMPE were prospectively studied. CFVR was calculated as the ratio of hyperemic to baseline peak diastolic velocities in the distal left anterior coronary artery. The replenishment velocity (ß), plateau of acoustic intensity (A(N)), and myocardial blood flow reserve were obtained from RTMPE. RESULTS: Mean CFVR was 2.07 ± 0.52, mean A(N) reserve was 1.05 ± 0.09, mean ß reserve was 2.05 ± 0.39, and mean myocardial blood flow reserve (A(N) × ß) was 2.15 ± 0.48. During a median follow-up period of 29 months, 45 patients had events (43 deaths and two urgent transplantations). Independent predictors of events were left atrial diameter (relative risk, 1.16; 95% confidence interval, 1.08-1.26; P < .001) and ß reserve ≤ 2.0 (relative risk, 3.22; 95% confidence interval, 1.18-8.79; P < .001). After adjustment for ß reserve, CFVR and myocardial blood flow reserve no longer had predictive value. Left atrial diameter added prognostic value over clinical factors and left ventricular ejection fraction (χ2 = 36.8-58.5, P < .001). Beta reserve added additional power to the model (χ2 = 70.2, P < .001). CONCLUSIONS: Increased left atrial diameter and depressed ß reserve were independent predictors of cardiac death and transplantation in patients with nonischemic dilated cardiomyopathy. Beta reserve by RTMPE provided incremental predictive value beyond that provided by current known prognostic clinical and echocardiographic factors.

Atorvastatin treatment improves myocardial and peripheral blood flow in familial hypercholesterolemia subjects without evidence of coronary atherosclerosis.

BACKGROUND: Hypercholesterolemia induces early microcirculatory functional and structural alterations that are reversible by cholesterol reduction. Real time myocardial contrast echocardiography (RTMCE) and vascular ultrasound evaluate the effects of hyperlipidemia on peripheral and central blood flow reserve. This study investigated the effects of lipid-lowering therapy on coronary and peripheral artery circulation in patients with familial hypercholesterolemia (FH). METHODS: RTMCE and vascular ultrasound were performed in 10 healthy volunteers (validation group) at baseline and after 12-week clinical observation, and in 16 age- and sex-matched FH patients without obstructive coronary artery disease (CAD) by computed tomography angiography at baseline and after 12-week atorvastatin treatment. Indexes of relative myocardial blood flow (MBF) were obtained at rest and during adenosine infusion. RESULTS: In validation group, there was no significant difference between flow-mediated dilation (FMD) at baseline and after 12 weeks (0.15 ± 0.02 vs. 0.14 ± 0.03; P = 0.39). Similarly, no differences were observed in MBF reserve at baseline and after 12 weeks (3.31 ± 0.63 vs. 3.48 ± 0.89; P = 0.89). FMD was blunted in FH patients, at baseline, as compared with validation group (0.08 ± 0.04 vs. 0.15 ± 0.02; P < 0.001) and became similar to that group (0.13 ± 0.05 vs. 0.14 ± 0.03; P = 0.07) after treatment. MBF reserve was blunted at baseline in FH patients in comparison with the validation group (2.78 ± 0.71 vs. 3.31 ± 0.63; P = 0.003). After treatment, MBF reserve values were no longer different (3.43 ± 0.66 and 3.48 ± 0.89; P = 0.84, respectively, for FH and validation groups). CONCLUSION: Patients with FH and no obstructive CAD have blunted MBF reserve and lower FMD values as compared with healthy volunteers. Both FMD and MBF reserve were normalized after atorvastatin treatment.