Cerebral Structure and Function in Stroke-free Patients with Atrial Fibrillation.

OBJECTIVES: Atrial fibrillation (AF) is associated with high risk of dementia and brain atrophy in stroke-free patients, but the mechanisms underlying this association remain unclear. We aimed to examine the brain volume and connectivity of paramount cognitive brain networks in stroke-free patients with AF without dementia. MATERIALS AND METHODS: Twenty-six stroke-free patients with AF and 26 age and sex-matched subjects without AF were submitted to a 3-tesla brain structural and functional MRI. An extensive clinical evaluation excluded stroke, dementia, low cardiac output, carotid stenosis and metabolic diseases without optimal therapy. We used CHA2DS2-VASc score to classify the cardiovascular risk factor burden and a broad neuropsychological battery to assess the cognitive performance. Voxel based morphometry analysis of. structural MRI defined whole-brain gray and white matter volumes. Finally, we used eco-plannar MRI images to compare the differences of functional connectivity of 7 large-scale resting-state networks between AF patients and controls. RESULTS: Taking into account the history of hypertension and heart failure, AF was associated to volume decrease of the right basal frontal lobe and right inferior cerebellum. Decreased connectivity of the ventral Default Mode Network (vDMN) was observed in the AF group. No disruption of connectivity was observed in the executive, visuospatial and salience networks. CONCLUSION: Individuals with AF without stroke or dementia have subtle reduction of gray and white matter, restricted to frontal areas and cerebellum. These patients show decreased vDMN connectivity, without other large-scale brain network disruption.

Default Mode Network Disruption in Stroke-Free Patients with Atrial Fibrillation.

BACKGROUND: Atrial fibrillation (AF) is a widely accepted risk for causing stroke. However, recent studies show AF as a risk factor for dementia, even without causing stroke. The mechanisms by which dementia develops in stroke-free patients with AF are still poorly understood and the association of AF with abnormal function of brain networks activities, such as the default mode network (DMN), has not been previously studied. We aimed to determine whether, in the absence of stroke and dementia, patients with AF have abnormal resting-state brain networks compared to controls without AF. METHODS: Twenty-one stroke-free patients with AF and 21 age- and sex-matched controls without AF underwent brain functional magnetic resonance imaging acquired at a 3.0 Tesla scanner. During the exam, the subjects were instructed to lie still with eyes closed. At first-level analysis, connectivity of the DMN was obtained for all subjects. Second-level analysis compared the DMN connectivity between AF patients and controls with a general linear model (two-sample t test, p < 0.05, False Discovery Rate corrected, minimum of 50 contiguous voxels). RESULTS: Patients with AF compared with controls showed decreased connectivity in regions of the DMN including the frontal lobe (left medial frontal gyrus, left superior frontal gyrus and anterior cingulate), left angular gyrus, and bilateral precuneus. CONCLUSIONS: Stroke-free patients with AF have evidence of abnormal DMN connectivity. This study adds evidence to the occurrence of cerebral dysfunction in patients with AF.

Determinants and prognostic value of in-hospital infection in patients waiting for permanent pacemaker implantation.

BACKGROUND: In-hospital delays in permanent cardiac pacemaker (PPM) implantation are common and may result in in-hospital infection among patients waiting for PPM implantation (pre-PPM-HI). This study investigated the predictors and prognostic impact of these events. METHODS: We retrospectively evaluated 905 consecutive patients (68.2 ± 16.0 years; 54% males) who underwent PPM implantation. Clinical characteristics, pre-PPM-HI and 30-day mortality were recorded and a risk score for pre-PPM-HI was generated using multivariable logistic regression coefficients. RESULTS: Eigthy-nine patients (10% of the sample) developed pre-PPM-HI. Multivariable logistic regression analysis identified urinary catheter use, complete atrioventricular block, implantation of temporary pacemaker and diabetes mellitus as independent predictors of pre-PPM-HI. The generated score (range 0-10.1) played a better role in predicting pre-PPM-HI than individual factors, yielding an area under the curve [95%CI] of 0.754 [0.705-0.803]. Patients with score ≥ 7.5 had 18-fold greater risk of developing pre-PPM-HI than those with score < 2.5. Furthermore, multivariable Cox-regression analysis showed that patients who developed pre-PPM-HI had greater 30-day mortality after PPM implantation (hazard ratio [95%CI] = 2.90 [1.18-7.16], p = 0.021) compared with their counterparts. CONCLUSIONS: This study reveals that pre-PPM-HI is an independent predictor of early mortality after PPM implantation. In addition, a clinical score developed from simple clinical variables accurately identified patients at high risk of pre-PPM-HI. In scenarios where delays in PPM implantation are unavoidable, such as reference hospitals with high demand, the use of this tool can potentially help in the hierarchy of patients and in the reduction of this adverse event.

Relationship of autonomic imbalance and circadian disruption with obesity and type 2 diabetes in resistant hypertensive patients.

BACKGROUND: Hypertension, diabetes and obesity are not isolated findings, but a series of interacting interactive physiologic derangements. Taking into account genetic background and lifestyle behavior, AI (autonomic imbalance) could be a common root for RHTN (resistant hypertension) or RHTN plus type 2 diabetes (T2D) comorbidity development. Moreover, circadian disruption can lead to metabolic and vasomotor impairments such as obesity, insulin resistance and resistant hypertension. In order to better understand the triggered emergence of obesity and T2D comorbidity in resistant hypertension, we investigated the pattern of autonomic activity in the circadian rhythm in RHTN with and without type 2 diabetes (T2D), and its relationship with serum adiponectin concentration. METHODS: Twenty five RHTN patients (15 non-T2D and 10 T2D, 15 males, 10 females; age range 34 to 70 years) were evaluated using the following parameters: BMI (body mass index), biochemical analysis, serum adiponectinemia, echocardiogram and ambulatory electrocardiograph heart rate variability (HRV) in time and frequency domains stratified into three periods: 24 hour, day time and night time. RESULTS: Both groups demonstrated similar characteristics despite of the laboratory analysis concerning T2D like fasting glucose, HbA1c levels and hypertriglyceridemia. Both groups also revealed disruption of the circadian rhythm: inverted sympathetic and parasympathetic tones during day (parasympathetic > sympathetic tone) and night periods (sympathetic > parasympathetic tone). T2D group had increased BMI and serum triglyceride levels (mean 33.7 ± 4.0 vs 26.6 ± 3.7 kg/m² - p = 0.00; 254.8 ± 226.4 vs 108.6 ± 48.7 mg/dL - p = 0.04), lower levels of adiponectin (6729.7 ± 3381.5 vs 10911.5 ± 5554.0 ng/mL - p = 0.04) and greater autonomic imbalance evaluated by HRV parameters in time domain compared to non-T2D RHTN patients. Total patients had HRV correlated positively with serum adiponectin (r = 0.37 [95% CI -0.04 - 1.00] p = 0.03), negatively with HbA1c levels (r = -0.58 [95% CI -1.00 - -0.3] p = 0.00) and also adiponectin correlated negatively with HbA1c levels (r = -0.40 [95% CI -1.00 - -0.07] p = 0.02). CONCLUSION: Type 2 diabetes comorbidity is associated with greater autonomic imbalance, lower adiponectin levels and greater BMI in RHTN patients. Similar circadian disruption was also found in both groups indicating the importance of lifestyle behavior in the genesis of RHTN.

P-wave duration is a predictor for long-term mortality in post-CABG patients.

Risk stratification in secondary prevention has emerged as an unmet clinical need in order to mitigate the Number-Needed-to-Treat and make expensive therapies both clinically relevant and cost-effective. P wave indices reflect atrial conduction, which is a sensitive marker for inflammatory, metabolic, and pressure overload myocardial cell remodeling; the three stimuli are traditional mechanisms for adverse clinical evolution. Accordingly, we sought to investigate the predictive role of P-wave indices to estimate residual risk in patients with chronic coronary artery disease (CAD). The cohort included 520 post-Coronary Artery Bypass Grafting patients with a median age of 60 years who were followed for a median period of 1025 days. The primary endpoint was long-term all-cause death. Cubic spline model demonstrated a linear association between P-wave duration and incidence rate of long-term all-cause death (p = 0.023). P-wave >110ms was a marker for an average of 425 days shorter survival as compared with P-wave under 80ms (Logrank p = 0.020). The Cox stepwise regression models retained P-wave duration as independent marker (HR:1.37; 95%CI:1.05-1.79,p = 0.023). In conclusion, the present study suggests that P-wave measurement may constitute a simple, inexpensive and accessible prognostic tool to be added in the bedside risk estimation in CAD patients.

Chronic Activation of γ2 AMPK Induces Obesity and Reduces ß Cell Function.

Despite significant advances in our understanding of the biology determining systemic energy homeostasis, the treatment of obesity remains a medical challenge. Activation of AMP-activated protein kinase (AMPK) has been proposed as an attractive strategy for the treatment of obesity and its complications. AMPK is a conserved, ubiquitously expressed, heterotrimeric serine/threonine kinase whose short-term activation has multiple beneficial metabolic effects. Whether these translate into long-term benefits for obesity and its complications is unknown. Here, we observe that mice with chronic AMPK activation, resulting from mutation of the AMPK γ2 subunit, exhibit ghrelin signaling-dependent hyperphagia, obesity, and impaired pancreatic islet insulin secretion. Humans bearing the homologous mutation manifest a congruent phenotype. Our studies highlight that long-term AMPK activation throughout all tissues can have adverse metabolic consequences, with implications for pharmacological strategies seeking to chronically activate AMPK systemically to treat metabolic disease.

Infarto do miocárdio conseqüente à endocardite infecciosa em bioprótese valvar / Acute myocardial infarction as a consequence of infective endocarditis in valvar bioprosthesis

Paciente do sexo masculino, branco, 16 anos, acompanhado no Serviço de Cardiologia da Unicamp, portador de prótese biológica mitral, foi internado com quadro clínico sugestivo de endocardite infecciosa. Faleceu após 2 semanas de evoluçäo, apesar de boa resposta á antibioticoterapia. A necrópsia demonstou alteraçöes da prótese biológica compatíveis com endocardite e oclusäo embólica da artéria coronária esquerda, no seu ramo circunflexo. Säo discutidas a ocorrência desta complicaçäo após a cirurgia de troca de válvula e a ausência de crescimento bacteriano em hemoculturas em casos de endocardite infecciosa

A sixteen year-old male,followed in the Unicamp Cardiology Clinic with a previous record of rheumatic heart disease and a biological mitral prosthesis, presented with infective endocarditis. In spite of a good initial response to antibiotic therapy, the patient died in two weeks. Autopsy disclosed endocarditis of the prosthetic valve and embolic occlusion of the circumflex branch of left coronary artery