Aging dilates atrium and pulmonary veins: implications for the genesis of atrial fibrillation

BACKGROUNDS: Aging plays a critical role in the pathophysiology of atrial fibrillation (AF). The left atrium (LA) and pulmonary veins (PVs) are essential components for the genesis and maintenance of AF. The purpose of this study was to investigate the effects of aging on the AF substrate and the initiator (PVs). METHODS: A total of 180 patients undergoing multidetector CT were enrolled and classified into six groups according to the decade of their age. LA, LA appendage (LAA), and orifice of the four PVs were measured. RESULTS: The LA anterior-posterior diameter and wall thickness became increased with aging after the age of 50 years (p < 0.001). Similarly, the LAA and four PV trunks also became dilated after the patients were > 50 years old (p < 0.001). The anterior wall was consistently thicker than the posterior wall in each group. Aging also increased both anterior and posterior wall thickness after the patients became > 50 years old. However, LA diameter, PV diameter, and LA wall thickness in the patients aged 70 to 79 years and > 80 years did not significantly differ. Age correlated well with the four PVs, LA diameter, and wall thickness with linear regression. CONCLUSIONS: Age significantly determines LA and PV structures. These findings show the important contributing effects involved in aging-induced AF in the general population.     

Exudative pleural effusion following thoracoscopic pulmonary vein isolation for paroxysmal atrial fibrillation

Surgical treatments for atrial fibrillation are gaining popularity. We present a case of post-cardiac injury syndrome following thoracoscopic pulmonary vein isolation.     

The impact of new-onset atrial fibrillation on in-hospital mortality following cardiac surgery

BACKGROUND: The impact of new-onset postoperative atrial fibrillation (NAF) on in-hospital mortality (IHM) following cardiac surgery is unknown. METHODS: All patients without preoperative atrial fibrillation undergoing isolated coronary artery bypass graft surgery (CABG) and concomitant CABG and valve surgery were identified (n = 7,347). The association between NAF and IHM was determined using logistic regression modeling. Also, propensity score analysis was used to create two matched subgroups of patients with and without NAF (n = 2,015 in each group). The secondary outcomes examined were stroke, myocardial infarction (MI), intra-aortic balloon pump use, GI complications, deep sternal wound infection (DSWI), septicemia, renal failure, and length of stay. RESULTS: NAF developed in 2,047 patients (27.9%). NAF was not an independent predictor of IHM (odds ratio, 0.8; 95% confidence interval, 0.6 to 1.2; p = 0.3). In multivariate analysis, NAF was associated with age >/= 60 years, combined procedures, preoperative MI within 7 days of surgery, COPD, cerebrovascular disease, and male gender. Propensity-adjusted results revealed no difference in IHM between NAF vs no-NAF patients (2.9% vs 3.5%, respectively; Bonferroni-corrected p = 0.99). However, GI complications (4.2% vs 2.1%), DSWI (1.3% vs 0.4%), septicemia (4.0% vs 1.1%), renal failure (7.6% vs 4.3%), and length of stay (8 days vs 6 days) were significantly increased in patients with NAF. CONCLUSION: NAF following cardiac surgery is not associated with increased IHM.     

Elevated platelet microparticle levels in nonvalvular atrial fibrillation: relationship to p-selectin and antithrombotic therapy

BACKGROUND: Platelet microparticles (PMPs), are procoagulant membrane vesicles that are derived from activated platelets, the levels of which are elevated in patients with hypertension, coronary artery disease (CAD), diabetes, and stroke, all of which are conditions that lead to (and are associated with) atrial fibrillation (AF). We hypothesized the following: (1) PMP levels are elevated in patients with AF compared to levels in both healthy control subjects (ie, patients without cardiovascular diseases who are in sinus rhythm) and disease control subjects (ie, patients with hypertension, CAD, diabetes or stroke, but who are in sinus rhythm); (2) PMP levels correlate with levels of soluble P-selectin (sP-selectin) [a marker of platelet activation]; and (3) PMP levels are related to the underlying factors in patients with AF that contribute to the overall risk of stroke secondary to AF. METHODS: We performed a case-control study of 70 AF patients, 46 disease control subjects and 33 healthy control subjects. Peripheral venous levels of PMP and sP-selectin were analyzed by flow cytometry and enzyme-linked immunosorbent assay, respectively. RESULTS: Both AF patients and disease control subjects had significantly higher levels of PMPs (p < 0.001) and sP-selectin (p = 0.001) compared to healthy control subjects, but there was no difference between AF patients and disease control subjects. There was no difference in PMP levels between patients with paroxysmal and permanent AF (p = 0.581), and between those receiving therapy with aspirin and warfarin (p = 0.779). No significant correlation was observed between PMP and sP-selectin levels (p = 0.463), and the clinical characteristics that contribute to increased stroke risk in patients with AF. On stepwise multiple regression analysis in the combined cohort of AF patients plus disease control subjects, the presence/absence of AF was not an independent determinant of PMP and sP-selectin levels. CONCLUSION: There is evidence of platelet activation (ie, high PMP and sP-selectin levels) in AF patients, but this is likely to be due to underlying cardiovascular diseases rather than the arrhythmia per se.     

Hyperuricemia and incident atrial fibrillation in a normotensive elderly population in Taiwan

Background and aimAtrial fibrillation (AF) is an important cardiovascular disease in the elderly. The association between hyperuricemia and AF is unclear. Therefore, we aimed to investigate the prospective relationship between uric acid and development of AF in a nationally representative cohort of elderly people.Methods and resultsA total of 1485 elderly people (age ≥ 65 yrs) from the Elderly Nutrition and Health Survey in Taiwan (1999–2000) were without AF on “electrocardiography” at baseline. Incident AF events (International Classification of Diseases, Ninth Revision, Clinical Modification, ICD-9-CM: 427.31) were identified using data from the National Health Insurance Dataset. Hyperuricemia was defined as levels of uric acid >7.0 mg/dL in men and 6.0 mg/dL in women. A Cox proportional hazards model was used to evaluate the association between hyperuricemia and incident AF.The follow-up period was from 1999 to 2000 to 2008. During the follow-up period (median: 9.16 yrs), 90 AF events occurred (44 in men and 46 in women). Older age, elevated systolic blood pressure, being an ex-smoker, and high uric acid were positively associated with incident AF. Hyperuricemia was positively associated with incident AF in normotensive (age-adjusted hazard ratio (HR): 2.65 and 95% confidence intervals: 1.05–6.69), but not in (1.20:0.74–1.94) hypertensive individuals (systolic blood pressure ≥130 or diastolic blood pressure ≥85 or using hypertensive medicine). A significant association between hyperuricemia and AF (3.78; 1.24–11.59) remained after adjusting for other potential confounders among normotensive older persons.ConclusionHyperuricemia is associated with the development of AF in elderly people with normal blood pressure.     

Influence of atrial fibrillation on plasma von willebrand factor, soluble E-selectin, and N-terminal pro B-type natriuretic peptide levels in systolic heart failure

BACKGROUND: Endothelial dysfunction is present in patients with heart failure (HF) due to left ventricular systolic dysfunction, as well as in patients with atrial fibrillation (AF) who have normal cardiac function. It is unknown whether AF influences the degree of endothelial dysfunction in patients with systolic HF. METHODS: We measured levels of plasma von Willebrand factor (vWF) and E-selectin (as indexes of endothelial damage/dysfunction and endothelial activation, respectively; both enzyme-linked immunosorbent assay) in patients with AF and HF (AF-HF), who were compared to patients with sinus rhythm and HF (SR-HF), as well as in age-matched, healthy, control subjects. We also assessed the relationship of vWF and E-selectin to plasma N-terminal pro B-type natriuretic peptide (NTpro-BNP), a marker for HF severity and prognosis. RESULTS: One hundred ninety patients (73% men; mean age, 69.0 +/- 10.1 years [+/- SD]) with systolic HF were studied, who were compared to 117 healthy control subjects: 52 subjects (27%) were in AF, while 138 subjects (73%) were in sinus rhythm. AF-HF patients were older than SR-HF patients (p = 0.046), but left ventricular ejection fraction and New York Heart Association class were similar. There were significant differences in NT-proBNP (p < 0.0001) and plasma vWF (p = 0.003) between patients and control subjects. On Tukey post hoc analysis, AF-HF patients had significantly increased NT-proBNP (p < 0.001) and vWF (p = 0.0183) but not E-selectin (p = 0.071) levels when compared to SR-HF patients. On multivariate analysis, the presence of AF was related to plasma vWF levels (p = 0.018). Plasma vWF was also significantly correlated with NT-proBNP levels (Spearman r = 0.139; p = 0.017). CONCLUSIONS: There is evidence of greater endothelial damage/dysfunction in AF-HF patients when compared to SR-HF patients. The clinical significance of this is unclear but may have prognostic value.     

Usefulness of the plasma glucose concentration-to-HbA1c ratio in predicting clinical outcomes during acute illness with extreme hyperglycaemia

AimsTo evaluate the correlation between the plasma glucose-to-glycated haemoglobin ratio (GAR) and clinical outcome during acute illness.MethodsThis retrospective observational cohort study enrolled 661 patients who visited the emergency department of our hospital between 1 July 2008 and 30 September 2010 with plasma glucose concentrations > 500 mg/dL. Systolic blood pressure, heart rate, white blood cells, neutrophils, haematocrit, blood urea nitrogen, serum creatinine, liver function and plasma glucose concentration were recorded at the initial presentation to the emergency department. Data on glycated haemoglobin over the preceding 6 months were reviewed from our hospital database. The glucose-to-HbA_1c ratio (GAR) was calculated as the plasma glucose concentration divided by glycated haemoglobin.ResultsThe GAR of those who died was significantly higher than that of the survivors (81.0 ± 25.9 vs 67.6 ± 25.0; P < 0.001). There was a trend towards a higher 90-day mortality rate in patients with higher GARs (log-rank test P < 0.0001 for trend). On multivariate Cox regression analysis, the GAR was significantly related to 90-day mortality (hazard ratio [HR] for 1 standard deviation [SD] change: 1.41, 95% confidence interval [CI]: 1.22–1.63; P < 0.001), but not to plasma glucose (HR: 0.89, 95% CI: 0.70–1.13; P = 0.328). Rates of intensive care unit (ICU) admission and mechanical ventilator use were also higher in those with higher GARs.ConclusionGAR independently predicted 90-day mortality, ICU admission and use of mechanical ventilation. It was also a better predictor of patient outcomes than plasma glucose alone in patients with extremely high glucose levels.     

Basal insulin treatment intensification in patients with type 2 diabetes mellitus: A comprehensive systematic review of current options

AimAs type 2 diabetes mellitus progresses, most patients require treatment with basal insulin in combination with another agent to achieve recommended glycaemic targets. The purpose of this systematic review was to examine the evidence supporting the use of the available add-on treatments [rapid-acting insulin (RAI), glucagon-like peptide-1 receptor agonists (GLP-1 RAs), dipeptidyl peptidase (DPP)-4 inhibitors and sodium–glucose cotransporter-2 (SGLT-2) inhibitors] to basal insulin.MethodsMEDLINE, EMBASE and EBSCOhost were searched for English-language articles, and all those captured were original articles (case studies and narrative reviews were omitted). Data on study design, population demographics, interventions and outcomes were tabulated. The extracted outcome data included changes in glycated haemoglobin (HbA_1c), fasting plasma glucose (FPG) and postprandial plasma glucose (PPG), as well as body weight and safety data.ResultsA total of 88 publications were deemed relevant. All treatments reduced HbA_1c and FPG. The most pronounced reductions in PPG, an unmet need in patients not controlled by basal insulin, were seen following administration of RAIs and short-acting GLP-1 RAs, although data for this outcome are generally lacking. Body weight benefits were observed with GLP-1 RAs and SGLT-2 inhibitors. However, as only articles in English were included, the result was a possible publication bias, while the diversity of study designs and drug combinations limited comparisons between studies.ConclusionThe evidence supports effectiveness of the available add-on treatments to basal insulin. However, other factors, such as potential body-weight increases, convenience/compliance and adverse events, particularly hypoglycaemia, should be considered on a patient-by-patient basis to optimalize treatment outcomes.     

Successful endovascular treatment of type B aortic dissection in a 15-year-old child

Aortic dissection is a rare condition in the pediatric and young adult population [1]. Here, we present an unusual case of a 15-year-old male patient with sudden onset of chest and back pain аnd numbness in the left leg. Chest and abdominal CT revealed Stanford type B (DeBakey type III) aortic dissection, leading to subocclusive stenosis of the superior mesenteric artery (causing critical intestinal dysfunction with ileus) and total occlusion of left iliac and left renal arteries. The child was admitted 48 h after chest pain onset in critical clinical condition. Revascularization was achieved by several consecutive endovascular procedures, and the patient was discharged after favorable clinical evolution with full restoration of flow in the target organ arteries. The first interventional treatment included stenting of the superior mesenteric artery, stenting of the abdominal aorta, and balloon dilatation of the left iliac artery. Due to resistant renovascular hypertension, stenting of the left renal artery, which was occluded, was conducted 20 days later, leading to optimal blood pressure control. Thirty-three days following the initial procedure, an endovascular endograft prosthesis implantation was performed to close the primary tear in the thoracic aorta. Genetic samples revealed ACTA2 mutation. This case is extraordinary because of its combined life-threatening aortic and vessel pathology, treated for the first time with endovascular means in a child, and highlights the feasibility of endovascular treatment in the pediatric population. We discuss the imaging, management, and successful outcome of this severe condition.