Isospin splittings in the light-baryon octet from lattice QCD and QED

While electromagnetic and up-down quark mass difference effects on octet baryon masses are very small, they have important consequences. The stability of the hydrogen atom against beta decay is a prominent example. Here, we include these effects by adding them to valence quarks in a lattice QCD calculation based on Nf=2+1 simulations with five lattice spacings down to 0.054 fm, lattice sizes up to 6 fm, and average up-down quark masses all the way down to their physical value. This allows us to gain control over all systematic errors, except for the one associated with neglecting electromagnetism in the sea. We compute the octet baryon isomultiplet mass splittings, as well as the individual contributions from electromagnetism and the up-down quark mass difference. Our results for the total splittings are in good agreement with experiment.

Clinical management of takotsubo cardiomyopathy

The clinical management of takotsubo cardiomyopathy is challenging. Its diagnosis must be made on clinical grounds and differentiated from alternative diagnoses with echocardiography, serum biomarkers, cardiac catheterization, and cardiac magnetic resonance imaging. Acute therapy includes supportive care, targeting the precipitating trigger if known, b-blockade, inhibitors of the renin-angiotensin system, and consideration of systemic anticoagulation in all patients. Recovery of left ventricular function to normal is expected regardless of early therapy. Although the prognosis is generally favorable, monitoring for early dangerous complications is essential. There is no evidence to support use of long-term medical therapy to reduce the risk of recurrence.

Acute decompensated heart failure: update on new and emerging evidence and directions for future research

Acute decompensated heart failure (ADHF) is a complex clinical event associated with excess morbidity and mortality. Managing ADHF patients is challenging because of the lack of effective treatments that both reduce symptoms and improve clinical outcomes. Existing guideline recommendations are largely based on expert opinion, but several recently published trials have yielded important data to inform both current clinical practice and future research directions. New insight has been gained regarding volume management, including dosing strategies for intravenous loop diuretics and the role of ultrafiltration in patients with heart failure and renal dysfunction. Although the largest ADHF trial to date (ASCEND-HF, using nesiritide) was neutral, promising results with other investigational agents have been reported. If these findings are confirmed in phase III trials, novel compounds, such as relaxin, omecamtiv mecarbil, and ularitide, among others, may become therapeutic options. Translation of research findings into quality clinical care can not be overemphasized. Although many gaps in knowledge exist, ongoing studies will address issues around delivery of evidence-based care to achieve the goal of improving the health status and clinical outcomes of patients with ADHF.

Freeze-out parameters: lattice meets experiment

We present our results for ratios of higher order fluctuations of electric charge as functions of the temperature. These results are obtained in a system of 2+1 quark flavors at physical quark masses and continuum extrapolated. We compare them to preliminary data on higher order moments of the net electric charge distribution from the STAR collaboration. This allows us to determine the freeze-out temperature and chemical potential from first principles. We also show continuum-extrapolated results for ratios of higher order fluctuations of baryon number. These will allow us to test the consistency of the approach, by comparing them to the corresponding experimental data (once they become available) and thus, extracting the freeze-out parameters in an independent way.

Heart failure in post-MI patients with persistent IRA occlusion: prevalence, risk factors, and the long-term effect of PCI in the Occluded Artery Trial (OAT)

BACKGROUND

The incidence and predictors of heart failure (HF) after myocardial infarction (MI) with modern post-MI treatment have not been well characterized.

METHODS AND RESULTS

A total of 2,201 stable patients with persistent infarct-related artery occlusion >24 hours after MI with left ventricular ejection fraction <50% and/or proximal coronary artery occlusion were randomized to percutaneous intervention plus optimal medical therapy (PCI) or optimal medical therapy (MED) alone. Centrally adjudicated HF hospitalizations for New York Heart Association (NYHA) III/IV HF and mortality were determined in patients with and without baseline HF, defined as a history of HF, Killip Class >I at index MI, rales, S3 gallop, NYHA II at randomization, or NYHA >I before index MI. Long-term follow-up data were used to determine 7-year life-table estimated event rates and hazard ratios. There were 150 adjudicated HF hospitalizations during a mean follow-up of 6 years with no difference between the randomized groups (7.4% PCI vs. 7.5% MED, P = .97). Adjudicated HF hospitalization was associated with subsequent death (44.0% vs. 13.1%, HR 3.31, 99% CI 2.21-4.92, P < .001). Baseline HF (present in 32% of patients) increased the risk of adjudicated HF hospitalization (13.6% vs. 4.7%, HR 3.43, 99% CI 2.23-5.26, P < .001) and death (24.7% vs. 10.8%, HR 2.31, 99% CI 1.71-3.10, P < .001).

CONCLUSIONS

In the overall Occluded Artery Trial (OAT) population, adjudicated HF hospitalizations occurred in 7.5% of subjects and were associated with increased risk of subsequent death. Baseline or prior HF was common in the OAT population and was associated with increased risk of hospitalization and death.

Indications for cardiac resynchronization therapy: 2011 update from the Heart Failure Society of America Guideline Committee

Cardiac resynchronization therapy (CRT) improves survival, symptoms, quality of life, exercise capacity, and cardiac structure and function in patients with New York Heart Association (NYHA) functional class II or ambulatory class IV heart failure (HF) with wide QRS complex. The totality of evidence supports the use of CRT in patients with less severe HF symptoms. CRT is recommended for patients in sinus rhythm with a widened QRS interval (≥150 ms) not due to right bundle branch block (RBBB) who have severe left ventricular (LV) systolic dysfunction and persistent NYHA functional class II-III symptoms despite optimal medical therapy (strength of evidence A). CRT may be considered for several other patient groups for whom evidence of benefit is clinically significant but less substantial, including patients with a QRS interval of ≥120 to <150 ms and severe LV systolic dysfunction who have persistent mild to severe HF despite optimal medical therapy (strength of evidence B), some patients with atrial fibrillation, and some with ambulatory class IV HF. Several evidence gaps remain that need to be addressed, including the ideal threshold for QRS duration, QRS morphology, lead placement, degree of myocardial scarring, and the modality for evaluating dyssynchrony. Recommendations will evolve over time as additional data emerge from completed and ongoing clinical trials.

Differential effects of low-carbohydrate and low-fat diets on inflammation and endothelial function in diabetes

OBJECTIVE

To characterize acute (postprandial) and chronic (after a 6-month period of weight loss) effects of a low-carbohydrate vs. a low-fat diet on subclinical markers of cardiovascular disease (CVD) in adults with type 2 diabetes.

DESIGN

At baseline and 6 months, measures of C-reactive protein (CRP), interleukin-6 (IL-6), soluble intercellular adhesion molecule (sICAM) and soluble E-selectin were obtained from archived samples (n = 51) of participants randomized in a clinical trial comparing a low-carbohydrate and a low-fat diet. In a subset of participants (n = 27), postprandial measures of these markers were obtained 3 h after a low-carbohydrate or low-fat liquid meal. Endothelial function was also measured by reactive hyperemic peripheral arterial tonometry during the meal test. Paired t tests and unpaired t tests compared within- and between-group changes.

RESULTS

There were no significant differences observed in postprandial measures of inflammation or endothelial function. After 6 months, CRP (mean ± S.E.) decreased in the low-fat arm from 4.0 ± 0.77 to 3.0 ± 0.77 (P = .01). In the low-carbohydrate arm, sICAM decreased from 234 ± 22 to 199 ± 23 (P = .001), and soluble E-selectin decreased from 93 ± 10 to 82 ± 10 (P = .05.) A significant correlation between change in high-density lipoprotein and change in soluble E-selectin (r = -0.33, P = .04) and with the change in ICAM (r = -0.43, P = .01) was observed.

CONCLUSIONS

Low-carbohydrate and low-fat diets both have beneficial effects on CVD markers. There may be different mechanisms through which weight loss with these diets potentially reduces CVD risk.

Clinical correlates of hemoconcentration during hospitalization for acute decompensated heart failure

BACKGROUND

Hemoconcentration has been proposed as a putative biomarker of effective decongestion therapy in heart failure patients. The prevalence and clinical correlates of hemoconcentration in hospitalized patients with acute decompensated heart failure (ADHF) have not been previously described.

METHODS AND RESULTS

We retrospectively reviewed paired values of hemoglobin at admission and discharge to identify evidence of hemoconcentration in 295 subjects hospitalized with ADHF and determined the association between hemoconcentration and risk of worsening renal function and survival. Subjects with hemoconcentration (n = 75) received higher diuretic doses and demonstrated greater weight loss during hospitalization when compared with subjects without hemoconcentration (median [IQR] loop diuretic dose 180 (120) versus 160 (150) mg, P = .014; mean ± SD weight loss 4.0 ± 3.1 versus 2.2 ± 3.1 kg, P < .001). In univariate analysis, hemoconcentration was associated with increased risk of worsening renal function (odds ratio 2.34, 95% CI 1.27-4.30, P = .006), but decreased risk of all-cause mortality (hazard ratio 0.53, 95% CI 0.29-0.96, P = .035). In multivariate analysis, hemoconcentration remained independently associated with worsening renal function, but not mortality.

CONCLUSIONS

Hemoconcentration is significantly associated with increased diuretic dose, greater weight loss, and increased risk of worsening renal function during hospitalization. Hemoconcentration was significantly associated with mortality in univariate analysis, but not in multivariate analysis.

Iron deficiency in community-dwelling US adults with self-reported heart failure in the National Health and Nutrition Examination Survey III: prevalence and associations with anemia and inflammation

BACKGROUND

Iron deficiency has been proposed as a potential therapeutic target in heart failure, but its prevalence and association with anemia and clinical outcomes in community-dwelling adults with heart failure have not been well characterized.

METHODS AND RESULTS

Using data from the Third National Health and Nutrition Examination Survey, we evaluated the associations between iron deficiency, hemoglobin, C-reactive protein (CRP), and all-cause and cardiovascular mortality in 574 adults with self-reported heart failure. Iron deficiency was defined in both absolute and functional terms as a ferritin level <100 μg/L or between 100 and 299 μg/L if the transferrin saturation was <20%. Iron deficiency was present in 61.3% of participants and was associated with reduced mean hemoglobin (13.6 versus 14.2 g/dL, P=0.007) and increased mean CRP (0.95 versus 0.63 mg/dL, P=0.04). Over a median of 6.7 years of follow-up, there were 300 all-cause deaths, 193 of which were from cardiovascular causes. In age- and sex-adjusted Cox proportional hazards models, hemoglobin, CRP, and transferrin saturation but not iron deficiency were significantly associated with all-cause and cardiovascular mortality. In multivariate models, hemoglobin remained an independent predictor of cardiovascular mortality, whereas CRP remained an independent predictor of both all-cause and cardiovascular mortality.

CONCLUSIONS

Iron deficiency is common in heart failure and is associated with decreased hemoglobin and increased CRP. In multivariate analysis, hemoglobin was associated with cardiovascular mortality while CRP was associated with both all-cause and cardiovascular mortality. Iron deficiency was not associated with all-cause or cardiovascular mortality in this cohort.

Comparison of quantity of left ventricular scarring and remodeling by magnetic resonance imaging in patients with versus without diabetes mellitus and with coronary artery disease

Diabetic patients with coronary artery disease (CAD) are more likely to develop heart failure (HF) than nondiabetic patients, but the mechanism responsible is unclear. Evidence suggests that infarct size and accompanying remodeling may not explain this difference. We used cardiac magnetic resonance (CMR) imaging to compare degree of left ventricular (LV) myocardial scar and remodeling in diabetic and nondiabetic patients with CAD. We evaluated 85 patients (39 diabetic, 46 nondiabetic) who underwent coronary angiography showing obstructive CAD and CMR imaging within 6 months of each other. Myocardial scar was measured by late gadolinium enhancement on CMR imaging and was graded according to spatial and transmural extents on a semiquantitative scale. More diabetic than nondiabetic patients had HF (69% vs 43%, p <0.03); however, groups did not differ in total scar burden (0.94 ± 0.60 vs 1.17 ± 0.74, p = NS), spatial extent of scar, or extent of transmural scar. Diabetes remained an independent predictor of HF after adjustment for CAD and other variables. LV ejection fraction (36 ± 12% vs 37 ± 14%, p = NS) and end-diastolic volume (215 ± 56 vs 217 ± 76 ml, p = NS) were similar for diabetic and nondiabetic patients, respectively. In conclusion, although diabetic patients with CAD had a higher prevalence of HF than nondiabetic patients, there was no difference in myocardial scar, LV volume, or LV ejection fraction. These findings support the theory that mechanisms other than extent of myocardial injury and negative remodeling play a significant role in the development of HF in diabetic patients with CAD.

Oral contraceptive use, iron stores and vascular endothelial function in healthy women

BACKGROUND

Increased iron stores are associated with greater cardiovascular risk in postmenopausal women. Oral contraceptive pill (OCP) use decreases the volume of menstrual blood loss and increases iron stores, but the link between OCP use, iron stores and cardiovascular risk in premenopausal women has not been characterized.

STUDY DESIGN

We conducted a cross-sectional study of 23 healthy OCP users to determine the association between type and duration of OCP exposure, iron stores, and vascular endothelial function [flow-mediated dilation (FMD) in the brachial artery].

RESULTS

Median duration of OCP use was 45 months. FMD in the brachial artery was significantly associated with progestin type used (estranes/gonanes vs. drospirenone) and duration of OCP use (both p<.05) but not iron stores. In multivariate analysis, progestin type was the only independent predictor of FMD.

CONCLUSIONS

Use of OCP containing drospirenone was independently associated with greater FMD in the brachial artery and, thus, a potentially more favorable cardiovascular risk profile, when compared with use of OCP containing estranes/gonanes.

HFSA 2010 Comprehensive Heart Failure Practice Guideline

Heart failure (HF) is a syndrome characterized by high mortality, frequent hospitalization, reduced quality of life, and a complex therapeutic regimen. Knowledge about HF is accumulating so rapidly that individual clinicians may be unable to readily and adequately synthesize new information into effective strategies of care for patients with this syndrome. Trial data, though valuable, often do not give direction for individual patient management. These characteristics make HF an ideal candidate for practice guidelines. The 2010 Heart Failure Society of America comprehensive practice guideline addresses the full range of evaluation, care, and management of patients with HF.

Potential role of statins in the treatment of heart failure

Based on the findings of retrospective studies, there has been growing interest in the potential therapeutic benefits of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) therapy in patients with heart failure. The first published prospective randomized study of statins in heart failure patients did not demonstrate improved clinical outcomes (death and nonfatal myocardial infarction or stroke) after treatment with 10 mg daily of rosuvastatin when compared with placebo. However, use of rosuvastatin was associated with a reduced risk of hospitalization when compared with placebo and was well tolerated. Until further information becomes available, routine use of statins is not recommended in the heart failure population.

Post-exercise heart rate recovery independently predicts mortality risk in patients with chronic heart failure

BACKGROUND

Post-exercise heart rate recovery (HRR) is an index of parasympathetic function associated with clinical outcomes in populations with and without documented coronary heart disease. Decreased parasympathetic activity is thought to be associated with disease progression in chronic heart failure (HF), but an independent association between post-exercise HRR and clinical outcomes among such patients has not been established.

METHODS AND RESULTS

We measured HRR (calculated as the difference between heart rate at peak exercise and after 1 minute of recovery) in 202 HF subjects and recorded 17 mortality and 15 urgent transplantation outcome events over 624 days of follow-up. Reduced post-exercise HRR was independently associated with increased event risk after adjusting for other exercise-derived variables (peak oxygen uptake and change in minute ventilation per change in carbon dioxide production slope), for the Heart Failure Survival Score (adjusted HR 1.09 for 1 beat/min reduction, 95% CI 1.05-1.13, P < .0001), and the Seattle Heart Failure Model score (adjusted HR 1.08 for one beat/min reduction, 95% CI 1.05-1.12, P < .0001). Subjects in the lowest risk tertile based on post-exercise HRR (>or=30 beats/min) had low risk of events irrespective of the risk predicted by the survival scores. In a subgroup of 15 subjects, reduced post-exercise HRR was associated with increased serum markers of inflammation (interleukin-6, r = 0.58, P = .024; high-sensitivity C-reactive protein, r = 0.66, P = .007).

CONCLUSIONS

Post-exercise HRR predicts mortality risk in patients with HF and provides prognostic information independent of previously described survival models. Pathophysiologic links between autonomic function and inflammation may be mediators of this association.

Comparison of blood volume characteristics in anemic patients with low versus preserved left ventricular ejection fractions

Anemia is a significant co-morbidity in patients with heart failure (HF) irrespective of the ejection fraction and is routinely quantified by hemoglobin concentration. Hemodilution as a cause of anemia has been described in systolic HF. The aim of this study was to further investigate the effects of plasma volume in patients with HF by (1) assessing the prevalence of dilutional anemia in patients with anemia and preserved ejection fractions and (2) exploring the relation between hemoglobin and red cell volume in these patients. Forty-six patients with anemia (as determined by standard hemoglobin measurement), 22 with HF and low ejection fractions (HFLEF) and 24 with HF and preserved ejection fractions (HFPEF), all underwent plasma volume measurement with iodine-131-labeled albumin. Hemoglobin values did not differ between subjects with HFLEF and those with HFPEF (10.8 +/- 1.0 vs 11.0 +/- 1.0 g/dl, p = 0.55), but a red cell deficit was found in 88% of patients with HFPEF compared with 59% of those with HFLEF (p = 0.04). This was the result of a higher prevalence of an expansion of plasma volume in patients with HFLEF (100%) compared with those with HFPEF (71%). Among all patients, no correlation was found between hemoglobin and red cell volume (r = 0.09, p = 0.54), but a correlation did exist in patients with normal blood volumes (r = 0.55, p = 0.02). In conclusion, dilutional anemia caused by an expansion in plasma volume without a red cell deficit occurs more commonly in patients with HFLEF than those with HFPEF, and hemoglobin does not correlate with red cell volume in patients with anemia and HF.

Insulin sensitivity, vascular function, and iron stores in voluntary blood donors

OBJECTIVE

Reduced iron stores after blood donation are associated with improved vascular function and decreased cardiovascular risk. We sought to determine whether iron-dependent changes in glucose metabolism may contribute to improved vascular function in blood donors.

RESEARCH DESIGN AND METHODS

We conducted a prospective cross-sectional study in 21 high-frequency blood donors (more than eight donations in the last 2 years) and 21 low-frequency blood donors (one to two donations in the last 2 years) aged 50-75 years. Serum markers of iron stores, whole-body insulin sensitivity index (WBISI) during oral glucose tolerance testing, and flow-mediated dilation in the brachial artery were determined in all subjects.

RESULTS

Serum ferritin was decreased (median values 23 vs. 36 ng/ml, P < 0.05) and flow-mediated dilation in the brachial artery was increased (median values 5.9 vs. 5.3%, P < 0.05) in high-frequency donors compared with low-frequency donors, respectively, but WBISI (median values 4.8 vs. 4.7) and related measures of glucose tolerance did not differ between groups. Flow-mediated dilation significantly decreased at 1 h after oral glucose loading in both groups, but the decrease in flow-mediated dilation at 1 h did not differ between high- and low-frequency donors.

CONCLUSIONS

High-frequency blood donation reduced serum ferritin and increased flow-mediated dilation compared with low-frequency donation but did not improve insulin sensitivity or protect the vascular endothelium from the adverse effects of acute hyperglycemia after oral glucose loading. These findings suggest that the mechanisms linking blood donation to improved vascular function are not likely related to changes in glucose metabolism.

Effects of recombinant human erythropoietin on antiplatelet action of aspirin and clopidogrel in healthy subjects: results of a double-blind, placebo-controlled randomized trial

BACKGROUND

Recombinant human erythropoietin (rHuEpo) reduces myocardial injury in experimental ischemia and has been proposed as a cardioprotective agent for potential use in acute coronary syndromes. Its safety profile in clinical acute ischemic settings is uncertain because rHuEpo has been reported to increase platelet reactivity and the risk of thromboembolism in some disease populations. Whether prothrombotic effects of rHuEpo mitigate the effects of antiplatelet agents used in acute coronary syndrome patients is unknown.

METHODS

Recombinant human erythropoietin 100, 200, 400 U/kg, or placebo was given intravenously once daily for 3 consecutive days in a double-blind randomized trial in 96 healthy subjects. A single oral dose of aspirin 325 mg or clopidogrel 300 mg was given immediately after the last dose of study drug. Bleeding time and in vitro high shear stress platelet function assays (PFA)-100 were determined before; 5 hours; and 1, 5, and 7 days after aspirin or clopidogrel.

RESULTS

Recombinant human erythropoietin at doses of 100 and 200 U/kg did not alter bleeding time or PFA-100 closure times at any time point when compared with placebo. Recombinant human erythropoietin at a dose of 400 U/kg significantly blunted the post-aspirin increase in bleeding time when compared with placebo (P = .03) but did not alter post-clopidogrel bleeding times nor PFA closure times. The 400-U/kg dose did not change hematocrit but did significantly increase the platelet count at 5 days after study drug administration when compared with placebo (P = .014).

CONCLUSION

Short-term rHuEpo at doses up to 200 U/kg did not mitigate the effects of administration of aspirin or clopidogrel on either in vivo or in vitro measures of platelet function in healthy subjects. The 400-U/kg dose attenuated the effects of aspirin on bleeding time and increased the platelet count. Studies of the effects of rHuEpo on platelet function in patients with coronary artery disease are warranted to further characterize dose/safety profile.

Blood Volume Assessment in the Diagnosis and Treatment of Chronic Heart Failure

Symptoms of intravascular volume overload and increased cardiac filling pressures in the systemic and pulmonary venous circulations are among the most common complaints in patients with chronic heart failure (CHF). The clinical utility of physical examination for estimation of intravascular volume status in patients with CHF is limited due to poor specificity and sensitivity of most signs of congestion. Direct measurement of blood volume with radioisotope techniques is FDA-approved and has been shown to be closely associated with invasive measurements of cardiac filling pressures in patients with CHF. Unrecognized volume overload is common in CHF patients and is associated with adverse clinical outcomes. Additional work is needed to determine the clinical utility of serial blood volume measurements in the management of patients with CHF.