Soil legacy nutrients contribute to the decreasing stoichiometric ratio of N and P loading from the Mississippi River Basin

Human-induced nitrogen-phosphorus (N, P) imbalance in terrestrial ecosystems can lead to disproportionate N and P loading to aquatic ecosystems, subsequently shifting the elemental ratio in estuaries and coastal oceans and impacting both the structure and functioning of aquatic ecosystems. The N:P ratio of nutrient loading to the Gulf of Mexico from the Mississippi River Basin increased before the late 1980s driven by the enhanced usage of N fertilizer over P fertilizer, whereafter the N:P loading ratio started to decrease although the N:P ratio of fertilizer application did not exhibit a similar trend. Here, we hypothesize that different release rates of soil legacy nutrients might contribute to the decreasing N:P loading ratio. Our study used a data-model integration framework to evaluate N and P dynamics and the potential for long-term accumulation or release of internal soil nutrient legacy stores to alter the ratio of N and P transported down the rivers. We show that the longer residence time of P in terrestrial ecosystems results in a much slower release of P to coastal oceans than N. If contemporary nutrient sources were reduced or suspended, P loading sustained by soil legacy P would decrease much slower than that of N, causing a decrease in the N and P loading ratio. The longer residence time of P in terrestrial ecosystems and the increasingly important role of soil legacy nutrients as a loading source may explain the decreasing N:P loading ratio in the Mississippi River Basin. Our study underscores a promising prospect for N loading control and the urgency to integrate soil P legacy into sustainable nutrient management strategies for aquatic ecosystem health and water security.

Rationale and design of a multicenter randomized clinical trial of vestibulodynia: understanding pathophysiology and determining appropriate treatments (vestibulodynia: UPDATe)

BACKGROUND

Limited data are available to establish evidence-based management protocols for vestibulodynia (VBD), a chronic vulvar pain condition that affects approximately 14 million women in the U.S. For the purposes of the study, our group subdivided VBD subtypes that may benefit from different types of treatment: 1) VBD peripheral (VBD-p), characterized by pain localized to the vulvar vestibule and 2) VBD central (VBD-c), characterized by VBD alongside one or more other chronic overlapping pain conditions (e.g. irritable bowel syndrome, temporomandibular disorder, and fibromyalgia syndrome) that affect remote body regions. Here, we describe the rationale and design of an NIH-funded multicenter clinical trial comparing the effectiveness of topical and/or systemic medication for alleviating pain and normalizing pain- relevant biomarkers among women with VBD-p and VBD-c.

METHODS

Participants will be randomly assigned to one of four parallel arms: peripheral treatment with 5% lidocaine + 0.5 mg/ml 0.02% oestradiol compound cream + oral placebo pill, 2) central treatment with the tricyclic antidepressant nortriptyline + placebo cream, 3) combined peripheral cream and central pill treatments, or 4) placebo cream and placebo pill. The treatment phase will last 16 weeks, with outcome measures and biomarkers assessed at 4 time points (0, 8, 16, and 24 weeks). First, we will compare the efficacy of treatments in alleviating pain using standardized tampon insertion with a numeric rating scale and self-reported pain on the short form McGill Pain Questionnaire. Next, we will compare the efficacy of treatments in improving perceived physical, mental, and sexual health using standardized questionnaires. Finally, we will measure cytokines and microRNAs in local vaginal and circulating blood samples using multiplex assays and RNA sequencing, and determine the ability of these biomarkers to predict treatment response.

CONCLUSION

This is the first multicenter randomized controlled trial to evaluate the efficacy of peripherally and centrally acting medications currently used in clinical practice for treating unique VBD subtypes based on distinct clinical and biological signatures.

ADMINISTRATIVE INFORMATION

Vestibulodynia UPDATe is a multi-centre, two-by-two factorial designed randomized, double-blind, placebo-controlled trial registered at clinical trials.gov (NCT03844412). This work is supported by the R01 HD096331 awarded to Drs. Nackley, Rapkin, Geller and Carey by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD).Key messagesPeripheral lidocaine and oestradiol and centrally-targeted nortriptyline medications are used for the treatment of pain in women with VBD, but there is a lack of data from well-powered RCTs.This two-by-two factorial RCT will test the efficacy of these medications in VBD subtypes characterized by distinct clinical characteristics and biomarker profiles.We hope that results will provide clinicians with scientific evidence of therapeutic efficacy in distinct VBD subtypes in an effort to direct and optimize treatment approaches.

Strategic roadmap to assess forest vulnerability under air pollution and climate change

Although it is an integral part of global change, most of the research addressing the effects of climate change on forests have overlooked the role of environmental pollution. Similarly, most studies investigating the effects of air pollutants on forests have generally neglected the impacts of climate change. We review the current knowledge on combined air pollution and climate change effects on global forest ecosystems and identify several key research priorities as a roadmap for the future. Specifically, we recommend (1) the establishment of much denser array of monitoring sites, particularly in the South Hemisphere; (2) further integration of ground and satellite monitoring; (3) generation of flux-based standards and critical levels taking into account the sensitivity of dominant forest tree species; (4) long-term monitoring of N, S, P cycles and base cations deposition together at global scale; (5) intensification of experimental studies, addressing the combined effects of different abiotic factors on forests by assuring a better representation of taxonomic and functional diversity across the ~73,000 tree species on Earth; (6) more experimental focus on phenomics and genomics; (7) improved knowledge on key processes regulating the dynamics of radionuclides in forest systems; and (8) development of models integrating air pollution and climate change data from long-term monitoring programs.

An improved method for quantifying total fine root decomposition in plantation forests combining measurements of soil coring and minirhizotrons with a mass balance model

Accurate measurement of total fine root decomposition (the amount of dead fine roots decomposed per unit soil volume) is essential for constructing a soil carbon budget. However, the ingrowth/soil core-based models are dependent on the assumptions that fine roots in litterbags/intact cores have the same relative decomposition rate as those in intact soils and that fine root growth and death rates remain constant over time, while minirhizotrons cannot quantify the total fine root decomposition. To improve the accuracy of estimates for total fine root decomposition, we propose a new method (balanced hybrid) with two models that integrate measurements of soil coring and minirhizotrons into a mass balance model. Model input parameters were fine root biomass, necromass and turnover rate for Model 1, and fine root biomass, necromass and death rate for Model 2. We tested the balanced hybrid method in a loblolly pine plantation forest in coastal North Carolina, USA. The total decomposition rate of absorptive fine roots (ARs) (a combination of first- and second-order fine roots) using Models 1 and 2 was 107 ± 13 g m-2 year-1 and 129 ± 12 g m-2 year-1, respectively. Monthly total AR decomposition was highest from August to November, which corresponded with the highest monthly total ARs mortality. The ARs imaged by minirhizotrons well represent those growing in intact soils, evident by a significant and positive relationship between the standing biomass and the standing length. The total decomposition estimate in both models was sensitive to changes in fine root biomass, turnover rate and death rate but not to change in necromass. Compared with Model 2, Model 1 can avoid the technical difficulty of deciding dead time of individual fine roots but requires greater time and effort to accurately measure fine root biomass dynamics. The balanced hybrid method is an improved technique for measuring total fine root decomposition in plantation forests in which the estimates are based on empirical data from soil coring and minirhizotrons, moving beyond assumptions of traditional approaches.

Annexin A1 is a Potential Novel Biomarker of Congestion in Acute Heart Failure

OBJECTIVES

This study sought to identify the role of annexin A1 (AnxA1) as a congestion marker in acute heart failure (AHF) and to identify its putative role in predicting clinical outcomes.

BACKGROUND

AnxA1 is a protein that inhibits inflammation following ischemia-reperfusion injury in cardiorenal tissues. Because AHF is a state of tissue hypoperfusion, we hypothesized that plasma AnxA1 levels are altered in AHF.

METHODS

In the Renal Optimization Strategies Evaluation (ROSE) trial, patients hospitalized for AHF with kidney injury were randomized to receive dopamine, nesiritide, or placebo for 72 hours in addition to diuresis. In a subanalysis, plasma AnxA1 levels were measured at baseline and at 72 hours in 275 patients. Participants were divided into 3 tertiles based on their baseline AnxA1 levels.

RESULTS

The prevalence of peripheral edema 2+ increased with increasing AnxA1 levels (P < .007). Cystatin C, blood urea nitrogen, and kidney injury molecule-1 plasma levels were higher among participants in tertile 3 vs tertiles 1 or 2 (P< .05). Patients with a congestion score of 4 had a mean baseline AnxA1 level 8.63 units higher than those with a congestion score of 0 (P = .03). Patients in tertiles 2 and 3 were twice as likely to experience creatinine elevation as patients in tertile 1 (P = .03). Patients in tertiles 2 and 3 were at a higher risk of 60-day all-cause mortality or heart failure hospitalization and 180-day all-cause mortality (P < .05).

CONCLUSIONS

Among patients hospitalized for AHF with impaired kidney function, elevated AnxA1 levels are associated with worse congestion, higher risk for further creatinine elevation, and higher rates of 60-day morbidity or all-cause mortality and 180-day all-cause mortality.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01132846.

Adverse Renal Response to Decongestion in the Obese Phenotype of Heart Failure With Preserved Ejection Fraction

BACKGROUND

Patients with heart failure (HF) with preserved ejection fraction (HFpEF) and obesity display a number of pathophysiologic features that may render them more or less vulnerable to negative effects of decongestion on renal function, including greater right ventricular remodeling, plasma volume expansion and pericardial restraint. We aimed to contrast the renal response to decongestion in obese compared to nonobese patients with HFpEF METHODS AND RESULTS: National Institutes of Health heart failure network studies that enrolled patients with acute decompensated HFpEF (EF ≥ 50%) were included (DOSE, CARRESS, ROSE, and ATHENA). Obese HFpEF was defined as a body mass index ≥ 30 kg/m². Compared to nonobese HFpEF (n = 118), patients with obese HFpEF (n = 214) were an average of 9 years younger (71 vs 80 years,< 0.001), were more likely to have diabetes (64% vs 31%, P< 0.001) but had less atrial fibrillation (56% vs 75%, P< 0.001). Renal dysfunction (glomerular filtration rate < 60 mL/min/1.73m²) was present in 82% of patients, and there was no difference at baseline between obese and nonobese patients. Despite similar weight loss through decongestive therapies, obese patients with HFpEF demonstrated greater rise in creatinine (Cr) and decline in glomerular filtration rate, with a 2-fold higher incidence of mild worsening renal function (rise in Cr ≥ 0.3 mg/dL) (28 vs 14%, P = 0.008) and a substantially greater increase in severe worsening of renal function (rise in Cr > 0.5 mg/dL) (9 vs 0%, P = 0.002).

CONCLUSIONS

Despite being nearly a decade younger, obese patients with HFpEF experience greater deterioration in renal function during decongestion than do nonobese patients with HFpEF. Further study to elucidate the complex relationships between volume distribution, cardiorenal hemodynamics and adiposity in HFpEF is needed.

Characterization of the Obese Phenotype of Heart Failure With Preserved Ejection Fraction: A RELAX Trial Ancillary Study

OBJECTIVE

To characterize the obese heart failure with preserved ejection fraction (HFpEF) phenotype in a multicenter cohort.

PATIENTS AND METHODS

This was a secondary analysis of the randomized clinical trial RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Heart Failure with Preserved Ejection Fraction) performed between October 1, 2008, and February 1, 2012. Patients with HFpEF were classified by body mass index (BMI) as obese (BMI≥35 kg/m²) and nonobese (BMI<30 kg/m²) for comparison.

RESULTS

Obese patients with HFpEF (n=81) were younger (median age, 64 [interquartile range (IQR), 67-79] years vs 73 [IQR, 56-70] years; P<.001) but had greater peripheral edema (31% [25] vs 9% [6]; P<.001), more orthopnea (76% [56] vs 53% [35]; P=.005), worse New York Heart Association class (P=.006), and more impaired quality of life (P<.001) as compared with nonobese patients with HFpEF (n=70). Despite more severe signs and symptoms, obese patients with HFpEF had lower N-terminal pro B-type natriuretic peptide level (median, 481 [IQR, 176-1183] pg/mL vs 825 [IQR, 380-1679] pg/mL [to convert to pmol/L, multiply by 0.118]; P=.007) and lower left atrial volume index (median, 38 [IQR, 31-47] mL/m² vs 54 [IQR, 41-63] mL/m²; P<.001). Serum C-reactive protein (median, 5.0 [IQR, 2.4-9.9] mg/dL vs 2.7 [IQR, 1.6-5.4] mg/dL [to convert to mg/L, multiply by 10^-3]; P<.001) and uric acid (median, 7.8 [IQR, 6.1-8.7] mg/dL vs 6.8 [IQR, 5.5-8.3] mg/dL; P=.03) levels were higher in obese HFpEF, indicating greater systemic inflammation, than in nonobese HFpEF. Peak oxygen consumption was impaired in obese HFpEF (median, 11.1 [IQR, 9.6-14.4] mL/kg per minute vs 13.1 [IQR, 11.3-14.7] mL/kg per minute; P=.008), as was submaximal exercise capacity (6-minute walk distance, 272 [IQR, 200-332] m vs 355 [IQR, 290-415] m; P<.0001).

CONCLUSION

Obese HFpEF is associated with decreased quality of life, worse symptoms of heart failure, greater systemic inflammation, worse exercise capacity, and higher metabolic cost of exertion as compared with nonobese HFpEF. Further study is required to understand the pathophysiology and potential distinct treatments for patients with the obese phenotype of HFpEF.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00763867.

Sildenafil Treatment in Heart Failure With Preserved Ejection Fraction: Targeted Metabolomic Profiling in the RELAX Trial

Importance

Phosphodiesterase-5 inhibition with sildenafil compared with a placebo had no effect on the exercise capacity or clinical status of patients with heart failure with preserved ejection fraction (HFpEF) in the PhosphodiesteRasE-5 Inhibition to Improve Clinical Status and Exercise Capacity in Diastolic Heart Failure with Preserved Ejection Fraction (RELAX) clinical trial. Metabolic impairments may explain the neutral results.

Objective

To test the hypothesis that profiling metabolites in the RELAX trial would clarify the mechanisms of sildenafil effects and identify metabolites associated with clinical outcomes in HFpEF.

Design, Setting, and Participants

Paired baseline and 24-week plasma samples of 160 stable outpatient individuals with HFpEF enrolled in the RELAX clinical trial were analyzed using flow injection tandem mass spectrometry (60 metabolites) and conventional assays (5 metabolites).

Interventions

Sildenafil (n = 79) or a placebo (n = 81) administered orally at 20 mg, 3 times daily for 12 weeks, followed by 60 mg, 3 times daily for 12 weeks.

Main Outcomes and Measures

The primary measure was metabolite level changes between baseline and 24 weeks stratified by treatments. Secondary measures included correlations between metabolite level changes and clinical biomarkers and associations between baseline metabolite levels and the composite clinical score.

Results

No metabolites changed between baseline and 24 weeks in the group treated with a placebo; however, 7 metabolites changed in the group treated with sildenafil, including decreased amino acids (alanine and proline; median change [25th-75th], -38.26 [-100.3 to 28.19] and -28.24 [-56.29 to 12.08], respectively; false discovery rate-adjusted P = .01 and .03, respectively), and increased short-chain dicarboxylacylcarnitines glutaryl carnitine, octenedioyl carnitine, and adipoyl carnitine (median change, 6.19 [-3.37 to 14.18], 2.72 [-3 to 12.57], and 10.72 [-11.23 to 29.57], respectively; false discovery rate-adjusted P = .01, .04, and .05, respectively), and 1 long-chain acylcarnitine metabolite (palmitoyl carnitine; median change, 7.83 [-5.64 to 26.99]; false discovery rate-adjusted P = .03). The increases in long-chain acylarnitine metabolites and short-chain dicarboxylacylcarnitines correlated with increases in endothelin-1 and creatinine/cystatin C, respectively. Higher baseline levels of short-chain dicarboxylacylcarnitine metabolite 3-hydroxyisovalerylcarnitine/malonylcarnitine and asparagine/aspartic acid were associated with worse clinical rank scores in both treatment groups (β, -96.60, P = .001 and β, -0.02, P = .01; after renal adjustment, P = .09 and .02, respectively).

Conclusions and Relevance

Our study provides a potential mechanism for the effects of sildenafil that, through adverse effects on mitochondrial function and endoplasmic reticulum stress, could have contributed to the neutral trial results in RELAX. Short-chain dicarboxylacylcarnitine metabolites and asparagine/aspartic acid could serve as biomarkers associated with adverse clinical outcomes in HFpEF.

Effect of Inorganic Nitrite vs Placebo on Exercise Capacity Among Patients With Heart Failure With Preserved Ejection Fraction: The INDIE-HFpEF Randomized Clinical Trial

IMPORTANCE

There are few effective treatments for heart failure with preserved ejection fraction (HFpEF). Short-term administration of inorganic nitrite or nitrate preparations has been shown to enhance nitric oxide signaling, which may improve aerobic capacity in HFpEF.

OBJECTIVE

To determine the effect of 4 weeks' administration of inhaled, nebulized inorganic nitrite on exercise capacity in HFpEF.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, double-blind, placebo-controlled, 2-treatment, crossover trial of 105 patients with HFpEF. Participants were enrolled from July 22, 2016, to September 12, 2017, at 17 US sites, with final date of follow-up of January 2, 2018.

INTERVENTIONS

Inorganic nitrite or placebo administered via micronebulizer device. During each 6-week phase of the crossover study, participants received no study drug for 2 weeks (baseline/washout) followed by study drug (nitrite or placebo) at 46 mg 3 times a day for 1 week followed by 80 mg 3 times a day for 3 weeks.

MAIN OUTCOMES AND MEASURES

The primary end point was peak oxygen consumption (mL/kg/min). Secondary end points included daily activity levels assessed by accelerometry, health status as assessed by the Kansas City Cardiomyopathy Questionnaire (score range, 0-100, with higher scores reflecting better quality of life), functional class, cardiac filling pressures assessed by echocardiography, N-terminal fragment of the prohormone brain natriuretic peptide levels, other exercise indices, adverse events, and tolerability. Outcomes were assessed after treatment for 4 weeks.

RESULTS

Among 105 patients who were randomized (median age, 68 years; 56% women), 98 (93%) completed the trial. During the nitrite phase, there was no significant difference in mean peak oxygen consumption as compared with the placebo phase (13.5 vs 13.7 mL/kg/min; difference, -0.20 [95% CI, -0.56 to 0.16]; P = .27). There were no significant between-treatment phase differences in daily activity levels (5497 vs 5503 accelerometry units; difference, -15 [95% CI, -264 to 234]; P = .91), Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (62.6 vs 61.9; difference, 1.1 [95% CI, -1.4 to 3.5]; P = .39), functional class (2.5 vs 2.5; difference, 0.1 [95% CI, -0.1 to 0.2]; P = .43), echocardiographic E/e' ratio (16.4 vs 16.6; difference, 0.1 [95% CI, -1.2 to 1.3]; P = .93), or N-terminal fragment of the prohormone brain natriuretic peptide levels (520 vs 533 pg/mL; difference, 11 [95% CI, -53 to 75]; P = .74). Worsening heart failure occurred in 3 participants (2.9%) during the nitrite phase and 8 (7.6%) during the placebo phase.

CONCLUSIONS AND RELEVANCE

Among patients with HFpEF, administration of inhaled inorganic nitrite for 4 weeks, compared with placebo, did not result in significant improvement in exercise capacity.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02742129.

Impaired left ventricular global longitudinal strain in patients with heart failure with preserved ejection fraction: insights from the RELAX trial

BACKGROUND

While abnormal left ventricular (LV) global longitudinal strain (GLS) has been described in patients with heart failure with preserved ejection fraction (HFpEF), its prevalence and clinical significance are poorly understood.

METHODS AND RESULTS

Patients enrolled in the RELAX trial of sildenafil in HFpEF (LV ejection fraction ≥50%) in whom two-dimensional, speckle-tracking LV GLS was possible (n = 187) were analysed. The distribution of LV GLS and its associations with clinical characteristics, LV structure and function, biomarkers, exercise capacity and quality of life were assessed. Baseline median LV GLS was -14.6% (25th and 75th percentile, -17.0% and -11.9%, respectively) and abnormal (≥ - 16%) in 122/187 (65%) patients. Patients in the tertile with the best LV GLS had lower N-terminal pro-brain natriuretic peptide (NT-proBNP) [median 505 pg/mL (161, 1065) vs. 875 pg/mL (488, 1802), P = 0.008) and lower collagen III N-terminal propeptide (PIIINP) levels [median 6.7 µg/L (5.1, 8.1) vs. 8.1 µg/L (6.5, 10.5), P = 0.001] compared with the tertile with the worst LV GLS. There was also a modest linear relationship with LV GLS and log-transformed NT-proBNP and PIIINP (r = 0.29, P < 0.001 and r = 0.19, P = 0.009, respectively). We observed no linear association of LV GLS with Minnesota Living with Heart Failure scores, 6-min walk distance, peak oxygen consumption, or expiratory minute ventilation/carbon dioxide excretion slope.

CONCLUSIONS

Impaired LV GLS is common among HFpEF patients, indicating the presence of covert systolic dysfunction despite normal LV ejection fraction. Impaired LV GLS was associated with biomarkers of wall stress and collagen synthesis and diastolic dysfunction but not with quality of life or exercise capacity, suggesting other processes may be more responsible for these aspects of the HFpEF syndrome.

Outbreak of Tsukamurella species bloodstream infection among patients at an oncology clinic, West Virginia, 2011-2012

OBJECTIVE

To determine the source and identify control measures of an outbreak of Tsukamurella species bloodstream infections at an outpatient oncology facility.

DESIGN

Epidemiologic investigation of the outbreak with a case-control study.

METHODS

A case was an infection in which Tsukamurella species was isolated from a blood or catheter tip culture during the period January 2011 through June 2012 from a patient of the oncology clinic. Laboratory records of area hospitals and patient charts were reviewed. A case-control study was conducted among clinic patients to identify risk factors for Tsukamurella species bloodstream infection. Clinic staff were interviewed, and infection control practices were assessed.

RESULTS

Fifteen cases of Tsukamurella (Tsukamurella pulmonis or Tsukamurella tyrosinosolvens) bloodstream infection were identified, all in patients with underlying malignancy and indwelling central lines. The median age of case patients was 68 years; 47% were male. The only significant risk factor for infection was receipt of saline flush from the clinic during the period September-October 2011 (P = .03), when the clinic had been preparing saline flush from a common-source bag of saline. Other infection control deficiencies that were identified at the clinic included suboptimal procedures for central line access and preparation of chemotherapy.

CONCLUSION

Although multiple infection control lapses were identified, the outbreak was likely caused by improper preparation of saline flush syringes by the clinic. The outbreak demonstrates that bloodstream infections among oncology patients can result from improper infection control practices and highlights the critical need for increased attention to and oversight of infection control in outpatient oncology settings.

Cardiovascular phenotype in HFpEF patients with or without diabetes: a RELAX trial ancillary study

BACKGROUND

The RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Heart Failure with Preserved Ejection Fraction) study was a multicenter, randomized trial of sildenafil versus placebo in heart failure with preserved ejection fraction (HFpEF) with rigorous entry criteria and extensive phenotypic characterization of participants.

OBJECTIVES

The aim of this study was to characterize clinical features, exercise capacity, and outcomes in patients with HFpEF with or without diabetes and gain insight into contributing pathophysiological mechanisms.

METHODS

The RELAX study enrolled 216 stable outpatients with heart failure, an ejection fraction ≥ 50%, increased natriuretic peptide or intracardiac pressures, and reduced exercise capacity. Prospectively collected data included echocardiography, cardiac magnetic resonance, a comprehensive biomarker panel, exercise testing, and clinical events over 6 months.

RESULTS

Compared with nondiabetic patients (n = 123), diabetic HFpEF patients (n = 93) were younger, more obese, and more often male and had a higher prevalence of hypertension, renal dysfunction, pulmonary disease, and vascular disease (p < 0.05 for all). Uric acid, C-reactive protein, galectin-3, carboxy-terminal telopeptide of collagen type I, and endothelin-1 levels were higher in diabetic patients (p < 0.05 for all). Diabetic patients had more ventricular hypertrophy, but systolic and diastolic ventricular function parameters were similar in diabetic and nondiabetic patients except for a trend toward higher filling pressures (E/e') in diabetic patients. Diabetic patients had worse maximal (peak oxygen uptake) and submaximal (6-min walk distance) exercise capacity (p < 0.01 for both). Diabetic patients were more likely to have been hospitalized for heart failure in the year before study entry (47% vs. 28%, p = 0.004) and had a higher incidence of cardiac or renal hospitalization at 6 months after enrollment (23.7% vs. 4.9%, p < 0.001).

CONCLUSIONS

HFpEF patients with diabetes are at increased risk of hospitalization and have reduced exercise capacity. Multimorbidity, impaired chronotropic reserve, left ventricular hypertrophy, and activation of inflammatory, pro-oxidative, vasoconstrictor, and profibrotic pathways may contribute to adverse outcomes in HFpEF patients with diabetes. (Evaluating the Effectiveness of Sildenafil at Improving Health Outcomes and Exercise Ability in People With Diastolic Heart Failure [The RELAX Study]; NCT00763867).

Macrolide/Azalide therapy for nodular/bronchiectatic mycobacterium avium complex lung disease

BACKGROUND

There is no large study validating the appropriateness of current treatment guidelines for Mycobacterium avium complex (MAC) lung disease. This is a retrospective single-center review evaluating the efficacy of macrolide/azalide-containing regimens for nodular/bronchiectatic (NB) MAC lung disease.

METHODS

Patients were treated according to contemporary guidelines with evaluation of microbiologic responses. Macrolide susceptibility of MAC isolates was done at initiation of therapy, 6 to 12 months during therapy, and on the first microbiologic recurrence isolate. Microbiologic recurrence isolates also underwent genotyping for comparison with the original isolates.

RESULTS

One hundred eighty patients completed > 12 months of macrolide/azalide multidrug therapy. Sputum conversion to culture negative occurred in 154 of 180 patients (86%). There were no differences in response between clarithromycin or azithromycin regimens. Treatment regimen modification occurred more frequently with daily (24 of 30 [80%]) vs intermittent (2 of 180 [1%]) therapy (P = .0001). No patient developed macrolide resistance during treatment. Microbiologic recurrences during therapy occurred in 14% of patients: 73% with reinfection MAC isolates, 27% with true relapse isolates (P = .03). Overall, treatment success (ie, sputum conversion without true microbiologic relapse) was achieved in 84% of patients. Microbiologic recurrences occurred in 74 of 155 patients (48%) after completion of therapy: 75% reinfection isolates, 25% true relapse isolates.

CONCLUSIONS

Current guidelines for macrolide/azalide-based therapies for NB MAC lung disease result in favorable microbiologic outcomes for most patients without promotion of macrolide resistance. Intermittent therapy is effective and significantly better tolerated than daily therapy. Microbiologic recurrences during or after therapy are common and most often due to reinfection MAC genotypes.

Resting ventricular-vascular function and exercise capacity in heart failure with preserved ejection fraction: a RELAX trial ancillary study

BACKGROUND

Exercise intolerance is a hallmark of heart failure, but factors associated with impaired exercise capacity in heart failure with preserved ejection fraction are unclear. We hypothesized that in heart failure with preserved ejection fraction, the severity of resting ventricular and vascular dysfunction are associated with impairment in exercise tolerance as assessed by peak oxygen consumption.

METHODS AND RESULTS

Subjects with heart failure with preserved ejection fraction enrolled in the PhosphodiesteRasE-5 Inhibition to Improve CLinical Status And EXercise Capacity in Diastolic Heart Failure (RELAX) clinical trial (n=216) underwent baseline Doppler echocardiography, cardiopulmonary exercise testing, and cardiac MRI. RELAX participants were elderly (median age 69 years) and 48% were women. Ejection fraction (60%) and stroke volume (77 mL) were normal, while diastolic dysfunction (medial E/e', 16; deceleration time, 185 ms; left atrial volume, 44 mL/m(2)) and increased arterial load (arterial elastance, 1.51 mm Hg/mL) were evident. Peak oxygen consumption was reduced (11.7 mLkg(-1)min(-1), 1141 mL/min) and age, sex, body mass index, hemoglobin, and chronotropic response collectively explained 64% of the variance in raw peak oxygen consumption (mL/min). After adjustment for these variables, left ventricular structure (diastolic dimension [1.5%, P=0.008] and left ventricular mass [1.6%, P=0.008]), resting stroke volume (2.0%, P=0.002), left ventricular diastolic dysfunction (deceleration time [0.9%, P=0.03] and E/e' [1.4%, P=0.009]), and arterial function (arterial elastance [2.1%, P=0.002] and systemic arterial compliance [1.5%, P=0.007]), each explained only a small additional portion of the variance in peak oxygen consumption.

CONCLUSIONS

In heart failure with preserved ejection fraction, potentially modifiable factors (obesity, anemia, and chronotropic incompetence) are strongly associated with exercise capacity, whereas resting measures of ventricular and vascular structure and function are not.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00763867.

Insertion site and distribution of a genomic island conferring DNA phosphorothioation in the Mycobacterium abscessus complex

Nearly half of US clinical isolates of the emerging pathogen Mycobacterium abscessus were reported to exhibit smeared DNA during PFGE. This DNA degradation (Dnd) phenotype results from DNA phosphorothioation, a sulfur modification found in other bacteria and conferred by dnd genes located on mobile elements. Putative dnd genes are located on a 19.6 kbp genomic island (GI) in the M. abscessus type strain ATCC 19977. We confirmed that ATCC 19977(T) is Dnd-positive by PFGE and we developed a PCR assay to predict Dnd phenotype. Dnd-positive strains generated an amplicon from dndC whereas Dnd-negative strains generated a bridge amplicon that spanned the GI insertion site, indicating they lacked the entire 'Dnd-GI'. Comparative analyses of sequences from the bridge amplicon with ATCC 19977(T) revealed the Dnd-GI is flanked by 22 bp repeats in M. abscessus sensu stricto and inserted downstream of a tRNA-Ala gene and between inverted repeats. Regions flanking the Dnd-GI were highly conserved within the M. abscessus complex. Bioinformatics studies suggest the Dnd-GI inserted independently into a strain of Mycobacterium massiliense and that other species of mycobacteria also have dnd genes, supporting reports that the Dnd phenotype is common among actinomycetes. Within the M. abscessus complex, Dnd-positive clinical isolates were primarily M. abscessus sensu stricto, and tandem repeat typing indicated these isolates were highly related, confirming previous PFGE studies and revealing a widespread family of strains with significance in human disease.

Obesity and the response to intensified diuretic treatment in decompensated heart failure: a DOSE trial substudy

BACKGROUND

Obesity could attenuate diuretic effectiveness in treatment of acute decompensated heart failure (HF).

METHODS AND RESULTS

The DOSE trial randomized 308 subjects with acute HF to low- versus high-intensification intravenous diuretic therapy. We tested for statistical interactions between obesity and dosing strategy across clinical end points. After 72 hours of treatment, obese subjects (body mass index >30 kg/m(2); n = 173) had greater volume loss than nonobese subjects (n = 119) but similar improvements in dyspnea and freedom from congestion. Both groups had greater fluid loss with high-intensification treatment. Obese subjects had a higher incidence of worsening renal function (WRF) at 72 hours with low-intensification treatment, compared with nonobese subjects. In contrast, nonobese and obese subjects had similar incidence of WRF with high-intensification treatment. There were no differences between obese and nonobese subjects in time to discharge and 60-day freedom from death, emergency department visit, or rehospitalization.

CONCLUSIONS

The incidence of WRF was greater in obese than in nonobese subjects with low-intensification treatment. However, the frequency of WRF was equivalent in obese and nonobese subjects with high-intensification treatment. Additional studies are needed to assess whether obese patients with acute HF benefit from an initial high-intensification treatment strategy.

Nontuberculous Mycobacteria in household plumbing as possible cause of chronic rhinosinusitis

Millions of Americans live with chronic sinus infection. Most infections are caused by either bacteria or fungi. Some of these infections can be hard to treat, eluding medical and surgical treatment and persisting for months or even years. A recent study in New York found that some patients with a chronic sinus infection had tuberculosis-like organisms (mycobacteria) in their sinuses and that the same organisms were also in the tap water at their homes. These mycobacteria can be resistant to commonly used antimicrobial drugs. Doctors should check for mycobacteria in patients with treatment-resistant sinus infection. Patients who flush their sinuses at home should use sterile saline, not tap water.

Symptoms of chronic rhinosinusitis (CRS) often persist despite treatment. Because nontuberculous mycobacteria (NTM) are resistant to commonly used antimicrobial drugs and are found in drinking water that patients may use for sinus irrigation, we investigated whether some CRS patients were infected with NTM in New York, New York, USA, during 2001–2011. Two approaches were chosen: 1) records of NTM-infected CRS patients were reviewed to identify common features of infection and Mycobacterium species; 2) samples from plumbing in households of 8 NTM-infected patients were cultured for NTM presence. In 3 households sampled, M. avium sharing rep-PCR and pulsed field gel electrophoresis fingerprints identified M. avium isolates clonally related to the patients’ isolates. We conclude that patients with treatment-resistant CRS may be infected with NTM and should have cultures performed for NTM so appropriate therapy can be instituted. In addition, the results suggest that CRS patients can be infected by NTM in their household plumbing.

Biomarkers in acutely decompensated heart failure with preserved or reduced ejection fraction

BACKGROUND

Acute decompensated heart failure (ADHF) occurs with preserved (heart failure with preserved ejection fraction [HFpEF] ≥50%) or reduced (heart failure with reduced ejection fraction [HFrEF] <50%) ejection fraction. Natriuretic peptide (NP) levels are lower in HFpEF than HFrEF. We hypothesized that lower NP levels in HFpEF may be associated with other differences in biomarkers, specifically, renin-angiotensin-aldosterone system (RAAS) activation, oxidative stress, and a biomarker that reflects collagen synthesis.

METHODS

In this prespecified ancillary analysis of patients with ADHF enrolled in the Diuretic Optimization Strategies Evaluation study, clinical features and N-terminal pro-B-type NP, cystatin C, plasma renin activity, aldosterone, oxidative stress (uric acid), and procollagen type III N-terminal peptide were compared in HFpEF and HFrEF at enrollment and 60-day follow-up.

RESULTS

Compared with HFrEF (n = 219), HFpEF (n = 81) patients were older, heavier, more commonly female, less treated with RAAS antagonists, but with similar New York Heart Association class, jugular venous pressure, and edema severity. N-terminal pro-B-type NP was lower, and systolic blood pressure and cystatin C were higher in HFpEF. Despite higher systolic blood pressure and less RAAS antagonist use in HFpEF, plasma renin activity and aldosterone levels were similar in HFpEF and HFrEF as were uric acid and procollagen type III N-terminal peptide levels. Changes in biomarker levels from enrollment to 60 days were similar between HFrEF (n = 149) and HFpEF (n = 50).

CONCLUSION

Lower NP levels in decompensated HFpEF occur in association with similar ADHF severity, more impaired vascular and renal function but similar elevation of biomarkers that reflect RAAS activation, oxidative stress, and collagen synthesis as in HFrEF.

Sulfonamide resistance in isolates of Nocardia spp. from a US multicenter survey

Recent reports of increasing in vitro sulfonamide resistance in Nocardia prompted us to investigate the findings. Despite the reports, there is a paucity of clinical reports of sulfonamide failure in treatment of nocardia disease. We reviewed 552 recent susceptibilities of clinical isolates of Nocardia from six major laboratories in the United States, and only 2% of the isolates were found to have resistant MICs of trimethoprim-sulfamethoxazole and/or sulfamethoxazole. We hypothesize that the discrepancies in the apparent sulfonamide resistance between our study and the previous findings may be associated with difficulty in the laboratory interpretation of in vitro MICs for trimethoprim-sulfamethoxazole and sulfamethoxazole and the lack of quality controls for Nocardia for these agents.

Short-course raltegravir intensification does not reduce persistent low-level viremia in patients with HIV-1 suppression during receipt of combination antiretroviral therapy

BACKGROUND

Combination antiretroviral therapy suppresses but does not eradicate human immunodeficiency virus type 1 (HIV-1) in infected persons, and low-level viremia can be detected despite years of suppressive antiretroviral therapy. Short-course (28-day) intensification of standard antiretroviral combination therapy is a useful approach to determine whether complete rounds of HIV-1 replication in rapidly cycling cells contribute to persistent viremia. We investigated whether intensification with the integrase inhibitor raltegravir decreases plasma HIV-1 RNA levels in patients receiving suppressive antiretroviral therapy.

METHODS

Subjects (n = 10) with long-term HIV-1 suppression receiving combination antiretroviral regimens had their regimens intensified for 4 weeks with raltegravir. Plasma HIV-1 RNA level was determined before, during, and after the 4-week intensification period, using a sensitive assay (limit of detection, 0.2 copies of HIV-1 RNA/mL of plasma). A 4-week intensification course was chosen to investigate potential HIV-1 replication in cells with relatively short (approximately 1-14-day) half-lives.

RESULTS

There was no evidence in any subject of a decline in HIV-1 RNA level during the period of raltegravir intensification or of rebound after discontinuation. Median levels of HIV-1 RNA before (0.17 log10 copies/mL), during (0.04 log10 copies/mL), and after (0.04 log10 copies/mL) raltegravir intensification were not significantly different (P > .1 for all comparisons in parametric analyses). High-performance liquid chromatography and mass spectroscopy experiments confirmed that therapeutic levels of raltegravir were achieved in plasma during intensification.

CONCLUSIONS

Intensification of antiretroviral therapy with a potent HIV-1 integrase inhibitor did not decrease persistent viremia in subjects receiving suppressive regimens, indicating that rapidly cycling cells infected with HIV-1 were not present. Eradication of HIV-1 from infected persons will require new therapeutic approaches.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00618371.

Platelet inhibition with cangrelor in patients undergoing PCI

BACKGROUND

Cangrelor, a nonthienopyridine adenosine triphosphate analogue, is an intravenous blocker of the adenosine diphosphate receptor P2Y(12). This agent might have a role in the treatment of patients who require rapid, predictable, and profound but reversible platelet inhibition.

METHODS

We performed a large-scale international trial comparing cangrelor with 600 mg of oral clopidogrel administered before percutaneous coronary intervention (PCI) in patients with acute coronary syndromes. The primary efficacy end point was a composite of death from any cause, myocardial infarction, or ischemia-driven revascularization at 48 hours.

RESULTS

We enrolled 8877 patients, and 8716 underwent PCI. At 48 hours, cangrelor was not superior to clopidogrel with respect to the primary composite end point, which occurred in 7.5% of patients in the cangrelor group and 7.1% of patients in the clopidogrel group (odds ratio, 1.05; 95% confidence interval [CI], 0.88 to 1.24; P=0.59). Likewise, cangrelor was not superior at 30 days. The rate of major bleeding (according to Acute Catheterization and Urgent Intervention Triage Strategy criteria) was higher with cangrelor, a difference that approached statistical significance (3.6% vs. 2.9%; odds ratio, 1.26; 95% CI, 0.99 to 1.60; P=0.06), but this was not the case with major bleeding (according to the Thrombolysis in Myocardial Infarction criteria) or severe or life-threatening bleeding (according to Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries criteria). A secondary exploratory end point of death from any cause, Q-wave myocardial infarction, or ischemia-driven revascularization showed a trend toward a reduction with cangrelor, but it was not significant (0.6% vs. 0.9%; odds ratio, 0.67; 95% CI, 0.39 to 1.14; P=0.14).

CONCLUSIONS

Cangrelor, when administered intravenously 30 minutes before PCI and continued for 2 hours after PCI, was not superior to an oral loading dose of 600 mg of clopidogrel, administered 30 minutes before PCI, in reducing the composite end point of death from any cause, myocardial infarction, or ischemia-driven revascularization at 48 hours. (ClinicalTrials.gov number, NCT00305162.)

Intravenous platelet blockade with cangrelor during PCI

BACKGROUND

Intravenous cangrelor, a rapid-acting, reversible adenosine diphosphate (ADP) receptor antagonist, might reduce ischemic events during percutaneous coronary intervention (PCI).

METHODS

In this double-blind, placebo-controlled study, we randomly assigned 5362 patients who had not been treated with clopidogrel to receive either cangrelor or placebo at the time of PCI, followed by 600 mg of clopidogrel. The primary end point was a composite of death, myocardial infarction, or ischemia-driven revascularization at 48 hours. Enrollment was stopped when an interim analysis concluded that the trial would be unlikely to show superiority for the primary end point.

RESULTS

The primary end point occurred in 185 of 2654 patients receiving cangrelor (7.0%) and in 210 of 2641 patients receiving placebo (8.0%) (odds ratio in the cangrelor group, 0.87; 95% confidence interval [CI], 0.71 to 1.07; P=0.17) (modified intention-to-treat population adjusted for missing data). In the cangrelor group, as compared with the placebo group, two prespecified secondary end points were significantly reduced at 48 hours: the rate of stent thrombosis, from 0.6% to 0.2% (odds ratio, 0.31; 95% CI, 0.11 to 0.85; P=0.02), and the rate of death from any cause, from 0.7% to 0.2% (odds ratio, 0.33; 95% CI, 0.13 to 0.83; P=0.02). There was no significant difference in the rate of blood transfusion (1.0% in the cangrelor group and 0.6% in the placebo group, P=0.13), though major bleeding on one scale was increased in the cangrelor group, from 3.5% to 5.5% (P<0.001), because of more groin hematomas.

CONCLUSIONS

The use of periprocedural cangrelor during PCI was not superior to placebo in reducing the primary end point. The prespecified secondary end points of stent thrombosis and death were lower in the cangrelor group, with no significant increase in the rate of transfusion. Further study of intravenous ADP blockade with cangrelor may be warranted. (ClinicalTrials.gov number, NCT00385138.)

Gender differences in correlates of troponin assay in diagnosis of myocardial infarction

Cardiac troponins are the most sensitive and specific biomarker for myocardial infarction (MI) diagnosis. If there is a gender bias in MI diagnosis, it could be reduced by more consistently applying objective diagnostic criteria to improve women's outcomes. This study set out to assess the accuracy and correlates of the cardiac troponin I (cTnI) assay in the diagnosis of non-ST-segment elevation MI, to determine how the assay accuracy and correlates vary by gender, and to explore the interaction between factors that may influence cTnI accuracy and affect gender differences in diagnosis. The data were obtained from the CHECKMATE study. It included 924 patients with possible myocardial ischemia excluding subjects with ST-segment elevation. The Dade-Behring Stratus CS STAT near-patient instrument (Dade Behring, Inc, Newark, Del) was used to measure cTnI. We assessed baseline troponin accuracy using a standard MI definition. There were 125 subjects with a definite MI diagnosis. Baseline troponin was 44% sensitive and 97% specific in predicting MI, with no significant gender differences. In contrast, other positive cardiac markers, namely rising or falling creatine-kinase MB fraction and positive electrocardiogram, occurred more frequently in men. Sensitivity (SE) of baseline troponin was higher in subjects where baseline troponin was obtained longer than 2 hours after the chest pain onset. The study did not observe a significant difference in the assay SE or specificity by gender. This observation, plus the fact that other positive cardiac markers occurred more frequently in men, suggest the troponin test may help to improve the diagnosis of MI in women.

An exploratory analysis of the impact of family functioning on treatment for depression in adolescents

This article explores aspects of family environment and parent-child conflict that may predict or moderate response to acute treatments among depressed adolescents (N = 439) randomly assigned to fluoxetine, cognitive behavioral therapy, their combination, or placebo. Outcomes were Week 12 scores on measures of depression and global impairment. Of 20 candidate variables, one predictor emerged: Across treatments, adolescents with mothers who reported less parent-child conflict were more likely to benefit than their counterparts. When family functioning moderated outcome, adolescents who endorsed more negative environments were more likely to benefit from fluoxetine. Similarly, when moderating effects were seen on cognitive behavioral therapy conditions, they were in the direction of being less effective among teens reporting poorer family environments.

Role of microvolt T-wave alternans in assessment of arrhythmia vulnerability among patients with heart failure and systolic dysfunction: primary results from the T-wave alternans sudden cardiac death in heart failure trial substudy

BACKGROUND

Sudden cardiac death remains a leading cause of mortality despite advances in medical treatment for the prevention of ischemic heart disease and heart failure. Recent studies showed a benefit of implantable cardioverter defibrillator implantation, but appropriate shocks for ventricular tachyarrhythmias were noted only in a minority of patients during 4 to 5 years of follow-up. Accordingly, better risk stratification is needed to optimize patient selection. In this regard, microvolt T-wave alternans (TWA) has emerged as a potentially useful measure of arrhythmia vulnerability, but it has not been evaluated previously in a prospective, randomized trial of implantable cardioverter defibrillator therapy.

METHODS AND RESULTS

This investigation was a prospective substudy of the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) that included 490 patients at 37 clinical sites. TWA tests were classified by blinded readers as positive (37%), negative (22%), or indeterminate (41%) by standard criteria. The composite primary end point was the first occurrence of any of the following events: sudden cardiac death, sustained ventricular tachycardia/fibrillation, or appropriate implantable cardioverter defibrillator discharge. During a median follow-up of 30 months, no significant differences in event rates were found between TWA-positive or -negative patients (hazard ratio 1.24, 95% confidence interval 0.60 to 2.59, P=0.56) or TWA-negative and nonnegative (positive and indeterminate) subjects (hazard ratio 1.28, 95% confidence interval 0.65 to 2.53, P=0.46). Similar results were obtained with the inclusion or exclusion of patients randomized to amiodarone in the analyses.

CONCLUSIONS

TWA testing did not predict arrhythmic events or mortality in SCD-HeFT, although a small reduction in events (20% to 25%) among TWA-negative patients cannot be excluded given the sample size of this study. Accordingly, these results suggest that TWA is not useful as an aid in clinical decision making on implantable cardioverter defibrillator therapy among patients with heart failure and left ventricular systolic dysfunction.