Catheter ablation for atrial fibrillation in adult congenital heart disease: an international registry study

Background

Life expectancies for patients with congenital heart disease (CHD) have dramatically increased in recent years, accompanied by a rise in atrial fibrillation (AF) prevalence. Data on AF ablation strategy and outcomes are limited in CHD.

Purpose

We aimed to investigate the characteristics of CHD patients presenting for AF ablation and their outcomes.

Methods

A multicenter, retrospective analysis was performed of CHD patients undergoing AF ablation between 2004 and 2020 at 13 participating centers. The severity of CHD was classified using the 2014 PACES/HRS guidelines. Clinical data were collected including ablation strategy and follow up. One-year procedural success was defined as freedom from AF in the absence of antiarrhythmic drugs (AADs, complete) or including previously failed AADs (partial).

Results

Of 240 patients, 127 (53.4%) had persistent AF, 62.5% were male, and mean age was 55.2±0.9 years. CHD complexity categories included 147 (61.3%) simple, 69 (28.8%) intermediate and 25 (10.4%) severe. The most common CHD type was atrial septal defect (n=78). More complex CHD conditions included transposition of the great arteries (n=14), anomalous pulmonary veins (n=13), tetralogy of Fallot (n=8), cor triatriatum (n=7), single ventricle physiology (n=2), among others. The majority (71.3%) of patients had AF despite at least one AAD. 46 patients (22.1%) had a reduced systemic ventricular ejection fraction <50%, and the mean left atrial diameter was 44.1±0.7 mm. PV isolation (PVI) was performed in 227 patients (94.6%); additional ablation strategies included left atrial linear ablations (25.4%), CFAE (19.2%), and cavotricuspid isthmus ablation (40.8). One-year complete and partial success rates were 45.0% and 20.5%, respectively, with no significant difference in the rate of complete success between complexity groups. Overall, 38 patients (15.8%) required more than one ablation procedure. There were 3 (1.3%) major and 13 (5.4%) minor procedural complications.

Conclusion

AF ablation in this complex population was safe and resulted in AF control in the majority of patients. Future work should address the most appropriate ablation targets in the challenging population.

Funding Acknowledgement

Type of funding sources: None.

An electrocardiographic diagnostic model for differentiating right from left ventricular outflow tract arrythmias origin

Background/Introduction

Several ECG signs have been proposed to discern the focal origin of ventricular outflow tract arrhythmias with a transition ≥V3. Their independent predictive value is unclear.

Purpose

The aim of the study is to establish a predictive model of independent ECG parameters to obtain an acute success in right-sided catheter ablation of isolated premature ventricular contractions (PVCs) or ventricular tachycardia (VT) from the ventricular outflow tract with a transition ≥V3.

Methods

We included 122 patients (62 women, mean age 54±16 years) with documented PVCs or VT showing a lower axis and predominantly negative QRS complexes in V1 and V2 who underwent ablation between January 2014 and June 2020. The achievement of acute ablation success from right endocardial positions was assessed. We performed a predictive model by multivariate logistic regression analysis including the following ECG variables associated with a right origin of the ventricular focus in previous studies: Transitional Zone (TZ) index, V2 transition ratio, V2S / V3R index, R-wave duration index, R/S-wave amplitude index in V2, variable coupling interval, and the presence of QS morphology in lead I.

Results

Two independent predictive ECG variables were identified: the V2S / V3R index (odds ratio 1.223; 95% CI, 1.024–1.460; p=0.026) and a coupling interval variability >60 ms (odds ratio 0.307; 95% CI, 0.129 - 0.731; p=0.008). The area under the curve of this model was 0.733 (Picture 1). Arrhythmias with transition in V3 present a greater electroanatomic overlap and, therefore, a higher probability of right failure (59.3% vs 73.5% in arrhythmias with transitions after V3). In these, the V2 transition ratio is useful to predict the origin of the ectopy.

Conclusion

Two easily identifiable ECG variables (the V2S / V3R index and coupling interval variability >60 ms) predict the acute success of a right-sided approach in the ablation of focal ventricular arrhythmias with predominantly negative QRS complexes in V1 and V2.

Funding Acknowledgement

Type of funding sources: None. Predictive accuracy of the ECG model

Rotational activity presence and its impact in persistent atrial fibrillation follow-up

Introduction

Treatment of atrial fibrillation (AF) remains sub-optimal, with low success in pulmonary vein isolation (PVI) ablation procedures in long-standing-persistent AF patients. The maintenance mechanisms of AF are still under debate. Rotational activity (RA) events, also known as rotors, may play a role in perpetuating AF. The characterisation of these drivers during electroanatomical (EA) guided ablation procedures in relationship with follow-up and recurrence ratios in AF patients is necessary to design new ablation strategies to improve the AF treatment success.

Purpose

We report an AF patient cohort of endocardial mapping and PVI ablation procedures with additional RA events detected during the EA study. We aim to study the presence and distribution of RA in AF patients and its impact on AF recurrence when only PVI ablation is performed.

Methods

75 persistent consecutive AF patients (age 60.7±9.8, 74.7% men) underwent EA mapping and RA detection with an automatic algorithm. The presence of RA was annotated on the EA map based on the unipolar electrograms (EGMs) registered with a 20-pole catheter. RA presence was analysed at different left atrial locations (37.2±14.8 sites per patient). AF recurrence was evaluated in follow-up after treatment.

Results

At follow-up (9±5 months), 50% of the patients presented AF recurrence. Patients with RA had more dilated atria in terms of volumes (p=0.002) and areas (p=0.001). Patients with RA exhibited higher mean voltage EGMs 0.6±0.3 mV vs 0.5±0.2 mV (p=0.036), with shorter cycle lengths 169.1±26.0 ms vs. 188.4±44.2 ms (p=0.044). Finally, patients with RA presented more AF recurrence rates than patients with no RA events (p=0.007). No significant differences were found in terms of comorbidities, e.g., heart failure, hypertension, COPD, stroke, SHD, or diabetes mellitus.

Conclusions

The results show that patients with more RA events and those with RA outside the PVI ablated regions presented higher AF recurrence episodes than those with no RA or events inside the areas affected by radio-frequency ablation. The study suggests that further ablation treatment of the areas harboring RA might be necessary to reduce the recurrence ratio in AF patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III; Sociedad Española de Cardiología

Evaluation of atrial complexity of patients undergoing atrial fibrillation ablation: a clinical computational study

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Supported in part by the Instituto de Salud Carlos III (PI16/01123, DTS16/0160, PI17/010559, PI17/01106 and PI20/01618); Spanish Ministry of Science and Innovation (CIRBER CV); and cofound by FEDER: Fondo Europeo de Desarrollo Regional. EITHealth 19600 AFFINE.

Background

Pulmonary veins (PV) electrical isolation is the cornerstone of atrial fibrillation (AF treatment), but other proarrhythmic areas of the atria may trigger or sustain AF.

Objective

We used computer simulations to analyze AF complexity measured using non-invasive electrocardiographic imaging (ECGi).

Methods

We included 30 patients that underwent PVI. Personalized simulations using biatrial anatomies segmented from MRI images and an automata model for modeling the electrical activity were compared with ECGi results to evaluate the long-term outcome of AF ablation.

Results

Simulation maps closely correlated with the rotors histogram obtained from patients´ ECGi: high entropy areas from simulations matched the areas with higher density of rotor presence on the ECGi. Simulations revealed that successful ablations occurred in patients with rotors mainly located at the PV area, while unsuccessful ablations presented an increased number of high entropy foci, greater distribution of rotors along the atria and lower number of PV rotors. The number of rotors attached to the PV was significantly higher in patients with favorable long-term ablation outcome (1-year AF Freedom: 1.61 ± 0.21 vs. AF: 1.40 ± 0.20; p-value = 0.018).

Conclusion

This simulation approach could improve patient screening and ablation design prior to the intervention providing information of the complexity of the atria. Abstract Figure. Rotor maps, ACM and ACB for 3 patients

Reverse remodeling of the atria in patients with rheumatic mitral stenosis: impact of balloon mitral commissurotomy plus atrial fibrillation ablation

Introduction

Chronic Atrial stretch is an important determinant for atrial fibrillation (AF) in patients with rheumatic mitral stenosis (RMS).

Purpose

We analysed the effect of balloon mitral commissurotomy (BMC) plus atrial fibrillation ablation on the long-term occurrence of AF as compared to isolated BMC.

Methods

We prospectively included 20 patients with severe RMS undergoing BMC+AF ablation (Intervention) and compared it with a retrospective sample of 53 RMS patients that underwent BMC (Control). AF ablation consisted in pulmonary vein isolation and driver ablation identified using intracardiac basket mapping. We followed patients for 1 year after the procedure in both groups. Clinical values were evaluated in both groups. Propensity score matching was computed in order to evaluate the effect of the intervention and to analyse the impact of clinical properties of each group.

Results

At baseline, there were no statistical differences in gender (90% vs. 85%) and mitral valve area (1.2±0.18 vs. 1.17±0.18 cm2) between intervention and control groups, respectively. In contrast, there were differences in age (65±12 vs. 72±12; p=0.01) and AF incidence prior to the procedure (90% vs. 62%; p=0.001) between intervention and control groups, respectively. Patients undergoing AF ablation underwent successful pulmonary vein isolation in all cases and driver ablation at sites located in the right atrium (RA) in 7 (35%) patients. Median dominant frequency was significantly higher in the right atrium (DF RA 4.9±0.6 vs. DF LA 3.9±0.7 Hz; p=0.003) prior the intervention. After the intervention, it was significantly reduced only in the left atrium (LA) (DF RA 4.5±1 vs. DF LA 3.2±0.6 Hz; p=0.02 for Pre vs. Post DF LA). Three (15%) patients converted to sinus rhythm during ablation, the remaining were cardioverted. After 1-year follow-up, the proportion of patients in sinus rhythm was significantly higher in patients undergoing BMC+AF (90%) vs. isolated BMC (45%; p<0.001) (Graph). In the isolated BMC group, 4 patients converted to sinus rhythm and 1 patient in sinus rhythm prior to the procedure converted to AF at 1-year.

Conclusion

This observational study demonstrates that the combination of BMC+AF ablation significantly increses the proportion of patients in sinus rhythm at 1-year as compared to isolated BMC. Reverse remodelling of the atrial substrate following isolated BMC also converted to sinus rhythm a small proportion of patients with persistent AF at baseline. Thus, although reversal of atrial stretch changes by BMC could potentially terminate AF in some patients, the combined intervention with catheter ablation will successfully maintain sinus rhythm in the majority of patients in the study.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): FIS by Instituto de Salud Carlos III

FRI0180 SURVEY ON HELP-SEEKING AND DISEASE TRAJECTORY IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Few studies in Latin America have analysed the time lag since patients experience the first joint symptoms until they consult a physician, and a diagnosis is made, and most of them have dealt with patients sustaining Rheumatoid Arthritis (RA)1-2.

Objectives:

To study both patient and disease factors that have some bearing on the time lag until a physician is first consulted and a diagnosis is made.

Methods:

Multiple-choice survey to patients of 18 years of age or older who metSystemic Lupus Erythematosus (SLE) Classification Criteria (2012). The following aspects were measured:time lag from symptom onset to first medical consultation (Time 1), time lag since first medical consultation until a diagnosis is made (Time 2), and time lag until the first consultation with a rheumatologist.

Patients were interviewed at the time or within 6 months of diagnosis, and asked about the physician they first consulted and the one who made the diagnosis. They were also requested to describe one disease onset out of 4 trajectories: acute, acute with temporary remissions, chronic with partial improvements, or sustained chronic. Patients were required to recount their response to the first symptoms, the limitations brought about by the disease (employing the Steinbrocker scale), and whether help-seeking was first aimed at consulting a physician or they decided to wait. A group of patients with Rheumatoid Arthritis (RA) answered the same survey. Every patient signed an informed consent form, and the study was approved by the Hospital Bioethics Committee.

Results:

Twenty-eight patients with SLE and 29 patients with RA filled in the survey. SLE patients were younger as expected (32 years vs 49 years; p <0.001). Acute was the most common disease trajectory in SLE patients (36% vs 34%; p 0.8) and chronic in RA (38% vs 32%; p 0.8). The first professional consulted was an on-duty physician in SLE (36% vs 24% in RA; p 0.5). Except for the matter of computer at home and/or a mobile phone with an Internet connection at home, both groups were similar, although SLE patients showed a trend to better level education and lesser impact of the disease on daily life at the beginning (see Table 1).

Table 1.SLERAPn2829Education (median)SecondarySecondary0.07Had a job11 (39%)15 (52%)0.5Had health insurance8 (29%)15 (52%)0.1Had computer/mobile phone with an Internet connection25(89%)18(62)%0.04Steinbrocker (median with range 25-75%)3(2-3)3(3-4)0.06Immediately sought medical help15 (54%)16 (56%)0.9Did not know what to do when the first symptoms appeared7 (25%)13(45%)0.2Diagnosis made by a rheumatologist20 (71%)23 (80%)0.7

Time 1 in patients with SLE was significantly lower with a median of 7 days, range(25-75%)1-30 days vs 30 days in RA, range 14-180 (p 0.01), and the former also showed a trend to lower median Time 2: 81 days, range 25-209 vs 185 days in RA, range 60-275 (p 0.1). Besides, they showed a significantly shorter time lag until the first visit to a rheumatologist with a median of 120 days, range 35-225 vs 330 days, range 120-450 in patients with RA (p 0.005).

Conclusion:

SLE patients consult a physician and visit a rheumatologist sooner than RA patients do, and they also show a trend to obtain a faster diagnosis. Education, health insurance, employment, the disease impact on their daily life and initial response to the symptoms do not appear to account for their swiftness in seeking medical help.

References:

[1]Mussano E, Missakian S, Onetti CM (2007) Estudio demográficosocial de pacientes con artritis reumatoidea en la provincia de Córdoba (Argentina). Rev Argent Reumatol 4:13–22.

[2]Rodríguez-Polanco E, Al Snih S, Kuo YF et al (2011) Lag time between onset of symptoms and diagnosis in Venezuelan patients with rheumatoid arthritis. Rheumatol Int 31:657–665. doi:10.1007/s00296-009-1358-9.

Disclosure of Interests:

None declared

FRI0605-HPR MORTALITY AND SURVIVAL IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS IN ARGENTINA. A MULTICENTER STUDY ON BEHALF GESAR-LES

Background:

The mortality rate in patients with systemic lupus erythematosus (SLE) is 2–3 times higher than in the general population. However, survival in these patients has improved significantly and is currently 95% at 5 years according to different studies. Since the last 20 years, there are no new reports on this issue in Argentina.

Objectives:

To analyze the factors associated with mortality, survival and causes of death in patients with SLE.

Methods:

Longitudinal - multicenter study, in which 10 rheumatology centers of Argentina participated. Patients with SLE (ACR 1997 and / or SLICC 2012 criteria) with a minimum follow-up of 6 months monitored between January 2008 and December 2018 were included. Demographic, clinical, laboratory, therapeutic variables (treatments received during the evolution of the disease and within 60 days prior to death or last control); mortality, causes of death and survival at 5, 10 and 20 years were evaluated. Statistical analysis: descriptive statistics, Kaplan-Meier survival curves and Cox regression model.

Results:

Three hundred and eighty two patients were included; 90% women and 82% mestizos. The mean of evolution time of SLE was 4.1 ± 6.7 years. The mean age at the last control or death was 37.2 ± 12.7 years, SLEDAI 3.2 ± 4.2 and SLICC 1.2 ± 1.9.

Mortality was 12% (95% CI [8-15]) and the causes of death were: Infections (27), cardiovascular disease (6), SLE activity (3), catastrophic antiphospholipid syndrome (2) and other causes (8). Using the variables associated with mortality in different Cox regression models, the variables that increased the risk of death significantly were: renal involvement (RR 3.3), cardiac involvement (RR 2.7), central nervous system involvement (RR 2.1), arterial thrombosis (RR 2.3), hyperlipemia (RR 2.4), number of infections (RR 1.2) and last SLEDAI (1.1).

The time of HCQ use greater than 36 months decreased the risk of death in this cohort by 40% (p 0.03). Prednisone (maximum dose and time) was not associated with mortality (p NS). When analyzing the last treatment and adjusting it for final SLEDAI, HCQ was a mortality protection factor (RR 0.4) while the use of cyclophosphamide alone or associated with prednisone was a risk factor for death (RR 5.2).

Significant differences were found when analyzing the causes of death according to the SLE evolution time (p 0.017): patients who died from infection had less evolution time (Me 2.25 years), than those who died due to cardiovascular causes (Me 10 years) or SLE activity (Me 15 years). In this cohort of patients, survival was 93% at 5 years, 88% at 10 years and 72% at 20 years.

Conclusion:

Mortality in this series of patients was 12% and infection was the leading cause of death. The use of HCQ for a period greater than 36 months, decreased the risk of death 40%.

Disclosure of Interests:

None declared

2397Lesion-specific risk for sudden cardiac death or life-threatening ventricular arrhythmias in adult congenital heart disease

Background

Risk models for primary prevention strategies in adult congenital heart disease (ACHD) must incorporate the heterogeneous risk for sudden cardiac death (SCD) and life-threatening ventricular arrhythmias (LTVA) as stratified by underlying lesion.

Objectives

To determine lesion-specific risk for SCD and LTVA in ACHD.

Methods

We analyzed 3311 ACHD patients (50% males) prospectively followed-up for 37510 person/years. SCD cases were confirmed by means of the Spanish National Death Registry. In addition, we identified all cases of resuscitated cardiac arrest or ventricular tachycardia requiring cardioversion. According to the incidence rate of the composite end-point of SCD and LTVA, lesions were stratified into four groups of risk. Cumulative freedom from SCD or LTVA in patients at high, moderate, low and very low risk were compared by using Cox regression model with left truncation. The c-index of this lesion-specific risk stratification was calculated by using the β-coefficients. The discriminative ability of this lesion-specific risk stratification was also tested in an external cohort of 203 SCD-LTVA cases and 2287 controls from 20 different centers.

Results

71 patients experienced an event (53 SCD, 18 LTVA). Patients at highest risk (incidence rate >1%) were those with Rastelli procedure, severe coronary abnormalities, complex Fallot and cyanotic patients, either Eisenmenger or non-Eisenmenger; at moderate risk (incidence rate 0.25–1.0%) non-complex Fallot, Mustard/Senning repair, Fontan procedures and congenitally corrected transposition; at low risk (incidence rate 0.1–0.25%) Ebstein anomaly and left heart lesions; and at very low risk (incidence rate <0.1%) left-to-right shunts and right ventricular outflow lesions. The discriminative ability in a multicenter external cohort was excellent (c-index ranged from 0.748 to 0.819 by center).

Lesion-specific risk and C-index

Conclusions

A lesion-specific risk stratification based on the incidence rate of SCD and LTVA was performed and validated. This approach could result in a more individualized risk assessment.

Acknowledgement/Funding

Instituto de Salud Carlos III, Ministerio de Economía y Competividad, Spain (Exp PI14/02099 and PI17/01327) and co-financed by FEDER

An admixture mapping meta-analysis implicates genetic variation at 18q21 with asthma susceptibility in Latinos

BACKGROUND

Asthma is a common but complex disease with racial/ethnic differences in prevalence, morbidity, and response to therapies.

OBJECTIVE

We sought to perform an analysis of genetic ancestry to identify new loci that contribute to asthma susceptibility.

METHODS

We leveraged the mixed ancestry of 3902 Latinos and performed an admixture mapping meta-analysis for asthma susceptibility. We replicated associations in an independent study of 3774 Latinos, performed targeted sequencing for fine mapping, and tested for disease correlations with gene expression in the whole blood of more than 500 subjects from 3 racial/ethnic groups.

RESULTS

We identified a genome-wide significant admixture mapping peak at 18q21 in Latinos (P = 6.8 × 10-6), where Native American ancestry was associated with increased risk of asthma (odds ratio [OR], 1.20; 95% CI, 1.07-1.34; P = .002) and European ancestry was associated with protection (OR, 0.86; 95% CI, 0.77-0.96; P = .008). Our findings were replicated in an independent childhood asthma study in Latinos (P = 5.3 × 10-3, combined P = 2.6 × 10-7). Fine mapping of 18q21 in 1978 Latinos identified a significant association with multiple variants 5' of SMAD family member 2 (SMAD2) in Mexicans, whereas a single rare variant in the same window was the top association in Puerto Ricans. Low versus high SMAD2 blood expression was correlated with case status (13.4% lower expression; OR, 3.93; 95% CI, 2.12-7.28; P < .001). In addition, lower expression of SMAD2 was associated with more frequent exacerbations among Puerto Ricans with asthma.

CONCLUSION

Ancestry at 18q21 was significantly associated with asthma in Latinos and implicated multiple ancestry-informative noncoding variants upstream of SMAD2 with asthma susceptibility. Furthermore, decreased SMAD2 expression in blood was strongly associated with increased asthma risk and increased exacerbations.

Breastfeeding associated with higher lung function in African American youths with asthma

OBJECTIVE

In the United States, Puerto Ricans and African Americans have lower prevalence of breastfeeding and worse clinical outcomes for asthma compared with other racial/ethnic groups. We hypothesize that the history of breastfeeding is associated with increased forced expiratory volume in 1 second (FEV1) % predicted and reduced asthma exacerbations in Latino and African American youths with asthma.

METHODS

As part of the Genes-environments & Admixture in Latino Americans (GALA II) Study and the Study of African Americans, asthma, Genes & Environments (SAGE II), we conducted case-only analyses in children and adolescents aged 8-21 years with asthma from four different racial/ethnic groups: African Americans (n = 426), Mexican Americans (n = 424), mixed/other Latinos (n = 255), and Puerto Ricans (n = 629). We investigated the association between any breastfeeding in infancy and FEV1% predicted using multivariable linear regression; Poisson regression was used to determine the association between breastfeeding and asthma exacerbations.

RESULTS

Prevalence of breastfeeding was lower in African Americans (59.4%) and Puerto Ricans (54.9%) compared to Mexican Americans (76.2%) and mixed/other Latinos (66.9%; p < 0.001). After adjusting for covariates, breastfeeding was associated with a 3.58% point increase in FEV1% predicted (p = 0.01) and a 21% reduction in asthma exacerbations (p = 0.03) in African Americans only.

CONCLUSION

Breastfeeding was associated with higher FEV1% predicted in asthma and reduced number of asthma exacerbations in African American youths, calling attention to continued support for breastfeeding.

Granulocyte colony-stimulating factor blockade enables dexamethasone to inhibit lipopolysaccharide-induced murine lung neutrophils

Glucocorticoids promote neutrophilic inflammation, the mechanisms of which are poorly characterized. Using a lipopolysaccharide (LPS)-induced acute murine lung injury model, we determined the role of granulocyte colony-stimulating factor (G-CSF) in mouse lung neutrophil numbers in the absence and presence of dexamethasone, a potent glucocorticoid. G-CSF was blocked using a neutralizing antibody. Airway neutrophil numbers, cytokine levels, and lung injury parameters were measured. Glucocorticoid treatment maintained LPS-induced airway G-CSF while suppressing TNF and IL-6. The addition of anti-G-CSF antibodies enabled dexamethasone to decrease airway G-CSF, neutrophils, and lung injury scores. In LPS-challenged murine lungs, structural cells and infiltrating leukocytes produced G-CSF. In vitro using BEAS 2B bronchial epithelial cells, A549 lung epithelial cells, human monocyte-derived macrophages, and human neutrophils, we found that dexamethasone and proinflammatory cytokines synergistically induced G-CSF. Blocking G-CSF production in BEAS 2B cells using shRNAs diminished the ability of BEAS 2B cells to protect neutrophils from undergoing spontaneous apoptosis. These data support that G-CSF plays a role in upregulation of airway neutrophil numbers by dexamethasone in the LPS-induced acute lung injury model.

Clinical Characteristics of Patients with Chronic Rhinosinusitis with Nasal Polyps, Asthma, and Aspirin-Exacerbated Respiratory Disease

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) comprises the triad of chronic rhinosinusitis with nasal polyps (CRSwNP), asthma, and intolerance to inhibitors of the cyclooxygenase-1 (COX-1) enzyme. The prevalence of AERD remains unclear, and few studies have compared the clinical characteristics of patients with AERD to those with CRSwNP alone, asthma alone, or both CRSwNP and asthma.

OBJECTIVE

To determine the prevalence of AERD within a tertiary care setting, and to identify unique clinical features that could distinguish these patients from those with both CRSwNP and asthma or with CRSwNP alone.

METHODS

Electronic medical records of patients at Northwestern in Chicago, Illinois, were searched by computer algorithm and then manual chart review to identify 459 patients with CRSwNP alone, 412 with both CRSwNP and asthma, 171 with AERD, and 300 with asthma only. Demographic and clinical features including sex, atopy, and sinus disease severity were characterized.

RESULTS

The prevalence of AERD among patients with CRSwNP was 16%. Patients with AERD had undergone 2-fold more sinus surgeries (P < .001) and were significantly younger at the time of their first surgery (40 ± 13 years) than were patients with CRSwNP (43 ± 14 years; P < .05). Atopy was significantly more prevalent in patients with AERD (84%) or asthma (85%) than in patients with CRSwNP (66%, P < .05). More patients with AERD (13%) had corticosteroid-dependent disease than patients with both CRSwNP and asthma (4%, P < .01) or asthma (1%, P < .001).

CONCLUSIONS

AERD is common among patients with CRSwNP; even though patients with AERD have CRSwNP and asthma, the clinical course of their disease is not the same as of patients who have CRSwNP and asthma but are tolerant to COX-1 inhibitors.

Sensitization to mouse and cockroach allergens and asthma morbidity in urban minority youth: Genes-environments and Admixture in Latino American (GALA-II) and Study of African-Americans, Asthma, Genes, and Environments (SAGE-II)

BACKGROUND

Pest allergen sensitization is associated with asthma morbidity in urban youth but minimally explored in Latino populations. Specifically, the effect of mouse sensitization on the risk of asthma exacerbation has been unexplored in Latino subgroups.

OBJECTIVE

To evaluate whether pest allergen sensitization is a predictor of asthma exacerbations and poor asthma control in urban minority children with asthma.

METHODS

Latino and African American children (8-21 years old) with asthma were recruited from 4 sites across the United States. Logistic regression models evaluated the association of mouse or cockroach sensitization with asthma-related acute care visits or hospitalizations.

RESULTS

A total of 1,992 children with asthma in the Genes-environments and Admixture in Latino American (GALA-II) and Study of African-Americans, Asthma, Genes, and Environments (SAGE-II) cohorts were studied. Asthmatic children from New York had the highest rate of pest allergen sensitization (42% mouse, 56% cockroach), with the lowest rate in San Francisco (4% mouse, 8% cockroach). Mouse sensitization, more than cockroach, was associated with increased odds of acute care visits (adjusted odds ratio [aOR], 1.47; 95% CI, 1.07-2.03) or hospitalizations (aOR, 3.07; 95% CI, 1.81-5.18), even after controlling for self-reported race and site of recruitment. In stratified analyses, Mexican youth sensitized to mouse allergen did not have higher odds of asthma exacerbation. Other Latino and Puerto Rican youth sensitized to mouse had higher odds of hospitalization for asthma (aORs, 4.57 [95% CI, 1.86-11.22] and 10.01 [95% CI, 1.77-56.6], respectively) but not emergency department visits.

CONCLUSION

Pest allergen sensitization is associated with a higher odds of asthma exacerbations in urban minority youth. Puerto Rican and Other Latino youth sensitized to mouse were more likely to have asthma-related hospitalizations than Mexican youth.

Investigating fusion plasma instabilities in the Mega Amp Spherical Tokamak using mega electron volt proton emissions (invited)

The proton detector (PD) measures 3 MeV proton yield distributions from deuterium-deuterium fusion reactions within the Mega Amp Spherical Tokamak (MAST). The PD's compact four-channel system of collimated and individually oriented silicon detectors probes different regions of the plasma, detecting protons (with gyro radii large enough to be unconfined) leaving the plasma on curved trajectories during neutral beam injection. From first PD data obtained during plasma operation in 2013, proton production rates (up to several hundred kHz and 1 ms time resolution) during sawtooth events were compared to the corresponding MAST neutron camera data. Fitted proton emission profiles in the poloidal plane demonstrate the capabilities of this new system.

Effect of vitamin D3 on asthma treatment failures in adults with symptomatic asthma and lower vitamin D levels: the VIDA randomized clinical trial

IMPORTANCE

In asthma and other diseases, vitamin D insufficiency is associated with adverse outcomes. It is not known if supplementing inhaled corticosteroids with oral vitamin D3 improves outcomes in patients with asthma and vitamin D insufficiency.

OBJECTIVE

To evaluate if vitamin D supplementation would improve the clinical efficacy of inhaled corticosteroids in patients with symptomatic asthma and lower vitamin D levels.

DESIGN, SETTING, AND PARTICIPANTS

The VIDA (Vitamin D Add-on Therapy Enhances Corticosteroid Responsiveness in Asthma) randomized, double-blind, parallel, placebo-controlled trial studying adult patients with symptomatic asthma and a serum 25-hydroxyvitamin D level of less than 30 ng/mL was conducted across 9 academic US medical centers in the National Heart, Lung, and Blood Institute's AsthmaNet network, with enrollment starting in April 2011 and follow-up complete by January 2014. After a run-in period that included treatment with an inhaled corticosteroid, 408 patients were randomized.

INTERVENTIONS

Oral vitamin D3 (100,000 IU once, then 4000 IU/d for 28 weeks; n = 201) or placebo (n = 207) was added to inhaled ciclesonide (320 µg/d). If asthma control was achieved after 12 weeks, ciclesonide was tapered to 160 µg/d for 8 weeks, then to 80 µg/d for 8 weeks if asthma control was maintained.

MAIN OUTCOMES AND MEASURES

The primary outcome was time to first asthma treatment failure (a composite outcome of decline in lung function and increases in use of β-agonists, systemic corticosteroids, and health care).

RESULTS

Treatment with vitamin D3 did not alter the rate of first treatment failure during 28 weeks (28% [95% CI, 21%-34%] with vitamin D3 vs 29% [95% CI, 23%-35%] with placebo; adjusted hazard ratio, 0.9 [95% CI, 0.6-1.3]). Of 14 prespecified secondary outcomes, 9 were analyzed, including asthma exacerbation; of those 9, the only statistically significant outcome was a small difference in the overall dose of ciclesonide required to maintain asthma control (111.3 µg/d [95% CI, 102.2-120.4 µg/d] in the vitamin D3 group vs 126.2 µg/d [95% CI, 117.2-135.3 µg/d] in the placebo group; difference of 14.9 µg/d [95% CI, 2.1-27.7 µg/d]).

CONCLUSIONS AND RELEVANCE

Vitamin D3 did not reduce the rate of first treatment failure or exacerbation in adults with persistent asthma and vitamin D insufficiency. These findings do not support a strategy of therapeutic vitamin D3 supplementation in patients with symptomatic asthma.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01248065.

Photocatalysis for continuous air purification in wastewater treatment plants: from lab to reality

The photocatalytic efficiency of TiO(2)-SiMgO(x) plates to oxidize H(2)S was first evaluated in a flat laboratory reactor with 50 mL min(-1) synthetic air containing 100 ppm H(2)S in the presence of humidity. The use of the photocatalyst-adsorbent hybrid material enhanced the photocatalytic activity in terms of pollutant conversion, selectivity, and catalyst lifetime compared to previous H(2)S tests with pure TiO(2) because total H(2)S elimination was maintained for more than 30 operating hours with SO(2) appearing in the outlet as reaction product only after 18 h. Subsequently, the hybrid material was successfully tested in a photoreactor prototype to treat real polluted air in a wastewater treatment plant. For this purpose, a new tubular photocatalytic reactor that may use solar radiation in combination with artificial radiation was designed; the lamp was turned on when solar UV-A irradiance was below 20 W m(-2), which was observed to be the minimum value to ensure 100% conversion. The efficient distribution of the opaque photocatalyst inside the tubular reactor was achieved by using especially designed star-shaped structures. These structures were employed for the arrangement of groups of eight TiO(2)-SiMgO(x) plates in easy-to-handle channelled units obtaining an adequate flow regime without shading. The prototype continuously removed during one month and under real conditions the H(2)S contained in a 1 L min(-1) air current with a variable inlet concentration in the range of tens of ppmv without release of SO(2).

Association of elevated plasminogen activator inhibitor 1 levels with diminished lung function in patients with asthma

BACKGROUND

We previously reported that plasminogen activator inhibitor 1 (PAI-1) was upregulated in human asthmatic airways and promotes airway fibrosis in an allergen-challenged murine model of asthma.

OBJECTIVES

To examine whether elevated plasma levels of PAI-1 are associated with poor lung function in asthmatic patients.

METHODS

Five hundred nineteen adults were eligible for the study, and ultimately 353 adults were enrolled and completed the baseline protocol between January 24, 2004, and July 30, 2005. Of these, 231 adults with asthma from the Chicago Initiative to Raise Asthma Health Equity study were randomly selected and the plasma levels of PAI-1 were measured by enzyme-linked immunosorbent assay. Asthma burden, medication, smoking status, and body mass index (BMI) were obtained by history and spirometry was performed. A multivariate regression analysis was performed to evaluate the association of PAI-1 levels and lung function and the potential determinant variables that were associated with PAI-1.

RESULTS

We found associations between PAI-1 and BMI (β = 0.606, P = .002), smoking (β = 7.526, P = .001), and African American race (β = -9.061, P = .01). Obese patients showed a significant increase in PAI-1, and current smokers demonstrated higher levels of PAI-1 compared with nonsmokers. When we evaluated the associations between lung function parameters and PAI-1, we found that PAI-1 was negatively associated with forced vital capacity (FVC) (β = -0.098, P = .011) but not with forced expiratory volume in 1 second (FEV(1)) or the FEV(1)/FVC ratio. There was a negative association between BMI and FVC, and PAI-1 may mediate some of this association.

CONCLUSIONS

This study suggests a significant association between PAI-1 and lung function in patients with asthma. The effect of obesity on FVC may in part be mediated by PAI-1.

Differential enzymatic activity of common haplotypic versions of the human acidic Mammalian chitinase protein

Mouse models have shown the importance of acidic mammalian chitinase activity in settings of chitin exposure and allergic inflammation. However, little is known regarding genetic regulation of AMCase enzymatic activity in human allergic diseases. Resequencing the AMCase gene exons we identified 8 non-synonymous single nucleotide polymorphisms including three novel variants (A290G, G296A, G339T) near the gene area coding for the enzyme active site, all in linkage disequilibrium. AMCase protein isoforms, encoded by two gene-wide haplotypes, and differentiated by these three single nucleotide polymorphisms, were recombinantly expressed and purified. Biochemical analysis revealed the isoform encoded by the variant haplotype displayed a distinct pH profile exhibiting greater retention of chitinase activity at acidic and basic pH values. Determination of absolute kinetic activity found the variant isoform encoded by the variant haplotype was 4-, 2.5-, and 10-fold more active than the wild type AMCase isoform at pH 2.2, 4.6, and 7.0, respectively. Modeling of the AMCase isoforms revealed positional changes in amino acids critical for both pH specificity and substrate binding. Genetic association analyses of AMCase haplotypes for asthma revealed significant protective associations between the variant haplotype in several asthma cohorts. The structural, kinetic, and genetic data regarding the AMCase isoforms are consistent with the Th2-priming effects of environmental chitin and a role for AMCase in negatively regulating this stimulus.

[Referral to internal medicine for alcoholism: influence on follow-up care]

BACKGROUND AND AIMS

The problem of high rates of patient drop-out in alcohol treatment programs is frequently reported in the literature. Our aim was to investigate if internal medicine referral could improve abstinence and retention rates in a cohort of alcoholic patients.

PATIENTS AND METHODS

A retrospective observational study was conducted comparing 200 alcoholic patients attending a psychiatric unit (group 1) with 100 patients attending both this unit and an internal medicine unit (group 2). We collected sociodemographic and clinical variables and analysed differences regarding abstinence and retention rates by means of univariate and multivariate analysis.

RESULTS

At 3 and 12 months follow-up, group 2 patients had higher retention and abstinence rates than group 1 patients. Multivariate analysis including potential confounding variables showed that independent predictors of one-year retention were internal medicine referral and being married. Independent predictors of one-year abstinence were being married, age > 44 years and receipt of drug treatment.

CONCLUSIONS

The higher retention rate found among patients referred to Internal Medicine specialists, a result that has not been previously reported to the best of our knowledge, emphasizes the importance of a multidisciplinary team approach in the treatment of alcoholism.

On the preparation of TiO2-sepiolite hybrid materials for the photocatalytic degradation of TCE: influence of TiO2 distribution in the mineralization

Hybrid structured photocatalysts based on sepiolite, an adsorbent, and TiO2 were prepared by extrusion of ceramic dough and conformed as plates. The influence of the photocatalyst configuration was studied either by including TiO2 in the extrusion process (incorporated materials) or by coating the sepiolite plates with a TiO2 film (coated materials). The influence of the OH- surface concentration in the photocatalytic performance was studied by treating the ceramic plates at different temperatures. The samples were characterized by N2 adsorption-desorption, MIP, SEM, XRD, and UV-vis-NIR spectroscopy and tested in the photocatalytic degradation of trichloroethylene (TCE) as a target VOC molecule. Most of the catalysts presented high photoactivity, but considerable differences were observed when the CO2 selectivity was analyzed. The results demonstrate that there is a significant effect of the catalyst configuration on the selectivity of the process. An intimate contact between the sepiolite fibers and TiO2 particles for incorporated materials with a corncob-like structure favored the migration of nondesirable reaction products such as COCl2 and dichloroacetyl chloride (DCAC) to the adsorbent, reacting with OH- groups of the adsorbent and favoring the TCE mimeralization.

Rhinovirus induces airway epithelial gene expression through double-stranded RNA and IFN-dependent pathways

Rhinovirus (RV) infection is the major cause of common colds and of asthma exacerbations. Because the epithelial cell layer is the primary target of RV infection, we hypothesize that RV-induced airway disease is associated with the perturbation of airway epithelial gene expression. In this study, well differentiated primary human airway epithelial cells were infected with either RV16 (major group) or RV1B (minor group). Transcriptional gene profiles from RV-infected and mock-infected control cells were analyzed by Affymetrix Genechip, and changes of the gene expression were confirmed by real-time RT-PCR analysis. At 24 h after infection, 48 genes induced by both viruses were identified. Most of these genes are related to the IFN pathway, and have been documented to have antiviral functions. Indeed, a significant stimulation of IFN-beta secretion was detected after RV16 infection. Neutralizing antibody specific to IFN-beta and a specific inhibitor of the Janus kinase pathway both significantly blocked the induction of RV-inducible genes. Further studies demonstrated that 2-aminopurine, a specific inhibitor double-stranded RNA-dependent protein kinase, could block both IFN-beta production and RV-induced gene expression. Thus, IFN-beta-dependent pathway is a part of the double-stranded RNA-initiated pathway that is responsible for RV-induced gene expression. Consistent with its indispensable role in the induction of antiviral genes, deactivation of this signaling pathway significantly enhanced viral production. Because increase of viral yield is associated with the severity of RV-induced airway illness, the discovery of an epithelial antiviral signaling pathway in this study will contribute to our understanding of the pathogenesis of RV-induced colds and asthma exacerbations.

Relationship between airway inflammation, hyperresponsiveness, and obstruction in asthma

BACKGROUND

Although the role of eosinophils in airway inflammation in chronic asthma has been extensively studied, a role for neutrophils has not been well characterized. Furthermore, prior studies have not systematically sought or controlled for factors that might confound the relationship between cellular markers of inflammation and physiologic measures of airway function.

OBJECTIVE

The purpose of this study was to determine whether eosinophilic and neutrophilic inflammation independently contribute to abnormalities of airway function in asthma.

METHODS

Multivariate analysis of data collected during screening and enrollment of 205 asthmatic adults for clinical trials was conducted to examine the relationships between cellular inflammation in induced sputum and FEV(1) and methacholine responsiveness (PC(20)) while confounding factors were controlled for.

RESULTS

We found that age, sex, ethnicity, and use of inhaled corticosteroids were important confounding factors of the relationship between cellular inflammation and airway function. When these factors were controlled for, multivariate analysis showed that eosinophil percentage in induced sputum is independently associated with lower FEV(1) and lower PC(20) (P = .005 and P = .005, respectively). In the same models, increased sputum neutrophil percentage is independently associated with lower FEV(1) (P = .038) but not with PC(20) (P = .49).

CONCLUSIONS

These results suggest that both eosinophilic inflammation and neutrophilic inflammation independently contribute to abnormalities of FEV(1) in asthma. Therapies directed specifically at control of neutrophilic inflammation might be useful in improving airway caliber in patients with chronic asthma.

Two active-site tyrosyl residues of protein TrwC act sequentially at the origin of transfer during plasmid R388 conjugation

Protein TrwC is the relaxase-helicase responsible for the initiation and termination reactions of DNA processing during plasmid R388 conjugation. Site-directed mutagenesis was used to change to phenylalanine each of a set of four conserved tyrosyl residues in the sequence of the N-terminal relaxation domain of the protein. Simultaneous mutation of both Y18 and Y26 was required to abolish in vitro cleavage and strand-transfer reactions catalyzed by protein TrwC on oligonucleotides containing the nic site. Thus, both Y18 and Y26 could be involved independently in the formation of oligonucleotide-protein covalent complexes that constitute presumed intermediates of these reactions. This hypothesis was confirmed by the observation of Y18 and Y26-specific peptide-oligonucleotide adducts after protease digestion of TrwC and mutant derivatives. Finally mutation Y18F, but not mutation Y26F, abolished nic-cleavage of a supercoiled DNA containing the R388 origin of transfer (oriT). These data allowed the construction of a model for conjugative DNA processing in which Y18 specifically catalyzes the initial cleavage reaction, while Y26 is used for the second strand-transfer reaction, which terminates conjugation. The model suggests a control mechanism that can be effective at each conjugative replication cycle.

A hot spot in plasmid F for site-specific recombination mediated by Tn21 integron integrase

Integron In2 integrase (IntI1)-mediated site-specific recombination between two primary sites occurs at a high frequency, while that between a primary and a secondary site occurs at frequencies around 10,000 times lower. Secondary sites consist of a pentanucleotide with only two fully conserved residues (GWTMW). The analysis of IntI1-mediated recombinants in the plasmid pOX38 revealed the existence in this plasmid of a site used at a frequency intermediate between those of primary and secondary sites. Analysis of this site showed two potentially relevant structural features: first, a set of two consensus pentanucleotides, separated by 5 bp and in opposite orientations, forming what will be called a double site; and second, a longer sequence with some extent of sequence symmetry with the double site at its 3' end. A recombinant plasmid, pSU18P, containing a double site was constructed. Examination of R388-pSU18P recombinants showed that double sites were used preferentially over single pentanucleotides by IntI1. Comparisons of the nucleotide sequences of known 59-bp elements showed that in most cases there was a double site at each element end. Mutagenesis of the F hot spot was carried out to make it look more like the consensus 59-bp element. The improved sites showed recombination frequencies and specificities almost comparable to those observed at IntI1 primary sites.

Genes involved in conjugative DNA processing of plasmid R6K

The conjugative transfer region of the IncX plasmid R6K (TRA(x)) was analysed by transposon mutagenesis and DNA sequencing. Tn5tac1 insertional mutations localized TRA(x) to a 14.8 kb segment containing the alpha origin of transfer (oriT alpha), genes involved in conjugative DNA-processing (Dtr(x)) and genes involved in pilus synthesis and assembly (Mpf(x)). A second functional oriT, oriTbeta, was located at a distance of 5.3 kb from oriT alpha and was outside TRA(x). Mpf(x) occupied a segment of 10kb, as judged by the location of insertions conferring resistance to infection by the X pilus-specific phage X-2. At both sides of Mpf(x) there were insertions that were Tra but X-2 sensitive, suggesting that the mutations were in Dtr(x). This region was sequenced and three genes were identified: taxA, taxB, and taxC. The overall organization was oriT alpha-taxA-taxC-Mpf(x)-taxB. taxC coded for a oriT-relaxase that belongs to the VirD2 family. taxA coded for a protein of 181 amino acids that showed similarity to TraY of F-like plasmids and to the Arc-repressor superfamily. TaxB showed similarity to TraG-like proteins, a protein superfamily probably involved in coupling the relaxosome to the DNA-transport apparatus. TaxA and TaxC are required for oriT nicking in vivo. The nicking reaction was mistakenly assumed by Flashner et al. (1996) to represent a feature of the vegetative replication origins. However, insertions or deletions disrupting taxA and taxC affected conjugation but not replication of R6K. Conversely, protein pi, which is absolutely required for replication of R6K, was not required for conjugative transfer. In addition, protein DDP3, which is also assumed to have a role in replication, was found to be a positive modulator of bacterial conjugation. Taken together, these results rule out a direct and essential involvement of conjugation proteins in R6K vegetative replication, and also rule out the requirement of replication protein pi for conjugation.