Long-term outcomes of index cryoballoon ablation or point-by-point radiofrequency ablation in patients with atrial fibrillation and systolic heart failure.

Catheter ablation is an established effective approach for the treatment of atrial fibrillation (AF) in patients with heart failure, however, the role of cryoablation in this setting is unclear. Procedural success and left ventricular systolic dysfunction (LVEF) improvement in patients with LVEF ≤ 45% undergoing index catheter ablation with cryoablation were evaluated. Freedom from AF recurrence was seen in 43% rising to 59% following repeat procedure. There were significant improvements in LVEF and functional status at long-term follow-up. Results were comparable to a contemporaneous cohort of heart failure patients undergoing index ablation with radiofrequency ablation. Cryoablation is an effective first-line AF ablation approach in the setting of heart failure.

Initial experience with the convergent procedure for longstanding persistent atrial fibrillation: A 5 year dataset.

In patients with longstanding persistent atrial fibrillation (AF), outcomes from catheter ablation remain suboptimal. The convergent procedure combines minimally invasive surgical ablation with subsequent catheter ablation, and may contribute towards maintenance of sinus rhythm in this patient group. We performed the convergent procedure on 43 patients with longstanding persistent AF from 2013-2018. Patients underwent clinical review at 3, 6, and 12 months and thereafter as necessitated by their symptoms. Our dataset describes patients' baseline characteristics and rhythm control protocols, as well as outcomes including arrhythmia recurrence, the need for antiarrhythmic drugs, requirement for repeat rhythm control procedures, and complications. These data provide a real world insight into the risks and benefits of the convergent procedure in patients with longstanding persistent AF.

The convergent procedure versus catheter ablation alone in longstanding persistent atrial fibrillation: A single centre, propensity-matched cohort study.

BACKGROUND: Maintenance of sinus rhythm is challenging in patients with longstanding persistent atrial fibrillation (PeAF). Minimally invasive surgical AF ablation may improve outcomes when combined with catheter ablation (the 'convergent' procedure). This study evaluates the safety and efficacy of the convergent procedure versus catheter ablation alone in longstanding PeAF. METHODS: 43 consecutive patients with longstanding PeAF underwent subxiphoid endoscopic ablation of the posterior left atrium followed by catheter ablation from 2013 to 2018. The primary outcome was AF-free survival at 12 months; secondary outcomes included change in EHRA class, echocardiographic data, procedural complications, freedom from anti-arrhythmic drugs (AADs), and long term arrhythmia-free survival. Outcomes were compared with a matched group of 43 patients who underwent catheter ablation alone. Both groups underwent multiple catheter ablations as required. Baseline characteristics were similar between groups. RESULTS: After 12 months, the convergent procedure was associated with increased AF-free survival on AADs (60.5% versus 25.6%, p = .002) and off AADs (37.2% versus 13.9%, p = .025), versus catheter ablation. Allowing for multiple procedures, after 30.5 ±â€¯13.3 months' follow-up the convergent procedure was associated with increased arrhythmia-free survival on AADs (58.1% versus 30.2%, p = .016) and off AADs (32.5% versus 11.6%, p = .036) versus catheter ablation. There were more complications in the convergent procedure group (11.6% versus 2.3%, p = .2). Multivariate analysis identified only the convergent procedure (OR 3.06 (1.23-7.6), p = .017) as predictive of arrhythmia-free survival long term. CONCLUSIONS: In longstanding PeAF, the convergent procedure is associated with improved arrhythmia-free survival versus catheter ablation alone. Complication rates are significant but have been shown to depreciate with experience.

Validation of a novel mapping system and utility for mapping complex atrial tachycardias.

INTRODUCTION: This study sought to validate a novel wavefront mapping system utilizing whole-chamber basket catheters (CARTOFINDER, Biosense Webster). The system was validated in terms of (1) mapping atrial-paced beats and (2) mapping complex wavefront patterns in atrial tachycardia (AT). METHODS AND RESULTS: Patients undergoing catheter ablation for AT and persistent AF were included. A 64-pole-basket catheter was used to acquire unipolar signals that were processed by CARTOFINDER mapping system to generate dynamic wavefront propagation maps. The left atrium was paced from four sites to demonstrate focal activation. ATs were mapped with the mechanism confirmed by conventional mapping, entrainment, and response to ablation. Twenty-two patients were included in the study (16 with AT and 6 with AF initially who terminated to AT during ablation). In total, 172 maps were created with the mapping system. It correctly identified atrial-pacing sites in all paced maps. It accurately mapped 9 focal/microreentrant and 18 macroreentrant ATs both in the left and right atrium. A third and fourth observer independently identified the sites of atrial pacing and the AT mechanism from the CARTOFINDER maps, while being blinded to the conventional activation maps. CONCLUSIONS: This novel mapping system was effectively validated by mapping focal activation patterns from atrial-paced beats. The system was also effective in mapping complex wavefront patterns in a range of ATs in patients with scarred atria. The system may therefore be of practical use in the mapping and ablation of AT and could have potential for mapping wavefront activations in AF.

Applications of cardiac computed tomography in electrophysiology intervention.

Cardiac electrophysiology is an evolving specialty that has seen rapid advances in recent years. Concurrently, there has been much progress in the field of cardiac imaging. Electrophysiologists are increasingly requesting cross-sectional imaging in advance of many procedures. Pulmonary vein isolation and left atrial appendage (LAA) occlusion are now an established treatment options for atrial fibrillation. In patients undergoing pulmonary vein isolation, applications of computed tomography (CT) include evaluating the left atrial and pulmonary venous anatomy, excluding LAA thrombus and assessing for pulmonary vein stenosis. In those undergoing LAA occlusion, CT may be of value in assessing the size, position, and morphology of the LAA as well as for determining correct positioning of the device and evaluating for peri-device leak. Implantable cardiac devices are now commonly used in the management of cardiac failure and cardiac arrhythmias. Applications of CT prior to device implantation include detecting myocardial scar, evaluating for mechanical dyssynchrony as well as visualising the coronary venous anatomy.

Analysis of pulmonary non-tuberculous mycobacterial infections after lung transplantation.

PURPOSE: Non-tuberculous mycobacteria (NTM) are important pathogens in lung transplant recipients. This study describes the spectrum of NTM respiratory tract infections and examines the association of NTM infections with lung transplant complications. METHODS: Data from 208 recipients transplanted from November 1990 to November 2005 were analyzed. Follow-up data were available to November 2010. Lung infection was defined by bronchoalveolar lavage, sputum, or blood cultures in the appropriate clinical setting. All identified NTM respiratory tract infections were tabulated. The cohort of patients with NTM lung infections (NTM+) were compared to the cohort without infection (NTM-). Univariate and multivariate analysis was performed to determine characteristics associated with NTM infection. Survival analyses for overall survival and development of bronchiolitis obliterans syndrome (BOS) were also performed. RESULTS: In total, 52 isolates of NTM lung infection were identified in 30 patients. The isolates included Mycobacterium abscessus (46%), Mycobacterium avium complex (MAC) (36%), Mycobacterium gordonae (9%), Mycobacterium chelonae (7%), and Mycobacterium fortuitum (2%), with multiple NTM isolates seen on 3 different occasions. The overall incidence was 14%, whereas cumulative incidences at 1, 3, and 5 years after lung transplantation were 11%, 15%, and 20%, respectively. Comparisons between the NTM+ and NTM- cohorts revealed that NTM+ patients were more likely to be African-American and have cytomegalovirus mismatch. Although no difference was seen in survival, the NTM+ cohort was more likely to develop BOS (80% vs. 58%, P = 0.02). NTM+ infection, however, was not independently associated with development of BOS by multivariate analysis. CONCLUSION: With nearly 20 years of follow-up, 14% of lung recipients develop NTM respiratory tract infections, with M. abscessus and MAC more commonly identified. M. gordonae was considered responsible for nearly 10% of NTM infections. Although survival of patients with NTM infections is similar, a striking difference in BOS rates is present in the NTM+ and NTM- groups.

Lung Quality and Utilization in Controlled Donation After Circulatory Determination of Death Within the United States.

Although controlled donation after circulatory determination of death (cDCDD) could increase the supply of donor lungs within the United States, the yield of lungs from cDCDD donors remains low compared with donation after neurologic determination of death (DNDD). To explore the reason for low lung yield from cDCDD donors, Scientific Registry of Transplant Recipient data were used to assess the impact of donor lung quality on cDCDD lung utilization by fitting a logistic regression model. The relationship between center volume and cDCDD use was assessed, and the distance between center and donor hospital was calculated by cDCDD status. Recipient survival was compared using a multivariable Cox regression model. Lung utilization was 2.1% for cDCDD donors and 21.4% for DNDD donors. Being a cDCDD donor decreased lung donation (adjusted odds ratio 0.101, 95% confidence interval [CI] 0.085-0.120). A minority of centers have performed cDCDD transplant, with higher volume centers generally performing more cDCDD transplants. There was no difference in center-to-donor distance or recipient survival (adjusted hazard ratio 1.03, 95% CI 0.78-1.37) between cDCDD and DNDD transplants. cDCDD lungs are underutilized compared with DNDD lungs after adjusting for lung quality. Increasing transplant center expertise and commitment to cDCDD lung procurement is needed to improve utilization.

Solid-substrate bioprocessing of cow dung for the production of carboxymethyl cellulase by Bacillus halodurans IND18.

The production of carboxymethyl cellulase (CMCase) by Bacillus halodurans IND18 under solid substrate fermentation (SSF) using cow dung was optimized through two level full factorial design and second order response surface methodology (RSM). The central composite design (CCD) was employed to optimize the vital fermentation parameters, such as pH of the substrate, concentration of nitrogen source (peptone) and ion (sodium dihydrogen phosphate) sources in medium for achieving higher enzyme production. The optimum medium composition was found to be 1.46% (w/w) peptone, 0.095% (w/w) sodium dihydrogen phosphate and pH 8.0. The model prediction of 4210IU/g enzyme activity at optimum conditions was verified experimentally as 4140IU/g. The enzyme was active over a broad temperature range (40-60±1°C) and pH (7.0-9.0) with maximal activity at 60±1°C and pH 8.0. This study demonstrated the potential of cow dung as novel substrate for CMCase production.

The natural history of atrial fibrillation in patients with permanent pacemakers: is atrial fibrillation a progressive disease?

OBJECTIVES: Atrial fibrillation (AF) is thought to be a progressive arrhythmia, starting with short paroxysmal episodes, until eventually, it becomes permanent. Evidence for this is limited to studies with short follow-up or with minimal cardiac rhythm monitoring. We utilised the continuous rhythm monitoring capabilities of implanted pacemakers to define better the natural history of AF. METHODS: The study included 356 patients with pacemaker devices capable of continuous atrial rhythm monitoring (186 male, mean age (± SD) 79.5 ± 8.9 years). All clinical records, including history/physical examination reports, laboratory results, ECGs and Holter monitoring data were reviewed. Patients were included if AF episodes >30 s were documented. Permanent pacemaker diagnostic data were reviewed at least every 12 months. ACC/AHA/ESC guidelines were used to define AF episodes as paroxysmal, persistent or long-standing persistent/permanent. RESULTS: Study follow-up period (± SD) was 7.2 ± 3.1 years. Over the study period, 179 of 356 patients (50.3 %) had at least one episode of persistent AF. Of the 356 patients, 314 (88.2 %) had paroxysmal AF and 42 (11.8 %) had persistent AF at the time of diagnosis. The predominant AF subtype, at latest follow-up, was paroxysmal for 192 patients (53.9 %), persistent for 77 (21.6 %) and long-standing persistent/permanent for 87 (24.4 %). Univariable predictors of progression to persistent AF were (1) male gender, (2) increasing left atrial diameter (LAD), (3) reduced atrial pacing (AP) and (4) increasing ventricular pacing. CONCLUSIONS: Although many patients with AF will have persistent episodes, long-term continuous pacemaker follow-up demonstrates that the majority will have a paroxysmal, as opposed to persistent, form of the arrhythmia.

Invasive mold infections in lung and heart-lung transplant recipients: Stanford University experience.

BACKGROUND: Recipients of lung transplantation (LT) and heart-lung transplantation (HLT) are at increased risk of infection, including invasive mold infections (IMIs). The clinical presentation, radiographic correlates, and outcomes of Aspergillus and non-AspergillusIMIs in this population have not been well documented. METHODS: LT and HLT recipients diagnosed with IMIs between 1990 and 2012 were identified using the Stanford Translational Research Integrated Database Environment and Stanford LT and HLT clinical database. Recipient clinical and radiographic characteristics were obtained via retrospective review of medical records and compared between Aspergillus and non-Aspergillus mold recipients. Risk factors for mortality were identified using multivariate logistic regression analysis. RESULTS: During the study period, 87 (14%) transplant recipients were diagnosed with IMIs. Aspergillus species were isolated in 63 (72%) and non-Aspergillus molds in 24 (28%) recipients. No significant difference was seen in presenting symptoms or radiographic findings between Aspergillus and non-Aspergillus mold recipients. Median time to diagnosis was 363 days in the Aspergillus group and 419 days in the non-Aspergillus group, with dissemination occurring only within the non-Aspergillus group (12.5%). Overall 90-day and 1-year mortality following IMI was 24% and 44%. One-year mortality was increased in the non-Aspergillus group (39.5% vs. 60.5%, P = 0.03). CONCLUSIONS: There is significant overlap in risk factors, presentation, and radiographic patterns in IMI in LT or HLT recipients. Non-Aspergillus molds were more likely to present late, with disseminated disease, and portend increased 1-year mortality.

Impact of the lung allocation score on survival beyond 1 year.

Implementation of the lung allocation score (LAS) in 2005 led to transplantation of older and sicker patients without altering 1-year survival. However, long-term survival has not been assessed and emphasizing the 1-year survival metric may actually sustain 1-year survival while not reflecting worsening longer-term survival. Therefore, we assessed overall and conditional 1-year survival; and the effect of crossing the 1-year threshold on hazard of death in three temporal cohorts: historical (1995-2000), pre-LAS (2001-2005) and post-LAS (2005-2010). One-year survival post-LAS remained similar to pre-LAS (83.1% vs. 82.1%) and better than historical controls (75%). Overall survival in the pre- and post-LAS cohorts was also similar. However, long-term survival among patients surviving beyond 1 year was worse than pre-LAS and similar to historical controls. Also, the hazard of death increased significantly in months 13 (1.44, 95% CI 1.10-1.87) and 14 (1.43, 95% CI 1.09-1.87) post-LAS but not in the other cohorts. While implementation of the LAS has not reduced overall survival, decreased survival among patients surviving beyond 1 year in the post-LAS cohort and the increased mortality occurring immediately after 1 year suggest a potential negative long-term effect of the LAS and an unintended consequence of increased emphasis on the 1-year survival metric.

Retrospective study of chikungunya outbreak in urban areas of India.

BACKGROUND & OBJECTIVES: A retrospective study on chikungunya outbreak in India in five States viz. Delhi, Madhya Pradesh, Orissa, Maharashtra and Kerala was conducted in 2007-2008 to know the distribution and determinants of chikungunya fever outbreak in India. METHODS: On the basis of high and low incidence of chikungunya fever, two districts from each State and two wards from the selected district were taken for random selection of 1000 households from 10 districts and 5 States. Semi-structured questionnaires were administered to individuals, patients, qualified health professionals and to stakeholders for collecting information. RESULTS: The educational background and occupation of the respondents showed variations across the study States. Only in high incidence ward of Maharashtra, water storage period for 3-6 days and emptying, drying of water containers on weekly basis was noted. The study through knowledge, attitude, belief, practice (KABP) obtained individual's perception of chikungunya fever, its prevention and control. Patients' expenditure on treatment was mainly recorded less than Rs 500 across study States. Health facility survey obtained an overview of the capacity of local health facilities. Stakeholders' perception regarding chikungunya fever was also noted. INTERPRETATION & CONCLUSIONS: The study revealed differences in awareness of chikungunya, cause of the disease, vector responsible, mode of transmission, biting time and elimination of breeding of mosquitoes statistically significant among high and low incidence wards of all the States. Expenditure on treatment was independent of economically active status and loss of man-days across all the States. Education and occupation did not have any relation with emptying/drying of water containers in high incidence wards. Strengthening of surveillance, information, education and communication (IEC) activities along with case management facilities may be provided by the State health department for prevention of chikungunya outbreaks in future. Stakeholders should be more involved in outbreak management and future planning.

A young patient with heart failure: picture quiz question.

Case report A 28 year old gentleman presented after an episode of collapse with loss of consciousness. He gave a history of non-specific malaise and myalgia over the previous 7 days, with fever, a generalised rash and a non productive cough. He developed progressive shortness of breath with sharp, pleuritic chest pain that was unresponsive to antibiotics in the community.

Multimodality imaging of cecal bascule: report of a case following pelvic surgery.

Volvulus of the cecum is a relatively insignificant cause of intestinal obstruction in the Western world, comprising <2 % of all cases. Cecal bascule is a related entity in which the cecum folds cephalad and anteromedially over the ascending colon, forming a 'flap-valve' occlusion in the transverse plane. We report a case of cecal bascule in a patient following pelvic surgery with emphasis on clinical presentation, radiologic findings and treatment.

Bioproduction of hydrolytic enzymes using apple pomace waste by A. niger: applications in biocontrol formulations and hydrolysis of chitin/chitosan.

Studies were carried out for ß-glucosidase production using apple pomace (AP) in solid-state fermentation using 2(4) factorial design and response surface methodology. The influence of four independent variables including initial moisture level and inducers [veratryl alcohol (VA), lactose (LAC) and copper sulfate (CS)] was studied. The experimental design showed that initial moisture level had significant negative effect on the response. Higher ß-glucosidase activity of 64.18 IU/gram fermented substrate (gfs) was achieved in solid-state tray fermentation with optimum conditions having initial moisture level 55% (v/w), pH 4.5, 2 mM/kg VA, 2% (w/w) LAC and 1.5 mM/kg CS concentration, respectively,. The non-specific chitinase 70.28 ± 6.34 IU/gfs and chitosanase activities 60.18 ± 6.82 to 64.20 ± 7.12 IU/gfs were observed. The study demonstrated that AP can be potentially used for the ß-glucosidase production by Aspergillus niger. Moreover, ß-glucosidase can be used for the hydrolysis of chitin/chitosan to depolymerized products and in the formulation of biocontrol agents for enhanced entomotoxicity levels.

Enhanced solid-state citric acid bio-production using apple pomace waste through surface response methodology.

AIMS: To evaluate the potential of apple pomace (AP) supplemented with rice husk for hyper citric acid production through solid-state fermentation by Aspergillus niger NRRL-567. Optimization of two key parameters, such as moisture content and inducer (ethanol and methanol) concentration was carried out by response surface methodology. METHODS AND RESULTS: In this study, the effect of two crucial process parameters for solid-state citric acid fermentation by A. niger using AP waste supplemented with rice husk were thoroughly investigated in Erlenmeyer flasks through response surface methodology. Moisture and methanol had significant positive effect on citric acid production by A. niger grown on AP (P < 0·05). Higher values of citric acid on AP by A. niger (342·41gkg(-1) and 248·42gkg(-1) dry substrate) were obtained with 75% (v/w) moisture along with two inducers [3% (v/w) methanol and 3% (v/w) ethanol] with fermentation efficiency of 93·90% and 66·42%, respectively depending upon the total carbon utilized after 144h of incubation period. With the same optimized parameters, conventional tray fermentation was conducted. The citric acid concentration of 187·96gkg(-1) dry substrate with 3% (v/w) ethanol and 303·34gkg(-1) dry substrate with 3% (v/w) methanol were achieved representing fermentation efficiency of 50·80% and 82·89% in tray fermentation depending upon carbon utilization after 120h of incubation period. CONCLUSIONS: Apple pomace proved to be the promising substrate for the hyper production of citric acid through solid-state tray fermentation, which is an economical technique and does not require any sophisticated instrumentation. SIGNIFICANCE AND IMPACT OF THE STUDY: The study established that the utilization of agro-industrial wastes have positive repercussions on the economy and will help to meet the increasing demands of citric acid and moreover will help to alleviate the environmental problems resulting from the disposal of agro-industrial wastes.

Lung function, radiological changes and exposure: analysis of ATSDR data from Libby, MT, USA.

In 2000, the Agency for Toxic Substances and Disease Registry (ATSDR; Atlanta, GA, USA) investigated lung disease in those exposed to the tremolite-contaminated vermiculite mine in Libby, MT, USA. Previously unreported spirometric results are presented here in relation to exposure and radiographic findings. 4,524 study participants were assigned to one of seven mutually exclusive exposure categories. Associations among radiographic findings, spirometric results and exposure were investigated, along with the effect of a reduction in exposure potential when production was moved to a wet process mill in the mid 1970s. Spirometry data for the total population by smoking status and age were within the normal range. Prevalence of pleural plaque increased with age, but was lowest in the environmentally exposed group (0.42-12.74%) and greatest in the W.R. Grace & Co. mineworkers (20-45.68%). For males, there was a significant (4.5%) effect of pleural plaques on forced vital capacity. For W.R. Grace & Co. workers and household contacts, a reduction in plaque (0.11 versus 1.64%) and in diffuse pleural thickening or costophrenic angle obliteration (1.94 and 0.13%) was noted for those exposed after 1976. These analyses do not support a clinically important reduction in spirometry of this cohort. The 1976 reductions in exposure have led to decrease in radiographic changes.

Increasing lung allocation scores predict worsened survival among lung transplant recipients.

Implemented in 2005, the lung allocation score (LAS) aims to distribute donor organs based on overall survival benefits for all potential recipients, rather than on waiting list time accrued. While prior work has shown that patients with scores greater than 46 are at increased risk of death, it is not known whether that risk is equivalent among such patients when stratified by LAS score and diagnosis. We retrospectively evaluated 5331 adult lung transplant recipients from May 2005 to February 2009 to determine the association of LAS (groups based on scores of < or =46, 47-59, 60-79 and > or =80) and posttransplant survival. When compared with patients with LAS < or = 46, only those with LAS > or = 60 had an increased risk of death (LAS 60-79: hazard ratio [HR], 1.52; 95% confidence interval [CI], 1.21-1.90; LAS > or = 80: HR, 2.03; CI, 1.61-2.55; p < 0.001) despite shorter median waiting list times. This risk persisted after adjusting for age, diagnosis, transplant center volume and donor characteristics. By specific diagnosis, an increased hazard was observed in patients with COPD with LAS > or = 80, as well as those with IPF with LAS > or = 60.

Climate change and threat of vector-borne diseases in India: are we prepared?

It is unequivocal that climate change is happening and is likely to expand the geographical distribution of several vector-borne diseases, including malaria and dengue etc. to higher altitudes and latitudes. India is endemic for six major vector-borne diseases (VBD) namely malaria, dengue, chikungunya, filariasis, Japanese encephalitis and visceral leishmaniasis. Over the years, there has been reduction in the incidence of almost all the diseases except chikungunya which has re-emerged since 2005. The upcoming issue of climate change has surfaced as a new threat and challenge for ongoing efforts to contain vector-borne diseases. There is greater awareness about the potential impacts of climate change on VBDs in India and research institutions and national authorities have initiated actions to assess the impacts. Studies undertaken in India on malaria in the context of climate change impact reveal that transmission windows in Punjab, Haryana, Jammu and Kashmir and north-eastern states are likely to extend temporally by 2-3 months and in Orissa, Andhra Pradesh and Tamil Nadu there may be reduction in transmission windows. Using PRECIS model (driven by HadRM2) at the resolution of 50 x 50 Km for daily temperature and relative humidity for year 2050, it was found that Orissa, West Bengal and southern parts of Assam will still remain malarious and transmission windows will open up in Himachal Pradesh and north-eastern states etc. Impact of climate change on dengue also reveals increase in transmission with 2 C rise in temperature in northern India. Re-emergence of kala-azar in northern parts of India and reappearance of chikungunya mainly in southern states of India has also been discussed. The possible need to address the threat and efforts made in India have also been highlighted. The paper concludes with a positive lead that with better preparedness threat of climate change on vector-borne diseases may be negated.