Safety and efficacy of multipolar pulmonary vein ablation catheter vs. irrigated radiofrequency ablation for paroxysmal atrial fibrillation: a randomized multicentre trial

Aims

The current challenge in atrial fibrillation (AF) treatment is to develop effective, efficient, and safe ablation strategies. This randomized controlled trial assesses the medium-term efficacy of duty-cycled radiofrequency ablation via the circular pulmonary vein ablation catheter (PVAC) vs. conventional electro-anatomically guided wide-area circumferential ablation (WACA).

Methods and results

One hundred and eighty-eight patients (mean age 62 ± 12 years, 116 M : 72 F) with paroxysmal AF were prospectively randomized to PVAC or WACA strategies and sequentially followed for 12 months. The primary endpoint was freedom from symptomatic or documented >30 s AF off medications for 7 days at 12 months post-procedure. One hundred and eighty-three patients completed 12 m follow-up. Ninety-four patients underwent PVAC PV isolation with 372 of 376 pulmonary veins (PVs) successfully isolated and all PVs isolated in 92 WACA patients. Three WACA and no PVAC patients developed tamponade. Fifty-six percent of WACA and 60% of PVAC patients were free of AF at 12 months post-procedure (P = ns) with a significant attrition rate from 77 to 78%, respectively, at 6 months. The mean procedure (140 ± 43 vs. 167 ± 42 min, P<0.0001), fluoroscopy (35 ± 16 vs. 42 ± 20 min, P<0.05) times were significantly shorter for PVAC than for WACA. Two patients developed strokes within 72 h of the procedure in the PVAC group, one possibly related directly to PVAC ablation in a high-risk patient and none in the WACA group (P = ns). Two of the 47 patients in the PVAC group who underwent repeat ablation had sub-clinical mild PV stenoses of 25–50% and 1 WACA patient developed delayed severe PV stenosis requiring venoplasty.

Conclusion

The pulmonary vein ablation catheter is equivalent in efficacy to WACA with reduced procedural and fluoroscopy times. However, there is a risk of thrombo-embolic and pulmonary stenosis complications which needs to be addressed and prospectively monitored.

ClinicalTrials.gov Identifier

NCT00678340.

Prediction of Efficacy of Vabicaserin, a 5-HT2C Agonist, for the Treatment of Schizophrenia Using a Quantitative Systems Pharmacology Model

A quantitative systems pharmacology model that combines in vitro/preclinical neurophysiology data, human imaging data, and patient disease information was used to blindly predict steady-state clinical efficacy of vabicaserin, a 5-HT2C full agonist, in monotherapy and, subsequently, to assess adjunctive therapy in schizophrenia. The model predicted a concentration-dependent improvement of positive and negative syndrome scales (PANSS) in schizophrenia monotherapy with vabicaserin. At the exposures of 100 and 200 mg b.i.d., the predicted improvements on PANSS in virtual patient trials were 5.12 (2.20, 8.56) and 6.37 (2.27, 10.40) (mean (95% confidence interval)), respectively, which are comparable to the observed phase IIa results. At the current clinical exposure limit of vabicaserin, the model predicted an ~9-point PANSS improvement in monotherapy, and <4-point PANSS improvement adjunctive with various antipsychotics, suggesting limited clinical benefit of vabicaserin in schizophrenia treatment. In conclusion, the updated quantitative systems pharmacology model of PANSS informed the clinical development decision of vabicaserin in schizophrenia.

Automatic oral fluid-based HIV testing in HIV screening programmes: automatic for the people

OBJECTIVES

UK guidelines recommend routine HIV testing in general clinical settings when the local HIV prevalence is > 0.2%. During pilot programmes evaluating the guidelines, we used laboratory-based testing of oral fluid from patients accepting tests. Samples (n = 3721) were tested manually using the Bio-Rad Genscreen Ultra HIV Ag-Ab test (Bio-Rad Laboratories Ltd, Hemel Hempstead, UK). This was a methodologically robust method, but handling of samples was labour intensive. We performed a validation study to ascertain whether automation of oral fluid HIV testing using the fourth-generation HIV test on the Abbott Architect (Abbott Diagnostics, Maidenhead, UK) platform was possible.

METHODS

Oral fluid was collected from 143 patients (56 known HIV-positive volunteers and 87 others having contemporaneous HIV serological tests) using the Oracol+ device (Malvern Medicals, Worcester, UK). Samples were tested concurrently: manually using the Genscreen Ultra test and automatically on the Abbott Architect.

RESULTS

For oral fluid, the level of agreement of results between the platforms was 100%. All results agreed with HIV serology. The use of the Oracol+ device produced high-quality samples. Subsequent field use of the test has shown a specificity of 99.97% after nearly 3000 tests.

CONCLUSIONS

Laboratory-based HIV testing of oral fluid requires less training of local staff, with fewer demands on clinical time and space than near-patient testing. It is acceptable to patients. The validation exercise and subsequent clinical experience support automation, with test performance preserved. Automation reduces laboratory workload and speeds up the release of results. Automated oral fluid testing is thus a viable option for large-scale HIV screening programmes.

Routine HIV testing in the emergency department: tough lessons in sustainability

OBJECTIVES

Routine HIV testing in nonspecialist settings has been shown to be acceptable to patients and staff in pilot studies. The question of how to embed routine HIV testing, and make it sustainable, remains to be answered.

METHODS

We established a service of routine HIV testing in an emergency department (ED) in London, delivered by ED staff as part of routine clinical care. All patients aged 16 to 65 years were offered an HIV test (latterly the upper age limit was removed). Meetings were held weekly and two outcome measures examined: test offer rate (coverage) and test uptake. Sustainability methodology (process mapping; plan-do-study-act (PDSA) cycles) was applied to maximize these outcome measures.

RESULTS

Over 30 months, 44,582 eligible patients attended the ED. The mean proportion offered an HIV test was 14%, varying from 6% to 54% per month over the testing period. The mean proportion accepting a test was 63% (range 33-100%). A total of 4327 HIV tests have been performed. Thirteen patients have been diagnosed with HIV infection (0.30%). PDSA cycles having the most positive and sustained effects on the outcome measures include the expansion to offer blood-based HIV tests in addition to the original oral fluid tests, and the engagement of ED nursing staff in the programme.

CONCLUSIONS

HIV testing can be delivered in the ED, but constant innovation and attention have been required to maintain it over 30 months. Patient uptake remains high, suggesting acceptability, but time will be required before true embedding in routine clinical practice is achieved.

Methylation-specific multiplex ligation-dependent probe amplification identifies promoter methylation events associated with survival in glioblastoma

DNA methylation plays an important role in cancer biology and methylation events are important prognostic and predictive markers in many tumor types. We have used methylation-specific multiplex ligation-dependent probe amplification to survey the methylation status of MGMT and 25 tumor suppressor genes in 73 glioblastoma cases. The data obtained was correlated with overall survival and response to treatment. The study revealed that methylation of promoter regions in TP73 (seven patients), THBS1 (eight patients) and PYCARD (nine patients) was associated with improved outcome, whereas GATA5 (21 patients) and WT1 (24 patients) promoter methylation were associated with poor outcome. In patients treated with temozolomide and radiation MGMT and PYCARD promoter methylation events remained associated with improved survival whereas GATA5 was associated with a poor outcome. The identification of GATA5 promoter methylation in glioblastoma has not previously been reported. Furthermore, a cumulative methylation score separated patients into survival groups better than any single methylation event. In conclusion, we have identified specific methylation events associated with patient outcome and treatment response in glioblastoma, and these may be of functional and predictive/prognostic significance. This study therefore provides novel candidates and approaches for future prospective validation.

A quantitative system pharmacology computer model for cognitive deficits in schizophrenia

Although the positive symptoms of schizophrenia are reasonably well-controlled by current antipsychotics, cognitive impairment remains largely unaddressed. The Matrics initiative lays out a regulatory path forward and a number of targets have been tested in the clinic, so far without much success. To address this translational disconnect, we have developed a mechanism-based humanized computer model of a relevant key cortical brain network with schizophrenia pathology involved with the maintenance aspect of working memory (WM). The model is calibrated using published clinical experiments on N-back WM tests. We further simulate the opposite effect of γ-aminobutyric acid (GABA) modulators lorazepam and flumazenil and of a published augmentation trial of clozapine with risperidone, illustrating the introduction of new targets and the capacity of predicting the effects of polypharmacy. This humanized approach allows for early prospective and quantitative assessment of cognitive outcome in a central nervous system (CNS) research and development project, thereby hopefully increasing the success rate of clinical trials.CPT: Pharmacometrics & Systems Pharmacology (2013) 2, e36; doi:10.1038/psp.2013.12; advance online publication 3 April 2013.

The 2009 Late Blight Pandemic in the Eastern United States - Causes and Results

The tomato late blight pandemic of 2009 made late blight into a household term in much of the eastern United States. Many home gardeners and many organic producers lost most if not all of their tomato crop, and their experiences were reported in the mainstream press. Some CSAs (Community Supported Agriculture) could not provide tomatoes to their members. In response, many questions emerged: How did it happen? What was unusual about this event compared to previous late blight epidemics? What is the current situation in 2012 and what can be done? It's easiest to answer these questions, and to understand the recent epidemics of late blight, if one knows a bit of the history of the disease and the biology of the causal agent, Phytophthora infestans.

Has the time come for predictive computer modeling in CNS drug discovery and development?

We discuss whether a new paradigm, quantitative systems pharmacology (QSP), based on computational neuroscience modeling combined with proper drug target engagement and pharmacology, human pathology, imaging studies, and calibration and validation using clinical studies in human subjects might improve the success rate of central nervous systems research and development (CNS R&D) projects. We suggest that an improved understanding of neuronal circuit interactions using a humanized computer-based integration of physiology and pharmacology knowledge can substantially de-risk new CNS projects.

Scintigraphic assessment of bone status at one year following hip resurfacing: Comparison of two surgical approaches using SPECT-CT scan

Objectives

To study the vascularity and bone metabolism of the femoral head/neck following hip resurfacing arthroplasty, and to use these results to compare the posterior and the trochanteric-flip approaches.

Methods

In our previous work, we reported changes to intra-operative blood flow during hip resurfacing arthroplasty comparing two surgical approaches. In this study, we report the vascularity and the metabolic bone function in the proximal femur in these same patients at one year after the surgery. Vascularity and bone function was assessed using scintigraphic techniques. Of the 13 patients who agreed to take part, eight had their arthroplasty through a posterior approach and five through a trochanteric-flip approach.

Results

One year after surgery, we found no difference in the vascularity (vascular phase) and metabolic bone function (delayed phase) at the junction of the femoral head/neck between the two groups of patients. Higher radiopharmaceutical uptake was found in the region of the greater trochanter in the trochanteric-flip group, related to the healing osteotomy.

Conclusions

Our findings using scintigraphic techniques suggest that the greater intra-operative reduction in blood flow to the junction of the femoral head/neck, which is seen with the posterior approach compared with trochanteric flip, does not result in any difference in vascularity or metabolic bone function one year after surgery.

Cricket World Cup: a stress test for the surveillance system in the Caribbean

OBJECTIVE

To describe the development and implementation of and major findings and recommendations from, a regional mass gathering surveillance system (MGSS) in support of the International Cricket Council Cricket World Cup West Indies 2007.

METHODS

The regional MGSS was developed by the Caribbean Epidemiology Centre (CAREC) and its member countries as an adaptation of the routine communicable disease surveillance system in order to rapidly detect unusual disease events during the tournament. The implementation of the MGSS required the identification of additional human and financial resources, capacity building activities, laboratory strengthening, and improved global epidemic surveillance and communication mechanisms.

RESULTS

Timeliness and completeness of data reporting in the MGSS were both > 85%. No unusual pathogens were identified in the region during the tournament. Only dengue and influenza, both endemic to the region, were identified. The early alert aetection software used identified a total of 24 aberrations from seven countries, the largest proportions being gastroenteritis, fever and respiratory symptoms and injuries. All aberrations were promptly investigated and most were found to be false alerts. Three unusual disease events were detected, all from one country. They were responded to in a timely manner and did not adversely affect the tournament.

CONCLUSIONS

The surveillance capacities gained in preparing for and supporting, the tournament assisted in strengthening and testing the already existing national and regional communicable disease surveillance systems. Events such as these should be utilized to strengthen already existing surveillance systems, which should be flexible enough to respond to changing events.

Directional limits on persistent gravitational waves using LIGO S5 science data

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10(-50)  strain(2) Hz(-1) and 5-35×10(-49)  strain(2) Hz(-1) sr(-1) for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN 1987A and the Galactic center as low as ≈7×10(-25) in the most sensitive frequency range near 160 Hz.

Mycotic aneurysm of the aorta as a complication of Bacillus Calmette-Guérin instillation

Bacillus Calmette-Guérin (BCG) is a live attenuated strain of Mycobacterium bovis that has been widely used for the treatment of superficial transitional cell carcinoma of the bladder. We describe a rare case of supra-renal mycotic aortic aneurysm secondary to BCG instillation in a 75-year-old male. Patients presenting with systemic symptoms post-instillation, possibly with an aneurysm, should raise suspicion of BCG dissemination, which requires early instigation of anti-mycobacterial drugs.

A phase III randomized, double-blind, placebo-controlled trial of the epidermal growth factor receptor inhibitor gefitinb in completely resected stage IB-IIIA non-small cell lung cancer (NSCLC): NCIC CTG BR.19

LBA7005

Background: In meta-analyses, platinum-based adjuvant (adj) chemotherapy (CT) in completely resected NSCLC increased cure rate by ∼5%. At BR.19 initiation, adj study results with third-generation agents were unavailable. Gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, showed activity in monotherapy trials. We report a trial of adj gefitinib versus placebo after complete resection of NSCLC.

Methods: Patients (pts) with stage IB-IIIA NSCLC were stratified by sex, stage, histology, post-op radiation, and after Jan 2003, adj CT. Pts were randomized to gefitinib 250 mg or placebo daily x 2 years. Study endpoints included overall survival (OS), disease free survival (DFS), toxicity, preplanned correlative studies. Study closed prematurely in Apr. 2005. Trial committee and NCIC CTG staff remained blinded to study drug.

Results: 503 pts randomized (Sep 2002-Apr 2005); median age 67, males 54%, PS 0 54%; stage IB 49%, II 38%, III 13%; adenocarcinoma 59%, squamous 28%; ever smokers 89%; adj CT 17%; lobectomy 82%. Commonest grade 3/4 toxicities = fatigue 5%, rash 4% and diarrhea 5%. grade 3+ pneumonitis in 7 (1.4%) pts and led to death in 1. Median follow-up is 4.7 yrs; median treatment time is 4.8 mos. For gefitinib versus placebo, median DFS is 4.2 yrs versus not yet reached (NYR) HR1.22 (95% C.I. 0.93-1.61), p=0.15 and median OS 5.1 yrs versus NYR HR 1.24 (95% C.I. 0.94-1.64), p=0.14. In multivariate analysis, tumor size >4cm was predictive of poor DFS (p<0.0001) and never smoking for better OS with gefitinib (p=0.02). Results for KRAS and EGFR copy are available on 350 and 348 pts respectively. KRAS mutations were neither prognostic HR 1.12 (95% C.I. 0.67-1.86), p=0.66 nor predictive of gefitinib benefit (p = 0.16) on OS. EGFRcopy whether low/high polysomy or amplification was neither prognostic (p=0.77) nor predictive of OS benefit from gefitinib.

Conclusions: Adjuvant gefitinib after complete resection of early stage NSCLC did not confer DFS or OS advantage in overall population. KRAS and EGFR copy were neither prognostic nor predictive of benefit from gefitinib. EGFR mutational analysis will be presented.

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