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Background: Experience with retrieval of the Micra transcatheter pacing system (TPS) is limited because of its relatively newer technology. Although abandonment of the TPS at end of life is recommended, certain situations such as endovascular infection or device embolization warrant retrieval., Objective: The purpose of this study was to report the worldwide experience with successful retrieval of the Micra TPS., Methods: A list of all successful retrievals of the currently available leadless pacemakers (LPs) was obtained from the manufacturer of Micra TPS. Pertinent details of retrieval, such as indication, days postimplantation, equipment used, complications, and postretrieval management, were obtained from the database collected by the manufacturer. Other procedural details were obtained directly from the operators at each participating site., Results: Data from the manufacturer consisted of 40 successful retrievals of the Micra TPS. Operators for 29 retrievals (73%) provided the consent and procedural details. Of the 29 retrievals, 11 patients underwent retrieval during the initial procedure (immediate retrieval); the other 18 patients underwent retrieval during a separate procedure (delayed retrieval). Median duration before delayed retrieval was 46 days (range 1-95 days). The most common reason for immediate retrieval was elevated pacing threshold after tether removal. The most common reasons for delayed retrieval included elevated pacing threshold at follow-up, endovascular infection, and need for transvenous device. Mean procedure duration was 63.11 ± 56 minutes. All retrievals involved snaring via a Micra TPS delivery catheter or steerable sheath. No serious complications occurred during the reported retrievals., Conclusion: Early retrieval of the Micra TPS is feasible and safe., (Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Early performance of the Micra transcatheter pacemaker from the global clinical trial reported a 99.2% implant success rate, low and stable pacing capture thresholds, and a low (4.0%) rate of major complications up to 6 months., Objective: The purpose of this report was to describe the prespecified long-term safety objective of Micra at 12 months and electrical performance through 24 months., Methods: The Micra Transcatheter Pacing Study was a prospective single-arm study designed to assess the safety and efficacy of the Micra VVIR leadless/intracardiac pacemaker. Enrolled patients met class I or II guideline recommendations for de novo ventricular pacing. The long-term safety objective was freedom from a system- or procedure-related major complication at 12 months. A predefined historical control group of 2667 patients with transvenous pacemakers was used to compare major complication rates., Results: The long-term safety objective was achieved with a freedom from major complication rate of 96.0% at 12 months (95% confidence interval 94.2%-97.2%; P < .0001 vs performance goal). The risk of major complications for patients with Micra (N = 726) was 48% lower than that for patients with transvenous systems through 12 months postimplant (hazard ratio 0.52; 95% confidence interval 0.35-0.77; P = .001). Across subgroups of age, sex, and comorbidities, Micra reduced the risk of major complications compared to transvenous systems. Electrical performance was excellent through 24 months, with a projected battery longevity of 12.1 years., Conclusion: Long-term performance of the Micra transcatheter pacemaker remains consistent with previously reported data. Few patients experienced major complications through 12 months of follow-up, and all patient subgroups benefited as compared to transvenous pacemaker historical control group., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Device repositioning during Micra leadless pacemaker implantation may be required to achieve optimal pacing thresholds., Objective: The purpose of this study was to describe the natural history of acute elevated Micra vs traditional transvenous lead thresholds., Methods: Micra study VVI patients with threshold data (at 0.24 ms) at implant (n = 711) were compared with Capture study patients with de novo transvenous leads at 0.4 ms (n = 538). In both cohorts, high thresholds were defined as >1.0 V and very high as >1.5 V. Change in pacing threshold (0-6 months) with high (1.0 to ≤1.5 V) or very high (>1.5 V) thresholds were compared using the Wilcoxon signed-rank test., Results: Of the 711 Micra patients, 83 (11.7%) had an implant threshold of >1.0 V at 0.24 ms. Of the 538 Capture patients, 50 (9.3%) had an implant threshold of >1.0 V at 0.40 ms. There were no significant differences in patient characteristics between those with and without an implant threshold of >1.0 V, with the exception of left ventricular ejection fraction in the Capture cohort (high vs low thresholds, 53% vs 58%; P = .011). Patients with an implant threshold of >1.0 V decreased significantly (P < .001) in both cohorts. Micra patients with high and very high thresholds decreased significantly (P < .01) by 1 month, with 87% and 85% having 6-month thresholds lower than the implant value. However, when the capture threshold at implant was >2 V, only 18.2% had a threshold of ≤1 V at 6 months and 45.5% had a capture threshold of >2 V., Conclusions: Pacing thresholds in most Micra patients with elevated thresholds decrease after implant. Micra device repositioning may not be necessary if the pacing threshold is ≤2 V., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The Micra transcatheter pacemaker was designed to have similar functionality to conventional transvenous VVIR pacing systems. It provides rate adaptive pacing using a programmable 3-axis accelerometer designed to detect patient activity in the presence of cardiac motion., Objective: The purpose of this study was to evaluate the system's performance during treadmill tests to maximum exertion in a subset of patients within the Micra Transcatheter Pacing Study., Methods: Patients underwent treadmill testing at 3 or 6 months postimplant with algorithm programming at physician discretion. Normalized sensor rate (SenR) relative to the programmed upper sensor rate was modeled as a function of normalized workload in metabolic equivalents (METS) relative to maximum METS achieved during the test. A normalized METS and SenR were determined at the end of each 1-minute treadmill stage. The proportionality of SenR to workload was evaluated by comparing the slope from this relationship to the prospectively defined tolerance margin (0.65-1.35)., Results: A total of 69 treadmill tests were attempted by 42 patients at 3 and 6 months postimplant. Thirty tests from 20 patients who completed ≥4 stages with an average slope of 0.86 (90% confidence interval 0.77-0.96) confirmed proportionality to workload. On an individual test basis, 25 of 30 point estimates (83.3%) had a normalized slope within the defined tolerance range (range 0.46-1.08)., Conclusion: Accelerometer-based rate adaptive pacing was proportional to workload, thus confirming rate adaptive pacing commensurate to workload is achievable with an entirely intracardiac pacing system., (Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Autoantibodies or antibodies against self-antigens are produced either during physiological processes to maintain homeostasis or pathological process such as trauma and infection. Infection with parasites including Plasmodium has been shown to generally induce elevated self-antibody (autoantibody) levels. Plasmodium knowlesi is increasingly recognized as one of the most important emerging human malaria in Southeast Asia that can cause severe infection leading to mortality. Autoimmune-like phenomena have been hypothesized to play a role in the protective immune responses in malaria infection., Methods: We studied the autoantibody profile from serum of eleven patients diagnosed with P. knowlesi. Autoantigen arrays were used to elucidate the autoantibody repertoire of P. knowlesi infected patients. The patented OGT Discovery Array with 1636 correctly folded antigen was employed., Results: Analysis of the patient versus control sera gave us 24 antigens with high reactivity with serum antibodies., Conclusions: Understanding the autoantibody profile of malarious patients infected with P. knowlesi would help to further understand the host-parasite interaction, host immune response and disease pathogenesis. These reactive antigens may serve as potential biomarkers for cases of asymptomatic malaria and mild malaria or predictive markers for severe malaria., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Angiostrongylus cantonensis is a bursate nematode parasite that causes eosinophilic meningitis (or meningoencephalitis) in humans in many parts of the world. The genomic data from A. cantonensis will form a useful resource for comparative genomic and chemogenomic studies to aid the development of diagnostics and therapeutics. We have sequenced, assembled and annotated the genome of A. cantonensis. The genome size is estimated to be ∼260 Mb, with 17,280 genomic scaffolds, 91X coverage, 81.45% for complete and 93.95% for partial score based on CEGMA analysis of genome completeness. The number of predicted genes of ≥300 bp was 17,482. A total of 7737 predicted protein-coding genes of ≥50 amino acids were identified in the assembled genome. Among the proteins of known function, kinases are the most abundant followed by transferases. The draft genome contains 34 excretory-secretory proteins (ES), a minimum of 44 Nematode Astacin (NAS) metalloproteases, 12 Homeobox (HOX) genes, and 30 neurotransmitters. The assembled genome size (260 Mb) is larger than those of Pristionchus pacificus, Caenorhabditis elegans, Necator americanus, Caenorhabditis briggsae, Trichinella spiralis, Brugia malayi and Loa loa, but smaller than Haemonchus contortus and Ascaris suum. The repeat content (25%) is similar to H. contortus. The GC content (41.17%) is lower compared to P. pacificus (42.7%) and H. contortus (43.1%) but higher compared to C. briggsae (37.69%), A. suum (37.9%) and N. americanus (40.2%) while the scaffold N50 is 42,191. This draft genome will facilitate the understanding of many unresolved issues on the parasite and the disorder it causes., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: Left ventricular (LV) lead implantation for cardiac resynchronization therapy (CRT) is associated with lead dislodgement rates ranging from 3% to 10%, and some implant approaches to prevent dislodgement may contribute to suboptimal CRT response. We report our early human experience with an LV lead with a side helix for active fixation to the coronary vein wall., Objectives: To assess the feasibility and safety of the Model 20066 LV lead and to evaluate the implant procedure., Methods: The Model 20066 is a 4-F bipolar steroid eluting lead that has a small exposed side helix and can be delivered using a guidewire or stylet. At the desired vein location, the lead body is rotated clockwise until the helix is fixated. This study was a single-arm, prospective, nonrandomized trial that enrolled 40 patients from 4 centers who met standard indications for CRT., Results: The lead was successfully implanted in 39 of 40 (98%) patients. In 38 of 40 (95%) patients, the implanters were successful at implanting at a predetermined target site. There were no Model 20066 LV lead dislodgements reported within 12 months of follow-up. The electrical performance of the tip and ring electrodes was stable through the 12-month follow-up visit and similar to other LV leads. Overall lead handling was rated as acceptable for all implants., Conclusion: This new LV lead specifically designed with an active fixation mechanism for stability and precise placement was successfully and safely deployed in the coronary vasculature., (Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, is associated with increased morbidity and mortality. AF has a slightly lower incidence and prevalence in Asian populations than in Western populations, but the associated relative risk of stroke and mortality is similar. Patients with AF in Asia have similar disease profiles and CHADS2 score distributions compared to those in the West, with the exception of a slightly higher prevalence of valvular heart diseases in Asia. Acute ventricular rate control should be the initial consideration in patients with AF and rapid ventricular rate. Anti-arrhythmic drugs have only a modest long-term effect on maintenance of sinus rhythm, and clinical trials in both the West and the East show that chronic rhythm control is not superior to chronic rate control in terms of cardiovascular outcomes, most likely because the benefit of anti-arrhythmic drugs in these trials was often offset by proarrhythmic effects. ECG-driven trials for AF should be replaced by outcome-driven ones. ATHENA is the largest outcome trial to confirm the superiority of a new anti-arrhythmic drug in improving cardiovascular outcomes. The choice of anti-arrhythmic drugs for AF should be based on both safety and efficacy in improving cardiovascular outcomes. For long-term rate control, a lenient strategy with a ventricular rate of less than 110bpm may be adequate, but more strict rate control may be required if patients continue to complain of symptoms. Catheter ablation should be reserved for patients who remain symptomatic despite optimal medical therapy., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Objective: Parkinson disease (PD) affects the lives of both the individuals and their family members. This study aims at investigating for clinical as well as socio-demographic factors associated with the perception of burden among the caregivers of individuals with PD in Malaysia., Methods: This is a descriptive, cross-sectional study on PD patients and their caregivers who attended the neurology clinics of 2 tertiary hospitals in Kuala Lumpur. Socio-demographic and clinical data of the patients were obtained, including caregivers' perception of burden using the Caregiver's Burden Scale (CBS)., Results: The patients' mean age was 62.12±9.69 years, almost half of them were in stage 2 of their illness, had developed PD at the age of 50-69 and had duration of illness of less than 5 years. The caregivers were mostly females and a third of them were wives. Factors which were significantly associated with increased caregiver burden were patients' advancing age, later stage of illness and those having longer duration of caring. Caregivers' perceived burden was related to their race gender, social status, kinship with patient or duration of care-giving., Conclusion: Burden of care is significantly more in PD patients of advanced age and stage of illness., (Copyright © 2011 Elsevier B.V. All rights reserved.)