MATERIALS AND METHODS: We tested a hypothesis implicating Na+ current alterations as a mechanism underlying these electrophysiological phenotypes. We applied loose patch-clamp techniques to intact young and aged, WT and Pgc-1β-/-, atrial cardiomyocyte preparations preserving their in vivo extracellular and intracellular conditions.
RESULTS AND DISCUSSION: Depolarising steps activated typical voltage-dependent activating and inactivating inward (Na+) currents whose amplitude increased or decreased with the amplitudes of the activating, or preceding inactivating, steps. Maximum values of peak Na+ current were independently influenced by genotype but not age or interacting effects of genotype and age on two-way ANOVA. Neither genotype, nor age, whether independently or interactively, influenced voltages at half-maximal current, or steepness factors, for current activation and inactivation, or time constants for recovery from inactivation following repolarisation. In contrast, delayed outward (K+) currents showed similar activation and rectification properties through all experimental groups. These findings directly demonstrate and implicate reduced Na+ in contrast to unchanged K+ current, as a mechanism for slowed conduction causing atrial arrhythmogenicity in Pgc-1β-/- hearts.
Methods: We selected the recent publication of a landmark international randomized controlled trial (RCT) comparing immediate and salvage radiotherapy for prostate cancer, RADICALS-RT, for discussion over the weekend of January 16 to 17, 2021. Coordination included open access to the article and an asynchronous portion to decrease barriers to participation, cooperation of study authors (CP, MS) who participated to share deeper insights including a live hour, and curation of related resources and tweet content through a blog post and Wakelet journal club summary.
Discussion of Results: Our conversations created 2,370,104 impressions over 599 tweets with 51 participants spanning 11 countries and 5 continents. A quarter of the participants were from the US (13/51) followed by 10% from the UK (5/51). Clinical or Radiation Oncologists comprised 59% of active participants (16/27) with 62% (18/29) reporting giving aRT within the last 5 years. Discussion was interdisciplinary with three urologists (11%), three trainees (11%), and two physiotherapists (7%). Four months after the journal club its article Altmetric score had increased by 7% (214 to 229). Thematic analysis of tweet content suggested participants wanted clarification on definitions of adjuvant (aRT) and salvage radiotherapy (sRT) including indications, timing, and decision-making tools including guidelines; more interdisciplinary and cross-sectoral collaboration including with patients for study design including survivorship and meaningful outcomes; more effective knowledge translation including faster clinical trials; and more data including mature results of current trials, particular high-risk features (Gleason Group 4+, pT4b+, and margin-positive disease), implications of newer technologies such as PSMA-PET and genomic classifiers, and better explanations for practice pattern variations including underutilization of radiotherapy. This was further explored in the context of relevant literature.
Conclusion: Together, this global collaborative review on the postoperative management of prostate cancer suggested a stronger signal for the uptake of early salvage radiation treatment with careful PSA monitoring, more sensitive PSA triggers, and expected access to radiotherapy. Questions still remain on potential exceptions and barriers to use. These require better decision-making tools for all practice settings, consideration of newer technologies, more pragmatic trials, and better use of social media for knowledge translation.
METHODS: We employ a dynamic Markov model of the effects of vector control on dengue in both vectors and humans over a 15-year period, in six countries: Brazil, Columbia, Malaysia, Mexico, the Philippines, and Thailand. We evaluate the cost (direct medical costs and control programme costs) and cost-effectiveness of sustained vector control, outbreak response and/or medical case management, in the presence of a (hypothetical) highly targeted and low cost immunization strategy using a (non-hypothetical) medium-efficacy vaccine.
RESULTS: Sustained vector control using existing technologies would cost little more than outbreak response, given the associated costs of medical case management. If sustained use of existing or upcoming technologies (of similar price) reduce vector populations by 70-90%, the cost per disability-adjusted life year averted is 2013 US$ 679-1331 (best estimates) relative to no intervention. Sustained vector control could be highly cost-effective even with less effective technologies (50-70% reduction in vector populations) and in the presence of a highly targeted and low cost immunization strategy using a medium-efficacy vaccine.
DISCUSSION: Economic evaluation of the first-ever dengue vaccine is ongoing. However, even under very optimistic assumptions about a highly targeted and low cost immunization strategy, our results suggest that sustained vector control will continue to play an important role in mitigating the impact of environmental change and urbanization on human health. If additional benefits for the control of other Aedes borne diseases, such as Chikungunya, yellow fever and Zika fever are taken into account, the investment case is even stronger. High-burden endemic countries should proceed to map populations to be covered by sustained vector control.
METHODS: We did a network meta-analysis based on a systematic review of randomised controlled trials comparing fibrinolytic drugs in patients with STEMI. Several databases were searched from inception up to Feb 28, 2017. We included only randomised controlled trials that compared fibrinolytic agents as a reperfusion therapy in adult patients with STEMI, whether given alone or in combination with adjunctive antithrombotic therapy, against other fibrinolytic agents, a placebo, or no treatment. Only trials investigating agents with an approved indication of reperfusion therapy in STEMI (streptokinase, tenecteplase, alteplase, and reteplase) were included. The primary efficacy outcome was all-cause mortality within 30-35 days and the primary safety outcome was major bleeding. This study is registered with PROSPERO (CRD42016042131).
FINDINGS: A total of 40 eligible studies involving 128 071 patients treated with 12 different fibrinolytic regimens were assessed. Compared with accelerated infusion of alteplase with parenteral anticoagulants as background therapy, streptokinase and non-accelerated infusion of alteplase were significantly associated with an increased risk of all-cause mortality (risk ratio [RR] 1·14 [95% CI 1·05-1·24] for streptokinase plus parenteral anticoagulants; RR 1·26 [1·10-1·45] for non-accelerated alteplase plus parenteral anticoagulants). No significant difference in mortality risk was recorded between accelerated infusion of alteplase, tenecteplase, and reteplase with parenteral anticoagulants as background therapy. For major bleeding, a tenecteplase-based regimen tended to be associated with lower risk of bleeding compared with other regimens (RR 0·79 [95% CI 0·63-1·00]). The addition of glycoprotein IIb or IIIa inhibitors to fibrinolytic therapy increased the risk of major bleeding by 1·27-8·82-times compared with accelerated infusion alteplase plus parenteral anticoagulants (RR 1·47 [95% CI 1·10-1·98] for tenecteplase plus parenteral anticoagulants plus glycoprotein inhibitors; RR 1·88 [1·24-2·86] for reteplase plus parenteral anticoagulants plus glycoprotein inhibitors).
INTERPRETATION: Significant differences exist among various fibrinolytic regimens as reperfusion therapy in STEMI and alteplase (accelerated infusion), tenecteplase, and reteplase should be considered over streptokinase and non-accelerated infusion of alteplase. The addition of glycoprotein IIb or IIIa inhibitors to fibrinolytic therapy should be discouraged.
FUNDING: None.
METHODS: A comprehensive search of major databases was performed. Only studies comparing TAVI with and without BAV were included. A total of nine full length articles was included in the analysis.
RESULTS: Among 2,650 patients, 1,043 underwent 'direct TAVI' without pre-BAV, while 1,607 underwent TAVI following BAV. Overall, there was no difference between the 30-day all-cause mortality (OR 0.96, 95% CI 0.63-1.47, p = 0.86), CVA (OR 0.81, 95% CI 0.34-1.92, p = 0.63) and PPM implantation (OR 0.84, 95% CI 0.66- 1.05, p = 0.12) between the two approaches. The rate of moderate to severe AR was significantly lower with direct TAVI implantation (OR 0.44, 95% CI 0.20-0.96, p = 0.04). In the case of self-expandable valves, direct TAVI was associated with a lower device success (OR 5.15, 95% CI 1.33-19.9, p = 0.02).
CONCLUSIONS: No difference was identified in mortality between direct TAVI and BAV-TAVI. However, direct TAVI is associated with a lower incidence of AR, a finding that would only be confirmed by conducting further randomized studies.
METHODS: We conducted a systematic review and meta-analysis of prospective observational studies that have investigated the relationship of door-to-balloon delay and clinical outcomes. The main outcomes include mortality and heart failure.
RESULTS: 32 studies involving 299 320 patients contained adequate data for quantitative reporting. Patients with ST-elevation MI who experienced longer (>90 min) door-to-balloon delay had a higher risk of short-term mortality (pooled OR 1.52, 95% CI 1.40 to 1.65) and medium-term to long-term mortality (pooled OR 1.53, 95% CI 1.13 to 2.06). A non-linear time-risk relation was observed (P=0.004 for non-linearity). The association between longer door-to-balloon delay and short-term mortality differed between those presented early and late after symptom onset (Cochran's Q 3.88, P value 0.049) with a stronger relationship among those with shorter prehospital delays.
CONCLUSION: Longer door-to-balloon delay in primary percutaneous coronary intervention for ST-elevation MI is related to higher risk of adverse outcomes. Prehospital delays modified this effect. The non-linearity of the time-risk relation might explain the lack of population effect despite an improved door-to-balloon time in the USA.
CLINICAL TRIAL REGISTRATION: PROSPERO (CRD42015026069).
Methods: A qualitative research methodology was adopted to explore HIV/AIDS patients' views about disease screening. A semi-structured interview guide was used for in-depth patient interviews. All interviews were audio-recorded and were subjected to a standard content analysis framework for data analysis.
Results: Most patients were positive about screening and the value of knowing about their status early. However, fear of social stigma, discrimination, lack of support system and lack of public understanding were identified as major concerns affecting their willingness to be screened. They were concerned about mandatory screening being implemented without improvement in support system and public education.
Conclusions: Reluctance to seek HIV screening is an important factor contributing to transmission in developing countries. In the Malaysian context, efforts should be made to strengthen screening strategies especially in the most-at-risk populations to monitor the epidemic and target prevention strategies.
Practice implications: In a multicultural context, HIV preventive strategies must include disease awareness, including measure to tackle barriers towards screening.
METHODS: Two stochastic models (SM2 and SM3) were developed using retrospective patient respiratory elastance (Ers) from two clinical cohorts which were averaged over time intervals of 10 and 30 min respectively. A stochastic model from a previous study (SM1) was used to benchmark performance. The stochastic models were clinically validated on an independent retrospective clinical cohort of 14 patients. Differences in predictive ability were evaluated using the difference in percentile lines and cumulative distribution density (CDD) curves.
RESULTS: Clinical validation shows all three models captured more than 98% (median) of future Ers data within the 5th - 95th percentile range. Comparisons of stochastic model percentile lines reported a maximum mean absolute percentage difference of 5.2%. The absolute differences of CDD curves were less than 0.25 in the ranges of 5
Objective: We explored the extent to which these age-dependent physiological changes correlated with alterations in gene transcription in murine Pgc-1β-/- atria.
Methods and Results: RNA isolated from murine atrial tissue samples from young (12-16 weeks) and aged (>52 weeks of age), wild type (WT) and Pgc-1β-/- mice were studied by pre-probed quantitative PCR array cards. We examined genes encoding sixty ion channels and other strategic atrial electrophysiological proteins. Pgc-1β-/- genotype independently reduced gene transcription underlying Na+-K+-ATPase, sarcoplasmic reticular Ca2+-ATPase, background K+ channel and cholinergic receptor function. Age independently decreased Na+-K+-ATPase and fibrotic markers. Both factors interacted to alter Hcn4 channel activity underlying atrial automaticity. However, neither factor, whether independently or interactively, affected transcription of cardiac Na+, voltage-dependent K+ channels, surface or intracellular Ca2+ channels. Nor were gap junction channels, β-adrenergic receptors or transforming growth factor-β affected.
Conclusion: These findings limit the possible roles of gene transcriptional changes in previously reported age-dependent pro-arrhythmic electrophysiologial changes observed in Pgc-1β-/- atria to an altered Ca2+-ATPase (Atp2a2) expression. This directly parallels previously reported arrhythmic mechanism associated with p21-activated kinase type 1 deficiency. This could add to contributions from the direct physiological outcomes of mitochondrial dysfunction, whether through reactive oxygen species (ROS) production or altered Ca2+ homeostasis.