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Medicare insurance claims may provide an efficient means to ascertain follow-up of older participants in clinical research. We sought to determine the accuracy and completeness of claims- versus site-based follow-up with clinical event committee (+CEC) adjudication of cardiovascular outcomes. We performed a retrospective study using linked Medicare and Duke Database of Clinical Trials data. Medicare claims were linked to clinical data from 7 randomized cardiovascular clinical trials. Of 52,476 trial participants, linking resulted in 5,839 (of 10,497 linkage-eligible) Medicare-linked trial participants with fee-for-service A and B coverage. Death, myocardial infarction (MI), stroke, and revascularization incidences were compared using Medicare inpatient claims only, site-reported events (+CEC) only, or a combination of the 2. Randomized treatment effects were compared as a function of whether claims-based, site-based (+CEC), or a combined system was used for event detection. Among the 5,839 study participants, the annual event rates were similar between claims- and site-based (+CEC) follow-up: death (overall rate 5.2% vs 5.2%; adjusted κ 0.99), MI (2.2% vs 2.3%; adjusted κ 0.96), stroke (0.7% vs 0.7%; adjusted κ 0.99), and any revascularization (7.4% vs 7.9%; adjusted κ 0.95). Of events detected by claims yet not reported by CEC, a minority were reported by sites but negatively adjudicated by CEC (39% of MIs and 18% of strokes). Differences in individual case concordance led to higher event rates when claims- and site-based (+CEC) systems were combined. Randomized treatment effects were similar among the 3 approaches for each outcome of interest. Claims- versus site-based (+CEC) follow-up identified similar overall cardiovascular event rates despite meaningful differences in the events detected. Randomized treatment effects were similar using the 2 methods, suggesting claims data could be used to support clinical research leveraging routinely collected data. This approach may lead to more effective evidence generation, synthesis, and appraisal of medical products and inform the strategic approaches toward the National Evaluation System for Health Technology.

Although several randomized clinical trials have demonstrated the safety and efficacy of catheter ablation of atrial fibrillation (AF) in experienced centers, the outcomes of this procedure in routine clinical practice and in patients with persistent and long-standing persistent AF remain uncertain. Brisk adoption of this therapy by physicians with diverse training and experience highlights potential concerns regarding the safety and effectiveness of this procedure. Some of these concerns could be addressed by a national registry of AF ablation procedures such as the Safety of Atrial Fibrillation Ablation Registry Initiative that was initially proposed at a Cardiac Safety Research Consortium Think Tank meeting in April 2009. In January 2010, the Cardiac Safety Research Consortium, in collaboration with the Duke Clinical Research Institute, the US Food and Drug Administration, the American College of Cardiology, and the Heart Rhythm Society, held a follow-up meeting of experts in the field to review the construct and progress to date. Other participants included the National Heart, Lung, and Blood Institute; the Centers for Medicare and Medicaid Services; the Agency for Healthcare Research and Quality; the AdvaMed AF working group; and additional industry representatives. This article summarizes the discussions that occurred at the meeting of the state of the Safety of Atrial Fibrillation Ablation Registry Initiative, the identification of a clear pathway for its implementation, and the exploration of solutions to potential issues in the execution of this registry.

Percutaneous coronary intervention (PCI) is an integral part of the treatment of coronary artery disease. The most common complication of PCI, bleeding, typically occurs at the vascular access site and is associated with short-term and long-term morbidity and mortality. Periprocedural bleeding also represents the primary safety concern of concomitant antithrombotic therapies essential for PCI success. Use of radial access for PCI reduces procedural bleeding and hence may change the risk profile and net clinical benefit of these drugs. This new drug-device safety interaction creates opportunities to advance the safe and effective use of antithrombotic agents during PCI. In June 2010 and March 2011, leaders from government, academia, professional societies, device manufacturing, and pharmaceutical industries convened for 2 think tank meetings. Titled TREAT I and II, these forums examined approaches to improve the overall safety of PCI by optimizing strategies for antithrombotic drug use and radial artery access. This article summarizes the content and proceedings of these sessions.

Atrial fibrillation (AF) is a major public health problem in the United States that is associated with increased mortality and morbidity. Of the therapeutic modalities available to treat AF, the use of percutaneous catheter ablation of AF is expanding rapidly. Randomized clinical trials examining the efficacy and safety of AF ablation are currently underway; however, such trials can only partially determine the safety and durability of the effect of the procedure in routine clinical practice, in more complex patients, and over a broader range of techniques and operator experience. These limitations of randomized trials of AF ablation, particularly with regard to safety issues, could be addressed using a synergistically structured national registry, which is the intention of the SAFARI. To facilitate discussions about objectives, challenges, and steps for such a registry, the Cardiac Safety Research Consortium and the Duke Clinical Research Institute, Durham, NC, in collaboration with the US Food and Drug Administration, the American College of Cardiology, and the Heart Rhythm Society, organized a Think Tank meeting of experts in the field. Other participants included the National Heart, Lung and Blood Institute, the Centers for Medicare and Medicaid Services, the Agency for Healthcare Research and Quality, the Society of Thoracic Surgeons, the AdvaMed AF working group, and additional industry representatives. The meeting took place on April 27 to 28, 2009, at the US Food and Drug Administration headquarters in Silver Spring, MD. This article summarizes the issues and directions presented and discussed at the meeting.

Percutaneous coronary intervention (PCI) is an integral part of the treatment of coronary artery disease. The most common complication of PCI, bleeding, typically occurs at the vascular access site and is associated with short-term and long-term morbidity and mortality. Periprocedural bleeding also represents the primary safety concern of concomitant antithrombotic therapies essential for PCI success. Use of radial access for PCI reduces procedural bleeding and hence may change the risk profile and net clinical benefit of these drugs. This new drug-device safety interaction creates opportunities to advance the safe and effective use of antithrombotic agents during PCI. In June 2010 and March 2011, leaders from government, academia, professional societies, device manufacturing, and pharmaceutical industries convened for 2 think tank meetings. Titled TREAT I and II, these forums examined approaches to improve the overall safety of PCI by optimizing strategies for antithrombotic drug use and radial artery access. This article summarizes the content and proceedings of these sessions.

Gap junctions are principally involved in forming the electrical connections between cardiomyocytes. Gap junction remodeling and underexpression are increasingly thought to play a role in cardiac disease and arrhythmogenesis. Intercellular uncoupling by gating or downregulation of gap junctions has been observed in both chronic and acute cardiac disease. While it is well established that slow conduction and increased gradients of repolarization are important to the initiation of reentrant arrhythmias, the specific role that decreases in intercellular communication play in arrhythmogenesis remains unknown. We used a specialized optical mapping system to study the mechanisms by which reduced intercellular uncoupling contributes to the formation of an arrhythmogenic substrate through the investigation of the following paradigms: (1) Mechanisms of Arrhythmogenesis: Intracellular uncoupling has been shown to slow conduction, and has been theorized to increase both the dispersion of repolarization and the heart rate threshold for discordant alternans, all of which are linked to proarrhythmia in clinically relevant models. (2) Inhibition of Arrhythmogenic Substrate: Previously, cellular uncoupling could be established though a multitude pharmacological agents, transgenes, or disease states, however, it has not been possible to enhance coupling through any means. The novel antiarrhythmic drug, ZP123, specifically targets gap junctions, increasing the conductance between cells, which may reverse the arrhythmogenic effects of cellular uncoupling. We found that Connexin43 (Cx43) downregulation via transgenic techniques slows conduction to an extent that is dependent on the level of downregulation. The properties of gap junctions are not altered by the downregulation process, indicating that there is no protein reserve for the enhancement of coupling under pathophysiologicaI conditions. Closure of gap junctions caused by ischemia may be prevented with the use of the gap junction modifying agent, ZP123. Treatment with this compound preserves conduction and reduces heterogeneities of repolarization during acidosis, the uncoupling component of ischemia. Furthermore, maintenance of coupling during ischemia reduced arrhythmogenic discordant alternans, preventing the generation of arrhythmogenic gradients of repolarization. These findings support gap junctions as an important therapeutic target for antiarrhythmic therapies, and provide several mechanisms through which enhanced gap junction communication may prevent the onset of cardiac arrhythmias.