Cardiac electrophysiology review
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Card Electrophysiol Rev · Dec 2003
Randomized Controlled Trial Multicenter Study Clinical TrialDo anticoagulation management services improve care? Implications of the Managing Anticoagulation Services Trial.
An Anticoagulation Clinic Service (ACS) has been proposed as one strategy for improving warfarin treatment for patients with atrial fibrillation. In the Managing Anticoagulation Services Trial (MAST), ACSs meeting specifications for high quality care were established in six managed care organizations (MCOs) which had the patients and resources to support this initiative. The trial followed 1165 patients age >or=65 years who had atrial fibrillation as the primary reason for anticoagulation and were enrolled in a participating MCO. ⋯ In both practice clusters, patients had subtherapeutic INR values (1.5 to 1.99) about one fourth of the time. Providing an ACS in a managed care setting did not appear to improve anticoagulation care over the usual care provided at the sites in this trial but could be a reasonable consideration in a practice setting where time in target range is less than 50%. A higher rate of utilization and a more aggressive stance toward subtherapeutic INR values could potentially enhance the effectiveness of an ACS.
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Card Electrophysiol Rev · Dec 2003
Randomized Controlled Trial Clinical TrialThe Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial: rationale, design, results, clinical implications and lessons for future trials.
T he Dual Chamber and VVI Implantable Defibrillator (DAVID) trial randomized 506 patients and tested the hypothesis that the dual-chamber pacing mode would produce improved hemodynamics and would in turn reduce congestive heart failure, heart failure hospitalizations, heart failure deaths, atrial fibrillation, strokes, ventricular arrhythmias, and total mortality compared to backup ventricular pacing in patients indicated for implantable defibrillator therapy. Patients had either primary prevention indications (47%) or secondary prevention indications (53%) for implantable defibrillator therapy but had no indications for bradycardia pacemaker support. All the patients had moderate to severe left ventricular dysfunction with a left ventricular ejection fraction of 40% or less (mean = 27%) and were consistently treated with angiotensin converting enzyme inhibitors or angiotensin II receptor blockers (86%) and beta adrenergic blocking agents (85%). ⋯ The more important question is what is the optimal pacing mode in these patients? The AAIR mode is under investigation in the DAVID II study in an attempt to identify a pacing mode that preserves atrio-ventricular synchrony, normal atrio-ventricular timing, prevents bradycardia and also prevents right ventricular stimulation. Caution should be taken to not directly apply these results to patients with either an indication for pacemaker therapy or to patients with an indication for cardiac resynchronization therapy since patients from neither population were included. However, considering the large magnitude of the deleterious effects associated with dual chamber pacing in the DAVID trial future studies should explore the possibility that left ventricular stimulation may be the only pacing mode capable of preventing bradycardia without increasing death and congestive heart failure.