The Ohio State University, Columbus, OH 43017, USA.
Am Heart J. 2010 Jun;159(6):944-948.e1. doi: 10.1016/j.ahj.2010.02.034.
The aim of the study was to describe the rationale, design, and end points of a randomized, double-blind, controlled trial evaluating frequent systematic optimization of atrioventricular (AV) and interventricular (VV) delays in patients receiving cardiac resynchronization therapy (CRT).
One thousand five hundred eighty heart failure patients, with standard clinical indications for CRT, were enrolled at 178 sites in 16 countries. Within 2 weeks after implantation of a CRT system capable of using a new device-based algorithm for AV and VV optimization, patients were randomly assigned to frequent optimization arm versus empiric device programming or any other non-device-based method of CRT optimization (standard of care arm). In patients in the frequent optimization arm, the AV and VV delays were calculated, reevaluated, and, if necessary, reprogrammed every 3 months. In patients in the standard of care arm, device programming was left to the implanting physician's discretion and remained unchanged throughout the trial unless mandated by a change in clinical status. The primary end point of the trial is the heart failure clinical composite, which classifies patients as worsened, unchanged, or improved based on prespecified definitions. Secondary end points include hospitalizations for cardiovascular reasons and all-cause mortality. End points are adjudicated by an independent committee blinded to study assignment.
The FREEDOM trial, expected to conclude late in 2009, will determine whether frequent optimization of CRT, using a new device-based algorithm, is associated with better clinical outcomes than current standard of care. In addition to improving patient care, this approach might alleviate the workload and economic burden imposed by current approaches to optimization of CRT devices.
本研究旨在描述一项随机、双盲、对照试验的原理、设计和终点，该试验评估了在接受心脏再同步治疗（CRT）的患者中频繁系统优化房室（AV）和室间（VV）延迟的效果。
在 16 个国家的 178 个地点，共纳入了 1580 例心力衰竭患者，这些患者均具有 CRT 的标准临床适应证。在植入能够使用新的基于设备的 AV 和 VV 优化算法的 CRT 系统后 2 周内，患者被随机分配到频繁优化组或经验性设备编程组或任何其他非设备为基础的 CRT 优化方法（标准护理组）。在频繁优化组的患者中，每隔 3 个月计算、重新评估并在必要时重新编程 AV 和 VV 延迟。在标准护理组的患者中，设备编程由植入医生自行决定，并且在整个试验过程中保持不变，除非临床状况发生变化需要更改。试验的主要终点是心力衰竭临床综合终点，该终点根据预设定义将患者归类为恶化、不变或改善。次要终点包括因心血管原因住院和全因死亡率。终点由一个独立委员会裁决，该委员会对研究分配情况不知情。
预计将于 2009 年底完成的 FREEDOM 试验将确定使用新的基于设备的算法频繁优化 CRT 是否与改善临床结局相关，优于当前的标准护理。除了改善患者的护理外，这种方法还可能减轻当前 CRT 设备优化方法带来的工作量和经济负担。
