Quartet Lead With Defibrillator Multisite Algorithmic Cardiac Resynchronisation Therapy Optimisation
试验速览
- 阶段
- 不适用
- 状态
- 撤回
- 试验地点
- 2
- 主要终点
- Change in left ventricular end-systolic volume in patients undergoing algorithmic optimisation of CRT-D compared with usual device settings
研究概览
简要总结
Cardiac resynchronisation therapy (CRT) improves outcomes and symptoms in selected patients with heart failure. However, around one third of suitable patients do not demonstrate benefit following device implantation when assessed by echocardiography (heart scanning). This group has poorer outcomes.
Response rate can be enhanced by altering timing delays between the pacing leads, but some patients still fail to improve.
Quadripolar left ventricular leads are now widely used in CRT. The lead's four poles increase the number of conformations available to the programmer, allowing multiple vectors to be programmed simultaneously or sequentially. This allows programming to avoid, for example, a patch of scar and find an area that will respond better to pacing. This technique is known as multi-site pacing. CRT is often implanted along with a defibrillator lead in the right ventricle, known as CRT-D. The defibrillator lead offers further combinations for pacing.
Goal of Research To evaluate an algorithm for assessing different multi-site pacing combinations in optimisation of CRT
Outline The investigators will recruit 24 consecutive patients undergoing CRT-D implantation for conventional indications at our hospital. At baseline, patients will undergo echocardiography, exercise testing and assessments of functional ability and quality of life. The device will be implanted as standard. Optimisation will be performed with an algorithm using different vector combinations and assessing the heart's efficiency through echocardiography and invasive pressure monitoring. The pacemaker will be programmed with standard settings. After twelve weeks, the baseline investigations and optimisation algorithm will be repeated and the device programmed according to the maximum efficiency. After a further 12 weeks, the same parameters will be measured to look for improved response to CRT.
Potential Benefit To increase the response rate to cardiac resynchronisation therapy and improve reliability of the technique
详细描述
Study Design: This is an open-label, single centre, prospective, cohort study to assess the effect of algorithmic, echocardiography-guided optimisation of CRT-D following implantation of a left ventricular quadripolar lead.
Introduction and background:
There is now considerable evidence that cardiac resynchronisation therapy (CRT) improves outcomes and symptoms in patients with heart failure. However, around a third of patients do not demonstrate any haemodynamic or functional benefit following device implantation. Earlier studies have used a cut-off of 15% reduction in left ventricular end-systolic volume to define response to CRT.
Failure to respond to CRT is felt to be multifactorial. Issues include:
- Anatomical limitations in terms of lead placement (the lead must be placed within a branch of the coronary sinus vein and therefore targeting to the site of maximum contraction delay can be difficult)
- Presence of areas of scar tissue, which are resistant to being paced
- Phrenic nerve stimulation with some pacing sites. The phrenic nerve runs close to the heart and may be stimulated by the pacemaker, with the effect that the patient's diaphragm is stimulated and they experience persistent hiccups.
- High pacing thresholds, which means that increased power from the pacemaker must be used to create a successful pacing stimulus (capture) and that in some instances, capture may not be achieved. This can be due to scar or to poor contact with the heart tissue.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Successful implantation of CRT-D device with quadripolar left ventricular lead and dual coil right ventricular lead.
排除标准
- •failed device implantation
- •inability to complete the follow-up process
- •inability to provide full written consent. Patients unable to perform cardiopulmonary exercise testing will be excluded from this assessment only and will be able to complete the remaining assessments.
结局指标
主要结局
Change in left ventricular end-systolic volume in patients undergoing algorithmic optimisation of CRT-D compared with usual device settings
时间窗: 24 weeks
End-systolic volume will be measured on echocardiography using Simpson's method. Where image quality precludes a full biplane assessment, single plane will be used with the apical 4-chamber view, or alternatively left ventricular end-systolic diameter will be used to calculate volume using the Teicholz method.
次要结局
- Feasibility of ultrasound cardiac output monitoring (USCOM) in optimisation of CRT devices in clinical practice(At baseline and at 12 weeks)
- Change in peak oxygen consumption with algorithmic CRT-D optimisation compared with usual device settings(24 weeks)
- Feasibility of algorithmic, echocardiography-guided CRT-D optimisation with quadripolar left ventricular leads in clinical practice(24 weeks)
- Correlation between invasive haemodynamic studies with non-invasive ultrasound-based methods in optimising CRT-D(24 weeks)
- Change in left ventricular end diastolic pressure with algorithmic optimisation of CRT-D compared with usual device settings(24 weeks)
- Change in left ventricular ejection fraction with algorithmic CRT-D optimisation compared with usual device settings.(24 weeks)
- Change in left ventricular end-diastolic volume with algorithmic CRT-D optimisation compared with usual device settings.(24 weeks)
- Change in left ventricular diastolic filling time with algorithmic CRT-D optimisation compared with usual device settings.(24 weeks)
- Change in left ventricular outflow tract velocity time integral (LVOT VTI) with algorithmic CRT-D optimisation compared with usual device settings.(24 weeks)
- Change in longitudinal and global longitudinal strain (GLS) with algorithmic CRT-D optimisation compared with usual device settings.(24 weeks)
- Change in radial strain with algorithmic CRT-D optimisation compared with usual device settings.(24 weeks)
- Change in distance walked on a 6-minute hall walk test with algorithmic CRT-D optimisation compared with usual device settings(24 weeks)
- Change in New York Heart Association functional class with algorithmic CRT-D optimisation compared with usual device settings.(24 weeks)
- Change in score in the Minnesota Living with Heart Failure Questionnaire (MLHFQ) between algorithmically optimised CRT-D and usual device settings.(24 weeks)
- Change in cardiac output measured by the novel technique of Ultra-Sound Cardiac Output Monitoring (USCOM) with algorithmic CRT-D optimisation compared with usual device settings(24 weeks)
- Number of patients suffering adverse events during the study period(From patient enrollment through study completion, an average of 1 year.)
研究者
Freya Lodge
Clinical Research Fellow
Cardiff and Vale University Health Board