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临床试验/NCT01652248
NCT01652248已完成不适用

Pacemaker Upgrade to Cardiac Resynchronisation Therapy in Patients With Left Ventricular Dysfunction Dependant Upon Right Ventricular Pacing.

University of Leeds2 个研究点 分布在 1 个国家目标入组 50 人开始时间: 2008年4月最近更新:
适应症

试验速览

阶段
不适用
状态
已完成
入组人数
50
试验地点
2
主要终点
Change in LV ejection fraction

研究概览

简要总结

Patients with pacemakers often have undiagnosed heart muscle weakness. When a pacemaker battery has run down, it is easily replaced by a short procedure. In those with heart muscle weakness, who use their pacemaker most of the time (rather than acting just as a back-up) the investigators want to find out if adding a further lead to their pacemaker system improves their heart's function, kidney function and exercise capacity.

详细描述

Background

  1. Chronic heart failure Chronic heart failure (CHF) is a common syndrome of breathlessness and fatigue associated with left ventricular systolic dysfunction. It affects 2% of individuals between 50 and 60 years of age, and increases in prevalence to 10% over the age of 80 years.
  2. Cardiac resynchronisation therapy Cardiac resynchronisation therapy (CRT) involves the implantation of a pacemaker capable of stimulating the heart (specifically the left ventricle) from both the front of the heart, the right ventricle RV (as is usual with conventional pacemakers) and from the back of the heart (known as the lateral wall) via the coronary sinus, aiming to improve the timing of cardiac contraction (dyssynchrony) and hence the pumping function of the heart in order to improve symptoms of breathlessness and fatigue.

Early data in patients with left bundle branch block and severe heart failure, suggested improved exercise capacity and left ventricular function. More recent data have demonstrated not only improved symptoms, but also reduced hospital admissions, and improved overall mortality.

Current guidelines drawn up using the data from randomised trials, suggest that CRT should be offered to patients with left bundle branch block with a QRS > 150ms and severe (class III and IV) heart failure despite optimal medical therapy. Patients with a QRS duration of between 120 and 150ms should be assessed for mechanical dyssynchrony before being offered a device. 3. Heart failure in the pacemaker population

  • Prevalence In 307 patients with pacemakers, 94 (31%) had left ventricular ejection fraction (LVEF) < 40% and 83 (27%) had symptoms of heart failure. RV pacing is associated with an increase in heart failure-related hospitalisation and mortality, and in patients with left ventricular dysfunction the presence of a right ventricular apical pacemaker is a strong predictor of future deterioration in left ventricular function.
  • Aetiology of pacemaker-related heart failure Many patients receiving RV pacemakers are elderly with a background of ischaemic heart disease or hypertension, both of which contribute to the development of heart failure. In addition RV pacing induces dyssynchrony, no different to that of left bundle branch block (LBBB). Dyssynchrony leads to altered regional blood flow and wall stress. The severity of these perfusion abnormalities, the regional wall motion abnormalities and the associated deterioration in global left ventricular function are directly related to the duration of pacing. These changes can be identified after only 18 months of pacing. The induction of dyssynchrony by RV apical pacing seems therefore to lead to adverse LV remodeling, LV dilatation, asymmetrical hypertrophy.
  • Management of pacemaker-related heart failure In any one patient the exact aetiology of a deterioration of LV dysfunction is often unclear. What has become routine practice however, is an attempt to avoid RV pacing unless absolutely necessary and several programmes within commercially available devices now exist to facilitate this. The options in patients with a high degree of heart block on the other hand remain limited to aggressive medical therapy with beta-blockers and angiotensin converting enzyme inhibitors.

研究设计

研究类型
Interventional
分配方式
Randomized
干预模型
Parallel
主要目的
Prevention
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

入选标准

  • Left ventricular dysfunction < 50%
  • Ability and willingness to sign consent form
  • Dependent upon RV pacing with no reprogramming options

排除标准

  • Severe heart failure symptoms indicated for CRT
  • Other serious life-threatening co-morbidity

结局指标

主要结局

Change in LV ejection fraction

时间窗: 6 months

Echocardiographic LV function change

次要结局

  • Peak exercise capacity(6 months)

研究者

申办方类型
Other
责任方
Principal Investigator
主要研究者

KK Witte

Senior Lecturer and Consultant Cardiologist

University of Leeds

研究点 (2)

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